1
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Park J, Kim JO, Kang SW. Lateral heterostructures of WS 2 and MoS 2 monolayers for photo-synaptic transistor. Sci Rep 2024; 14:6922. [PMID: 38519613 PMCID: PMC10959970 DOI: 10.1038/s41598-024-57642-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/20/2024] [Indexed: 03/25/2024] Open
Abstract
Von Neumann architecture-based computing, while widely successful in personal computers and embedded systems, faces inherent challenges including the von Neumann bottleneck, particularly amidst the ongoing surge of data-intensive tasks. Neuromorphic computing, designed to integrate arithmetic, logic, and memory operations, has emerged as a promising solution for improving energy efficiency and performance. This approach requires the construction of an artificial synaptic device that can simultaneously perform signal processing, learning, and memory operations. We present a photo-synaptic device with 32 analog multi-states by exploiting field-effect transistors based on the lateral heterostructures of two-dimensional (2D) WS2 and MoS2 monolayers, formed through a two-step metal-organic chemical vapor deposition process. These lateral heterostructures offer high photoresponsivity and enhanced efficiency of charge trapping at the interface between the heterostructures and SiO2 due to the presence of the WS2 monolayer with large trap densities. As a result, it enables the photo-synaptic transistor to implement synaptic behaviors of long-term plasticity and high recognition accuracy. To confirm the feasibility of the photo-synapse, we investigated its synaptic characteristics under optical and electrical stimuli, including the retention of excitatory post-synaptic currents, potentiation, habituation, nonlinearity factor, and paired-pulse facilitation. Our findings suggest the potential of versatile 2D material-synapse with a high density of device integration.
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Affiliation(s)
- Jaeseo Park
- Strategic Technology Research Institute, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Jun Oh Kim
- Strategic Technology Research Institute, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Sang-Woo Kang
- Strategic Technology Research Institute, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea.
- Precision Measurement, University of Science and Technology, Daejeon, 34113, Republic of Korea.
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2
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Fukui T, Nishimura T, Miyata Y, Ueno K, Taniguchi T, Watanabe K, Nagashio K. Single-Gate MoS 2 Tunnel FET with a Thickness-Modulated Homojunction. ACS APPLIED MATERIALS & INTERFACES 2024; 16:8993-9001. [PMID: 38324211 DOI: 10.1021/acsami.3c15535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Two-dimensional (2D) materials stand as a promising platform for tunnel field-effect transistors (TFETs) in the pursuit of low-power electronics for the Internet of Things era. This promise arises from their dangling bond-free van der Waals heterointerface. Nevertheless, the attainment of high device performance is markedly impeded by the requirement of precise control over the 2D assembly with multiple stacks of different layers. In this study, we addressed a thickness-modulated n/p+-homojunction prepared from Nb-doped p+-MoS2 crystal, where the issue on interface traps can be neglected without any external interface control due to the homojunction. Notably, our observations reveal the existence of a negative differential resistance, even at room temperature (RT). This signifies the successful realization of TFET operation under type III band alignment conditions by a single gate at RT, suggesting that the dominant current mechanism is band-to-band tunneling due to the ideal interface.
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Affiliation(s)
- Tomohiro Fukui
- Department of Materials Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Tomonori Nishimura
- Department of Materials Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Yasumitsu Miyata
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Keiji Ueno
- Department of Chemistry, Saitama University, Saitama 338-8570, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, Ibaraki 305-0044, Japan
| | - Kosuke Nagashio
- Department of Materials Engineering, The University of Tokyo, Tokyo 113-8656, Japan
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3
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Xu C, Barden N, Alexeev EM, Wang X, Long R, Cadore AR, Paradisanos I, Ott AK, Soavi G, Tongay S, Cerullo G, Ferrari AC, Prezhdo OV, Loh ZH. Ultrafast Charge Transfer and Recombination Dynamics in Monolayer-Multilayer WSe 2 Junctions Revealed by Time-Resolved Photoemission Electron Microscopy. ACS NANO 2024; 18:1931-1947. [PMID: 38197410 DOI: 10.1021/acsnano.3c06473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
The ultrafast carrier dynamics of junctions between two chemically identical, but electronically distinct, transition metal dichalcogenides (TMDs) remains largely unknown. Here, we employ time-resolved photoemission electron microscopy (TR-PEEM) to probe the ultrafast carrier dynamics of a monolayer-to-multilayer (1L-ML) WSe2 junction. The TR-PEEM signals recorded for the individual components of the junction reveal the sub-ps carrier cooling dynamics of 1L- and 7L-WSe2, as well as few-ps exciton-exciton annihilation occurring on 1L-WSe2. We observe ultrafast interfacial hole (h) transfer from 1L- to 7L-WSe2 on an ∼0.2 ps time scale. The resultant excess h density in 7L-WSe2 decays by carrier recombination across the junction interface on an ∼100 ps time scale. Reminiscent of the behavior at a depletion region, the TR-PEEM image reveals the h density accumulation on the 7L-WSe2 interface, with a decay length ∼0.60 ± 0.17 μm. These charge transfer and recombination dynamics are in agreement with ab initio quantum dynamics. The computed orbital densities reveal that charge transfer occurs from the basal plane, which extends over both 1L and ML regions, to the upper plane localized on the ML region. This mode of charge transfer is distinctive to chemically homogeneous junctions of layered materials and constitutes an additional carrier deactivation pathway that should be considered in studies of 1L-TMDs found alongside their ML, a common occurrence in exfoliated samples.
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Affiliation(s)
- Ce Xu
- School of Chemistry, Chemical Engineering and Biotechnology, and School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Natalie Barden
- School of Chemistry, Chemical Engineering and Biotechnology, and School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Evgeny M Alexeev
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Xiaoli Wang
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Alisson R Cadore
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | | | - Anna K Ott
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Giancarlo Soavi
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
- Institute of Solid State Physics, Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - Sefaattin Tongay
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Giulio Cerullo
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- IFN-CNR, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Zhi-Heng Loh
- School of Chemistry, Chemical Engineering and Biotechnology, and School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
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4
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Rangnekar SV, Sangwan VK, Jin M, Khalaj M, Szydłowska BM, Dasgupta A, Kuo L, Kurtz HE, Marks TJ, Hersam MC. Electroluminescence from Megasonically Solution-Processed MoS 2 Nanosheet Films. ACS NANO 2023; 17:17516-17526. [PMID: 37606956 DOI: 10.1021/acsnano.3c06034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Due to their superior optoelectronic properties, monolayer two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted significant attention for electroluminescent devices. However, challenges in isolating optoelectronically active TMD monolayers using scalable liquid phase exfoliation have precluded electroluminescence in large-area, solution-processed TMD films. Here, we overcome these limitations and demonstrate electroluminescence from molybdenum disulfide (MoS2) nanosheet films by employing a monolayer-rich MoS2 ink produced by electrochemical intercalation and megasonic exfoliation. Characteristic monolayer MoS2 photoluminescence and electroluminescence spectral peaks at 1.88-1.90 eV are observed in megasonicated MoS2 films, with the emission intensity increasing with film thickness over the range 10-70 nm. Furthermore, employing a vertical light-emitting capacitor architecture enables uniform electroluminescence in large-area devices. These results indicate that megasonically exfoliated MoS2 monolayers retain their direct bandgap character in electrically percolating thin films even following multistep solution processing. Overall, this work establishes megasonicated MoS2 inks as an additive manufacturing platform for flexible, patterned, and miniaturized light sources that can likely be expanded to other TMD semiconductors.
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Affiliation(s)
- Sonal V Rangnekar
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Vinod K Sangwan
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Mengru Jin
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Maryam Khalaj
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Beata M Szydłowska
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Anushka Dasgupta
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Lidia Kuo
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Heather E Kurtz
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Tobin J Marks
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States
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5
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Radhakrishnan S, Vishnu SNS, Ahmed SI, Thiruvengadathan R. Effects of Channel Length Scaling on the Electrical Characteristics of Multilayer MoS 2 Field Effect Transistor. MICROMACHINES 2023; 14:275. [PMID: 36837975 PMCID: PMC9963916 DOI: 10.3390/mi14020275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/05/2023] [Accepted: 01/14/2023] [Indexed: 06/18/2023]
Abstract
With the rapid miniaturization of integrated chips in recent decades, aggressive geometric scaling of transistor dimensions to nanometric scales has become imperative. Recent works have reported the usefulness of 2D transition metal dichalcogenides (TMDs) like MoS2 in MOSFET fabrication due to their enhanced active surface area, thin body, and non-zero bandgap. However, a systematic study on the effects of geometric scaling down to sub-10-nm nodes on the performance of MoS2 MOSFETs is lacking. Here, the authors present an extensive study on the performance of MoS2 FETs when geometrically scaled down to the sub-10 nm range. Transport properties are modelled using drift-diffusion equations in the classical regime and self-consistent Schrödinger-Poisson solution using NEGF formulation in the quantum regime. By employing the device modeling tool COMSOL for the classical regime, drain current vs. gate voltage (ID vs. VGS) plots were simulated. On the other hand, NEGF formulation for quantum regions is performed using MATLAB, and transfer characteristics are obtained. The effects of scaling device dimensions, such as channel length and contact length, are evaluated based on transfer characteristics by computing performance metrics like drain-induced barrier lowering (DIBL), on-off currents, subthreshold swing, and threshold voltage.
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Affiliation(s)
- Sreevatsan Radhakrishnan
- SIERS Research Laboratory, Department of Electronics and Communication Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India
| | - Suggula Naga Sai Vishnu
- SIERS Research Laboratory, Department of Electronics and Communication Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India
| | - Syed Ishtiyaq Ahmed
- SIERS Research Laboratory, Department of Electronics and Communication Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India
| | - Rajagopalan Thiruvengadathan
- SIERS Research Laboratory, Department of Electronics and Communication Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore 641112, India
- Mechanical Engineering Program, Department of Engineering and Technology, Southern Utah University, Cedar City, UT 84720, USA
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6
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Jing H, Lyu B, Tang Y, Baek S, Park JH, Lee BH, Lee JY, Lee S. β‐Mercaptoethanol‐Enabled Long‐Term Stability and Work Function Tuning of MXene. SMALL SCIENCE 2022. [DOI: 10.1002/smsc.202200057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Hongyue Jing
- SKKU Advanced Institute of Nanotechnology (SAINT) Sungkyunkwan University Suwon 440-746 Korea
| | - Benzheng Lyu
- Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong 518057 China
| | - Yingqi Tang
- Department of Chemistry Sungkyunkwan University Suwon 16419 Korea
| | - Sungpyo Baek
- SKKU Advanced Institute of Nanotechnology (SAINT) Sungkyunkwan University Suwon 440-746 Korea
| | - Jin-Hong Park
- SKKU Advanced Institute of Nanotechnology (SAINT) Sungkyunkwan University Suwon 440-746 Korea
| | - Byoung Hun Lee
- Department of Electrical Engineering Pohang University of Science and Technology Pohang 37673 Korea
| | - Jin Yong Lee
- Department of Chemistry Sungkyunkwan University Suwon 16419 Korea
| | - Sungjoo Lee
- SKKU Advanced Institute of Nanotechnology (SAINT) Sungkyunkwan University Suwon 440-746 Korea
- Department of Nano Engineering Sungkyunkwan University Suwon 440-746 Korea
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7
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Xia H, Luo M, Wang W, Wang H, Li T, Wang Z, Xu H, Chen Y, Zhou Y, Wang F, Xie R, Wang P, Hu W, Lu W. Pristine PN junction toward atomic layer devices. LIGHT, SCIENCE & APPLICATIONS 2022; 11:170. [PMID: 35661682 PMCID: PMC9167816 DOI: 10.1038/s41377-022-00814-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/23/2022] [Accepted: 04/24/2022] [Indexed: 05/25/2023]
Abstract
In semiconductor manufacturing, PN junction is formed by introducing dopants to activate neighboring electron and hole conductance. To avoid structural distortion and failure, it generally requires the foreign dopants localize in the designated micro-areas. This, however, is challenging due to an inevitable interdiffusion process. Here we report a brand-new junction architecture, called "layer PN junction", that might break through such limit and help redefine the semiconductor device architecture. Different from all existing semiconductors, we find that a variety of van der Waals materials are doping themselves from n- to p-type conductance with an increasing/decreasing layer-number. It means the capability of constructing homogeneous PN junctions in monolayers' dimension/precision, with record high rectification-ratio (>105) and low cut-off current (<1 pA). More importantly, it spawns intriguing functionalities, like gate-switchable-rectification and noise-signal decoupled avalanching. Findings disclosed here might open up a path to develop novel nanodevice applications, where the geometrical size becomes the only critical factor in tuning charge-carrier distribution and thus functionality.
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Affiliation(s)
- Hui Xia
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Man Luo
- Jiangsu Key Laboratory of ASIC Design, School of Information Science and Technology, Nantong University, Nantong, 226019, Jiangsu, China
| | - Wenjing Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Hailu Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Tianxin Li
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Zhen Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Hangyu Xu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yue Chen
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yong Zhou
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Fang Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Runzhang Xie
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Peng Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Weida Hu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Wei Lu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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8
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Beechem TE, Smith SW, Copeland RG, Liu F, Ohta T. Spectral and polarization based imaging in deep-ultraviolet excited photoelectron microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:053701. [PMID: 35649785 DOI: 10.1063/5.0077867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Using photoelectron emission microscopy, nanoscale spectral imaging of atomically thin MoS2 buried between Al2O3 and SiO2 is achieved by monitoring the wavelength and polarization dependence of the photoelectron signal excited by deep-ultraviolet light. Although photons induce the photoemission, images can exhibit resolutions below the photon wavelength as electrons sense the response. To validate this concept, the dependence of photoemission yield on the wavelength and polarization of the exciting light was first measured and then compared to simulations of the optical response quantified with classical optical theory. A close correlation between experiment and theory indicates that photoemission probes the optical interaction of UV-light with the material stack directly. The utility of this probe is then demonstrated when both the spectral and polarization dependence of photoemission observe spatial variation consistent with grains and defects in buried MoS2. Taken together, these new modalities of photoelectron microscopy allow mapping of optical property variation at length scales unobtainable with conventional light-based microscopy.
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Affiliation(s)
- Thomas E Beechem
- School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - Sean W Smith
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - R Guild Copeland
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Fangze Liu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Taisuke Ohta
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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9
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Shrestha S, Li X, Tsai H, Hou CH, Huang HH, Ghosh D, Shyue JJ, Wang L, Tretiak S, Ma X, Nie W. Long carrier diffusion length in two-dimensional lead halide perovskite single crystals. Chem 2022. [DOI: 10.1016/j.chempr.2022.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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10
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Minority carrier decay length extraction from scanning photocurrent profiles in two-dimensional carrier transport structures. Sci Rep 2021; 11:21863. [PMID: 34751191 PMCID: PMC8575939 DOI: 10.1038/s41598-021-01446-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/28/2021] [Indexed: 11/09/2022] Open
Abstract
Carrier transport was studied both numerically and experimentally using scanning photocurrent microscopy (SPCM) in two-dimensional (2D) transport structures, where the structure size in the third dimension is much smaller than the diffusion length and electrodes cover the whole terminal on both sides. Originally, one would expect that with increasing width in 2D transport structures, scanning photocurrent profiles will gradually deviate from those of the ideal one-dimensional (1D) transport structure. However, the scanning photocurrent simulation results surprisingly showed almost identical profiles from structures with different widths. In order to clarify this phenomenon, we observed the spatial distribution of carriers. The simulation results indicate that the integrated carrier distribution in the 2D transport structures with finite width can be well described by a simple-exponential-decay function with the carrier decay length as the fitting parameter, just like in the 1D transport structures. For ohmic-contact 2D transport structures, the feasibility of the fitting formula from our previous 1D analytical model was confirmed. On the other hand, the application of a simple-exponential-decay function in scanning photocurrent profiles for the diffusion length extraction in Schottky-contact 2D transport structures was also justified. Furthermore, our simulation results demonstrate that the scanning photocurrent profiles in the ohmic- or Schottky-contact three-dimensional (3D) transport structures with electrodes covering the whole terminal on both sides will reduce to those described by the corresponding 1D fitting formulae. Finally, experimental SPCM on a p-type InGaAs air-bridge two-terminal thin-film device was carried out. The measured photocurrent profiles can be well fitted by the specific fitting formula derived from our previous 1D analytical model and the extracted electron mobility-lifetime product of this thin-film device is 6.6 × 10–7 cm2·V−1. This study allows us to extract the minority carrier decay length and to obtain the mobility-lifetime product which can be used to evaluate the performance of 2D carrier transport devices.
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11
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Hight-Huf N, Nagar Y, Levi A, Pagaduan JN, Datar A, Katsumata R, Emrick T, Ramasubramaniam A, Naveh D, Barnes MD. Polarization-Driven Asymmetric Electronic Response of Monolayer Graphene to Polymer Zwitterions Probed from Both Sides. ACS APPLIED MATERIALS & INTERFACES 2021; 13:47945-47953. [PMID: 34607423 DOI: 10.1021/acsami.1c13505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigated the nature of graphene surface doping by zwitterionic polymers and the implications of weak in-plane and strong through-plane screening using a novel sample geometry that allows direct access to either the graphene or the polymer side of a graphene/polymer interface. Using both Kelvin probe and electrostatic force microscopies, we observed a significant upshift in the Fermi level in graphene of ∼260 meV that was dominated by a change in polarizability rather than pure charge transfer with the organic overlayer. This physical picture is supported by density functional theory (DFT) calculations, which describe a redistribution of charge in graphene in response to the dipoles of the adsorbed zwitterionic moieties, analogous to a local DC Stark effect. Strong metallic-like screening of the adsorbed dipoles was observed by employing an inverted geometry, an effect identified by DFT to arise from a strongly asymmetric redistribution of charge confined to the side of graphene proximal to the zwitterion dipoles. Transport measurements confirm n-type doping with no significant impact on carrier mobility, thus demonstrating a route to desirable electronic properties in devices that combine graphene with lithographically patterned polymers.
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Affiliation(s)
- Nicholas Hight-Huf
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Yehiel Nagar
- Faculty of Engineering and Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Adi Levi
- Faculty of Engineering and Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - James Nicolas Pagaduan
- Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Avdhoot Datar
- Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Reika Katsumata
- Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Todd Emrick
- Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Ashwin Ramasubramaniam
- Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Doron Naveh
- Faculty of Engineering and Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Michael D Barnes
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, United States
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12
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Setayeshmehr K, Hashemi M, Ansari N. Photoconversion efficiency in atomically thin TMDC-based heterostructures. OPTICS EXPRESS 2021; 29:32910-32921. [PMID: 34809113 DOI: 10.1364/oe.438386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Nowadays, two-dimensional materials such as graphene, phosphorene, and transition metal dichalcogenides (TMDCs) are widely employed in designing photovoltaic devices. Despite their atomically thin (AT) thicknesses, the high absorption of the TMDCs makes them a unique choice in designing solar absorptive heterostructures. In our exploration of finding the most efficient TMDC contacts for generating higher photocurrents, we carefully examined the physics behind the external and internal quantum efficiencies (EQEs and IQEs) of different AT heterostructures at the solar spectrum. By minute examination of the EQEs of the selected TMDC-based heterostructures, we show that the absorption of each consisting TMDC and the gradient of the electronic structure of them at their contact, determine mostly the photocurrent generation efficiency of the solar cells. The promising EQE (IQE) value of 0.5% (1.4%) is achieved in WSe2/MoSe2 contact at the wavelength of 433 nm. In the case of the multilayers of TMDCs, together with the light absorption increase of the multilayers the EQE of the heterostructures generally increases, while the competitive nature of the electronic structure gradient and the absorption makes this increase nonmonotonic. The TMDC-based heterostructures which are investigated in this work, pave a new way in designing miniaturized and efficient optoelectronic devices.
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13
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Han N, Xie W, Zhang J, Liu L, Zhao J, West D, Zhang S. Remote Passivation in Two-Dimensional Materials: The Case of the Monolayer-Bilayer Lateral Junction of MoSe 2. J Phys Chem Lett 2021; 12:8046-8052. [PMID: 34433273 DOI: 10.1021/acs.jpclett.1c02457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Two-dimensional (2D) monolayer-bilayer (ML-BL) lateral junctions (LJs) have recently attracted attention due to their straightforward synthesis and resulting clean interface. Such systems consist of an extended ML with a secondary layer present only over half of the system, leading to an interface that is associated with the terminating edge of the secondary half layer. Our first-principles calculations reveal that the edges of the half layer completely lack reconstruction in the presence of unintentional dopants, in this case, Re. This observation is in startling contrast to the known physics of three-dimensional (3D) semiconductor surfaces where reconstruction has been widely observed. Herein, the electrostatics of the reduced dimensionality allows for greater separation between compensating defects, enabling dopants to remotely passivate edge states without needing to directly participate in the chemistry.
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Affiliation(s)
- Nannan Han
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi'an 710072, China
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy 12180, United States
| | - Weiyu Xie
- China Academy of Engineering Physics Institute of Chemical Materials, Mianyang 621999, China
| | - Junfeng Zhang
- School of Physics and Information Engineering, Shanxi Normal University, Linfen 041004, China
| | - Lizhao Liu
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China
| | - Damien West
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy 12180, United States
| | - Shengbai Zhang
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy 12180, United States
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14
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Wong J, Davoyan A, Liao B, Krayev A, Jo K, Rotenberg E, Bostwick A, Jozwiak CM, Jariwala D, Zewail AH, Atwater HA. Spatiotemporal Imaging of Thickness-Induced Band-Bending Junctions. NANO LETTERS 2021; 21:5745-5753. [PMID: 34152777 DOI: 10.1021/acs.nanolett.1c01481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
van der Waals materials exhibit naturally passivated surfaces and an ability to form versatile heterostructures to enable an examination of carrier transport mechanisms not seen in traditional materials. Here, we report a new type of homojunction termed a "band-bending junction" whose potential landscape depends solely on the difference in thickness between the two sides of the junction. Using MoS2 on Au as a prototypical example, we find that surface potential differences can arise from the degree of vertical band bending in thin and thick regions. Furthermore, by using scanning ultrafast electron microscopy, we examine the spatiotemporal dynamics of charge carriers generated at this junction and find that lateral carrier separation is enabled by differences in the band bending in the vertical direction, which we verify with simulations. Band-bending junctions may therefore enable new optoelectronic devices that rely solely on band bending arising from thickness variations to separate charge carriers.
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Affiliation(s)
| | - Artur Davoyan
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095 United States
| | - Bolin Liao
- Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Andrey Krayev
- Horiba Scientific, Novato, California 94949, United States
| | - Kiyoung Jo
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Eli Rotenberg
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720,United States
| | - Aaron Bostwick
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720,United States
| | - Chris M Jozwiak
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720,United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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15
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Sulas-Kern DB, Zhang H, Li Z, Blackburn JL. Interplay between microstructure, defect states, and mobile charge generation in transition metal dichalcogenide heterojunctions. NANOSCALE 2021; 13:8188-8198. [PMID: 33884391 DOI: 10.1039/d1nr00384d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Two-dimensional transition metal dichalcogenides (2D-TMDCs) have gained attention for their promise in next-generation energy-harvesting and quantum computing technologies, but realizing these technologies requires a greater understanding of TMDC properties that influence their photophysics. To this end, we discuss here the interplay between TMDC microstructure and defects with the charge generation yield, lifetime, and mobility. As a model system, we compare monolayer-only and monolayer-rich MoS2 grown by chemical vapor deposition, and we employ the TMDCs in Type-II charge-separating heterojunctions with semiconducting single-walled carbon nanotubes (s-SWCNTs). Our results suggest longer lifetimes and higher yields of mobile carriers in samples containing a small fraction of defect-rich multilayer islands on predominately monolayer MoS2. Compared to the monolayer-only heterojunctions, the carrier lifetimes increase from 0.73 μs to 4.71 μs, the hole transfer yield increases from 23% to 34%, and the electron transfer yield increases from 39% to 59%. We reach these conclusions using a unique combination of microwave photoconductivity (which probes only mobile carriers) along with transient absorption spectroscopy (which identifies spectral signatures unique to each material and type of photoexcited quasiparticle, but does not probe mobility). Our results highlight the substantial changes in photophysics that can occur from small changes in TMDC microstructure and defect density, where the presence of defects does not necessarily preclude improvements in charge generation.
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Affiliation(s)
- Dana B Sulas-Kern
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA.
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16
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Wang F, Pei K, Li Y, Li H, Zhai T. 2D Homojunctions for Electronics and Optoelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005303. [PMID: 33644885 DOI: 10.1002/adma.202005303] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/19/2020] [Indexed: 05/21/2023]
Abstract
In the post-Moore era, 2D materials with rich physical properties have attracted widespread attention from the scientific and industrial communities. Among 2D materials, the 2D homojunctions are of great promise in designing novel electronic and optoelectronic devices due to their unique geometries and properties such as homogeneous components, perfect lattice matching, and efficient charge transfer at the interface. In this article, a pioneering review focusing on the structural design and device application of 2D homojunctions such as p-n homojunctions, heterophase homojunctions, and layer-engineered homojunctions is provided. The preparation strategies to construct 2D homojunctions including vapor-phase deposition, lithium intercalation, laser irradiation, chemical doping, electrostatic doping, and photodoping are summarized in detail. Specifically, a careful review on the applications of the 2D homojunctions in electronics (e.g., field-effect transistors, rectifiers, and inverters) and optoelectronics (e.g., light-emitting diodes, photovoltaics, and photodetectors) is provided. Eventually, the current challenges and future perspectives are commented for promoting the rapid development of 2D homojunctions.
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Affiliation(s)
- Fakun Wang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Ke Pei
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Yuan Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Huiqiao Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
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17
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Mao CH, Dubey A, Lee FJ, Chen CY, Tang SY, Ranjan A, Lu MY, Chueh YL, Gwo S, Yen TJ. An Ultrasensitive Gateless Photodetector Based on the 2D Bilayer MoS 2-1D Si Nanowire-0D Ag Nanoparticle Hybrid Structure. ACS APPLIED MATERIALS & INTERFACES 2021; 13:4126-4132. [PMID: 33432802 DOI: 10.1021/acsami.0c15819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atomically thin transition metal dichalcogenides (TMDC) have received much attention due to their wide variety of optical and electronic properties. Among various TMDC materials, molybdenum disulfide (MoS2) has been intensely studied owing to its potential applications in nanoelectronics and optoelectronics. However, two-dimensional MoS2 photodetectors suffer from low responsivity due to low optical cross section. Combining MoS2 with plasmonic nanostructures can drastically increase scattering cross section and enhance local light-matter interaction. Moreover, suspended MoS2 has been shown to exhibit higher photoluminescence intensity and strong photogating effect, which can be employed in photodetectors. Herein, we propose an approach to utilize plasmonic nanostructures and physical suspension for 2D MoS2 photosensing enhancement by hybridizing 2D bilayer MoS2, 1D silicon nanowires, and 0D silver nanoparticles. The hybrid structure shows a gateless responsivity of 402.4 A/W at a wavelength of 532 nm, which represents the highest value among the ever reported gateless plasmonic MoS2 photodetector. The great responsivity and large active area results in an exceptional detectivity of 2.34 × 1012 Jones. This study provides a new approach for designing high-performance 2D TMDC-based optoelectronic devices.
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Affiliation(s)
- Ching-Han Mao
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Abhishek Dubey
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Fang-Jing Lee
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chun-Yen Chen
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shin-Yi Tang
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ashok Ranjan
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ming-Yen Lu
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yu-Lun Chueh
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shangjr Gwo
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ta-Jen Yen
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
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18
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Wang H, Wang F, Xia H, Wang P, Li T, Li J, Wang Z, Sun J, Wu P, Ye J, Zhuang Q, Yang Z, Fu L, Hu W, Chen X, Lu W. Direct observation and manipulation of hot electrons at room temperature. Natl Sci Rev 2020; 8:nwaa295. [PMID: 34691730 PMCID: PMC8433094 DOI: 10.1093/nsr/nwaa295] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/26/2020] [Accepted: 12/02/2020] [Indexed: 12/03/2022] Open
Abstract
In modern electronics and optoelectronics, hot electron behaviors are highly concerned, as they determine the performance limit of a device or system, like the associated thermal or power constraint of chips and the Shockley-Queisser limit for solar cell efficiency. To date, however, the manipulation of hot electrons has been mostly based on conceptual interpretations rather than a direct observation. The problem arises from a fundamental fact that energy-differential electrons are mixed up in real-space, making it hard to distinguish them from each other by standard measurements. Here we demonstrate a distinct approach to artificially (spatially) separate hot electrons from cold ones in semiconductor nanowire transistors, which thus offers a unique opportunity to observe and modulate electron occupied state, energy, mobility and even path. Such a process is accomplished through the scanning-photocurrent-microscopy measurements by activating the intervalley-scattering events and 1D charge-neutrality rule. Findings here may provide a new degree of freedom in manipulating non-equilibrium electrons for both electronic and optoelectronic applications.
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Affiliation(s)
- Hailu Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fang Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Xia
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Tianxin Li
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Juzhu Li
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
| | - Zhen Wang
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Jiamin Sun
- School of Microelectronics, Shandong University, Jinan 250100, China
| | - Peisong Wu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiafu Ye
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiandong Zhuang
- Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
| | - Zaixing Yang
- School of Microelectronics, Shandong University, Jinan 250100, China
| | - Lan Fu
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Weida Hu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoshuang Chen
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Lu
- State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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19
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Li L, Shao L, Liu X, Gao A, Wang H, Zheng B, Hou G, Shehzad K, Yu L, Miao F, Shi Y, Xu Y, Wang X. Room-temperature valleytronic transistor. NATURE NANOTECHNOLOGY 2020; 15:743-749. [PMID: 32690885 DOI: 10.1038/s41565-020-0727-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 06/03/2020] [Indexed: 06/11/2023]
Abstract
Valleytronics, based on the valley degree of freedom rather than charge, is a promising candidate for next-generation information devices beyond complementary metal-oxide-semiconductor (CMOS) technology1-4. Although many intriguing valleytronic properties have been explored based on excitonic injection or the non-local response of transverse current schemes at low temperature4-7, demonstrations of valleytronic building blocks similar to transistors in electronics, especially at room temperature, remain elusive. Here, we report a solid-state device that enables a full sequence of generating, propagating, detecting and manipulating valley information at room temperature. Chiral nanocrescent plasmonic antennae8 are used to selectively generate valley-polarized carriers in MoS2 through hot-electron injection under linearly polarized infrared excitation. These long-lived valley-polarized free carriers can be detected in a valley Hall configuration9-11 even without charge current, and can propagate over 18 μm by means of drift. In addition, electrostatic gating allows us to modulate the magnitude of the valley Hall voltage. The electrical valley Hall output could drive the valley manipulation of a cascaded stage, rendering the device able to serve as a transistor free of charge current with pure valleytronic input/output. Our results demonstrate the possibility of encoding and processing information by valley degree of freedom, and provide a universal strategy to study the Berry curvature dipole in quantum materials.
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Affiliation(s)
- Lingfei Li
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China
- Colleges of ISEE and Microelectronics, ZJU-Hangzhou Global Scientific and Technological Innovation Center, ZJU-UIUC Institute, State Key Labs of Silicon Materials and Modern Optical Instruments, Zhejiang University, Hangzhou, China
| | - Lei Shao
- Beijing Computational Science Research Centre, Beijing, China
| | - Xiaowei Liu
- School of Physics, Nanjing University, Nanjing, China
| | - Anyuan Gao
- School of Physics, Nanjing University, Nanjing, China
| | - Hao Wang
- Beijing Computational Science Research Centre, Beijing, China
| | - Binjie Zheng
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China
| | - Guozhi Hou
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China
| | - Khurram Shehzad
- Colleges of ISEE and Microelectronics, ZJU-Hangzhou Global Scientific and Technological Innovation Center, ZJU-UIUC Institute, State Key Labs of Silicon Materials and Modern Optical Instruments, Zhejiang University, Hangzhou, China
| | - Linwei Yu
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China
| | - Feng Miao
- School of Physics, Nanjing University, Nanjing, China
| | - Yi Shi
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China
| | - Yang Xu
- Colleges of ISEE and Microelectronics, ZJU-Hangzhou Global Scientific and Technological Innovation Center, ZJU-UIUC Institute, State Key Labs of Silicon Materials and Modern Optical Instruments, Zhejiang University, Hangzhou, China.
| | - Xiaomu Wang
- School of Electronic Science and Engineering, Nanjing University, Nanjing, China.
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20
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Borah CK, Tyagi PK, Kumar S. The prospective application of a graphene/MoS 2 heterostructure in Si-HIT solar cells for higher efficiency. NANOSCALE ADVANCES 2020; 2:3231-3243. [PMID: 36134254 PMCID: PMC9418949 DOI: 10.1039/d0na00309c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/08/2020] [Indexed: 06/02/2023]
Abstract
The efficiency of a Si-HIT (heterojunction with intrinsic thin layer) solar cell based on a graphene/MoS2 heterostructure has been optimized by varying the various parameters of graphene (Gr) as a transparent conducting electrode (TCE) and n-type molybdenum disulfide (n-MoS2) as an emitter layer. The photovoltaic performance of a graphene/n-MoS2/a-Si:H/p-cSi/Au single facial HIT solar cell has been studied using AFORS-HET v2.5 simulation software. A maximum output efficiency of 25.61% has been achieved. The obtained results were compared with the results from a commercially available a-Si:H layer and p-cSi wafer after simulation. Moreover, the dependence of the cell performance on changes in the TCE and the back contact materials has also been studied. Finally, it has been demonstrated that the graphene layer and n-MoS2 layer could act as a TCE and an efficient emitter layer, respectively, in a n-MoS2/p-cSi based HIT solar cell.
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Affiliation(s)
- Chandra Kamal Borah
- Centre of Advanced Research, Department of Physics, Rajiv Gandhi University Arunachal Pradesh-791112 India
| | - Pawan K Tyagi
- Department of Physics, Central University of Haryana Haryana-123029 India
- Department of Applied Physics, Delhi Technological University Delhi-110042 India
| | - Sanjeev Kumar
- Centre of Advanced Research, Department of Physics, Rajiv Gandhi University Arunachal Pradesh-791112 India
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21
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Ohoka T, Nouchi R. Staircase-like transfer characteristics in multilayer MoS 2 field-effect transistors. NANO EXPRESS 2020. [DOI: 10.1088/2632-959x/ab70e6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
Layered semiconductors, such as MoS2, have attracted interest as channel materials for post-silicon and beyond-CMOS electronics. Much attention has been devoted to the monolayer limit, but the monolayer channel is not necessarily advantageous in terms of the performance of field-effect transistors (FETs). Therefore, it is important to investigate the characteristics of FETs that have multilayer channels. Here, we report the staircase-like transfer characteristics of FETs with exfoliated multilayer MoS2 flakes. Atomic force microscope characterizations reveal that the presence of thinner terraces at the edges of the flakes accompanies the staircase-like characteristics. The anomalous staircase-like characteristics are ascribable to a difference in threshold-voltage shift by charge transfer from surface adsorbates between the channel center and the thinner terrace at the edge. This study reveals the importance of the uniformity of channel thickness.
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22
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Fang L, Yuan X, Liu K, Li L, Zhou P, Ma W, Huang H, He J, Tao S. Direct bilayer growth: a new growth principle for a novel WSe 2 homo-junction and bilayer WSe 2 growth. NANOSCALE 2020; 12:3715-3722. [PMID: 31993600 DOI: 10.1039/c9nr09874g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Homo-junction and multi-layer structures of transition metal chalcogenide (TMD) materials provide great flexibility for band-structure engineering and designing photoelectric devices. However, the knowledge of van der Waals epitaxy growth limits the development of these heterostructures. Herein, we employed the chemical vapor deposition (CVD) growth strategy to synthesize novel WSe2 homo-junction samples with a triangular monolayer in the center and three AA stacking bilayer flakes connected to the vertexes of the monolayer. The emitted photon energy from the bilayer near the junction showed a blueshift in energy of up to 24 meV compared with bare bilayer WSe2, confirming the charge transfer effect from monolayer to bilayer WSe2. Further growth studies revealed the shape evolution from WSe2 homo-junction to bilayer. The whole homo-junction formation and evolution process cannot be explained by the traditional layer-by-layer growth mechanism. Instead, a direct bilayer growth approach is proposed to explain the bilayer formation and evolution at the vertexes of the bottom layer of WSe2. These findings suggest that the growth of bilayer TMDs is more complex than our previous understanding. This work presents deepens insight into van der Waals epitaxy growth, and thus is valuable for guiding the fabrication of novel homo-junctions for both fundamental science and optoelectronic applications.
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Affiliation(s)
- Long Fang
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Xiaoming Yuan
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Kunwu Liu
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Lin Li
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Peng Zhou
- Hunan Provincial Key Defense Laboratory of High Temperature Wear-Resisting Materials and Preparation Technology, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
| | - Wei Ma
- Engineering Research Center of Advanced Functional Material Manufacturing of Ministry of Education, School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Han Huang
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Jun He
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
| | - Shaohua Tao
- Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China.
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23
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Blackburn JL, Zhang H, Myers AR, Dunklin JR, Coffey DC, Hirsch RN, Vigil-Fowler D, Yun SJ, Cho BW, Lee YH, Miller EM, Rumbles G, Reid OG. Measuring Photoexcited Free Charge Carriers in Mono- to Few-Layer Transition-Metal Dichalcogenides with Steady-State Microwave Conductivity. J Phys Chem Lett 2020; 11:99-107. [PMID: 31790587 DOI: 10.1021/acs.jpclett.9b03117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Photoinduced generation of mobile charge carriers is the fundamental process underlying many applications, such as solar energy harvesting, solar fuel production, and efficient photodetectors. Monolayer transition-metal dichalcogenides (TMDCs) are an attractive model system for studying photoinduced carrier generation mechanisms in low-dimensional materials because they possess strong direct band gap absorption, large exciton binding energies, and are only a few atoms thick. While a number of studies have observed charge generation in neat TMDCs for photoexcitation at, above, or even below the optical band gap, the role of nonlinear processes (resulting from high photon fluences), defect states, excess charges, and layer interactions remains unclear. In this study, we introduce steady-state microwave conductivity (SSMC) spectroscopy for measuring charge generation action spectra in a model WS2 mono- to few-layer TMDC system at fluences that coincide with the terrestrial solar flux. Despite utilizing photon fluences well below those used in previous pump-probe measurements, the SSMC technique is sensitive enough to easily resolve the photoconductivity spectrum arising in mono- to few-layer WS2. By correlating SSMC with other spectroscopy and microscopy experiments, we find that photoconductivity is observed predominantly for excitation wavelengths resonant with the excitonic transition of the multilayer portions of the sample, the density of which can be controlled by the synthesis conditions. These results highlight the potential of layer engineering as a route toward achieving high yields of photoinduced charge carriers in neat TMDCs, with implications for a broad range of optoelectronic applications.
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Affiliation(s)
- Jeffrey L Blackburn
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - Hanyu Zhang
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - Alexis R Myers
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
- Department of Chemistry and Biochemistry , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Jeremy R Dunklin
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - David C Coffey
- Department of Physics , Warren Wilson College , 701 Warren Wilson Road , Swannanoa , North Carolina 28778 , United States
| | - Rebecca N Hirsch
- Department of Chemistry and Biochemistry , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Derek Vigil-Fowler
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - Seok Joon Yun
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea
| | - Byeong Wook Cho
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP) , Institute for Basic Science (IBS) , Suwon 16419 , Republic of Korea
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Republic of Korea
| | - Elisa M Miller
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
| | - Garry Rumbles
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
- Renewable and Sustainable Energy Institute , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Obadiah G Reid
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , 15013 Denver West Parkway , Golden , Colorado 80401 , United States
- Renewable and Sustainable Energy Institute , University of Colorado Boulder , Boulder , Colorado 80309 , United States
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24
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Wang L, Tahir M, Chen H, Sambur JB. Probing Charge Carrier Transport and Recombination Pathways in Monolayer MoS 2/WS 2 Heterojunction Photoelectrodes. NANO LETTERS 2019; 19:9084-9094. [PMID: 31738855 DOI: 10.1021/acs.nanolett.9b04209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Monolayer heterojunctions such as MoS2/WS2 are attractive for solar energy conversion applications because the interfacial electric field spatially separates charge carriers in less than 100 fs. Photoelectrochemical cells represent an intriguing platform to collect the spatially separated carriers. However, the recombination, transport, and interfacial charge transfer processes that take place following the ultrafast charge separation step have not been investigated. Here we demonstrate novel charge recombination and transport pathways in monolayer MoS2/WS2 photoelectrochemical cells by spatially resolving the net collection of carriers (i.e., the photocurrent) at the single nanosheet level. We discovered an excitation-wavelength-dependent recombination pathway that depends on the heterojunction stacking configuration and the carrier generation profile in the heterostructure. Photocurrent mapping measurements revealed that charge transport occurs parallel to the layers over micrometer-scale distances even though the indium tin oxide electrode and liquid electrolyte provide efficient charge extraction pathways via intimate electron- and hole-selective contacts. Our results reveal how composition heterogeneity influences the performance of bulk heterojunction electrodes made from randomly oriented nanosheets and provide critical insight into the design of efficient heterojunction photoelectrodes for solar energy conversion applications.
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25
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Guo J, Wang L, Yu Y, Wang P, Huang Y, Duan X. SnSe/MoS 2 van der Waals Heterostructure Junction Field-Effect Transistors with Nearly Ideal Subthreshold Slope. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1902962. [PMID: 31618496 DOI: 10.1002/adma.201902962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/06/2019] [Indexed: 05/07/2023]
Abstract
The minimization of the subthreshold swing (SS) in transistors is essential for low-voltage operation and lower power consumption, both critical for mobile devices and internet of things (IoT) devices. The conventional metal-oxide-semiconductor field-effect transistor requires sophisticated dielectric engineering to achieve nearly ideal SS (60 mV dec-1 at room temperature). However, another type of transistor, the junction field-effect transistor (JFET) is free of dielectric layer and can reach the theoretical SS limit without complicated dielectric engineering. The construction of a 2D SnSe/MoS2 van der Waals (vdW) heterostructure-based JFET with nearly ideal SS is reported. It is shown that the SnSe/MoS2 vdW heterostructure exhibits excellent p-n diode rectifying characteristics with low saturate current. Using the SnSe as the gate and MoS2 as the channel, the SnSe/MoS2 vdW heterostructure exhibit well-behavioured n-channel JFET characteristics with a small pinch-off voltage VP of -0.25 V, nearly ideal subthreshold swing SS of 60.3 mV dec-1 and high ON/OFF ratio over 106 , demonstrating excellent electronic performance especially in the subthreshold regime.
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Affiliation(s)
- Jian Guo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Laiyuan Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Yiwei Yu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Peiqi Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Yu Huang
- Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Xiangfeng Duan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
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26
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Sahoo PK, Memaran S, Nugera FA, Xin Y, Díaz Márquez T, Lu Z, Zheng W, Zhigadlo ND, Smirnov D, Balicas L, Gutiérrez HR. Bilayer Lateral Heterostructures of Transition-Metal Dichalcogenides and Their Optoelectronic Response. ACS NANO 2019; 13:12372-12384. [PMID: 31532628 DOI: 10.1021/acsnano.9b04957] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional lateral heterojunctions based on monolayer transition-metal dichalcogenides (TMDs) have received increasing attention given that their direct band gap makes them very attractive for optoelectronic applications. Although bilayer TMDs present an indirect band gap, their electrical properties are expected to be less susceptible to ambient conditions, with higher mobilities and density of states when compared to monolayers. Bilayers and few-layers single domain devices have already demonstrated higher performance in radio frequency and photosensing applications. Despite these advantages, lateral heterostructures based on bilayer domains have been less explored. Here, we report the controlled synthesis of multi-junction bilayer lateral heterostructures based on MoS2-WS2 and MoSe2-WSe2 monodomains. The heterojunctions are created via sequential lateral edge-epitaxy that happens simultaneously in both the first and the second layers. A phenomenological mechanism is proposed to explain the growth mode with self-limited thickness that happens within a certain window of growth conditions. With respect to their as-grown monolayer counterparts, bilayer lateral heterostructures yield nearly 1 order of magnitude higher rectification currents. They also display a clear photovoltaic response, with short circuit currents ∼103 times larger than those extracted from the as-grown monolayers, in addition to room-temperature electroluminescence. The improved performance of bilayer heterostructures significantly expands the potential of two-dimensional materials for optoelectronics.
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Affiliation(s)
- Prasana Kumar Sahoo
- Department of Physics , University of South Florida , Tampa , Florida 33620 , United States
| | - Shahriar Memaran
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
- Department of Physics , Florida State University , Tallahassee , Florida 32306 , United States
| | - Florence Ann Nugera
- Department of Physics , University of South Florida , Tampa , Florida 33620 , United States
| | - Yan Xin
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Tania Díaz Márquez
- Department of Physics , University of South Florida , Tampa , Florida 33620 , United States
| | - Zhengguang Lu
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
- Department of Physics , Florida State University , Tallahassee , Florida 32306 , United States
| | - Wenkai Zheng
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
- Department of Physics , Florida State University , Tallahassee , Florida 32306 , United States
| | - Nikolai D Zhigadlo
- Department of Chemistry and Biochemistry , University of Bern , Bern 3012 , Switzerland
- CrystMat Company , Zurich 8046 , Switzerland
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
- Department of Physics , Florida State University , Tallahassee , Florida 32306 , United States
| | - Luis Balicas
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
- Department of Physics , Florida State University , Tallahassee , Florida 32306 , United States
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27
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Reconfigurable Local Photoluminescence of Atomically-Thin Semiconductors via Ferroelectric-Assisted Effects. NANOMATERIALS 2019; 9:nano9111620. [PMID: 31731643 PMCID: PMC6915559 DOI: 10.3390/nano9111620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/04/2019] [Accepted: 11/11/2019] [Indexed: 11/16/2022]
Abstract
Combining a pair of materials of different structural dimensions and functional properties into a hybrid material system may realize unprecedented multi-functional device applications. Especially, two-dimensional (2D) materials are suitable for being incorporated into the heterostructures due to their colossal area-to-volume ratio, excellent flexibility, and high sensitivity to interfacial and surface interactions. Semiconducting molybdenum disulfide (MoS2), one of the well-studied layered materials, has a direct band gap as one molecular layer and hence, is expected to be one of the promising key materials for next-generation optoelectronics. Here, using lateral 2D/3D heterostructures composed of MoS2 monolayers and nanoscale inorganic ferroelectric thin films, reversibly tunable photoluminescence has been demonstrated at the microscale to be over 200% upon ferroelectric polarization reversal by using nanoscale conductive atomic force microscopy tips. Also, significant ferroelectric-assisted modulation in electrical properties has been achieved from field-effect transistor devices based on the 2D/3D heterostructrues. Moreover, it was also shown that the MoS2 monolayer can be an effective electric field barrier in spite of its sub-nanometer thickness. These results would be of close relevance to exploring novel applications in the fields of optoelectronics and sensor technology.
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28
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Ultrasensitive MoS 2 photodetector by serial nano-bridge multi-heterojunction. Nat Commun 2019; 10:4701. [PMID: 31619671 PMCID: PMC6796006 DOI: 10.1038/s41467-019-12592-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/12/2019] [Indexed: 12/04/2022] Open
Abstract
The recent reports of various photodetectors based on molybdenum disulfide (MoS2) field effect transistors showed that it was difficult to obtain optoelectronic performances in the broad detection range [visible–infrared (IR)] applicable to various fields. Here, by forming a mono-/multi-layer nano-bridge multi-heterojunction structure (more than > 300 junctions with 25 nm intervals) through the selective layer control of multi-layer MoS2, a photodetector with ultrasensitive optoelectronic performances in a broad spectral range (photoresponsivity of 2.67 × 106 A/W at λ = 520 nm and 1.65 × 104 A/W at λ = 1064 nm) superior to the previously reported MoS2-based photodetectors could be successfully fabricated. The nano-bridge multi-heterojunction is believed to be an important device technology that can be applied to broadband light sensing, highly sensitive fluorescence imaging, ultrasensitive biomedical diagnostics, and ultrafast optoelectronic integrated circuits through the formation of a nanoscale serial multi-heterojunction, just by adding a selective layer control process. Fabrication of photodetector devices by selective etching of 2D materials can enable broadband detection. Here, the authors design mono- and multi-layer nano-bridge multi-heterojunction photodetectors based on MoS2 with high responsivities of 2.67 × 106 A/W and 1.65 × 104 A/W in the visible–infrared wavelength range and fast photoresponse.
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29
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Yamamoto M, Nouchi R, Kanki T, Nakaharai S, Hattori AN, Watanabe K, Taniguchi T, Wakayama Y, Ueno K, Tanaka H. Barrier Formation at the Contacts of Vanadium Dioxide and Transition-Metal Dichalcogenides. ACS APPLIED MATERIALS & INTERFACES 2019; 11:36871-36879. [PMID: 31525896 DOI: 10.1021/acsami.9b13763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phase-transition field-effect transistors (FETs) are a class of steep-slope devices that show abrupt on/off switching owing to the metal-insulator transition (MIT) induced in the contacting materials. An important avenue to develop phase-transition FETs is to understand the charge injection mechanism at the junction of the contacting MIT materials and semiconductor channels. Here, toward the realization of high-performance phase-transition FETs, we investigate the contact properties of heterojunctions between semiconducting transition-metal dichalcogenides (TMDCs) and vanadium dioxide (VO2) that undergoes a MIT at a critical temperature (Tc) of approximately 340 K. We fabricated transistors based on molybdenum disulfide (MoS2) and tungsten diselenide (WSe2) in contact with the VO2 source/drain electrodes. The VO2-contacted MoS2 transistor exhibited n-type transport both below and above Tc. Across the MIT, the on-current was observed to increase only by a factor of 5, in contrast to the order-of-magnitude change in the resistance of the VO2 electrodes, suggesting the existence of high contact resistance. The Arrhenius analyses of the gate-dependent drain current confirmed the formation of the interfacial barrier at the VO2/MoS2 contacts, irrespective of the phase state of VO2. The VO2-contacted WSe2 transistor showed ambipolar transport, indicating that the Fermi level lies near the mid gap of WSe2. These observations provide insights into the contact properties of phase-transition FETs based on VO2 and TMDCs and suggest the need for contact engineering for high-performance operations.
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Affiliation(s)
- Mahito Yamamoto
- Institute of Scientific and Industrial Research , Osaka University , Ibaraki , Osaka 567-0047 , Japan
| | - Ryo Nouchi
- Graduate School of Engineering , Osaka Prefecture University , Sakai , Osaka 599-8570 , Japan
- JST PRESTO , Kawaguchi , Saitama 332-0012 , Japan
| | - Teruo Kanki
- Institute of Scientific and Industrial Research , Osaka University , Ibaraki , Osaka 567-0047 , Japan
| | - Shu Nakaharai
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Azusa N Hattori
- Institute of Scientific and Industrial Research , Osaka University , Ibaraki , Osaka 567-0047 , Japan
| | - Kenji Watanabe
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Takashi Taniguchi
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Yutaka Wakayama
- National Institute for Materials Science , Tsukuba , Ibaraki 305-0044 , Japan
| | - Keiji Ueno
- Department of Chemistry, Graduate School of Science and Engineering , Saitama University , Saitama 338-8570 , Japan
| | - Hidekazu Tanaka
- Institute of Scientific and Industrial Research , Osaka University , Ibaraki , Osaka 567-0047 , Japan
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30
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Lee H, Deshmukh S, Wen J, Costa VZ, Schuder JS, Sanchez M, Ichimura AS, Pop E, Wang B, Newaz AKM. Layer-Dependent Interfacial Transport and Optoelectrical Properties of MoS 2 on Ultraflat Metals. ACS APPLIED MATERIALS & INTERFACES 2019; 11:31543-31550. [PMID: 31364836 DOI: 10.1021/acsami.9b09868] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Layered materials based on transition-metal dichalcogenides (TMDs) are promising for a wide range of electronic and optoelectronic devices. Realizing such practical applications often requires metal-TMD connections or contacts. Hence, a complete understanding of electronic band alignments and potential barrier heights governing the transport through metal-TMD junctions is critical. However, it is presently unclear how the energy bands of a TMD align while in contact with a metal as a function of the number of layers. In pursuit of removing this knowledge gap, we have performed conductive atomic force microscopy (CAFM) of few-layered (1 to 5 layers) MoS2 immobilized on ultraflat conducting Au surfaces [root-mean-square (rms) surface roughness < 0.2 nm] and indium-tin oxide (ITO) substrates (rms surface roughness < 0.7 nm) forming a vertical metal (CAFM tip)-semiconductor-metal device. We have observed that the current increases with the number of layers up to five layers. By applying Fowler-Nordheim tunneling theory, we have determined the barrier heights for different layers and observed how this barrier decreases as the number of layers increases. Using density functional theory calculations, we successfully demonstrated that the barrier height decreases as the layer number increases. By illuminating TMDs on a transparent ultraflat conducting ITO substrate, we observed a reduction in current when compared to the current measured in the dark, hence demonstrating negative photoconductivity. Our study provides a fundamental understanding of the local electronic and optoelectronic behaviors of the TMD-metal junction, which depends on the numbers of TMD layers and may pave an avenue toward developing nanoscale electronic devices with tailored layer-dependent transport properties.
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Affiliation(s)
| | | | - Jing Wen
- School of Chemical, Biological and Materials Engineering , University of Oklahoma , Norman , Oklahoma 73019 , United States
- Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering , Harbin Normal University , Harbin 150025 , P. R. China
| | | | | | | | | | | | - Bin Wang
- School of Chemical, Biological and Materials Engineering , University of Oklahoma , Norman , Oklahoma 73019 , United States
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31
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Jia Z, Shi J, Shang Q, Du W, Shan X, Ge B, Li J, Sui X, Zhong Y, Wang Q, Bao L, Zhang Q, Liu X. Charge-Transfer-Induced Photoluminescence Properties of WSe 2 Monolayer-Bilayer Homojunction. ACS APPLIED MATERIALS & INTERFACES 2019; 11:20566-20573. [PMID: 31082257 DOI: 10.1021/acsami.9b06017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The charge-transfer process in transition-metal dichalcogenides (TMDCs) lateral homojunction affects the electron-hole recombination process of in optoelectronic devices. However, the optical properties of the homojunction reflecting the charge-transfer process has not been observed and studied. In this work, we investigated the charge-transfer-induced emission properties based on monolayer (1L)-bilayer (2L) WSe2 lateral homojunction with dozens of nanometer monolayer region. On the one hand, the photoluminescence (PL) emission of bilayer WSe2 from the homojunction area blue shifts ∼23 and ∼31 meV for direct and indirect bandgap emission, respectively, compared with the bare WSe2 bilayer region. The blue shift of the emission spectrum in the bilayer WSe2 is ascribed to the decrease in binding energy induced by charge transfer from monolayer to bilayer. On the other hand, the energy shift shows a tendency to increase as the temperature decreases. The energy blue shift is ∼57 meV for direct bandgap emission at 80 K, which is larger than that (∼23 meV) at room temperature. The larger-energy blue shift at low temperature is derived from the larger driving force under larger band offset. Our observations of the unique optical properties induced by efficient charge transfer are very helpful for exploring novel TMDC-based optoelectronic devices.
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Affiliation(s)
- Zhili Jia
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
| | - Jia Shi
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , 19 A Yuquan Rd, Shijingshan District , Beijing 100049 , P. R. China
| | - Qiuyu Shang
- Department of Materials Science and Engineering, College of Engineering , Peking University , Beijing 100871 , P. R. China
| | - Wenna Du
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
| | - Xinyan Shan
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Binghui Ge
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
- Institutes of Physical Science and Information Technology , Anhui University , Hefei 230601 , China
| | - Jing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials , Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190 , China
| | - Xinyu Sui
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , 19 A Yuquan Rd, Shijingshan District , Beijing 100049 , P. R. China
| | - Yangguang Zhong
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
| | - Qi Wang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
| | - Lihong Bao
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - Qing Zhang
- Department of Materials Science and Engineering, College of Engineering , Peking University , Beijing 100871 , P. R. China
| | - Xinfeng Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , P. R. China
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32
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Ávalos-Ovando O, Mastrogiuseppe D, Ulloa SE. Lateral heterostructures and one-dimensional interfaces in 2D transition metal dichalcogenides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:213001. [PMID: 30794993 DOI: 10.1088/1361-648x/ab0970] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The growth and exfoliation of two-dimensional (2D) materials have led to the creation of edges and novel interfacial states at the juncture between crystals with different composition or phases. These hybrid heterostructures (HSs) can be built as vertical van der Waals stacks, resulting in a 2D interface, or as stitched adjacent monolayer crystals, resulting in one-dimensional (1D) interfaces. Although most attention has been focused on vertical HSs, increasing theoretical and experimental interest in 1D interfaces is evident. In-plane interfacial states between different 2D materials inherit properties from both crystals, giving rise to robust states with unique 1D non-parabolic dispersion and strong spin-orbit effects. With such unique characteristics, these states provide an exciting platform for realizing 1D physics. Here, we review and discuss advances in 1D heterojunctions, with emphasis on theoretical approaches for describing those between semiconducting transition metal dichalcogenides MX 2 (with M = Mo, W and X = S, Se, Te), and how the interfacial states can be characterized and utilized. We also address how the interfaces depend on edge geometries (such as zigzag and armchair) or strain, as lattice parameters differ across the interface, and how these features affect excitonic/optical response. This review is intended to serve as a resource for promoting theoretical and experimental studies in this rapidly evolving field.
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Affiliation(s)
- O Ávalos-Ovando
- Department of Physics and Astronomy, and Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701-2979, United States of America
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33
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Amsterdam SH, Stanev TK, Zhou Q, Lou AJT, Bergeron H, Darancet P, Hersam MC, Stern NP, Marks TJ. Electronic Coupling in Metallophthalocyanine-Transition Metal Dichalcogenide Mixed-Dimensional Heterojunctions. ACS NANO 2019; 13:4183-4190. [PMID: 30848891 DOI: 10.1021/acsnano.8b09166] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Mixed-dimensional heterojunctions, such as zero-dimensional (0D) organic molecules deposited on two-dimensional (2D) transition metal dichalcogenides (TMDCs), often exhibit interfacial effects that enhance the properties of the individual constituent layers. Here we report a systematic study of interfacial charge transfer in metallophthalocyanine (MPc) - MoS2 heterojunctions using optical absorption and Raman spectroscopy to elucidate M core (M = first row transition metal), MoS2 layer number, and excitation wavelength effects. Observed phenomena include the emergence of heterojunction-specific optical absorption transitions and strong Raman enhancement that depends on the M identity. In addition, the Raman enhancement is tunable by excitation laser wavelength and MoS2 layer number, ultimately reaching a maximum enhancement factor of 30x relative to SiO2 substrates. These experimental results, combined with density functional theory (DFT) calculations, indicate strong coupling between nonfrontier MPc orbitals and the MoS2 band structure as well as charge transfer across the heterojunction interface that varies as a function of the MPc electronic structure.
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Affiliation(s)
- Samuel H Amsterdam
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
- Center for Light Energy Activated Redox Processes , Evanston , Illinois 60208 , United States
| | - Teodor K Stanev
- Department of Physics and Astronomy , Northwestern University , Evanston , Illinois 60208 , United States
| | - Qunfei Zhou
- Department of Materials Science and Engineering and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
- Center for Nanoscale Materials , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Alexander J-T Lou
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Hadallia Bergeron
- Department of Materials Science and Engineering and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Pierre Darancet
- Center for Nanoscale Materials , Argonne National Laboratory , Lemont , Illinois 60439 , United States
- Northwestern Argonne Institute for Science and Engineering , Evanston , Illinois 60208 , United States
| | - Mark C Hersam
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
- Center for Light Energy Activated Redox Processes , Evanston , Illinois 60208 , United States
- Department of Materials Science and Engineering and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
| | - Nathaniel P Stern
- Department of Physics and Astronomy , Northwestern University , Evanston , Illinois 60208 , United States
- Northwestern Argonne Institute for Science and Engineering , Evanston , Illinois 60208 , United States
| | - Tobin J Marks
- Department of Chemistry and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
- Center for Light Energy Activated Redox Processes , Evanston , Illinois 60208 , United States
- Department of Materials Science and Engineering and the Materials Research Center , Northwestern University , Evanston , Illinois 60208 , United States
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34
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Yuan J, Sun T, Hu Z, Yu W, Ma W, Zhang K, Sun B, Lau SP, Bao Q, Lin S, Li S. Wafer-Scale Fabrication of Two-Dimensional PtS 2/PtSe 2 Heterojunctions for Efficient and Broad band Photodetection. ACS APPLIED MATERIALS & INTERFACES 2018; 10:40614-40622. [PMID: 30387989 DOI: 10.1021/acsami.8b13620] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The fabrication of van der Waals heterostructures mainly extends to two-dimensional (2D) materials that are exfoliated from their bulk counterparts, which is greatly limited by high-volume manufacturing. Here, we demonstrate multilayered PtS2/PtSe2 heterojunctions covering a large area on the SiO2/Si substrate with a maximum size of 2″ in diameter, offering throughputs that can meet the practical application demand. Theoretical simulation was carried out to understand the electronic properties of the PtS2/PtSe2 heterojunctions. Zero-bias photoresponse in the heterojunctions is observed under laser illumination of different wavelengths (405-2200 nm). The PtS2/PtSe2 heterojunctions exhibit broad band photoresponse and high quantum efficiency at infrared wavelengths with lower bounds for the external quantum efficiencies being 1.2% at 1064 nm, 0.2% at 1550 nm, and 0.05% at 2200 nm, and also relatively fast response time at the dozens of millisecond level. The large area, broad band 2D heterojunction photodetector demonstrated in this work further corroborates the great potential of 2D materials in the future low-energy optoelectronics.
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Affiliation(s)
- Jian Yuan
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , Suzhou 215123 , People's Republic of China
- School of Physics and Electronic Information , Huaibei Normal University , Huaibei 235000 , Anhui , People's Republic of China
| | - Tian Sun
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , Suzhou 215123 , People's Republic of China
| | - Zhixin Hu
- Center for Joint Quantum Studies and Department of Physics , Institute of Science, Tianjin University , Tianjin 300350 , People's Republic of China
| | - Wenzhi Yu
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , Suzhou 215123 , People's Republic of China
| | - Weiliang Ma
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , Suzhou 215123 , People's Republic of China
| | - Kai Zhang
- i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics , Chinese Academy of Sciences , Suzhou 215123 , Jiangsu , People's Republic of China
| | - Baoquan Sun
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , Suzhou 215123 , People's Republic of China
| | - Shu Ping Lau
- Department of Applied Physics , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong SAR , People's Republic of China
| | - Qiaoliang Bao
- Department of Materials Science and Engineering, and ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET) , Monash University , Clayton , Victoria 3800 , Australia
| | - Shenghuang Lin
- Department of Applied Physics , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong SAR , People's Republic of China
| | - Shaojuan Li
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Collaborative Innovation Center of Suzhou Nano Science and Technology, and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices , Soochow University , Suzhou 215123 , People's Republic of China
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35
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Bertolazzi S, Gobbi M, Zhao Y, Backes C, Samorì P. Molecular chemistry approaches for tuning the properties of two-dimensional transition metal dichalcogenides. Chem Soc Rev 2018; 47:6845-6888. [PMID: 30043037 DOI: 10.1039/c8cs00169c] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Two-dimensional (2D) semiconductors, such as ultrathin layers of transition metal dichalcogenides (TMDs), offer a unique combination of electronic, optical and mechanical properties, and hold potential to enable a host of new device applications spanning from flexible/wearable (opto)electronics to energy-harvesting and sensing technologies. A critical requirement for developing practical and reliable electronic devices based on semiconducting TMDs consists in achieving a full control over their charge-carrier polarity and doping. Inconveniently, such a challenging task cannot be accomplished by means of well-established doping techniques (e.g. ion implantation and diffusion), which unavoidably damage the 2D crystals resulting in degraded device performances. Nowadays, a number of alternatives are being investigated, including various (supra)molecular chemistry approaches relying on the combination of 2D semiconductors with electroactive donor/acceptor molecules. As yet, a large variety of molecular systems have been utilized for functionalizing 2D TMDs via both covalent and non-covalent interactions. Such research endeavours enabled not only the tuning of the charge-carrier doping but also the engineering of the optical, electronic, magnetic, thermal and sensing properties of semiconducting TMDs for specific device applications. Here, we will review the most enlightening recent advancements in experimental (supra)molecular chemistry methods for tailoring the properties of atomically-thin TMDs - in the form of substrate-supported or solution-dispersed nanosheets - and we will discuss the opportunities and the challenges towards the realization of novel hybrid materials and devices based on 2D semiconductors and molecular systems.
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Affiliation(s)
- Simone Bertolazzi
- Université de Strasbourg, CNRS, ISIS, 8 alleé Gaspard Monge, 67000 Strasbourg, France.
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36
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Kim W, Arpiainen S, Xue H, Soikkeli M, Qi M, Sun Z, Lipsanen H, Chaves FA, Jiménez D, Prunnila M. Photoresponse of Graphene-Gated Graphene-GaSe Heterojunction Devices. ACS APPLIED NANO MATERIALS 2018; 1:3895-3902. [PMID: 30259010 PMCID: PMC6150651 DOI: 10.1021/acsanm.8b00684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/31/2018] [Indexed: 05/13/2023]
Abstract
Because of their extraordinary physical properties, low-dimensional materials including graphene and gallium selenide (GaSe) are promising for future electronic and optoelectronic applications, particularly in transparent-flexible photodetectors. Currently, the photodetectors working at the near-infrared spectral range are highly indispensable in optical communications. However, the current photodetector architectures are typically complex, and it is normally difficult to control the architecture parameters. Here, we report graphene-GaSe heterojunction-based field-effect transistors with broadband photodetection from 730-1550 nm. Chemical-vapor-deposited graphene was employed as transparent gate and contact electrodes with tunable resistance, which enables effective photocurrent generation in the heterojunctions. The photoresponsivity was shown from 10 to 0.05 mA/W in the near-infrared region under the gate control. To understand behavior of the transistor, we analyzed the results via simulation performed using a model for the gate-tunable graphene-semiconductor heterojunction where possible Fermi level pinning effect is considered.
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Affiliation(s)
- Wonjae Kim
- VTT
Technical Research Center of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
| | - Sanna Arpiainen
- VTT
Technical Research Center of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
- E-mail:
| | - Hui Xue
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo 02150, Finland
| | - Miika Soikkeli
- VTT
Technical Research Center of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
| | - Mei Qi
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo 02150, Finland
| | - Zhipei Sun
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo 02150, Finland
- QTF
Centre of Excellence, Department of Applied Physics, Aalto University, Aalto FI-00076, Finland
| | - Harri Lipsanen
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo 02150, Finland
| | - Ferney A. Chaves
- Department
d’Enginyeria Electrònica, Escola d’Enginyeria, Universitat Autònoma de Barcelona, Campus UAB, Bellaterra E-08193, Spain
| | - David Jiménez
- Department
d’Enginyeria Electrònica, Escola d’Enginyeria, Universitat Autònoma de Barcelona, Campus UAB, Bellaterra E-08193, Spain
| | - Mika Prunnila
- VTT
Technical Research Center of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland
- QTF
Centre of Excellence, Department of Applied Physics, Aalto University, Aalto FI-00076, Finland
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37
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Wang Z, Ou Q, Zhang Y, Zhang Q, Hoh HY, Bao Q. Degradation of Two-Dimensional CH 3NH 3PbI 3 Perovskite and CH 3NH 3PbI 3/Graphene Heterostructure. ACS APPLIED MATERIALS & INTERFACES 2018; 10:24258-24265. [PMID: 29877688 DOI: 10.1021/acsami.8b04310] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Hybrid organic-inorganic metal halide perovskites have been considered as promising materials for boosting the performance of photovoltaics and optoelectronics. Reduced-dimensional condiments and tunable properties render two-dimensional (2D) perovskite as novel building blocks for constructing micro-/nanoscale devices in high-performance optoelectronic applications. However, the stability is still one major obstacle for long-term practical use. Herein, we provide microscale insights into the degradation kinetics of 2D CH3NH3PbI3 (MAPbI3) perovskite and CH3NH3PbI3/graphene heterostructures. It is found that the degradation is mainly caused by cation evaporation, which consequently affects the microstructure, light-matter interaction, and the photoluminescence quantum yield efficiency of the 2D perovskite. Interestingly, the encapsulation of perovskite by monolayer graphene can largely preserve the structure of the perovskite nanosheet and maintain reasonable optical properties upon exposure to high temperature and humidity. The heterostructure consisting of perovskite and another 2D impermeable material affords new possibilities to construct high-performance and stable perovskite-based optoelectronic devices.
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Affiliation(s)
- Ziyu Wang
- Department of Materials Science and Engineering , Monash University , Wellington Road , Clayton , Victoria 3800 , Australia
| | - Qingdong Ou
- Department of Materials Science and Engineering , Monash University , Wellington Road , Clayton , Victoria 3800 , Australia
| | - Yupeng Zhang
- College of Electronic Science and Technology , Shenzhen University , Shenzhen 518000 , P. R. China
| | | | - Hui Ying Hoh
- College of Electronic Science and Technology , Shenzhen University , Shenzhen 518000 , P. R. China
| | - Qiaoliang Bao
- Department of Materials Science and Engineering , Monash University , Wellington Road , Clayton , Victoria 3800 , Australia
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38
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Li T, Li M, Lin Y, Cai H, Wu Y, Ding H, Zhao S, Pan N, Wang X. Probing Exciton Complexes and Charge Distribution in Inkslab-Like WSe 2 Homojunction. ACS NANO 2018; 12:4959-4967. [PMID: 29718657 DOI: 10.1021/acsnano.8b02060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
By virtue of the layer-dependent band structure and valley-selected optical/electronic properties, atomically layered transition-metal dichalcogenides (TMDs) exhibit great potentials such as in valleytronics and quantum devices, and have captured significant attentions. Precise control of the optical and electrical properties of TMDs is always the pursuing goal for real applications, and constructing advanced structures that allow playing with more degrees of freedom may hold the key. Here, we introduce a triangular inkslab-like WSe2 homojunction with a monolayer in the inner surrounded by a multilayer frame. Benefit from this interesting structure, the photoluminescence (PL) peaks redshift up to 50 meV and the charge density increases about 6 times from the center to the edge region of the inner monolayer. We demonstrated that the Se-deficient multilayer frame offers the excessive free electrons for the generation of the electron density gradient inside the monolayer, which also results in the spatial variation and distribution gradient of a series of exciton complexes. Furthermore, we observed the strong rectifying characteristic and clear photovoltaic response across the homojunction through measuring and mapping the photocurrent of the devices. Our result provides another route for efficient modulation of the exciton-complex emissions of TMDs, which is exceptionally desirable for the "layer- and charge-engineered" photonic and optoelectronic devices.
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Affiliation(s)
- Taishen Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Mingling Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Yue Lin
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Hongbing Cai
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Synergetic Innovation Center of Quantum Information & Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences,School of Physical Sciences , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Yiming Wu
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Huaiyi Ding
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Synergetic Innovation Center of Quantum Information & Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences,School of Physical Sciences , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Siwen Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Nan Pan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Synergetic Innovation Center of Quantum Information & Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences,School of Physical Sciences , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
| | - Xiaoping Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Synergetic Innovation Center of Quantum Information & Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences,School of Physical Sciences , University of Science and Technology of China , Hefei , Anhui 230026 , P. R. China
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39
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Frisenda R, Molina-Mendoza AJ, Mueller T, Castellanos-Gomez A, van der Zant HSJ. Atomically thin p-n junctions based on two-dimensional materials. Chem Soc Rev 2018; 47:3339-3358. [PMID: 29683464 DOI: 10.1039/c7cs00880e] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Recent research in two-dimensional (2D) materials has boosted a renovated interest in the p-n junction, one of the oldest electrical components which can be used in electronics and optoelectronics. 2D materials offer remarkable flexibility to design novel p-n junction device architectures, not possible with conventional bulk semiconductors. In this Review we thoroughly describe the different 2D p-n junction geometries studied so far, focusing on vertical (out-of-plane) and lateral (in-plane) 2D junctions and on mixed-dimensional junctions. We discuss the assembly methods developed to fabricate 2D p-n junctions making a distinction between top-down and bottom-up approaches. We also revise the literature studying the different applications of these atomically thin p-n junctions in electronic and optoelectronic devices. We discuss experiments on 2D p-n junctions used as current rectifiers, photodetectors, solar cells and light emitting devices. The important electronics and optoelectronics parameters of the discussed devices are listed in a table to facilitate their comparison. We conclude the Review with a critical discussion about the future outlook and challenges of this incipient research field.
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Affiliation(s)
- Riccardo Frisenda
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Campus de Cantoblanco, E-28049 Madrid, Spain.
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40
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Henning A, Sangwan VK, Bergeron H, Balla I, Sun Z, Hersam MC, Lauhon LJ. Charge Separation at Mixed-Dimensional Single and Multilayer MoS 2/Silicon Nanowire Heterojunctions. ACS APPLIED MATERIALS & INTERFACES 2018; 10:16760-16767. [PMID: 29682958 DOI: 10.1021/acsami.8b03133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Layered two-dimensional (2-D) semiconductors can be combined with other low-dimensional semiconductors to form nonplanar mixed-dimensional van der Waals (vdW) heterojunctions whose charge transport behavior is influenced by the heterojunction geometry, providing a new degree of freedom to engineer device functions. Toward that end, we investigated the photoresponse of Si nanowire/MoS2 heterojunction diodes with scanning photocurrent microscopy and time-resolved photocurrent measurements. Comparison of n-Si/MoS2 isotype heterojunctions with p-Si/MoS2 heterojunction diodes under varying biases shows that the depletion region in the p-n heterojunction promotes exciton dissociation and carrier collection. We measure an instrument-limited response time of 1 μs, which is 10 times faster than the previously reported response times for planar Si/MoS2 devices, highlighting the advantages of the 1-D/2-D heterojunction. Finite element simulations of device models provide a detailed understanding of how the electrostatics affect charge transport in nanowire/vdW heterojunctions and inform the design of future vdW heterojunction photodetectors and transistors.
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41
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Murthy AA, Stanev TK, Cain JD, Hao S, LaMountain T, Kim S, Speiser N, Watanabe K, Taniguchi T, Wolverton C, Stern NP, Dravid VP. Intrinsic Transport in 2D Heterostructures Mediated through h-BN Tunneling Contacts. NANO LETTERS 2018; 18:2990-2998. [PMID: 29678116 DOI: 10.1021/acs.nanolett.8b00444] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Understanding the electronic transport of monolayer transition metal dichalcogenides (TMDs) and their heterostructures is complicated by the difficulty in achieving electrical contacts that do not perturb the material. Typically, metal deposition on monolayer TMDs leads to hybridization between the TMD and the metal, which produces Schottky barriers at the metal/semiconductor interface. In this work, we apply the recently reported hexagonal boron nitride (h-BN) tunnel contact scheme to probe the junction characteristics of a lateral TMD heterostructure grown via chemical vapor deposition. We first measure the electronic properties across the junction before elucidating optoelectronic generation mechanisms via scanning photocurrent microscopy. We find that the rectification ratio measured using the encapsulated, tunnel contact scheme is almost 2 orders of magnitude smaller than that observed via conventional metal contact geometry, which implies that the metal/semiconductor Schottky barriers play large roles in this aspect. Furthermore, we find that both the photovoltaic as well as hot carrier generation effects are dominant mechanisms driving photoresponse, depending on the external biasing conditions. This work is the first time that this encapsulation scheme has been applied to lateral heterostructures and serves as a reference for future electronic measurements on this material. It also simultaneously serves as a framework to more accurately assess the electronic transport characteristics of 2D heterostructures and better inform future device architectures.
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Affiliation(s)
| | | | | | | | | | | | | | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan
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42
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Xia C, Xiong W, Du J, Wang T, Peng Y, Wei Z, Li J, Jia Y. Type-I Transition Metal Dichalcogenides Lateral Homojunctions: Layer Thickness and External Electric Field Effects. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1800365. [PMID: 29683270 DOI: 10.1002/smll.201800365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 03/11/2018] [Indexed: 06/08/2023]
Abstract
Transition metal dichalcogenide (TMD) heterostructures have been widely explored due to the formation of type-II band alignment and interlayer exciton. However, the studies of type-I TMD heterostructures are still lacking, which limit their applications in luminescence devices. Here, the 1L/nL MX2 (n = 2, 3, 4; M = Mo, W; X = S, Se) lateral homojunction based on the layer-dependent band gaps of TMD nanosheets is theoretically simulated. The studies show that the TMD homojunction presents with high thermal stability and type-I band alignment. The band offset and quantum confinement of carriers can be easily tuned by controlling the thickness of the multilayer region. Moreover, the electric field can decrease the band gaps of 1L/3L and 1L/4L homojunctions linearly. Interestingly, for the 1L/2L MX2 homojunction, the gap value is robust to the weak electric field, while it drops sharply under a strong electric field. This study sheds light on the physical pictures in the TMD lateral homojunction, and provides a practicable and general approach to engineer a type-I homojunction based 2D semiconductor materials.
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Affiliation(s)
- Congxin Xia
- College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007, China
| | - Wenqi Xiong
- College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007, China
| | - Juan Du
- College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007, China
| | - Tianxing Wang
- College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007, China
| | - Yuting Peng
- Department of Physics, University of Texas at Arlington, TX, 76019, USA
| | - Zhongming Wei
- Institutes of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Jingbo Li
- Institutes of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Yu Jia
- Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng, 475004, China
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43
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Li D, Xiao Z, Mu S, Wang F, Liu Y, Song J, Huang X, Jiang L, Xiao J, Liu L, Ducharme S, Cui B, Hong X, Jiang L, Silvain JF, Lu Y. A Facile Space-Confined Solid-Phase Sulfurization Strategy for Growth of High-Quality Ultrathin Molybdenum Disulfide Single Crystals. NANO LETTERS 2018; 18:2021-2032. [PMID: 29351373 DOI: 10.1021/acs.nanolett.7b05473] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Single-crystal transition metal dichalcogenides (TMDs) and TMD-based heterojunctions have recently attracted significant research and industrial interest owing to their intriguing optical and electrical properties. However, the lack of a simple, low-cost, environmentally friendly, synthetic method and a poor understanding of the growth mechanism post a huge challenge to implementing TMDs in practical applications. In this work, we developed a novel approach for direct formation of high-quality, monolayer and few-layer MoS2 single crystal domains via a single-step rapid thermal processing of a sandwiched reactor with sulfur and molybdenum (Mo) film in a confined reaction space. An all-solid-phase growth mechanism was proposed and experimentally/theoretically evidenced by analyzing the surface potential and morphology mapping. Compared with the conventional chemical vapor deposition approaches, our method involves no complicated gas-phase reactant transfer or reactions and requires very small amount of solid precursors [e.g., Mo (∼3 μg)], no carrier gas, no pretreatment of the precursor, no complex equipment design, thereby facilitating a simple, low-cost, and environmentally friendly growth. Moreover, we examined the symmetry, defects, and stacking phase in as-grown MoS2 samples using simultaneous second-harmonic-/sum-frequency-generation (SHG/SFG) imaging. For the first time, we observed that the SFG (peak intensity/position) polarization can be used as a sensitive probe to identify the orientation of TMDs' crystallographic axes. Furthermore, we fabricated ferroelectric programmable Schottky junction devices via local domain patterning using the as-grown, single-crystal monolayer MoS2, revealing their great potential in logic and optoelectronic applications. Our strategy thus provides a simple, low-cost, and scalable path toward a wide variety of TMD single crystal growth and novel functional device design.
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Affiliation(s)
- Dawei Li
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
| | - Zhiyong Xiao
- Department of Physics and Astronomy , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
- Nebraska Center for Materials and Nanoscience , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0299 , United States
| | - Sai Mu
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6124 , United States
| | - Fei Wang
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Ying Liu
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
| | - Jingfeng Song
- Department of Physics and Astronomy , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
- Nebraska Center for Materials and Nanoscience , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0299 , United States
| | - Xi Huang
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
| | - Lijia Jiang
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
| | - Jun Xiao
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
| | - Lei Liu
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
| | - Stephen Ducharme
- Department of Physics and Astronomy , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
- Nebraska Center for Materials and Nanoscience , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0299 , United States
| | - Bai Cui
- Nebraska Center for Materials and Nanoscience , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0299 , United States
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Xia Hong
- Department of Physics and Astronomy , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
- Nebraska Center for Materials and Nanoscience , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0299 , United States
| | - Lan Jiang
- School of Mechanical Engineering , Beijing Institute of Technology , Beijing 100081 , China
| | - Jean-Francois Silvain
- Institut de Chimie de la Matière Condensée de Bordeaux , Avenue du Docteur Albert Schweitzer F-33608 Pessac Cedex , France
| | - Yongfeng Lu
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588-0511 , United States
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Sangwan VK, Beck ME, Henning A, Luo J, Bergeron H, Kang J, Balla I, Inbar H, Lauhon LJ, Hersam MC. Self-Aligned van der Waals Heterojunction Diodes and Transistors. NANO LETTERS 2018; 18:1421-1427. [PMID: 29385342 DOI: 10.1021/acs.nanolett.7b05177] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A general self-aligned fabrication scheme is reported here for a diverse class of electronic devices based on van der Waals materials and heterojunctions. In particular, self-alignment enables the fabrication of source-gated transistors in monolayer MoS2 with near-ideal current saturation characteristics and channel lengths down to 135 nm. Furthermore, self-alignment of van der Waals p-n heterojunction diodes achieves complete electrostatic control of both the p-type and n-type constituent semiconductors in a dual-gated geometry, resulting in gate-tunable mean and variance of antiambipolar Gaussian characteristics. Through finite-element device simulations, the operating principles of source-gated transistors and dual-gated antiambipolar devices are elucidated, thus providing design rules for additional devices that employ self-aligned geometries. For example, the versatility of this scheme is demonstrated via contact-doped MoS2 homojunction diodes and mixed-dimensional heterojunctions based on organic semiconductors. The scalability of this approach is also shown by fabricating self-aligned short-channel transistors with subdiffraction channel lengths in the range of 150-800 nm using photolithography on large-area MoS2 films grown by chemical vapor deposition. Overall, this self-aligned fabrication method represents an important step toward the scalable integration of van der Waals heterojunction devices into more sophisticated circuits and systems.
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Affiliation(s)
- Vinod K Sangwan
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Megan E Beck
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Alex Henning
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Jiajia Luo
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Hadallia Bergeron
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Junmo Kang
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Itamar Balla
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Hadass Inbar
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Lincoln J Lauhon
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Materials Science and Engineering, ‡Department of Chemistry, and §Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States
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45
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Li C, Cao Q, Wang F, Xiao Y, Li Y, Delaunay JJ, Zhu H. Engineering graphene and TMDs based van der Waals heterostructures for photovoltaic and photoelectrochemical solar energy conversion. Chem Soc Rev 2018; 47:4981-5037. [DOI: 10.1039/c8cs00067k] [Citation(s) in RCA: 255] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This review provides a systematic overview of the integration, surface, and interfacial engineering of 2D/3D and 2D/2D homo/heterojunctions for PV and PEC applications.
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Affiliation(s)
- Changli Li
- State Key Laboratory of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Qi Cao
- School of Engineering
- The University of Tokyo
- Tokyo 113-8656
- Japan
| | - Faze Wang
- Institute of Fundamental and Frontier Sciences
- University of Electronic Science and Technology of China
- Chengdu
- China
| | - Yequan Xiao
- Institute of Fundamental and Frontier Sciences
- University of Electronic Science and Technology of China
- Chengdu
- China
| | - Yanbo Li
- Institute of Fundamental and Frontier Sciences
- University of Electronic Science and Technology of China
- Chengdu
- China
| | | | - Hongwei Zhu
- State Key Laboratory of New Ceramics and Fine Processing
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
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46
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Zhao J, Cheng K, Han N, Zhang J. Growth control, interface behavior, band alignment, and potential device applications of 2D lateral heterostructures. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2017. [DOI: 10.1002/wcms.1353] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology); Ministry of Education; Dalian China
| | - Kai Cheng
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology); Ministry of Education; Dalian China
| | - Nannan Han
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology); Ministry of Education; Dalian China
| | - Junfeng Zhang
- School of Physics and Information Engineering; Shanxi Normal University; Linfen China
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47
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Zhang Y, Xu J, Shi S, Gao Y, Zhao X, Wei C, Zhang X, Li L. Photoelectric response properties under UV/red light irradiation of ZnO nanorod arrays coated with vertically aligned MoS 2 nanosheets. NANOTECHNOLOGY 2017; 28:415202. [PMID: 28812544 DOI: 10.1088/1361-6528/aa8686] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
MoS2 with layered structure and distinct physical properties has attracted attention for electronic or optoelectronic devices. The photoelectric response properties of MoS2/ZnO heterojunctions based devices fabricated by spin-coating MoS2 nanosheets solutions on ZnO nanorod arrays (NRs) were investigated. The results revealed that MoS2 nanosheets were vertically aligned on the surface of ZnO NRs and the devices exhibit good photoresponse stability and reproducibility under UV and red light illuminations. The vertically aligned MoS2 nanosheets facilitate the fast photogenerated carrier separation and transport. The devices with few-layered MoS2 nanosheets show a high responsivity and detectivity under UV and red light illuminations, which can be attributed to small contact resistance between MoS2 nanosheets and ZnO NRs. These results provide important insights in the facile fabrication strategy and understanding electronic and optoelectronic devices based on the heterostructures with vertically aligned MoS2.
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Affiliation(s)
- Yuzhu Zhang
- Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin University of Technology, Tianjin 300384, People's Republic of China
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48
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Interfacing 2D Semiconductors with Functional Oxides: Fundamentals, Properties, and Applications. CRYSTALS 2017. [DOI: 10.3390/cryst7090265] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Two-dimensional semiconductors, such as transition-metal dichalcogenides (TMDs) and black phosphorous (BP), have found various potential applications in electronic and opto-electronic devices. However, several problems including low carrier mobility and low photoluminescence efficiencies still limit the performance of these devices. Interfacing 2D semiconductors with functional oxides provides a way to address the problems by overcoming the intrinsic limitations of 2D semiconductors and offering them multiple functionalities with various mechanisms. In this review, we first focus on the physical effects of various types of functional oxides on 2D semiconductors, mostly on MoS2 and BP as they are the intensively studied 2D semiconductors. Insulating, semiconducting, conventional piezoelectric, strongly correlated, and magnetic oxides are discussed. Then we introduce the applications of these 2D semiconductors/functional oxides systems in field-effect devices, nonvolatile memory, and photosensing. Finally, we discuss the perspectives and challenges within this research field. Our review provides a comprehensive understanding of 2D semiconductors/functional oxide heterostructures, and could inspire novel ideas in interface engineering to improve the performance of 2D semiconductor devices.
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49
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Wang X, Ling Y, Chiu YC, Du Y, Barreda JL, Perez-Orive F, Ma B, Xiong P, Gao H. Dynamic Electronic Junctions in Organic-Inorganic Hybrid Perovskites. NANO LETTERS 2017; 17:4831-4839. [PMID: 28661680 DOI: 10.1021/acs.nanolett.7b01665] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Organic-inorganic hybrid perovskites have shown great potential as building blocks for low-cost optoelectronics for their exceptional optical and electrical properties. Despite the remarkable progress in device demonstration, fundamental understanding of the physical processes in halide perovskites remains limited, especially the unusual electronic behaviors such as the current-voltage hysteresis and the switchable photovoltaic effect. These phenomena are of particular interests for being closely related to device functionalities and performance. In this work, a microscopic picture of electric fields in halide perovskite thin films was obtained using scanning laser microscopy. Unlike conventional semiconductors, distribution of the built-in electric fields in the halide perovskite evolves dynamically under the stimulation of external biases. The observations can be well explained using a model based on field-assisted ion migration, indicating that the mechanism responsible for the evolving charge transport observed in this material is not purely electronic. The anomalous dynamic responses to the applied bias are found to be effectively suppressed by operating the devices at reduced temperature or processing the materials at elevated temperature, which provide potential strategies for designing and creating halide perovskites with more stable charge transport properties in the development of viable perovskite-based optoelectronics.
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Affiliation(s)
- Xi Wang
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Yichuan Ling
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Yu-Che Chiu
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Yijun Du
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Jorge Luis Barreda
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Fernando Perez-Orive
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Biwu Ma
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Peng Xiong
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
| | - Hanwei Gao
- Department of Physics and ‡Materials Science Program, Florida State University , Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory and ⊥Department of Chemical & Biomedical Engineering, Florida State University , Tallahassee, Florida 32310, United States
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50
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Wong J, Jariwala D, Tagliabue G, Tat K, Davoyan AR, Sherrott MC, Atwater HA. High Photovoltaic Quantum Efficiency in Ultrathin van der Waals Heterostructures. ACS NANO 2017; 11:7230-7240. [PMID: 28590713 DOI: 10.1021/acsnano.7b03148] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report experimental measurements for ultrathin (<15 nm) van der Waals heterostructures exhibiting external quantum efficiencies exceeding 50% and show that these structures can achieve experimental absorbance >90%. By coupling electromagnetic simulations and experimental measurements, we show that pn WSe2/MoS2 heterojunctions with vertical carrier collection can have internal photocarrier collection efficiencies exceeding 70%.
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Affiliation(s)
- Joeson Wong
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
| | - Deep Jariwala
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
| | - Giulia Tagliabue
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
| | - Kevin Tat
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
| | - Artur R Davoyan
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
| | - Michelle C Sherrott
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
| | - Harry A Atwater
- Department of Applied Physics and Materials Science, ‡Resnick Sustainability Institute, §Kavli Nanoscience Institute, and ∥Joint Center for Artificial Photosynthesis, California Institute of Technology , Pasadena, California 91125, United States
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