1
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Guba M, Höltzl T. Stability and Electronic Structure of Nitrogen-Doped Graphene-Supported Cu n ( n = 1-5) Clusters in Vacuum and under Electrochemical Conditions: Toward Sensor and Catalyst Design. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:4677-4686. [PMID: 38533239 PMCID: PMC10961840 DOI: 10.1021/acs.jpcc.3c06475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/28/2024]
Abstract
Here, we present a detailed computational study of the stability and the electronic structure of nitrogen-doped graphene (N4V2) supported Cun (n = 1-5) clusters, which are promising carbon-dioxide electroreduction catalysts. The binding of the clusters to the nitrogen-doped graphene and the electronic structure of these systems were investigated under vacuum and electrochemical conditions. The stability analysis showed that among the systems, the nitrogen-doped graphene bound Cu4 is the most stable in vacuum, while in an electrolyte, and at a negative potential, the N4V2-Cu3 is energetically more favorable. The ground state electronic structure of the nitrogen-doped graphene substrate undergoes topological phase transition, from a semimetallic state, and we observed a metallic and topologically trivial state after the clusters are deposited. The electrode potential adjusts the type and density of the charge carriers in the semimetallic models, while the structures containing copper exhibit bands which are deformed and relaxed by the modified number of electrons.
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Affiliation(s)
- Márton Guba
- Department
of Inorganic and Analytical Chemistry and HUN-REN-BME Computation
Driven Chemistry Research Group, Budapest
University of Technology and Economics, Szent Gellért tér 4, Budapest H-1111, Hungary
| | - Tibor Höltzl
- Department
of Inorganic and Analytical Chemistry and HUN-REN-BME Computation
Driven Chemistry Research Group, Budapest
University of Technology and Economics, Szent Gellért tér 4, Budapest H-1111, Hungary
- Nanomaterials
Science Group, Furukawa Electric Institute
of Technology, Késmárk
utca 28/A, Budapest H-1158, Hungary
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2
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Wang L, Guo Z, Lan Q, Song W, Zhong Z, Yang K, Zhao T, Huang H, Zhang C, Shi W. Controllable Carrier Doping in Two-Dimensional Materials Using Electron-Beam Irradiation and Scalable Oxide Dielectrics. MICROMACHINES 2023; 14:2125. [PMID: 38004982 PMCID: PMC10673063 DOI: 10.3390/mi14112125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 11/26/2023]
Abstract
Two-dimensional (2D) materials, characterized by their atomically thin nature and exceptional properties, hold significant promise for future nano-electronic applications. The precise control of carrier density in these 2D materials is essential for enhancing performance and enabling complex device functionalities. In this study, we present an electron-beam (e-beam) doping approach to achieve controllable carrier doping effects in graphene and MoS2 field-effect transistors (FETs) by leveraging charge-trapping oxide dielectrics. By adding an atomic layer deposition (ALD)-grown Al2O3 dielectric layer on top of the SiO2/Si substrate, we demonstrate that controllable and reversible carrier doping effects can be effectively induced in graphene and MoS2 FETs through e-beam doping. This new device configuration establishes an oxide interface that enhances charge-trapping capabilities, enabling the effective induction of electron and hole doping beyond the SiO2 breakdown limit using high-energy e-beam irradiation. Importantly, these high doping effects exhibit non-volatility and robust stability in both vacuum and air environments for graphene FET devices. This methodology enhances carrier modulation capabilities in 2D materials and holds great potential for advancing the development of scalable 2D nano-devices.
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Affiliation(s)
- Lu Wang
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Zejing Guo
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Qing Lan
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Wenqing Song
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Zhipeng Zhong
- Shanghai Frontiers Science Research Base of Intelligent Optoelectronic and Perception, Institute of Optoelectronic and Department of Material Science, Fudan University, Shanghai 200433, China
| | - Kunlin Yang
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Tuoyu Zhao
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Hai Huang
- Shanghai Frontiers Science Research Base of Intelligent Optoelectronic and Perception, Institute of Optoelectronic and Department of Material Science, Fudan University, Shanghai 200433, China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Wu Shi
- State Key Laboratory of Surface Physics, Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
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3
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Saha D, Waters D, Yeh CC, Mhatre SM, Tran NTM, Hill HM, Watanabe K, Taniguchi T, Newell DB, Yankowitz M, Rigosi AF. Graphene-Based Analog of Single-Slit Electron Diffraction. PHYSICAL REVIEW. B 2023; 108:10.1103/physrevb.108.125420. [PMID: 37841515 PMCID: PMC10572097 DOI: 10.1103/physrevb.108.125420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
This work reports the experimental demonstration of single-slit diffraction exhibited by electrons propagating in encapsulated graphene with an effective de Broglie wavelength corresponding to their attributes as massless Dirac fermions. Nanometer-scale device designs were implemented to fabricate a single-slit followed by five detector paths. Predictive calculations were also utilized to readily understand the observations reported. These calculations required the modeling of wave propagation in ideal case scenarios of the reported device designs to more accurately describe the observed single-slit phenomenon. This experiment was performed at room temperature and 190 K, where data from the latter highlighted the exaggerated asymmetry between electrons and holes, recently ascribed to slightly different Fermi velocities near the K point. This observation and device concept may be used for building diffraction switches with versatile applicability.
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Affiliation(s)
- Dipanjan Saha
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Dacen Waters
- Intelligence Community Postdoctoral Research Fellowship Program, University of Washington, Seattle, WA 98195, United States
- Department of Physics, University of Washington, Seattle, WA 98195, United States
| | - Ching-Chen Yeh
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Swapnil M. Mhatre
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Ngoc Thanh Mai Tran
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Heather M. Hill
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - David B. Newell
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Matthew Yankowitz
- Department of Physics, University of Washington, Seattle, WA 98195, United States
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, United States
| | - Albert F. Rigosi
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
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4
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Wang J, Zeng H, Duan W, Huang H. Intrinsic Nonlinear Hall Detection of the Néel Vector for Two-Dimensional Antiferromagnetic Spintronics. PHYSICAL REVIEW LETTERS 2023; 131:056401. [PMID: 37595209 DOI: 10.1103/physrevlett.131.056401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/29/2023] [Accepted: 06/30/2023] [Indexed: 08/20/2023]
Abstract
The respective unique merit of antiferromagnets and two-dimensional (2D) materials in spintronic applications inspires us to exploit 2D antiferromagnetic spintronics. However, the detection of the Néel vector in 2D antiferromagnets remains a great challenge because the measured signals usually decrease significantly in the 2D limit. Here we propose that the Néel vector of 2D antiferromagnets can be efficiently detected by the intrinsic nonlinear Hall (INH) effect which exhibits unexpected significant signals. As a specific example, we show that the INH conductivity of the monolayer manganese chalcogenides MnX (X=S, Se, Te) can reach the order of nm·mA/V^{2}, which is orders of magnitude larger than experimental values of paradigmatic antiferromagnetic spintronic materials. The INH effect can be accurately controlled by shifting the chemical potential around the band edge, which is experimentally feasible via electric gating or charge doping. Moreover, we explicitly demonstrate its 2π-periodic dependence on the Néel vector orientation based on an effective k·p model. Our findings enable flexible design schemes and promising material platforms for spintronic memory device applications based on 2D antiferromagnets.
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Affiliation(s)
- Jizhang Wang
- School of Physics, Peking University, Beijing 100871, China
| | - Hui Zeng
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wenhui Duan
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Huaqing Huang
- School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Center for High Energy Physics, Peking University, Beijing 100871, China
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5
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Ekanayaka T, Jiang T, Delahaye E, Perez O, Sutter JP, Le D, N'Diaye AT, Streubel R, Rahman TS, Dowben PA. Evidence of symmetry breaking in a Gd 2 di-nuclear molecular polymer. Phys Chem Chem Phys 2023; 25:6416-6423. [PMID: 36779815 DOI: 10.1039/d2cp03050k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A chiral 3D coordination compound, [Gd2(L)2(ox)2(H2O)2], arranged around a dinuclear Gd unit has been characterized by X-ray photoemission and X-ray absorption measurements in the context of density functional theory studies. Core level photoemission of the Gd 5p multiplet splittings indicates that spin orbit coupling dominates over j-J coupling evident in the 5p core level spectra of Gd metal. Indications of spin-orbit coupling are consistent with the absence of inversion symmetry due to the ligand field. Density functional theory predicts antiferromagnet alignment of the Gd2 dimers and a band gap of the compound consistent with optical absorption.
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Affiliation(s)
- Thilini Ekanayaka
- Department of Physics and Astronomy, Theodore Jorgensen Hall, 855 North 16th Street, University of Nebraska-Lincoln, Lincoln, NE, 68588-0299, USA.
| | - Tao Jiang
- Department of Physics, University of Central Florida, 4000 Central Florida Blvd, Building 121 PS 430, Orlando, FL, 32816, USA.
| | - Emilie Delahaye
- Laboratoire de Chimie de Coordination du CNRS (LCC), Université de Toulouse, CNRS, Toulouse, France.
| | - Olivier Perez
- Normandie Univ, ENSICAEN, Unicaen, CNRS, CRISMAT, 14000, Caen, France
| | - Jean-Pascal Sutter
- Laboratoire de Chimie de Coordination du CNRS (LCC), Université de Toulouse, CNRS, Toulouse, France.
| | - Duy Le
- Department of Physics, University of Central Florida, 4000 Central Florida Blvd, Building 121 PS 430, Orlando, FL, 32816, USA.
| | - Alpha T N'Diaye
- Lawrence Berkeley National Laboratory, Advanced Light Source, Berkeley, CA, 94720, USA
| | - Robert Streubel
- Department of Physics and Astronomy, Theodore Jorgensen Hall, 855 North 16th Street, University of Nebraska-Lincoln, Lincoln, NE, 68588-0299, USA.
| | - Talat S Rahman
- Department of Physics, University of Central Florida, 4000 Central Florida Blvd, Building 121 PS 430, Orlando, FL, 32816, USA.
| | - Peter A Dowben
- Department of Physics and Astronomy, Theodore Jorgensen Hall, 855 North 16th Street, University of Nebraska-Lincoln, Lincoln, NE, 68588-0299, USA.
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6
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Cao B, Grass T, Gazzano O, Patel KA, Hu J, Müller M, Huber-Loyola T, Anzi L, Watanabe K, Taniguchi T, Newell DB, Gullans M, Sordan R, Hafezi M, Solomon GS. Chiral Transport of Hot Carriers in Graphene in the Quantum Hall Regime. ACS NANO 2022; 16:18200-18209. [PMID: 36326218 PMCID: PMC9706666 DOI: 10.1021/acsnano.2c05502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Photocurrent (PC) measurements can reveal the relaxation dynamics of photoexcited hot carriers beyond the linear response of conventional transport experiments, a regime important for carrier multiplication. Here, we study the relaxation of carriers in graphene in the quantum Hall regime by accurately measuring the PC signal and modeling the data using optical Bloch equations. Our results lead to a unified understanding of the relaxation processes in graphene over different magnetic field strength regimes, which is governed by the interplay of Coulomb interactions and interactions with acoustic and optical phonons. Our data provide clear indications of a sizable carrier multiplication. Moreover, the oscillation pattern and the saturation behavior of PC are manifestations of not only the chiral transport properties of carriers in the quantum Hall regime but also the chirality change at the Dirac point, a characteristic feature of a relativistic quantum Hall effect.
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Affiliation(s)
- Bin Cao
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
| | - Tobias Grass
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, Castelldefels
(Barcelona) 08860, Spain
- DIPC—Donostia
International Physics Center, San
Sebastian20018, Spain
- Ikerbasque—Basque Foundation for Science, Bilbao48013, Spain
| | - Olivier Gazzano
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
| | | | - Jiuning Hu
- National
Institute of Standards and Technology, Gaithersburg, Maryland20878, United States
| | - Markus Müller
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
| | - Tobias Huber-Loyola
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
| | - Luca Anzi
- L-NESS,
Department of Physics, Politecnico di Milano, Via Anzani 42, 22100Como, Italy
| | - Kenji Watanabe
- National
Institute for Materials Science, 1-1 Namiki, 305-0044Tsukuba, Japan
| | - Takashi Taniguchi
- National
Institute for Materials Science, 1-1 Namiki, 305-0044Tsukuba, Japan
| | - David B. Newell
- National
Institute of Standards and Technology, Gaithersburg, Maryland20878, United States
| | - Michael Gullans
- Joint
Center for Quantum Information and Computer Science, NIST/University of Maryland, College
Park, Maryland20742, United States
| | - Roman Sordan
- L-NESS,
Department of Physics, Politecnico di Milano, Via Anzani 42, 22100Como, Italy
| | - Mohammad Hafezi
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
- IREAP, University
of Maryland, College Park, Maryland20742, United States
| | - Glenn S. Solomon
- Joint
Quantum Institute, NIST/University of Maryland, College Park, Maryland20742, United States
- Department
of Physics and IPAS, University of Adelaide, Adelaide, South Australia5005, Australia
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7
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Chen CC, Chai JD. Electronic Properties of Hexagonal Graphene Quantum Rings from TAO-DFT. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12223943. [PMID: 36432229 PMCID: PMC9694783 DOI: 10.3390/nano12223943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/04/2022] [Accepted: 11/06/2022] [Indexed: 06/01/2023]
Abstract
The reliable prediction of electronic properties associated with graphene nanosystems can be challenging for conventional electronic structure methods, such as Kohn-Sham (KS) density functional theory (DFT), due to the presence of strong static correlation effects in these systems. To address this challenge, TAO (thermally assisted occupation) DFT has been recently proposed. In the present study, we employ TAO-DFT to predict the electronic properties of n-HGQRs (i.e., the hexagonal graphene quantum rings consisting of n aromatic rings fused together at each side). From TAO-DFT, the ground states of n-HGQRs are singlets for all the cases investigated (n = 3-15). As the system size increases, there should be a transition from the nonradical to polyradical nature of ground-state n-HGQR. The latter should be intimately related to the localization of active TAO-orbitals at the inner and outer edges of n-HGQR, which increases with increasing system size.
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Affiliation(s)
- Chi-Chun Chen
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Jeng-Da Chai
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Center for Theoretical Physics and Center for Quantum Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei 10617, Taiwan
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8
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Topological current divider in a Chern insulator junction. Nat Commun 2022; 13:5967. [PMID: 36216927 PMCID: PMC9550783 DOI: 10.1038/s41467-022-33645-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 09/21/2022] [Indexed: 11/08/2022] Open
Abstract
A Chern insulator is a two-dimensional material that hosts chiral edge states produced by the combination of topology with time reversal symmetry breaking. Such edge states are perfect one-dimensional conductors, which may exist not only on sample edges, but on any boundary between two materials with distinct topological invariants (or Chern numbers). Engineering of such interfaces is highly desirable due to emerging opportunities of using topological edge states for energy-efficient information transmission. Here, we report a chiral edge-current divider based on Chern insulator junctions formed within the layered topological magnet MnBi2Te4. We find that in a device containing a boundary between regions of different thickness, topological domains with different Chern numbers can coexist. At the domain boundary, a Chern insulator junction forms, where we identify a chiral edge mode along the junction interface. We use this to construct topological circuits in which the chiral edge current can be split, rerouted, or switched off by controlling the Chern numbers of the individual domains. Our results demonstrate MnBi2Te4 as an emerging platform for topological circuits design.
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9
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Hashimoto S, Kaneko H, De Feyter S, Tobe Y, Tahara K. Symmetry and spacing controls in periodic covalent functionalization of graphite surfaces templated by self-assembled molecular networks. NANOSCALE 2022; 14:12595-12609. [PMID: 35861168 DOI: 10.1039/d2nr02858a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We herein present the periodic covalent functionalization of graphite surfaces, creating a range of patterns of different symmetries and pitches at the nanoscale. Self-assembled molecular networks (SAMNs) of rhombic-shaped bis(dehydrobenzo[12]annulene) (bisDBA) derivatives having alkyl chain substituents of different lengths were used as templates for covalent grafting of electrochemically generated aryl radicals. Scanning tunneling microscopy (STM) observations at the 1,2,4-trichlorobenzene/graphite interface revealed that these molecules form a variety of networks that contain pores of different shapes and sizes. The covalently functionalized surfaces show hexagonal, oblique, and quasi-rectangular periodicities. This is attributed to the favorable aryl radical addition at the pore(s). We also confirmed the successful transmission of chirality information from the SAMNs to the alignment of the grafted aryls. In one case, the addition of a guest molecule was used to switch the SAMN symmetry and periodicity, leading to a change in the functionalized surface periodicity from oblique to hexagonal in the presence of the guest molecule. This contribution highlights the potential of SAMNs as templates for the controlled formation of nanopatterned carbon materials.
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Affiliation(s)
- Shingo Hashimoto
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
| | - Hiromasa Kaneko
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
| | - Steven De Feyter
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200 F, 3001 Leuven, Belgium
| | - Yoshito Tobe
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30030, Taiwan
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Kazukuni Tahara
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
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10
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Wicaksono Y, Harfah H, Sunnardianto GK, Majidi MA, Kusakabe K. Colossal in-plane magnetoresistance ratio of graphene sandwiched with Ni nanostructures. RSC Adv 2022; 12:13985-13991. [PMID: 35558854 PMCID: PMC9092117 DOI: 10.1039/d2ra00957a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/01/2022] [Indexed: 11/21/2022] Open
Abstract
In this study, we present a theoretical study on the in-plane conductance of graphene partially sandwiched between Ni(111) nanostructures with a width of ∼12.08 Å. In the sandwiched part, the gapped Dirac cone of the graphene was controlled using a pseudospin by changing the magnetic alignment of the Ni(111) nanostructures. Upon considering the antiparallel configuration of Ni(111) nanostructures, the transmission probability calculation of the in-plane conductance of graphene shows a gap-like transmission at E − EF = 0.2 and 0.65 eV from the pd-hybridization and controllable Dirac cone of graphene, respectively. In the parallel configuration, the transmission probability calculation showed a profile similar to that of the pristine graphene. High and colossal magnetoresistance ratios of 284% and 3100% were observed at E − EF = 0.65 eV and 0.2 eV, respectively. Furthermore, a magnetoresistance beyond 3100% was expected at E − EF = 0.65 eV when the width of the Ni(111) nanostructures on the nanometer scale was considered. In this study, we present a theoretical study on the in-plane conductance of graphene partially sandwiched between Ni(111) nanostructures with a width of ∼12.08 Å.![]()
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Affiliation(s)
- Yusuf Wicaksono
- Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama-cho Toyonaka Osaka 5608531 Japan
| | - Halimah Harfah
- Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama-cho Toyonaka Osaka 5608531 Japan
| | - Gagus Ketut Sunnardianto
- Research Center for Quantum Physics, The National Research and Innovation Agency (BRIN) Kawasan Puspiptek Serpong Tangerang Selatan Banten 15314 Indonesia.,School of Science, Graduate School of Science, University of Hyogo 3-2-1 Kouto, Kamigori-cho Ako-gun Hyogo 678-1297 Japan
| | - Muhammad Aziz Majidi
- Department of Physics, Faculty of Mathematics and Natural Science, Universitas Indonesia Kampus UI Depok Depok Jawa Barat 16424 Indonesia
| | - Koichi Kusakabe
- School of Science, Graduate School of Science, University of Hyogo 3-2-1 Kouto, Kamigori-cho Ako-gun Hyogo 678-1297 Japan
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11
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Zhang H, He R, Niu Y, Han F, Li J, Zhang X, Xu F. Graphene-enabled wearable sensors for healthcare monitoring. Biosens Bioelectron 2022; 197:113777. [PMID: 34781177 DOI: 10.1016/j.bios.2021.113777] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 01/19/2023]
Abstract
Wearable sensors in healthcare monitoring have recently found widespread applications in biomedical fields for their non- or minimal-invasive, user-friendly and easy-accessible features. Sensing materials is one of the major challenges to achieve these superiorities of wearable sensors for healthcare monitoring, while graphene-based materials with many favorable properties have shown great efficiency in sensing various biochemical and biophysical signals. In this paper, we review state-of-the-art advances in the development and modification of graphene-based materials (i.e., graphene, graphene oxide and reduced graphene oxide) for fabricating advanced wearable sensors with 1D (fibers), 2D (films) and 3D (foams/aerogels/hydrogels) macroscopic structures. We summarize the structural design guidelines, sensing mechanisms, applications and evolution of the graphene-based materials as wearable sensors for healthcare monitoring of biophysical signals (e.g., mechanical, thermal and electrophysiological signals) and biochemical signals from various body fluids and exhaled gases. Finally, existing challenges and future prospects are presented in this area.
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Affiliation(s)
- Huiqing Zhang
- Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, School of Energy & Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; The Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, China
| | - Rongyan He
- The Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, China
| | - Yan Niu
- The Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, China
| | - Fei Han
- The Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jing Li
- Department of Plastic and Burn Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710038, China
| | - Xiongwen Zhang
- Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, School of Energy & Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, 710049, China.
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12
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Li Y, Li B, Liu Y, Qu Y, Tian J, Li W. A wrinkled nanosurface causes accelerated protein unfolding revealing its critical role in nanotoxicity. RSC Adv 2022; 12:30976-30984. [PMID: 36349047 PMCID: PMC9619238 DOI: 10.1039/d2ra05489b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/14/2022] [Indexed: 11/05/2022] Open
Abstract
Wrinkles are often found to have a strong influence on the properties of nanomaterials and have attracted extensive research interest. However, the consequences of the use of wrinkled nanomaterials in biological systems remain largely unknown. Here, using molecular dynamics simulations, we studied the interactions of a wrinkled graphene with proteins, using the villin headpiece (HP35) as the representative model. Our results clearly revealed that the wrinkle, especially the wrinkle corner, showed stronger binding affinity to HP35 than the planar surface where HP35 experienced accelerated and more severe unfolding. This is because the transverse translocation of the aromatic residues of the protein is highly confined at the wrinkle corner. The movement of other parts of the protein causes unfolding of the protein secondary structure and releases hydrophobic residues to bind to graphene, causing complete denaturation. Further free energy analyses revealed that this is attributed to the stronger binding affinity of residues to the wrinkle corner than to the planar surface. The present findings provide a deeper understanding of the effect of graphene wrinkles on protein stability. This finding may be generalized to other types of biomolecules and may also guide the design of biomedical nanomaterials through surface structural engineering. Wrinkled nanosurface can cause more severe protein distorsions than planar nanosurface because of stronger interactions.![]()
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Affiliation(s)
- Yuezheng Li
- School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Baoyu Li
- School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China
| | - Yang Liu
- School of Physics, Shandong University, Jinan 250100, China
| | - Yuanyuan Qu
- School of Physics, Shandong University, Jinan 250100, China
| | - Jian Tian
- School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Weifeng Li
- School of Physics, Shandong University, Jinan 250100, China
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13
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Pure Graphene Oxide Vertical p-n Junction with Remarkable Rectification Effect. Molecules 2021; 26:molecules26226849. [PMID: 34833941 PMCID: PMC8618643 DOI: 10.3390/molecules26226849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 11/17/2022] Open
Abstract
Graphene p-n junctions have important applications in the fields of optical interconnection and low-power integrated circuits. Most current research is based on the lateral p-n junction prepared by chemical doping and other methods. Here, we report a new type of pure graphene oxide (pGO) vertical p-n junctions which do not dope any other elements but only controls the oxygen content of GO. The I-V curve of the pGO vertical p-n junction demonstrates a remarkable rectification effect. In addition, the pGO vertical p-n junction shows stability of its rectification characteristic over long-term storage for six months when sealed and stored in a PE bag. Moreover, the pGO vertical p-n junctions have obvious photoelectric response and various rectification effects with different thicknesses and an oxygen content of GO, humidity, and temperature. Hall effect test results show that rGO is an n-type semiconductor; theoretical calculations and research show that GO is generally a p-type semiconductor with a bandgap, thereby forming a p-n junction. Our work provides a method for preparing undoped GO vertical p-n junctions with advantages such as simplicity, convenience, and large-scale industrial preparation. Our work demonstrates great potential for application in electronics and highly sensitive sensors.
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14
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Interactions between Reduced Graphene Oxide with Monomers of (Calcium) Silicate Hydrates: A First-Principles Study. NANOMATERIALS 2021; 11:nano11092248. [PMID: 34578564 PMCID: PMC8466668 DOI: 10.3390/nano11092248] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 12/13/2022]
Abstract
Graphene is a two-dimensional material, with exceptional mechanical, electrical, and thermal properties. Graphene-based materials are, therefore, excellent candidates for use in nanocomposites. We investigated reduced graphene oxide (rGO), which is produced easily by oxidizing and exfoliating graphite in calcium silicate hydrate (CSHs) composites, for use in cementitious materials. The density functional theory was used to study the binding of moieties, on the rGO surface (e.g., hydroxyl-OH/rGO and epoxide/rGO groups), to CSH units, such as silicate tetrahedra, calcium ions, and OH groups. The simulations indicate complex interactions between OH/rGO and silicate tetrahedra, involving condensation reactions and selective repairing of the rGO lattice to reform pristine graphene. The condensation reactions even occurred in the presence of calcium ions and hydroxyl groups. In contrast, rGO/CSH interactions remained close to the initial structural models of the epoxy rGO surface. The simulations indicate that specific CSHs, containing rGO with different interfacial topologies, can be manufactured using coatings of either epoxide or hydroxyl groups. The results fill a knowledge gap, by establishing a connection between the chemical compositions of CSH units and rGO, and confirm that a wet chemical method can be used to produce pristine graphene by removing hydroxyl defects from rGO.
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15
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Wang D, Li XB, Sun HB. Modulation Doping: A Strategy for 2D Materials Electronics. NANO LETTERS 2021; 21:6298-6303. [PMID: 34232050 DOI: 10.1021/acs.nanolett.1c02192] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
It remains a remarkable challenge to develop practical techniques for controllable and nondestructive doping in two-dimensional (2D) materials for their use in electronics and optoelectronics. Here, we propose a modulation doping strategy, wherein the perfect n-/p-type channel layer is achieved by accepting/donating electrons from/to the defects inside an adjacent encapsulation layer. We demonstrate this strategy in the heterostructures of BN/graphene, BN/MoS2, where the previously believed useless deep defects, such as the nitrogen vacancy in BN, can provide free carriers to the graphene and MoS2. The carrier density is further modulated by engineering the surroundings of the encapsulation layer. Moreover, the defects and carriers are naturally separated in space, eliminating the effects of Coulomb impurity scattering and thus allowing high mobility in the 2D limit. This doping strategy provides a highly viable route to tune 2D channel materials without inducing any structural damage, paving the way for high-performance 2D nanoelectronic devices.
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Affiliation(s)
- Dan Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 eighth Street, Troy, New York 12180, United States
| | - Xian-Bin Li
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
| | - Hong-Bo Sun
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
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16
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Kim S, Schwenk J, Walkup D, Zeng Y, Ghahari F, Le ST, Slot MR, Berwanger J, Blankenship SR, Watanabe K, Taniguchi T, Giessibl FJ, Zhitenev NB, Dean CR, Stroscio JA. Edge channels of broken-symmetry quantum Hall states in graphene visualized by atomic force microscopy. Nat Commun 2021; 12:2852. [PMID: 33990565 PMCID: PMC8121811 DOI: 10.1038/s41467-021-22886-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 03/30/2021] [Indexed: 11/09/2022] Open
Abstract
The quantum Hall (QH) effect, a topologically non-trivial quantum phase, expanded the concept of topological order in physics bringing into focus the intimate relation between the "bulk" topology and the edge states. The QH effect in graphene is distinguished by its four-fold degenerate zero energy Landau level (zLL), where the symmetry is broken by electron interactions on top of lattice-scale potentials. However, the broken-symmetry edge states have eluded spatial measurements. In this article, we spatially map the quantum Hall broken-symmetry edge states comprising the graphene zLL at integer filling factors of [Formula: see text] across the quantum Hall edge boundary using high-resolution atomic force microscopy (AFM) and show a gapped ground state proceeding from the bulk through to the QH edge boundary. Measurements of the chemical potential resolve the energies of the four-fold degenerate zLL as a function of magnetic field and show the interplay of the moiré superlattice potential of the graphene/boron nitride system and spin/valley symmetry-breaking effects in large magnetic fields.
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Affiliation(s)
- Sungmin Kim
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Johannes Schwenk
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Daniel Walkup
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Yihang Zeng
- Department of Physics, Columbia University, New York, NY, USA
| | - Fereshte Ghahari
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Son T Le
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Theiss Research, La Jolla, CA, USA
| | - Marlou R Slot
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- Department of Physics, Georgetown University, Washington, DC, USA
| | - Julian Berwanger
- Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany
| | - Steven R Blankenship
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
| | - Franz J Giessibl
- Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany
| | - Nikolai B Zhitenev
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Cory R Dean
- Department of Physics, Columbia University, New York, NY, USA.
| | - Joseph A Stroscio
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
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17
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Amirmaleki M, Cui T, Zhao Y, Tam J, Goel A, Sun Y, Sun X, Filleter T. Fracture and Fatigue of Al 2O 3-Graphene Nanolayers. NANO LETTERS 2021; 21:437-444. [PMID: 33373247 DOI: 10.1021/acs.nanolett.0c03868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Al2O3-graphene nanolayers are widely used within integrated micro/nanoelectronic systems; however, their lifetimes are largely limited by fracture both statically and dynamically. Here, we present a static and fatigue study of thin (1-11 nm) free-standing Al2O3-graphene nanolayers. A remarkable fatigue life of greater than one billion cycles was obtained for films <2.2 nm thick under large mean stress levels, which was up to 3 orders of magnitude longer than that of its thicker (11 nm) counterpart. A similar thickness dependency was also identified for the elastic and static fracture behavior, where the enhancement effect of graphene is prominent only within a thickness of ∼3.3 nm. Moreover, plastic deformation, manifested by viscous creep, was observed and appeared to be more substantial for thicker films. This study provides mechanistic insights on both the static and dynamic reliability of Al2O3-graphene nanolayers and can potentially guide the design of graphene-based devices.
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Affiliation(s)
- Maedeh Amirmaleki
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada M5S 3G8
| | - Teng Cui
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada M5S 3G8
| | - Yang Zhao
- Department of Mechanical and Materials Engineering, University of Western Ontario, London, Canada N6A 5B9
| | - Jason Tam
- Department of Materials Science and Engineering, University of Toronto, Toronto, Canada M5S 3E4
| | - Anukalp Goel
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada M5S 3G8
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada M5S 3G8
| | - Xueliang Sun
- Department of Mechanical and Materials Engineering, University of Western Ontario, London, Canada N6A 5B9
| | - Tobin Filleter
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada M5S 3G8
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18
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Tan C, Wang H, Zhu X, Gao W, Li H, Chen J, Li G, Chen L, Xu J, Hu X, Li L, Zhai T. A Self-Powered Photovoltaic Photodetector Based on a Lateral WSe 2-WSe 2 Homojunction. ACS APPLIED MATERIALS & INTERFACES 2020; 12:44934-44942. [PMID: 32909433 DOI: 10.1021/acsami.0c11456] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lateral homojunctions made of two-dimensional (2D) layered materials are promising for optoelectronic and electronic applications. Here, we report the lateral WSe2-WSe2 homojunction photodiodes formed spontaneously by thickness modulation in which there are unique band structures of a unilateral depletion region. The electrically tunable junctions can be switched from n-n to p-p diodes, and the corresponding rectification ratio increases from about 1 to 1.2 × 104. In addition, an obvious photovoltaic behavior is observed at zero gate voltage, which exhibits a large open voltage of 0.49 V and a short-circuit current of 0.125 nA under visible light irradiation. In addition, due to the unilateral depletion region, the diode can achieve a high detectivity of 4.4 × 1010 Jones and a fast photoresponse speed of 0.18 ms at Vg = 0 and Vds = 0. The studies not only demonstrated the great potential of the lateral homojunction photodiodes for a self-power photodetector but also allowed for the development of other functional devices, such as a nonvolatile programmable diode for logic rectifiers.
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Affiliation(s)
- Chaoyang Tan
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Huanhuan Wang
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Xiangde Zhu
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory of the Chinese Academy of Science, Hefei 230031, P. R. China
| | - Wenshuai Gao
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Hui Li
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Jiawang Chen
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Gang Li
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Lijie Chen
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Junmin Xu
- Key Laboratory of Material Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
| | - Xiaozong Hu
- State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, P. R. China
| | - Liang Li
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University), Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, P. R. China
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19
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Chang L, Liu Y, Tian R, Meng L, Zhang H, Gao Y, Zhang F, Ruan X, Zhu B, Li J, Yi X, Hui G. Rapid glucose detection using graphene oxide modified foam nickel electrode with optimized basic solution. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2020. [DOI: 10.1080/10942912.2020.1812638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Liyang Chang
- Renal Department, Hangzhou, Zhejiang Province, PRC
| | - Yi Liu
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | | | - Lu Meng
- Department of Nursing, Zhejiang Chinese Medical University, Zhejiang Province, Hangzhou, PRC
| | | | - Yuanyuan Gao
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | - Feixiang Zhang
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | - Xiaorong Ruan
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | - Bowei Zhu
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | - Jian Li
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | - Xiaomei Yi
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
| | - Guohua Hui
- Department of Computer Science and Technology, Key Laboratory of Forestry Sensing Technology and Intelligent Equipment of China Ministry of Forestry, Key Laboratory of Forestry Intelligent Monitoring of Zhejiang Province, Zhejiang A&F University, Hangzhou, PRC
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20
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Intercalation-assisted Exfoliation Strategy for Two-dimensional Materials Preparation. Chem Res Chin Univ 2020. [DOI: 10.1007/s40242-020-0159-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Chen H, Zhou P, Liu J, Qiao J, Oezyilmaz B, Martin J. Gate controlled valley polarizer in bilayer graphene. Nat Commun 2020; 11:1202. [PMID: 32139694 PMCID: PMC7058031 DOI: 10.1038/s41467-020-15117-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/19/2020] [Indexed: 11/19/2022] Open
Abstract
Sign reversal of Berry curvature across two oppositely gated regions in bilayer graphene can give rise to counter-propagating 1D channels with opposite valley indices. Considering spin and sub-lattice degeneracy, there are four quantized conduction channels in each direction. Previous experimental work on gate-controlled valley polarizer achieved good contrast only in the presence of an external magnetic field. Yet, with increasing magnetic field the ungated regions of bilayer graphene will transit into the quantum Hall regime, limiting the applications of valley-polarized electrons. Here we present improved performance of a gate-controlled valley polarizer through optimized device geometry and stacking method. Electrical measurements show up to two orders of magnitude difference in conductance between the valley-polarized state and gapped states. The valley-polarized state displays conductance of nearly 4e2/h and produces contrast in a subsequent valley analyzer configuration. These results pave the way to further experiments on valley-polarized electrons in zero magnetic field.
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Affiliation(s)
- Hao Chen
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore
| | - Pinjia Zhou
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore, Singapore
| | - Jiawei Liu
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore
| | - Jiabin Qiao
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore, Singapore
| | - Barbaros Oezyilmaz
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore
| | - Jens Martin
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore, Singapore.
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore.
- Leibniz Institut für Kristallzüchtung, Max-Born-Strasse 2, 12489, Berlin, Germany.
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22
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Rhee D, Paci JT, Deng S, Lee WK, Schatz GC, Odom TW. Soft Skin Layers Enable Area-Specific, Multiscale Graphene Wrinkles with Switchable Orientations. ACS NANO 2020; 14:166-174. [PMID: 31675210 DOI: 10.1021/acsnano.9b06325] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This paper reports a method to realize crack-free graphene wrinkles with variable spatial wavelengths and switchable orientations. Graphene supported on a thin fluoropolymer and prestrained elastomer substrate can exhibit conformal wrinkling after strain relief. The wrinkle orientation could be switched beyond the intrinsic fracture limit of graphene for hundreds of cycles of stretching and releasing without forming cracks. Mechanical modeling revealed that the fluoropolymer layer mediated the structural evolution of the graphene wrinkles without crack formation or delamination. Patterned fluoropolymer layers with different thicknesses produced wrinkles with controlled wavelengths and orientations while maintaining the mechanical integrity of graphene under high tensile strain.
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Affiliation(s)
| | - Jeffrey T Paci
- Department of Chemistry , University of Victoria , Victoria , British Columbia V8P 5C2 , Canada
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23
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Singh A, Torubaev Y, Ansari SN, Singh SK, Mobin SM, Mathur P. The borderline: exploring the structural landscape of triptycene in cocrystallization with ferrocene. CrystEngComm 2020. [DOI: 10.1039/c9ce01734h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
When the effective packing of triptycene (TripH)–ferrocene chain oligomers in their cocrystal could not be achieved, we reached a borderline at the structural landscape of TripH, where the packing of TripH molecules reproduces the pattern in the native TripH crystal.
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Affiliation(s)
- Ajeet Singh
- Discipline of Chemistry
- Indian Institute of Technology Indore
- India
| | - Yury Torubaev
- N.S. Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences
- Moscow
- Russia
| | | | - Sandip K. Singh
- Discipline of Chemistry
- Indian Institute of Technology Indore
- India
| | - Shaikh M. Mobin
- Discipline of Chemistry
- Indian Institute of Technology Indore
- India
- Discipline of Metallurgy Engineering and Materials Science
- Indian Institute of Technology Indore
| | - Pradeep Mathur
- Discipline of Chemistry
- Indian Institute of Technology Indore
- India
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24
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Liu CI, Scaletta DS, Patel DK, Kruskopf M, Levy A, Hill HM, Rigosi AF. Analysing quantized resistance behaviour in graphene Corbino p-n junction devices. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2020; 53:10.1088/1361-6463/ab83bb. [PMID: 32831402 PMCID: PMC7431976 DOI: 10.1088/1361-6463/ab83bb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Just a few of the promising applications of graphene Corbino pnJ devices include two-dimensional Dirac fermion microscopes, custom programmable quantized resistors, and mesoscopic valley filters. In some cases, device scalability is crucial, as seen in fields like resistance metrology, where graphene devices are required to accommodate currents of the order 100 μA to be compatible with existing infrastructure. However, fabrication of these devices still poses many difficulties. In this work, unusual quantized resistances are observed in epitaxial graphene Corbino p-n junction devices held at the ν = 2 plateau (R H ≈ 12906 Ω) and agree with numerical simulations performed with the LTspice circuit simulator. The formulae describing experimental and simulated data are empirically derived for generalized placement of up to three current terminals and accurately reflects observed partial edge channel cancellation. These results support the use of ultraviolet lithography as a way to scale up graphene-based devices with suitably narrow junctions that could be applied in a variety of subfields.
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Affiliation(s)
- Chieh-I Liu
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, United States
| | - Dominick S Scaletta
- Department of Physics, Mount San Jacinto College, Menifee, CA 92584, United States
| | - Dinesh K Patel
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Mattias Kruskopf
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
- Joint Quantum Institute, University of Maryland, College Park, MD 20742, United States
- Electricity Division, Physikalisch-Technische Bundesanstalt, Braunschweig 38116, Germany
| | - Antonio Levy
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Heather M Hill
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Albert F Rigosi
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
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25
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Li H, Su S, Liang C, Zhang T, An X, Huang M, Tao H, Ma X, Ni Z, Tian H, Chen X. UV Rewritable Hybrid Graphene/Phosphor p-n Junction Photodiode. ACS APPLIED MATERIALS & INTERFACES 2019; 11:43351-43358. [PMID: 31657205 DOI: 10.1021/acsami.9b14461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Graphene-based p-n junction photodiodes have a potential application prospect in photodetection due to their broadband spectral response, large operating bandwidth, and mechanical flexibility. Here, we report an ultraviolet (UV) rewritable p-n junction photodiode in a configuration of graphene coated with an amorphous phosphor of 4-bromo-1,8-naphthalic anhydride derivative polymer (poly-BrNpA). Under moderate UV irradiation, occurrence of photoisomerization reaction in the poly-BrNpA film leads to its drastically modified optical characteristics and a concurrent n-type doping in the underneath graphene. Meanwhile, the poly-BrNpA film, highly sensitive to water molecules, has a capability of restoring graphene to its initial p-type doping status by means of water adsorption. Based on these findings, a lateral graphene/poly-BrNpA p-n junction photodiode, responsive to visible light at the junction interface, can be written by UV irradiation and then erased via water adsorption. The p-n junction photodiode is rewritable upon such repetitive loops showing repeatable optoelectronic properties. This study provides a new scheme and perspective of making graphene-based rewritable p-n junction photodiodes in a flexible and controllable way, and it may contribute to expanding new families of optoelectronic devices based on two-dimensional materials.
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Affiliation(s)
- Hao Li
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Shubin Su
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Chenhui Liang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Ting Zhang
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry and Molecular Engineering , East China University of Science & Technology , Shanghai 200237 , China
| | - Xuhong An
- Department of Physics , Southeast University , Nanjing 211189 , China
| | - Meizhen Huang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Haihua Tao
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
| | - Xiang Ma
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry and Molecular Engineering , East China University of Science & Technology , Shanghai 200237 , China
| | - Zhenhua Ni
- Department of Physics , Southeast University , Nanjing 211189 , China
| | - He Tian
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry and Molecular Engineering , East China University of Science & Technology , Shanghai 200237 , China
| | - Xianfeng Chen
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy , Shanghai Jiao Tong University , Shanghai 200240 , China
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26
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Wang K, Harzheim A, Taniguchi T, Watanabei K, Lee JU, Kim P. Tunneling Spectroscopy of Quantum Hall States in Bilayer Graphene p-n Junctions. PHYSICAL REVIEW LETTERS 2019; 122:146801. [PMID: 31050489 DOI: 10.1103/physrevlett.122.146801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 01/08/2019] [Indexed: 06/09/2023]
Abstract
We report tunneling transport in spatially controlled networks of quantum Hall (QH) edge states in bilayer graphene. By manipulating the separation, location, and spatial span of QH edge states via gate-defined electrostatics, we observe resonant tunneling between copropagating QH states across incompressible strips. Employing spectroscopic tunneling measurements and an analytical model, we characterize the energy gap, width, density of states, and compressibility of the QH edge states with high precision and sensitivity within the same device. The capability to engineer the QH edge network also provides an opportunity to build future quantum electronic devices with electrostatic manipulation of QH edge states, supported by rich underlying physics.
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Affiliation(s)
- Ke Wang
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55116, USA
| | - Achim Harzheim
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Takashi Taniguchi
- National Institute for Materials Science, Namiki, Ibaraki 305-0044, Japan
| | - Kenji Watanabei
- National Institute for Materials Science, Namiki, Ibaraki 305-0044, Japan
| | - Ji Ung Lee
- College of Nanoscale Engineering and Technology Innovation, SUNY Polytechnic Institute, Albany, New York 12203, USA
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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27
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Banerjee A, Sundaresh A, Biswas S, Ganesan R, Sen D, Anil Kumar PS. Topological insulator n-p-n junctions in a magnetic field. NANOSCALE 2019; 11:5317-5324. [PMID: 30843549 DOI: 10.1039/c8nr10306b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Electrical transport in three dimensional topological insulators (TIs) occurs through spin-momentum locked topological surface states that enclose an insulating bulk. In the presence of a magnetic field, surface states get quantized into Landau levels giving rise to chiral edge states that are naturally spin-polarized due to spin momentum locking. It has been proposed that p-n junctions of TIs exposed to external magnetic fields can manifest unique spin dependent effects, apart from forming basic building blocks for highly functional spintronic devices. Here, for the first time we study electrostatically defined n-p-n junctions of dual-gated devices of the three dimensional topological insulator BiSbTe1.25Se1.75 in the presence of a strong magnetic field, revealing striking signatures of suppressed or enhanced electrical transport depending upon the chirality of quantum Hall edge states created at the n-p and p-n junction interfaces. Theoretical modeling combining the electrostatics of the dual gated TI n-p-n junction with the Landauer Buttiker formalism for transport through a network of chiral edge states explains our experimental data. Our work not only opens up a route towards exotic spintronic devices but also provides a test bed for investigating the unique signatures of quantum Hall effects in topological insulators.
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Affiliation(s)
- Abhishek Banerjee
- Department of Physics, Indian Institute of Science, Bengaluru 560012, India.
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28
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Ahmad NF, Komatsu K, Iwasaki T, Watanabe K, Taniguchi T, Mizuta H, Wakayama Y, Hashim AM, Morita Y, Moriyama S, Nakaharai S. Fabry-Pérot resonances and a crossover to the quantum Hall regime in ballistic graphene quantum point contacts. Sci Rep 2019; 9:3031. [PMID: 30816251 PMCID: PMC6395604 DOI: 10.1038/s41598-019-39909-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 02/04/2019] [Indexed: 11/09/2022] Open
Abstract
We report on the observation of quantum transport and interference in a graphene device that is attached with a pair of split gates to form an electrostatically-defined quantum point contact (QPC). In the low magnetic field regime, the resistance exhibited Fabry-Pérot (FP) resonances due to np'n(pn'p) cavities formed by the top gate. In the quantum Hall (QH) regime with a high magnetic field, the edge states governed the phenomena, presenting a unique condition where the edge channels of electrons and holes along a p-n junction acted as a solid-state analogue of a monochromatic light beam. We observed a crossover from the FP to QH regimes in ballistic graphene QPC under a magnetic field with varying temperatures. In particular, the collapse of the QH effect was elucidated as the magnetic field was decreased. Our high-mobility graphene device enabled observation of such quantum coherence effects up to several tens of kelvins. The presented device could serve as one of the key elements in future electronic quantum optic devices.
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Grants
- 15K21722 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JPMJCR15F3 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- 15K21722 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JPMJCR15F3 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- 26630139 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
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Affiliation(s)
- Nurul Fariha Ahmad
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
- Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100, Kuala Lumpur, Malaysia
| | - Katsuyoshi Komatsu
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
| | - Takuya Iwasaki
- International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, NIMS, Tsukuba, Ibaraki, 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Functional Materials, NIMS, Tsukuba, Ibaraki, 305-0044, Japan
| | - Hiroshi Mizuta
- School of Material Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1211, Japan
- Hitachi Cambridge Laboratory, Hitachi Europe Ltd., J. J. Thomson Avenue, Cambridge, United Kingdom
| | - Yutaka Wakayama
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
| | - Abdul Manaf Hashim
- Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100, Kuala Lumpur, Malaysia
| | - Yoshifumi Morita
- Faculty of Engineering, Gunma University, Kiryu, Gunma, 376-8515, Japan
| | - Satoshi Moriyama
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
| | - Shu Nakaharai
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan.
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29
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Rigosi AF, Elmquist RE. The Quantum Hall Effect in the Era of the New SI. SEMICONDUCTOR SCIENCE AND TECHNOLOGY 2019; 34:10.1088/1361-6641/ab37d3. [PMID: 32165778 PMCID: PMC7067285 DOI: 10.1088/1361-6641/ab37d3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The quantum Hall effect (QHE), and devices reliant on it, will continue to serve as the foundation of the ohm while also expanding its territory into other SI derived units. The foundation, evolution, and significance of all of these devices exhibiting some form of the QHE will be described in the context of optimizing future electrical resistance standards. As the world adapts to using the quantum SI, it remains essential that the global metrology community pushes forth and continues to innovate and produce new technologies for disseminating the ohm and other electrical units.
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Affiliation(s)
- Albert F Rigosi
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America
| | - Randolph E Elmquist
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America
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30
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Rigosi AF, Patel D, Marzano M, Kruskopf M, Hill HM, Jin H, Hu J, Walker ARH, Ortolano M, Callegaro L, Liang CT, Newell DB. Atypical Quantized Resistances in Millimeter-Scale Epitaxial Graphene p-n Junctions. CARBON 2019; 154:10.1016/j.carbon.2019.08.002. [PMID: 32165760 PMCID: PMC7067286 DOI: 10.1016/j.carbon.2019.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have demonstrated the millimeter-scale fabrication of monolayer epitaxial graphene p-n junction devices using simple ultraviolet photolithography, thereby significantly reducing device processing time compared to that of electron beam lithography typically used for obtaining sharp junctions. This work presents measurements yielding nonconventional, fractional multiples of the typical quantized Hall resistance at ν = 2 (R H ≈ 12906 Ω) that take the form:a b R H . Here, a and b have been observed to take on values such 1, 2, 3, and 5 to form various coefficients of R H. Additionally, we provide a framework for exploring future device configurations using the LTspice circuit simulator as a guide to understand the abundance of available fractions one may be able to measure. These results support the potential for drastically simplifying device processing time and may be used for many other two-dimensional materials.
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Affiliation(s)
- Albert F. Rigosi
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Dinesh Patel
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Martina Marzano
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
- Department of Electronics and Telecommunications, Politecnico di Torino, Torino 10129, Italy
- Istituto Nazionale di Ricerca Metrologica, Torino 10135, Italy
| | - Mattias Kruskopf
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
- Joint Quantum Institute, University of Maryland, College Park, MD 20742, USA
| | - Heather M. Hill
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Hanbyul Jin
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
- Joint Quantum Institute, University of Maryland, College Park, MD 20742, USA
| | - Jiuning Hu
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
- Joint Quantum Institute, University of Maryland, College Park, MD 20742, USA
| | | | - Massimo Ortolano
- Department of Electronics and Telecommunications, Politecnico di Torino, Torino 10129, Italy
| | - Luca Callegaro
- Istituto Nazionale di Ricerca Metrologica, Torino 10135, Italy
| | - Chi-Te Liang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - David B. Newell
- National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
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31
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Wang J, Lian B. Multiple Chiral Majorana Fermion Modes and Quantum Transport. PHYSICAL REVIEW LETTERS 2018; 121:256801. [PMID: 30608855 DOI: 10.1103/physrevlett.121.256801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Indexed: 06/09/2023]
Abstract
The chiral Majorana fermion is a massless self-conjugate fermionic particle that could arise as the quasiparticle edge state of a two-dimensonal topological state of matter. Here we propose a new platform for a chiral topological superconductor (TSC) in two dimensions with multiple N chiral Majorana fermions from a quantized anomalous Hall insulator in proximity to an s-wave superconductor with nontrivial band topology. A concrete example is that a N=3 chiral TSC is realized by coupling a magnetic topological insulator to the ion-based superconductor such as FeTe_{0.55}Se_{0.45}. We further propose the electrical and thermal transport experiments to detect the Majorana nature of three chiral edge fermions. A smoking gun signature is that the two-terminal electrical conductance of a quantized anomalous Hall-TSC junction obeys a unique distribution averaged to (2/3)e^{2}/h, which is due to the random edge mode mixing of chiral Majorana fermions and is distinguished from possible trivial explanations. The homogenous system proposed here provides an ideal platform for studying the exotic physics of chiral Majorana fermions.
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Affiliation(s)
- Jing Wang
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Biao Lian
- Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA
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32
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Wei DS, van der Sar T, Lee SH, Watanabe K, Taniguchi T, Halperin BI, Yacoby A. Electrical generation and detection of spin waves in a quantum Hall ferromagnet. Science 2018; 362:229-233. [PMID: 30309954 DOI: 10.1126/science.aar4061] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 08/19/2018] [Indexed: 11/02/2022]
Abstract
Spin waves are collective excitations of magnetic systems. An attractive setting for studying long-lived spin-wave physics is the quantum Hall (QH) ferromagnet, which forms spontaneously in clean two-dimensional electron systems at low temperature and in a perpendicular magnetic field. We used out-of-equilibrium occupation of QH edge channels in graphene to excite and detect spin waves in magnetically ordered QH states. Our experiments provide direct evidence for long-distance spin-wave propagation through different ferromagnetic phases in the N = 0 Landau level, as well as across the insulating canted antiferromagnetic phase. Our results will enable experimental investigation of the fundamental magnetic properties of these exotic two-dimensional electron systems.
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Affiliation(s)
- Di S Wei
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | | | - Seung Hwan Lee
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | | | - Amir Yacoby
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. .,Department of Physics, Harvard University, Cambridge, MA 02138, USA
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33
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Wang G, Zhang M, Chen D, Guo Q, Feng X, Niu T, Liu X, Li A, Lai J, Sun D, Liao Z, Wang Y, Chu PK, Ding G, Xie X, Di Z, Wang X. Seamless lateral graphene p-n junctions formed by selective in situ doping for high-performance photodetectors. Nat Commun 2018; 9:5168. [PMID: 30518867 PMCID: PMC6281711 DOI: 10.1038/s41467-018-07555-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 10/29/2018] [Indexed: 11/09/2022] Open
Abstract
Lateral graphene p–n junctions are important since they constitute the core components in a variety of electronic/photonic systems. However, formation of lateral graphene p–n junctions with a controllable doping levels is still a great challenge due to the monolayer feature of graphene. Herein, by performing selective ion implantation and in situ growth by dynamic chemical vapor deposition, direct formation of seamless lateral graphene p–n junctions with spatial control and tunable doping is demonstrated. Uniform lattice substitution with heteroatoms is achieved in both the boron-doped and nitrogen-doped regions and photoelectrical assessment reveals that the seamless lateral p–n junctions exhibit a distinct photocurrent response under ambient conditions. As ion implantation is a standard technique in microelectronics, our study suggests a simple and effective strategy for mass production of graphene p–n junctions with batch capability and spatial controllability, which can be readily integrated into the production of graphene-based electronics and photonics. Fabricating lateral graphene p–n junctions with controlled doping levels is instrumental to realize ultrafast and efficient optoelectronic devices. Here, the authors report a seamless graphene based photodetector doped by selective ion implantation and in-situ chemical vapour deposition.
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Affiliation(s)
- Gang Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China.,Department of Microelectronic Science and Engineering, Faculty of Science, Ningbo University, Ningbo, 315211, P.R. China
| | - Miao Zhang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Da Chen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China.,Department of Microelectronic Science and Engineering, Faculty of Science, Ningbo University, Ningbo, 315211, P.R. China
| | - Qinglei Guo
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Xuefei Feng
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Tianchao Niu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Xiaosong Liu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Ang Li
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Jiawei Lai
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, P.R. China
| | - Dong Sun
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, P.R. China
| | - Zhimin Liao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P.R. China
| | - Yongqiang Wang
- Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA
| | - Paul K Chu
- Department of Physics and Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P.R. China
| | - Guqiao Ding
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Xiaoming Xie
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
| | - Zengfeng Di
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China.
| | - Xi Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, P.R. China
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34
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Souri M, Mohammadi K. Theoretical investigation of the defect position effect on the NLO properties of N and B doped graphenes. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Liu X, Li F, Xu M, Shen T, Yang Z, Fan W, Qi J. High Response, Self-Powered Photodetector Based on the Monolayer MoS 2/P-Si Heterojunction with Asymmetric Electrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:14151-14157. [PMID: 30375876 DOI: 10.1021/acs.langmuir.8b02171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Here, a self-powered photodetector based on the monolayer MoS2/P-Si heterojunction with asymmetric electrodes was fabricated. The MoS2/p-Si heterojunction photodetector with asymmetric electrodes offers the advantages over the conventional heterojunction photodetector on optoelectronic applications in terms of strong built-in electric field and fast photogenerated carrier separation and transport. Significantly, the MoS2/P-Si heterojunction exhibited an obvious photovoltaic effect, which can be used as the self-powered photodetector operating without any bias voltage. At a voltage bias of 0 V, the photocurrent of the detector is 23 nA, and its photoresponse/recovery time is 84 ms/136 ms. When at bias, the detector shows a ratio of photocurrent to dark current up to 3120, high responsivity of 117 A W-1, and fast photoresponse/recovery time of 74 ms/115 ms. Our work illustrates the great potential of the MoS2/P-Si heterojunction device with asymmetric electrodes on photovoltaic applications.
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Affiliation(s)
- Xinxin Liu
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
| | - Feng Li
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
| | - Minxuan Xu
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
| | - Tao Shen
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
| | - Zonglin Yang
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
| | - Weili Fan
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
| | - Junjie Qi
- University of Science and Technology Beijing , Beijing 100083 , People's Republic of China
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36
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Zhang JL, Han C, Hu Z, Wang L, Liu L, Wee ATS, Chen W. 2D Phosphorene: Epitaxial Growth and Interface Engineering for Electronic Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802207. [PMID: 30101443 DOI: 10.1002/adma.201802207] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/17/2018] [Indexed: 06/08/2023]
Abstract
Black phosphorus (BP), first synthesized in 1914 and rediscovered as a new member of the family of 2D materials in 2014, combines many extraordinary properties of graphene and transition-metal dichalcogenides, such as high charge-carrier mobility, and a tunable direct bandgap. In addition, it displays other distinguishing properties, e.g., ambipolar transport and highly anisotropic properties. The successful application of BP in electronic and optoelectronic devices has stimulated significant research interest in other allotropes and alloys of 2D phosphorene, a class of 2D materials consisting of elemental phosphorus. As an atomically thin sheet, the various interfaces presented in 2D phosphorene (substrate/phosphorene, electrode/phosphorene, dielectric/phosphorene, atmosphere/phosphorene) play dominant roles in its bottom-up synthesis, and determine several key characteristics for the devices, such as carrier injection, carrier transport, carrier concentration, and device stability. The rational design/engineering of interfaces provides an effective way to manipulate the growth of 2D phosphorene, and modulate its electronic and optoelectronic properties to realize high-performance multifunctional devices. Here, recent progress of the interface engineering of 2D phosphorene is highlighted, including the epitaxial growth of single-layer blue phosphorus on different substrates, surface functionalization of BP for high-performance complementary devices, and the investigation of the BP degradation mechanism in ambient air.
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Affiliation(s)
- Jia Lin Zhang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Cheng Han
- SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Shenzhen University, Shenzhen, 518060, China
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Zehua Hu
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Li Wang
- Institute for Advanced Study and Department of Physics, Nanchang University, 999 Xue Fu Da Dao, Nanchang, 330031, China
| | - Lei Liu
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, No. 3888 Dongnanhu Road, Changchun, 130033, China
| | - Andrew T S Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
| | - Wei Chen
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Shenzhen University, Shenzhen, 518060, China
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiang Su, 215123, China
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37
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Hu J, Rigosi AF, Kruskopf M, Yang Y, Wu BY, Tian J, Panna AR, Lee HY, Payagala SU, Jones GR, Kraft ME, Jarrett DG, Watanabe K, Taniguchi T, Elmquist RE, Newell DB. Towards epitaxial graphene p-n junctions as electrically programmable quantum resistance standards. Sci Rep 2018; 8:15018. [PMID: 30301948 PMCID: PMC6177418 DOI: 10.1038/s41598-018-33466-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/27/2018] [Indexed: 11/18/2022] Open
Abstract
We report the fabrication and measurement of top gated epitaxial graphene p-n junctions where exfoliated hexagonal boron nitride (h-BN) is used as the gate dielectric. The four-terminal longitudinal resistance across a single junction is well quantized at the von Klitzing constant [Formula: see text] with a relative uncertainty of 10-7. After the exploration of numerous parameter spaces, we summarize the conditions upon which these devices could function as potential resistance standards. Furthermore, we offer designs of programmable electrical resistance standards over six orders of magnitude by using external gating.
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Affiliation(s)
- Jiuning Hu
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA.
- Joint Quantum Institute, University of Maryland, College Park, MD, 20742, USA.
| | - Albert F Rigosi
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA.
| | - Mattias Kruskopf
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
- Joint Quantum Institute, University of Maryland, College Park, MD, 20742, USA
| | - Yanfei Yang
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
- Joint Quantum Institute, University of Maryland, College Park, MD, 20742, USA
| | - Bi-Yi Wu
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
- Graduate Institute of Applied Physics, National Taiwan University, Taipei, 10617, Taiwan
| | - Jifa Tian
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
- Department of Physics and Astronomy, and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, 47907, USA
| | - Alireza R Panna
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - Hsin-Yen Lee
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
- Theiss Research, La Jolla, CA, 92037, USA
| | - Shamith U Payagala
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - George R Jones
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - Marlin E Kraft
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - Dean G Jarrett
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - 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
| | - Randolph E Elmquist
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - David B Newell
- Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
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38
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Abstract
Semiconductor pn junctions are elementary building blocks of many electronic devices such as transistors, solar cells, photodetectors, and integrated circuits. Due to the absence of an energy bandgap and massless Dirac-like behaviour of charge carriers, graphene pn junction with electrical current rectification characteristics is hardly achieved. Here we show a graphene pn junction diode can be made exclusively from carbon materials by laminating two layers of positively and negatively charged graphene oxides. As the interdiffusion of oppositely charged mobile counterions, a built-in potential is created to rectify the current by changing the tunnelling probability of electrons across the junction. This graphene diode is semi-transparent, can perform simple logic operations, and since it has carbon nanotubes electrodes, we demonstrate an all carbon materials pn diode. We expect this graphene diode will expand material choices and provide functionalities (e.g. grafting recognition units on graphene oxides) beyond that of traditional semiconductor pn junctions. Chemically functionalized graphene oxide-based pn junction diodes have potential for future electronic device applications. Here, the authors report an all carbon pn diode with graphene oxide and carbon nanotubes electrodes showing excellent current rectification and efficient logic gates.
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39
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Tang S. Extracting the Energy Sensitivity of Charge Carrier Transport and Scattering. Sci Rep 2018; 8:10597. [PMID: 30006531 PMCID: PMC6045660 DOI: 10.1038/s41598-018-28288-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 06/15/2018] [Indexed: 11/09/2022] Open
Abstract
It is a challenge to extract the energy sensitivity of charge carriers’ transport and scattering from experimental data, although a theoretical estimation in which the existing scattering mechanism(s) are preliminarily assumed can be easily done. To tackle this problem, we have developed a method to experimentally determine the energy sensitivities, which can then serve as an important statistical measurement to further understand the collective behaviors of multi-carrier transport systems. This method is validated using a graphene system at different temperatures. Further, we demonstrate the application of this method to other two-dimensional (2D) materials as a guide for future experimental work on the optimization of materials performance for electronic components, Peltier coolers, thermoelectricity generators, thermocouples, thermopiles, electrical converters and other conductivity and/or Seebeck-effect-related sensors.
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Affiliation(s)
- Shuang Tang
- College of Engineering, State University of New York, Polytechnic Institute, Albany, New York, 12203, USA.
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40
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Wu YF, Zhang L, Li CZ, Zhang ZS, Liu S, Liao ZM, Yu D. Dirac Semimetal Heterostructures: 3D Cd 3 As 2 on 2D Graphene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707547. [PMID: 29995347 DOI: 10.1002/adma.201707547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 05/28/2018] [Indexed: 06/08/2023]
Abstract
Dirac semimetal is an emerging class of quantum matters, ranging from 2D category, such as, graphene and surface states of topological insulator to 3D category, for instance, Cd3 As2 and Na3 Bi. As 3D Dirac semimetals typically possess Fermi-arc surface states, the 2D-3D Dirac van der Waals heterostructures should be promising for future electronics. Here, graphene-Cd3 As2 heterostructures are fabricated through direct layer-by-layer stacking. The electronic coupling results in a notable interlayer charge transfer, which enables us to modulate the Fermi level of graphene through Cd3 As2 . A planar graphene p-n-p junction is achieved by selective modification, which demonstrates quantized conductance plateaus. Moreover, compared with the bare graphene device, the graphene-Cd3 As2 hybrid device presents large nonlocal signals near the Dirac point due to the charge transfer from the spin-polarized surface states in the adjacent Cd3 As2 . The results enrich the family of van der Waals heterostructure and should inspire more studies on the application of Dirac/Weyl semimetals in spintronics.
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Affiliation(s)
- Yan-Fei Wu
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen, 518055, P. R. China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, P. R. China
| | - Liang Zhang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Cai-Zhen Li
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Zhen-Sheng Zhang
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen, 518055, P. R. China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, P. R. China
| | - Song Liu
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen, 518055, P. R. China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, P. R. China
| | - Zhi-Min Liao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
- Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, 100871, P. R. China
| | - Dapeng Yu
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China, Shenzhen, 518055, P. R. China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, P. R. China
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41
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Thermal Conductance along Hexagonal Boron Nitride and Graphene Grain Boundaries. ENERGIES 2018. [DOI: 10.3390/en11061553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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42
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Xu X, Liu C, Sun Z, Cao T, Zhang Z, Wang E, Liu Z, Liu K. Interfacial engineering in graphene bandgap. Chem Soc Rev 2018. [PMID: 29513306 DOI: 10.1039/c7cs00836h] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Graphene exhibits superior mechanical strength, high thermal conductivity, strong light-matter interactions, and, in particular, exceptional electronic properties. These merits make graphene an outstanding material for numerous potential applications. However, a graphene-based high-performance transistor, which is the most appealing application, has not yet been produced, which is mainly due to the absence of an intrinsic electronic bandgap in this material. Therefore, bandgap opening in graphene is urgently needed, and great efforts have been made regarding this topic over the past decade. In this review article, we summarise recent theoretical and experimental advances in interfacial engineering to achieve bandgap opening. These developments are divided into two categories: chemical engineering and physical engineering. Chemical engineering is usually destructive to the pristine graphene lattice via chemical functionalization, the introduction of defects, doping, chemical bonds with substrates, and quantum confinement; the latter largely maintains the atomic structure of graphene intact and includes the application of an external field, interactions with substrates, physical adsorption, strain, electron many-body effects and spin-orbit coupling. Although these pioneering works have not met all the requirements for electronic applications of graphene at once, they hold great promise in this direction and may eventually lead to future applications of graphene in semiconductor electronics and beyond.
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Affiliation(s)
- Xiaozhi Xu
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
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43
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Zheng LM, Wang XR, Lü WM, Li CJ, Paudel TR, Liu ZQ, Huang Z, Zeng SW, Han K, Chen ZH, Qiu XP, Li MS, Yang S, Yang B, Chisholm MF, Martin LW, Pennycook SJ, Tsymbal EY, Coey JMD, Cao WW. Ambipolar ferromagnetism by electrostatic doping of a manganite. Nat Commun 2018; 9:1897. [PMID: 29765044 PMCID: PMC5953920 DOI: 10.1038/s41467-018-04233-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 04/12/2018] [Indexed: 11/09/2022] Open
Abstract
Complex-oxide materials exhibit physical properties that involve the interplay of charge and spin degrees of freedom. However, an ambipolar oxide that is able to exhibit both electron-doped and hole-doped ferromagnetism in the same material has proved elusive. Here we report ambipolar ferromagnetism in LaMnO3, with electron-hole asymmetry of the ferromagnetic order. Starting from an undoped atomically thin LaMnO3 film, we electrostatically dope the material with electrons or holes according to the polarity of a voltage applied across an ionic liquid gate. Magnetotransport characterization reveals that an increase of either electron-doping or hole-doping induced ferromagnetic order in this antiferromagnetic compound, and leads to an insulator-to-metal transition with colossal magnetoresistance showing electron-hole asymmetry. These findings are supported by density functional theory calculations, showing that strengthening of the inter-plane ferromagnetic exchange interaction is the origin of the ambipolar ferromagnetism. The result raises the prospect of exploiting ambipolar magnetic functionality in strongly correlated electron systems.
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Affiliation(s)
- L M Zheng
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China
| | - X Renshaw Wang
- School of Physical and Mathematical Sciences & School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
| | - W M Lü
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China.
| | - C J Li
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - T R Paudel
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska, 68588, USA
| | - Z Q Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Z Huang
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - S W Zeng
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - Kun Han
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - Z H Chen
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, Guangzhou, 518055, China
| | - X P Qiu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & Pohl Institute of Solid State Physics & School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - M S Li
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Shize Yang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - B Yang
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China
| | - Matthew F Chisholm
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - S J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - E Y Tsymbal
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska, 68588, USA
| | - J M D Coey
- School of Physics, Trinity College, Dublin, 2, Ireland.,Faculty of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - W W Cao
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China.,Department of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA
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44
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Kim JB, Li J, Choi Y, Whang D, Hwang E, Cho JH. Photosensitive Graphene P-N Junction Transistors and Ternary Inverters. ACS APPLIED MATERIALS & INTERFACES 2018; 10:12897-12903. [PMID: 29553702 DOI: 10.1021/acsami.8b00483] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We investigate the electric transport in a graphene-organic dye hybrid and the formation of p-n junctions. In the conventional approach, graphene p-n junctions are produced by using multiple electrostatic gates or local chemical doping, which produce different types of carriers in graphene. Instead of using multiple gates or typical chemical doping, a different approach to fabricate p-n junctions is proposed. The approach is based on optical gating of photosensitive dye molecules; this method can produce a well-defined sharp junction. The potential difference in the proposed p-n junction can be controlled by varying the optical power of incident light. A theoretical calculation based on the effective medium theory is performed to thoroughly explain the experimental data. The characteristic transport behavior of the photosensitive graphene p-n junction opens new possibilities for graphene-based devices, and we use the results to fabricate ternary inverters. Our strategy of building a simple hybrid p-n junction can further offer many opportunities in the near future of tuning it for other optoelectronic functionalities.
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45
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Ou Q, Zhang Y, Wang Z, Yuwono JA, Wang R, Dai Z, Li W, Zheng C, Xu ZQ, Qi X, Duhm S, Medhekar NV, Zhang H, Bao Q. Strong Depletion in Hybrid Perovskite p-n Junctions Induced by Local Electronic Doping. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1705792. [PMID: 29493028 DOI: 10.1002/adma.201705792] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/25/2017] [Indexed: 05/19/2023]
Abstract
A semiconductor p-n junction typically has a doping-induced carrier depletion region, where the doping level positively correlates with the built-in potential and negatively correlates with the depletion layer width. In conventional bulk and atomically thin junctions, this correlation challenges the synergy of the internal field and its spatial extent in carrier generation/transport. Organic-inorganic hybrid perovskites, a class of crystalline ionic semiconductors, are promising alternatives because of their direct badgap, long diffusion length, and large dielectric constant. Here, strong depletion in a lateral p-n junction induced by local electronic doping at the surface of individual CH3 NH3 PbI3 perovskite nanosheets is reported. Unlike conventional surface doping with a weak van der Waals adsorption, covalent bonding and hydrogen bonding between a MoO3 dopant and the perovskite are theoretically predicted and experimentally verified. The strong hybridization-induced electronic coupling leads to an enhanced built-in electric field. The large electric permittivity arising from the ionic polarizability further contributes to the formation of an unusually broad depletion region up to 10 µm in the junction. Under visible optical excitation without electrical bias, the lateral diode demonstrates unprecedented photovoltaic conversion with an external quantum efficiency of 3.93% and a photodetection responsivity of 1.42 A W-1 .
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Affiliation(s)
- Qingdong Ou
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
| | - Yupeng Zhang
- College of Electronic Science and Technology and College of Optoelectronics Engineering, Shenzhen University, Shenzhen, 518000, P. R. China
| | - Ziyu Wang
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
| | - Jodie A Yuwono
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
| | - Rongbin Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
- Institut für Physik, Humboldt-Universität zu Berlin, 12489, Berlin, Germany
| | - Zhigao Dai
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
- Laboratory of Printable Functional Nanomaterials and Printed Electronics, School of Printing and Packaging, Wuhan University, Wuhan, 430072, P. R. China
| | - Wei Li
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
| | - Changxi Zheng
- Department of Civil Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Zai-Quan Xu
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
| | - Xiang Qi
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
- School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, P. R. China
| | - Steffen Duhm
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, P. R. China
| | - Nikhil V Medhekar
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
| | - Han Zhang
- College of Electronic Science and Technology and College of Optoelectronics Engineering, Shenzhen University, Shenzhen, 518000, P. R. China
| | - Qiaoliang Bao
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria, 3800, Australia
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46
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Yasuda K, Mogi M, Yoshimi R, Tsukazaki A, Takahashi KS, Kawasaki M, Kagawa F, Tokura Y. Quantized chiral edge conduction on domain walls of a magnetic topological insulator. Science 2018; 358:1311-1314. [PMID: 29217573 DOI: 10.1126/science.aan5991] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 10/24/2017] [Indexed: 11/02/2022]
Abstract
Electronic ordering in magnetic and dielectric materials forms domains with different signs of order parameters. The control of configuration and motion of the domain walls (DWs) enables nonvolatile responses against minute external fields. Here, we realize chiral edge states (CESs) on the magnetic DWs of a magnetic topological insulator. We design and fabricate the magnetic domains in the quantum anomalous Hall state with the tip of a magnetic force microscope and prove the existence of the chiral one-dimensional edge conduction along the prescribed DWs through transport measurements. The proof-of-concept devices based on reconfigurable CESs and Landauer-Büttiker formalism are realized for multiple-domain configurations with well-defined DW channels. Our results may lead to the realization of low-power-consumption spintronic devices.
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Affiliation(s)
- K Yasuda
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan
| | - M Mogi
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan
| | - R Yoshimi
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - A Tsukazaki
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - K S Takahashi
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0075, Japan
| | - M Kawasaki
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.,RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - F Kagawa
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Y Tokura
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656, Japan.,RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
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47
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Zhang C, Jiao Y, He T, Bottle S, Frauenheim T, Du A. Predicting Two-Dimensional C 3B/C 3N van der Waals p-n Heterojunction with Strong Interlayer Electron Coupling and Enhanced Photocurrent. J Phys Chem Lett 2018; 9:858-862. [PMID: 29406724 DOI: 10.1021/acs.jpclett.7b03449] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The interlayer coupling in 2D van der Waals (vdW) heterostructures (HTS) plays the main role in generating new physics. However, the interlayer coupling is often weak, and little information on the strength of interlayer interaction in HTS is available. On the basis of density functional theory, we demonstrate that an effective electron coupling can be created in 2D C3B/C3N vdW HTS. The experimentally synthesized monolayers C3B and C3N are p- and n-type doped large gap semiconductors, respectively. However, the formed vdW HTS exhibits novel Dirac fermion. The strong interlayer electron coupling results in a large interlayer built-in electric field and improved optical properties of the 2D C3B/C3N vdW HTS. Moreover, a simple tight-binding model of C3B/C3N HTS with the nonzero interlayer hopping parameters captures the physical picture of interlayer coupling. Our results demonstrate the importance of interlayer electron coupling in the modulation of materials properties of 2D vdW HTS.
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Affiliation(s)
- Chunmei Zhang
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Gardens Point Campus, Brisbane, Queensland 4001, Australia
| | - Yalong Jiao
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Gardens Point Campus, Brisbane, Queensland 4001, Australia
| | - Tianwei He
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Gardens Point Campus, Brisbane, Queensland 4001, Australia
| | - Steven Bottle
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Gardens Point Campus, Brisbane, Queensland 4001, Australia
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen , Am Falturm 1, 28359 Bremen, Germany
| | - Aijun Du
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology , Gardens Point Campus, Brisbane, Queensland 4001, Australia
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48
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Li J, Wen H, Watanabe K, Taniguchi T, Zhu J. Gate-Controlled Transmission of Quantum Hall Edge States in Bilayer Graphene. PHYSICAL REVIEW LETTERS 2018; 120:057701. [PMID: 29481178 DOI: 10.1103/physrevlett.120.057701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 12/01/2017] [Indexed: 06/08/2023]
Abstract
The edge states of the quantum Hall and fractional quantum Hall effect of a two-dimensional electron gas carry key information of the bulk excitations. Here we demonstrate gate-controlled transmission of edge states in bilayer graphene through a potential barrier with tunable height. The backscattering rate is continuously varied from 0 to close to 1, with fractional quantized values corresponding to the sequential complete backscattering of individual modes. Our experiments demonstrate the feasibility to controllably manipulate edge states in bilayer graphene, thus opening the door to more complex experiments.
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Affiliation(s)
- Jing Li
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Hua Wen
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Kenji Watanabe
- National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Jun Zhu
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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49
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Influence of defect locations and nitrogen doping configurations on the mechanical properties of armchair graphene nanoribbons. J Mol Model 2018; 24:43. [PMID: 29352756 DOI: 10.1007/s00894-018-3581-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/05/2018] [Indexed: 10/18/2022]
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Liu X, Li F, Xu M, Qi J. Self-powered, high response and fast response speed metal–insulator–semiconductor structured photodetector based on 2D MoS2. RSC Adv 2018; 8:28041-28047. [PMID: 35542732 PMCID: PMC9084249 DOI: 10.1039/c8ra05511d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 07/27/2018] [Indexed: 12/14/2022] Open
Abstract
Here, we firstly fabricated a metal–insulator–semiconductor (MIS) (Pd/Al2O3/MoS2) self-powered photodetector based on MoS2, which is sensitive to the illumination of light without any external bias, exhibiting a high responsivity of 308 mA W−1. Under bias, it shows a ratio of photocurrent to dark current exceeding 3705, a high photoresponsivity of 5.04 A W−1, and a fast response/recovery time of 468 ms/543 ms. The optoelectronic performances of the photodetector are closely related to the insulating layer, which can suppress the dark current of the photodetectors, and prevent strong current drifting and degradation by environmental effects, playing a key role in carrier tunneling. Furthermore, we used a thin HfO2 film as the insulating layer to improve the optoelectronics performance of the MIS structured self-powered photodetector, which presented a high responsivity of 538 mA W−1 at 0 bias. With an applied bias, it exhibits an on/off ratio up to 6653, a photoresponsivity of 25.46 A W−1, and a response/recovery time of 7.53 ms/159 ms. Our results lead to a new way for future application of high performance MIS structured photodetectors based on 2D MoS2. A MIS structured self-powered photodetector of Pd/HfO2/MoS2 was fabricated by inserting a thin insulator, which has a fast response/recovery speed.![]()
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Affiliation(s)
- Xinxin Liu
- State Key Laboratory for Advanced Metals and Materials
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Feng Li
- State Key Laboratory for Advanced Metals and Materials
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Minxuan Xu
- State Key Laboratory for Advanced Metals and Materials
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Junjie Qi
- State Key Laboratory for Advanced Metals and Materials
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
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