1
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Kim H, Uddin I, Watanabe K, Taniguchi T, Whang D, Kim GH. Conversion of Charge Carrier Polarity in MoTe 2 Field Effect Transistor via Laser Doping. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13101700. [PMID: 37242116 DOI: 10.3390/nano13101700] [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: 04/17/2023] [Revised: 05/04/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
A two-dimensional (2D) atomic crystalline transition metal dichalcogenides has shown immense features, aiming for future nanoelectronic devices comparable to conventional silicon (Si). 2D molybdenum ditelluride (MoTe2) has a small bandgap, appears close to that of Si, and is more favorable than other typical 2D semiconductors. In this study, we demonstrate laser-induced p-type doping in a selective region of n-type semiconducting MoTe2 field effect transistors (FET) with an advance in using the hexagonal boron nitride as passivation layer from protecting the structure phase change from laser doping. A single nanoflake MoTe2-based FET, exhibiting initial n-type and converting to p-type in clear four-step doping, changing charge transport behavior in a selective surface region by laser doping. The device shows high electron mobility of about 23.4 cm2V-1s-1 in an intrinsic n-type channel and hole mobility of about 0.61 cm2V-1s-1 with a high on/off ratio. The device was measured in the range of temperature 77-300 K to observe the consistency of the MoTe2-based FET in intrinsic and laser-dopped region. In addition, we measured the device as a complementary metal-oxide-semiconductor (CMOS) inverter by switching the charge-carrier polarity of the MoTe2 FET. This fabrication process of selective laser doping can potentially be used for larger-scale MoTe2 CMOS circuit applications.
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Affiliation(s)
- Hanul Kim
- Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Inayat Uddin
- Department of Electrical and Computer Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Material Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Dongmok Whang
- Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
- Department of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Gil-Ho Kim
- Sungkyunkwan Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
- Department of Electrical and Computer Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
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2
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Yang H, Kim NY. Material-Inherent Noise Sources in Quantum Information Architecture. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2561. [PMID: 37048853 PMCID: PMC10094895 DOI: 10.3390/ma16072561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/17/2022] [Accepted: 11/22/2022] [Indexed: 06/19/2023]
Abstract
NISQ is a representative keyword at present as an acronym for "noisy intermediate-scale quantum", which identifies the current era of quantum information processing (QIP) technologies. QIP science and technologies aim to accomplish unprecedented performance in computation, communications, simulations, and sensing by exploiting the infinite capacity of parallelism, coherence, and entanglement as governing quantum mechanical principles. For the last several decades, quantum computing has reached to the technology readiness level 5, where components are integrated to build mid-sized commercial products. While this is a celebrated and triumphant achievement, we are still a great distance away from quantum-superior, fault-tolerant architecture. To reach this goal, we need to harness technologies that recognize undesirable factors to lower fidelity and induce errors from various sources of noise with controllable correction capabilities. This review surveys noisy processes arising from materials upon which several quantum architectures have been constructed, and it summarizes leading research activities in searching for origins of noise and noise reduction methods to build advanced, large-scale quantum technologies in the near future.
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Affiliation(s)
- HeeBong Yang
- Institute of Quantum Computing, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
- Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
| | - Na Young Kim
- Institute of Quantum Computing, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
- Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
- Department of Physics and Astronomy, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
- Department of Chemistry, University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada
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3
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Xu X, Lou J, Gao M, Wu S, Fang G, Huang Y. Ultrafast Modulation of THz Waves Based on MoTe 2-Covered Metasurface. SENSORS (BASEL, SWITZERLAND) 2023; 23:1174. [PMID: 36772214 PMCID: PMC9921109 DOI: 10.3390/s23031174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/14/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The sixth generation (6G) communication will use the terahertz (THz) frequency band, which requires flexible regulation of THz waves. For the conventional metallic metasurface, its electromagnetic properties are hard to be changed once after being fabricated. To enrich the modulation of THz waves, we report an all-optically controlled reconfigurable electromagnetically induced transparency (EIT) effect in the hybrid metasurface integrated with a 10-nm thick MoTe2 film. The experimental results demonstrate that under the excitation of the 800 nm femtosecond laser pulse with pump fluence of 3200 μJ/cm2, the modulation depth of THz transmission amplitude at the EIT window can reach 77%. Moreover, a group delay variation up to 4.6 ps is observed to indicate an actively tunable slow light behavior. The suppression and recovery of the EIT resonance can be accomplished within sub-nanoseconds, enabling an ultrafast THz photo-switching and providing a promising candidate for the on-chip devices of the upcoming 6G communication.
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Affiliation(s)
- Xing Xu
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Innovation Laboratory of Terahertz Biophysics, National Innovation Institute of Defense Technology, Beijing 100071, China
- Key Laboratory of Electromagnetic Radiation and Sensing Technology, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Lou
- Innovation Laboratory of Terahertz Biophysics, National Innovation Institute of Defense Technology, Beijing 100071, China
| | - Mingxin Gao
- Innovation Laboratory of Terahertz Biophysics, National Innovation Institute of Defense Technology, Beijing 100071, China
| | - Shiyou Wu
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Key Laboratory of Electromagnetic Radiation and Sensing Technology, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangyou Fang
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Key Laboratory of Electromagnetic Radiation and Sensing Technology, Chinese Academy of Sciences, Beijing 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yindong Huang
- Innovation Laboratory of Terahertz Biophysics, National Innovation Institute of Defense Technology, Beijing 100071, China
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4
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Chen C, Yang S, Lin C, Lee M, Tsai M, Yang F, Chang Y, Li M, Lee K, Ueno K, Shi Y, Lien C, Wu W, Chiu P, Li W, Lo S, Lin Y. Reversible Charge-Polarity Control for Multioperation-Mode Transistors Based on van der Waals Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2106016. [PMID: 35831244 PMCID: PMC9404391 DOI: 10.1002/advs.202106016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Van der Waals (vdW) heterostructures-in which layered materials are purposely selected to assemble with each other-allow unusual properties and different phenomena to be combined and multifunctional electronics to be created, opening a new chapter for the spread of internet-of-things applications. Here, an O2 -ultrasensitive MoTe2 material and an O2 -insensitive SnS2 material are integrated to form a vdW heterostructure, allowing the realization of charge-polarity control for multioperation-mode transistors through a simple and effective rapid thermal annealing strategy under dry-air and vacuum conditions. The charge-polarity control (i.e., doping and de-doping processes), which arises owing to the interaction between O2 adsorption/desorption and tellurium defects at the MoTe2 surface, means that the MoTe2 /SnS2 heterostructure transistors can reversibly change between unipolar, ambipolar, and anti-ambipolar transfer characteristics. Based on the dynamic control of the charge-polarity properties, an inverter, output polarity controllable amplifier, p-n diode, and ternary-state logics (NMIN and NMAX gates) are demonstrated, which inspire the development of reversibly multifunctional devices and indicates the potential of 2D materials.
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Affiliation(s)
- Ciao‐Fen Chen
- Department of Electrophysics and Center for Emergent Functional Matter Science (CEFMS)National Yang Ming Chiao Tung UniversityHsinchu30010Taiwan
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
| | - Shih‐Hsien Yang
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology (Ministry of Education)Engineering Technology Research Center for 2D Material Information Functional Devices and Systems (Guangdong Province)Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen518060China
| | - Che‐Yi Lin
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
| | - Mu‐Pai Lee
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
- Department of Materials Science and EngineeringNational Yang Ming Chiao Tung UniversityHsinchu300Taiwan
| | - Meng‐Yu Tsai
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
- Institute of Electronics EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan
| | - Feng‐Shou Yang
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
- Institute of Electronics EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan
| | - Yuan‐Ming Chang
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
| | - Mengjiao Li
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
| | - Ko‐Chun Lee
- Institute of Electronics EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan
| | - Keiji Ueno
- Department of ChemistryGraduate School of Science and EngineeringSaitama UniversitySaitama338–8570Japan
| | - Yumeng Shi
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology (Ministry of Education)Engineering Technology Research Center for 2D Material Information Functional Devices and Systems (Guangdong Province)Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen518060China
| | - Chen‐Hsin Lien
- Institute of Electronics EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan
| | - Wen‐Wei Wu
- Department of Materials Science and EngineeringNational Yang Ming Chiao Tung UniversityHsinchu300Taiwan
- Center for the Intelligent Semiconductor Nano‐system Technology ResearchNational Yang Ming Chiao Tung UniversityHsinchu300Taiwan
| | - Po‐Wen Chiu
- Institute of Electronics EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan
| | - Wenwu Li
- Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Zhangjiang Fudan International Innovation CenterInstitute of OptoelectronicsDepartment of Materials ScienceFudan UniversityShanghai200433China
| | - Shun‐Tsung Lo
- Department of Electrophysics and Center for Emergent Functional Matter Science (CEFMS)National Yang Ming Chiao Tung UniversityHsinchu30010Taiwan
| | - Yen‐Fu Lin
- Department of PhysicsNational Chung Hsing UniversityTaichung40227Taiwan
- Department of Materials Science and EngineeringInstitute of Nanosciencei‐Center for Advanced Science and Technology (i‐CAST)National Chung Hsing UniversityTaichung40227Taiwan
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5
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Zhang B, Hu C, Xin Y, Li Y, Xie Y, Xing Q, Guo Z, Xue Z, Li D, Zhang G, Geng L, Ke Z, Wang C. Analysis of Low-Frequency 1/f Noise Characteristics for MoTe 2 Ambipolar Field-Effect Transistors. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:1325. [PMID: 35458035 PMCID: PMC9030018 DOI: 10.3390/nano12081325] [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: 03/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 11/29/2022]
Abstract
Low-frequency electronic noise is an important parameter used for the electronic and sensing applications of transistors. Here, we performed a systematic study on the low-frequency noise mechanism for both p-channel and n-channel MoTe2 field-effect transistors (FET) at different temperatures, finding that low-frequency noise for both p-type and n-type conduction in MoTe2 devices come from the variable range hopping (VRH) transport process where carrier number fluctuations (CNF) occur. This process results in the broad distribution of the waiting time of the carriers between successive hops, causing the noise to increase as the temperature decreases. Moreover, we found the noise magnitude for p-type MoTe2 FET hardly changed after exposure to the ambient conditions, whereas for n-FET, the magnitude increased by nearly one order. These noise characteristics may provide useful guidelines for developing high-performance electronics based on the emerging transition metal dichalcogenides.
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Affiliation(s)
- Bing Zhang
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Congzhen Hu
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Youze Xin
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Yaoxin Li
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Yiyun Xie
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Qian Xing
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Zhuoqi Guo
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Zhongming Xue
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Dan Li
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Guohe Zhang
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Li Geng
- School of Microelectronics, Xi’an Jiaotong University, Xi’an 710049, China; (C.H.); (Y.X.); (Y.L.); (Y.X.); (Q.X.); (Z.G.); (Z.X.); (D.L.); (G.Z.); (L.G.)
- Key Lab of Micro-Nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Zungui Ke
- Detector Laboratory of Southwest Institute of Technical Physics, Chengdu 610041, China;
| | - Chi Wang
- ABAX Sensing Inc., Ningbo 315502, China;
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6
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Ji E, Kim JH, Lee W, Shin JC, Seo H, Ihm K, Park JW, Lee GH. Modulation of electrical properties in MoTe 2 by XeF 2-mediated surface oxidation. NANOSCALE ADVANCES 2022; 4:1191-1198. [PMID: 36131764 PMCID: PMC9417833 DOI: 10.1039/d1na00783a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/04/2022] [Indexed: 06/15/2023]
Abstract
Transition metal dichalcogenides (TMDs) are promising candidates for the semiconductor industry owing to their superior electrical properties. Their surface oxidation is of interest because their electrical properties can be easily modulated by an oxidized layer on top of them. Here, we demonstrate the XeF2-mediated surface oxidation of 2H-MoTe2 (alpha phase MoTe2). MoTe2 exposed to XeF2 gas forms a thin and uniform oxidized layer (∼2.5 nm-thick MoO x ) on MoTe2 regardless of the exposure time (within ∼120 s) due to the passivation effect and simultaneous etching. We used the oxidized layer for contacts between the metal and MoTe2, which help reduce the contact resistance by overcoming the Fermi level pinning effect by the direct metal deposition process. The MoTe2 field-effect transistors (FETs) with a MoO x interlayer exhibited two orders of magnitude higher field-effect hole mobility of 6.31 cm2 V-1 s-1 with a high on/off current ratio of ∼105 than that of the MoTe2 device with conventional metal contacts (0.07 cm2 V-1 s-1). Our work shows a straightforward and effective method for forming a thin oxide layer for MoTe2 devices, applicable for 2D electronics.
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Affiliation(s)
- Eunji Ji
- Department of Material Science and Engineering, Yonsei University Seoul 03722 Korea
| | - Jong Hun Kim
- Department of Material Science and Engineering, Yonsei University Seoul 03722 Korea
- Department of Materials Science and Engineering, Seoul National University Seoul 08826 Korea
- Research Institute of Advanced Materials (RIAM), Seoul National University Seoul 08826 Korea
| | - Wanggon Lee
- Department of Energy Systems Research, Ajou University Suwon 16499 Republic of Korea
| | - June-Chul Shin
- Department of Materials Science and Engineering, Seoul National University Seoul 08826 Korea
| | - Hyungtak Seo
- Department of Materials Science and Engineering, Ajou University Suwon 16499 Republic of Korea
| | - Kyuwook Ihm
- Department of Physics and Pohang Accelerator Laboratory, Pohang University of Science and Technology 37673 Pohang Korea
| | - Jin-Woo Park
- Department of Material Science and Engineering, Yonsei University Seoul 03722 Korea
| | - Gwan-Hyoung Lee
- Department of Materials Science and Engineering, Seoul National University Seoul 08826 Korea
- Research Institute of Advanced Materials (RIAM), Seoul National University Seoul 08826 Korea
- Institute of Engineering Research, Seoul National University Seoul 08826 Korea
- Institute of Applied Physics, Seoul National University Seoul 08826 Korea
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7
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Hermawan A, Septiani NLW, Taufik A, Yuliarto B, Yin S. Advanced Strategies to Improve Performances of Molybdenum-Based Gas Sensors. NANO-MICRO LETTERS 2021; 13:207. [PMID: 34633560 PMCID: PMC8505593 DOI: 10.1007/s40820-021-00724-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/22/2021] [Indexed: 05/29/2023]
Abstract
Molybdenum-based materials have been intensively investigated for high-performance gas sensor applications. Particularly, molybdenum oxides and dichalcogenides nanostructures have been widely examined due to their tunable structural and physicochemical properties that meet sensor requirements. These materials have good durability, are naturally abundant, low cost, and have facile preparation, allowing scalable fabrication to fulfill the growing demand of susceptible sensor devices. Significant advances have been made in recent decades to design and fabricate various molybdenum oxides- and dichalcogenides-based sensing materials, though it is still challenging to achieve high performances. Therefore, many experimental and theoretical investigations have been devoted to exploring suitable approaches which can significantly enhance their gas sensing properties. This review comprehensively examines recent advanced strategies to improve the nanostructured molybdenum-based material performance for detecting harmful pollutants, dangerous gases, or even exhaled breath monitoring. The summary and future challenges to advance their gas sensing performances will also be presented.
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Affiliation(s)
- Angga Hermawan
- Faculty of Textile Science and Engineering, Shinshu University, 3-15-1 Tokida, Ueda, Nagano, 386-8567, Japan
- Institute of Multidisciplinary Research for Advanced Material (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Ni Luh Wulan Septiani
- Advanced Functional Materials Research Group, Institut Teknologi Bandung, Bandung, 40132, Indonesia
- Research Center for Nanosciences and Nanotechnology (RCNN), Institut Teknologi Bandung, Bandung, 40132, Indonesia
| | - Ardiansyah Taufik
- Institute of Multidisciplinary Research for Advanced Material (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan
| | - Brian Yuliarto
- Advanced Functional Materials Research Group, Institut Teknologi Bandung, Bandung, 40132, Indonesia.
- Research Center for Nanosciences and Nanotechnology (RCNN), Institut Teknologi Bandung, Bandung, 40132, Indonesia.
| | - Shu Yin
- Institute of Multidisciplinary Research for Advanced Material (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan.
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8
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Deng Y, Zhao X, Zhu C, Li P, Duan R, Liu G, Liu Z. MoTe 2: Semiconductor or Semimetal? ACS NANO 2021; 15:12465-12474. [PMID: 34379388 DOI: 10.1021/acsnano.1c01816] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Transition metal tellurides (TMTs) have attracted intense interest due to their intriguing physical properties arising from their diverse phase topologies. To date, a wide range of physical properties have been discovered for TMTs, including that they can act as topological insulators, semiconductors, Weyl semimetals, and superconductors. Among the TMT families, MoTe2 is a representative material because of its Janus nature and rich phases. In this Perspective, we first introduce phase structures in monolayer and bulk MoTe2 and then summarize MoTe2 synthesis strategies. We highlight recent advances of Janus MoTe2 in terms of material structures and emerging quantum states. We also provide insight into the opportunities and challenges faced by MoTe2-associated device design and applications.
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Affiliation(s)
- Ya Deng
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Xiaoxu Zhao
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Chao Zhu
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Peiling Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ruihuan Duan
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Guangtong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore
- CINTRA CNRS/NTU/THALES, UMI 3288, 637553 Singapore
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9
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Li M, Lin CY, Chang YM, Yang SH, Lee MP, Chen CF, Lee KC, Yang FS, Chou Y, Lin YC, Ueno K, Shi Y, Chou YC, Tsukagoshi K, Lin YF. Facile and Reversible Carrier-Type Manipulation of Layered MoTe 2 Toward Long-Term Stable Electronics. ACS APPLIED MATERIALS & INTERFACES 2020; 12:42918-42924. [PMID: 32864950 DOI: 10.1021/acsami.0c09922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Flexible manipulation of the carrier transport behaviors in two-dimensional materials determines their values of practical application in logic circuits. Here, we demonstrated the carrier-type manipulation in field-effect transistors (FETs) containing α-phase molybdenum ditelluride (MoTe2) by a rapid thermal annealing (RTA) process in dry air for hole-dominated and electron-beam (EB) treatment for electron-dominated FETs. EB treatment induced a distinct shift of the transfer curve by around 135 V compared with that of the FET-processed RTA treatment, indicating that the carrier density of the EB-treated FET was enhanced by about 1 order of magnitude. X-ray photoelectron spectroscopy analysis revealed that the atomic ratio of Te decreased from 66.4 to 60.8% in the MoTe2 channel after EB treatment. The Fermi level is pinned near the new energy level resulting from the Te vacancies produced by the EB process, leading to the electron-dominant effect of the MoTe2 FET. The electron-dominated MoTe2 FET showed excellent stability for more than 700 days. Thus, we not only realized the reversible modulation of carrier-type in layered MoTe2 FETs but also demonstrated MoTe2 channels with desirable performance, including long-term stability.
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Affiliation(s)
- Mengjiao Li
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
| | - Che-Yi Lin
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
| | - Yuan-Ming Chang
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
| | - Shih-Hsien Yang
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of the Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
| | - Mu-Pai Lee
- Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Ciao-Fen Chen
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
| | - Ko-Chun Lee
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Feng-Shou Yang
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu 30010, Taiwan
| | - Yi Chou
- Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yi-Chun Lin
- Instrument Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Keiji Ueno
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Yumeng Shi
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of the Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
- Engineering Technology Research Center for 2D Material Information Functional Devices and Systems of Guangdong Province, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China
| | - Yi-Chia Chou
- Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Kazuhito Tsukagoshi
- WPI Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | - Yen-Fu Lin
- Department of Physics, National Chung Hsing University, Taichung 40227, Taiwan
- Institute of Nanoscience and Research Center for Sustainable Energy and Nanotechnology, National Chung Hsing University, Taichung 40227, Taiwan
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10
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Oxidation-boosted charge trapping in ultra-sensitive van der Waals materials for artificial synaptic features. Nat Commun 2020; 11:2972. [PMID: 32532980 PMCID: PMC7293344 DOI: 10.1038/s41467-020-16766-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/15/2020] [Indexed: 11/30/2022] Open
Abstract
Exploitation of the oxidation behaviour in an environmentally sensitive semiconductor is significant to modulate its electronic properties and develop unique applications. Here, we demonstrate a native oxidation-inspired InSe field-effect transistor as an artificial synapse in device level that benefits from the boosted charge trapping under ambient conditions. A thin InOx layer is confirmed under the InSe channel, which can serve as an effective charge trapping layer for information storage. The dynamic characteristic measurement is further performed to reveal the corresponding uniform charge trapping and releasing process, which coincides with its surface-effect-governed carrier fluctuations. As a result, the oxide-decorated InSe device exhibits nonvolatile memory characteristics with flexible programming/erasing operations. Furthermore, an InSe-based artificial synapse is implemented to emulate the essential synaptic functions. The pattern recognition capability of the designed artificial neural network is believed to provide an excellent paradigm for ultra-sensitive van der Waals materials to develop electric-modulated neuromorphic computation architectures. Developing efficient memory and artificial synaptic systems based on environmentally sensitive van der Waals materials remains a challenge. Here, the authors present a native oxidation-inspired InSe field-effect transistor that benefits from a boosted charge trapping behavior under ambient conditions.
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11
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Chen X, Liu C, Mao S. Environmental Analysis with 2D Transition-Metal Dichalcogenide-Based Field-Effect Transistors. NANO-MICRO LETTERS 2020; 12:95. [PMID: 34138098 PMCID: PMC7770660 DOI: 10.1007/s40820-020-00438-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 03/23/2020] [Indexed: 05/27/2023]
Abstract
Field-effect transistors (FETs) present highly sensitive, rapid, and in situ detection capability in chemical and biological analysis. Recently, two-dimensional (2D) transition-metal dichalcogenides (TMDCs) attract significant attention as FET channel due to their unique structures and outstanding properties. With the booming of studies on TMDC FETs, we aim to give a timely review on TMDC-based FET sensors for environmental analysis in different media. First, theoretical basics on TMDC and FET sensor are introduced. Then, recent advances of TMDC FET sensor for pollutant detection in gaseous and aqueous media are, respectively, discussed. At last, future perspectives and challenges in practical application and commercialization are given for TMDC FET sensors. This article provides an overview on TMDC sensors for a wide variety of analytes with an emphasize on the increasing demand of advanced sensing technologies in environmental analysis.
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Affiliation(s)
- Xiaoyan Chen
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, USA
| | - Chengbin Liu
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China
| | - Shun Mao
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, People's Republic of China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China.
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12
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Zhu H, Addou R, Wang Q, Nie Y, Cho K, Kim MJ, Wallace RM. Surface and interfacial study of atomic layer deposited Al 2O 3 on MoTe 2 and WTe 2. NANOTECHNOLOGY 2020; 31:055704. [PMID: 31618710 DOI: 10.1088/1361-6528/ab4e44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The atomic layer deposition (ALD) of high-k dielectrics could build an efficient barrier against moisture and O2 adsorption. Such a barrier is highly needed for MoTe2 and WTe2 transition metal dichalcogenides because of the poor structural stability and the fast oxidization in ambient air. In situ x-ray photoelectron spectroscopy and ex situ atomic force microscopy and scanning transmission electron microscopy were employed to report a comparative study between the growth of Al2O3 on MoTe2 and WTe2 by means of traditional thermal ALD and plasma-enhanced ALD (PEALD). Similar to what has been observed on other 2D materials such as MoS2 and Graphene, the thermal ALD results in an islanding growth of Al2O3 on MoTe2 due to the dearth of dangling bonds, whereas, a uniform coverage of Al2O3 on WTe2 is observed and likely contributed to the high concentration of intrinsic structural defects. The PEALD behavior is consistent between MoTe2 and WTe2 providing a conformal and linear growth rate (∼0.08 nm/cycle), which correlates with the creation of Te-O and metal-O nucleation sites. However, a thin layer of interfacial Mo or W oxides gradually forms, resulting from the plasma-induced damage in the topmost (1-2) layers. Attempts to enhance the Al2O3/MoTe2 interfacial quality by physically evaporating an Al2O3 seed layer are investigated as well. However, the evaporated Al2O3 process causes thermal damage on MoTe2, necessitating a more 'gentle' ALD technique for the surface passivation.
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Affiliation(s)
- H Zhu
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, United States of America
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13
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Probing Charge Transport Difference in Parallel and Vertical Layered Electronics with Thin Graphite Source/Drain Contacts. Sci Rep 2019; 9:20087. [PMID: 31882987 PMCID: PMC6934711 DOI: 10.1038/s41598-019-56576-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 12/13/2019] [Indexed: 11/13/2022] Open
Abstract
In the present study, we aim to help improve the design of van der Waals stacking, i.e., vertical 2D electronics, by probing charge transport differences in both parallel and vertical conducting channels of layered molybdenum disulfide (MoS2), with thin graphite acting as source and drain electrodes. To avoid systematic errors and variable contact contributions to the MoS2 channel, parallel and vertical electronics are all fabricated and measured on the same conducting material. Large differences in the on/off current ratio, mobility, and charge fluctuations, between parallel and vertical electronics are evident in electrical performance as well as in charge transport mechanisms. Further insights are drawn from a well-constrained analysis of both temperature-dependent current-voltage characteristics and low-frequency (LF) current fluctuations. This work offers significant insight into the fundamental understanding of charge transport and the development of future layered-materials-based integration technology.
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14
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Yang SH, Lin CY, Chang YM, Li M, Lee KC, Chen CF, Yang FS, Lien CH, Ueno K, Watanabe K, Taniguchi T, Tsukagoshi K, Lin YF. Oxygen-Sensitive Layered MoTe 2 Channels for Environmental Detection. ACS APPLIED MATERIALS & INTERFACES 2019; 11:47047-47053. [PMID: 31746187 DOI: 10.1021/acsami.9b15036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The oxygen (O2)-dependent resistance change of multilayered molybdenum ditelluride (MoTe2) channels was characterized. A variation of the channel resistance could reproducibly determine relative O2 content (denoted as the O2 index). We found that Joule heating in a layered MoTe2 field-effect transistor caused the O2 index to decrease drastically from 100 to 12.1% in back gate modulation. Furthermore, Joule heating caused effective O2 desorption from the MoTe2 surface and repeatable O2 detection by multilayered MoTe2 channels was realized. This work not only explored the influence of O2 on the electrical properties of multilayered MoTe2 channels but also revealed that MoTe2 channels are promising for sensing O2 in an environmental condition.
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Affiliation(s)
- Shih-Hsien Yang
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics , Shenzhen University , Shenzhen 518060 , China
| | - Che-Yi Lin
- Department of Electrophysics , National Chiao Tung University , Hsinchu 30010 , Taiwan
| | | | | | - Ko-Chun Lee
- Department of Electrical Engineering and Institute of Electronic Engineering , National Tsing Hua University , Hsinchu 30010 , Taiwan
| | | | - Feng-Shou Yang
- Department of Electrical Engineering and Institute of Electronic Engineering , National Tsing Hua University , Hsinchu 30010 , Taiwan
| | - Chen-Hsin Lien
- Department of Electrical Engineering and Institute of Electronic Engineering , National Tsing Hua University , Hsinchu 30010 , Taiwan
| | - Keiji Ueno
- Department of Chemistry, Graduate School of Science and Engineering , Saitama University , Saitama 338-8570 , Japan
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15
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Tsai TH, Yang FS, Ho PH, Liang ZY, Lien CH, Ho CH, Lin YF, Chiu PW. High-Mobility InSe Transistors: The Nature of Charge Transport. ACS APPLIED MATERIALS & INTERFACES 2019; 11:35969-35976. [PMID: 31532619 DOI: 10.1021/acsami.9b11052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
InSe is a high-mobility layered semiconductor with mobility being highly sensitive to any surrounding media that could act as a source of extrinsic scattering. However, little effort has been made to understand electronic transport in thin InSe layers with native surface oxide formed spontaneously upon exposure to an ambient environment. Here, we explore the influence of InOx/InSe interfacial trap states on electronic transport in thin InSe layers. We show that wet oxidation (processed in an ambient environment) causes massive deep-lying band-tail states, through which electrons conduct via 2D variable-range hopping with a short localization length of 1-3 nm. In contrast, a high-quality InOx/InSe interface can be formed in dry oxidation (processed in pure oxygen), with a low trap density of 1012 eV-1 cm-2. Metal-insulator transition can be thus observed in the gate sweep of the field-effect transistors (FETs), indicative of band transport predominated by extended states above the mobility edge. A room-temperature band mobility of 103 cm2/V s is obtained. The profound difference in the transport behavior between the wet and dry InSe FETs suggests that fluctuating Coulomb potential arising from trapped charges at the InOx/InSe interface is the dominant source of disorders in thin InSe channels.
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Affiliation(s)
- Tsung-Han Tsai
- Department of Electrical Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| | - Feng-Shou Yang
- Department of Electrical Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
- Department of Physics , National Chung Hsing University , Taichung 40227 , Taiwan
| | - Po-Hsun Ho
- Department of Electrical Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| | - Zheng-Yong Liang
- Department of Electrical Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| | - Chen-Hsin Lien
- Department of Electrical Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
| | - Ching-Hwa Ho
- Graduate Institute of Applied Science and Technology , National Taiwan University of Science and Technology , Taipei 10617 , Taiwan
| | - Yen-Fu Lin
- Department of Physics , National Chung Hsing University , Taichung 40227 , Taiwan
| | - Po-Wen Chiu
- Department of Electrical Engineering , National Tsing Hua University , Hsinchu 30013 , Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 10617 , Taiwan
- Frontier Research Center on Fundamental and Applied Science of Maters , National Tsing Hua University , Hsinchu 30013 , Taiwan
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16
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Bolotsky A, Butler D, Dong C, Gerace K, Glavin NR, Muratore C, Robinson JA, Ebrahimi A. Two-Dimensional Materials in Biosensing and Healthcare: From In Vitro Diagnostics to Optogenetics and Beyond. ACS NANO 2019; 13:9781-9810. [PMID: 31430131 DOI: 10.1021/acsnano.9b03632] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Since the isolation of graphene in 2004, there has been an exponentially growing number of reports on layered two-dimensional (2D) materials for applications ranging from protective coatings to biochemical sensing. Due to the exceptional, and often tunable, electrical, optical, electrochemical, and physical properties of these materials, they can serve as the active sensing element or a supporting substrate for diverse healthcare applications. In this review, we provide a survey of the recent reports on the applications of 2D materials in biosensing and other emerging healthcare areas, ranging from wearable technologies to optogenetics to neural interfacing. Specifically, this review provides (i) a holistic evaluation of relevant material properties across a wide range of 2D systems, (ii) a comparison of 2D material-based biosensors to the state-of-the-art, (iii) relevant material synthesis approaches specifically reported for healthcare applications, and (iv) the technological considerations to facilitate mass production and commercialization.
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Affiliation(s)
| | | | - Chengye Dong
- State Key Lab of Electrical Insulation and Power Equipment , Xi'an Jiaotong University , Xi'an , Shaanxi 710049 , People's Republic of China
| | | | - Nicholas R Glavin
- Materials and Manufacturing Directorate , Air Force Research Laboratory , WPAFB , Ohio 45433 , United States
| | - Christopher Muratore
- Department of Chemical and Materials Engineering , University of Dayton , Dayton , Ohio 45469 , United States
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17
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Mleczko MJ, Yu AC, Smyth CM, Chen V, Shin YC, Chatterjee S, Tsai YC, Nishi Y, Wallace RM, Pop E. Contact Engineering High-Performance n-Type MoTe 2 Transistors. NANO LETTERS 2019; 19:6352-6362. [PMID: 31314531 DOI: 10.1021/acs.nanolett.9b02497] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Semiconducting MoTe2 is one of the few two-dimensional (2D) materials with a moderate band gap, similar to silicon. However, this material remains underexplored for 2D electronics due to ambient instability and predominantly p-type Fermi level pinning at contacts. Here, we demonstrate unipolar n-type MoTe2 transistors with the highest performance to date, including high saturation current (>400 μA/μm at 80 K and >200 μA/μm at 300 K) and relatively low contact resistance (1.2 to 2 kΩ·μm from 80 to 300 K), achieved with Ag contacts and AlOx encapsulation. We also investigate other contact metals (Sc, Ti, Cr, Au, Ni, Pt), extracting their Schottky barrier heights using an analytic subthreshold model. High-resolution X-ray photoelectron spectroscopy reveals that interfacial metal-Te compounds dominate the contact resistance. Among the metals studied, Sc has the lowest work function but is the most reactive, which we counter by inserting monolayer hexagonal boron nitride between MoTe2 and Sc. These metal-insulator-semiconductor (MIS) contacts partly depin the metal Fermi level and lead to the smallest Schottky barrier for electron injection. Overall, this work improves our understanding of n-type contacts to 2D materials, an important advance for low-power electronics.
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Affiliation(s)
- Michal J Mleczko
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Andrew C Yu
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Christopher M Smyth
- Department of Materials Science and Engineering , University of Texas at Dallas , Richardson , Texas 75083 , United States
| | - Victoria Chen
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Yong Cheol Shin
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Sukti Chatterjee
- Applied Materials, Inc. , Santa Clara , California 95054 , United States
| | - Yi-Chia Tsai
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
- Department of Electrical and Computer Engineering , National Chiao Tung University , Hsinchu 300 , Taiwan
| | - Yoshio Nishi
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Robert M Wallace
- Department of Materials Science and Engineering , University of Texas at Dallas , Richardson , Texas 75083 , United States
| | - Eric Pop
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
- Department of Materials Science and Engineering , Stanford University , Stanford , California 94305 , United States
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18
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Lin CY, Chen CF, Chang YM, Yang SH, Lee KC, Wu WW, Jian WB, Lin YF. A Triode Device with a Gate Controllable Schottky Barrier: Germanium Nanowire Transistors and Their Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1900865. [PMID: 31264786 DOI: 10.1002/smll.201900865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 06/12/2019] [Indexed: 06/09/2023]
Abstract
Electrical contacts often dominate charge transport properties at the nanoscale because of considerable differences in nanoelectronic device interfaces arising from unique geometric and electrostatic features. Transistors with a tunable Schottky barrier between the metal and semiconductor interface might simplify circuit design. Here, germanium nanowire (Ge NW) transistors with Cu3 Ge as source/drain contacts formed by both buffered oxide etching treatments and rapid thermal annealing are reported. The transistors based on this Cu3 Ge/Ge/Cu3 Ge heterostructure show ambipolar transistor behavior with a large on/off current ratio of more than 105 and 103 for the hole and electron regimes at room temperature, respectively. Investigations of temperature-dependent transport properties and low-frequency current fluctuations reveal that the tunable effective Schottky barriers of the Ge NW transistors accounted for the ambipolar behaviors. It is further shown that this ambipolarity can be used to realize binary-signal and data-storage functions, which greatly simplify circuit design compared with conventional technologies.
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Affiliation(s)
- Che-Yi Lin
- Department of Electrophysics, National Chiao Tung University, Hsinchu, 300, Taiwan
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Chao-Fu Chen
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Yuan-Ming Chang
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Shih-Hsien Yang
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Ko-Chun Lee
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Wen-Wei Wu
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, 300, Taiwan
- Center for the Intelligent Semiconductor Nano-system Technology Research, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Wen-Bin Jian
- Department of Electrophysics, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Yen-Fu Lin
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
- Institute of Nanoscience, National Chung Hsing University, Taichung, 40227, Taiwan
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19
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Yang SH, Yao YT, Xu Y, Lin CY, Chang YM, Suen YW, Sun H, Lien CH, Li W, Lin YF. Atomically thin van der Waals tunnel field-effect transistors and its potential for applications. NANOTECHNOLOGY 2019; 30:105201. [PMID: 30530943 DOI: 10.1088/1361-6528/aaf765] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Power dissipation is a crucial problem as the packing density of transistors increases in modern integrated circuits. Tunnel field-effect transistors (TFETs), which have high energy filtering provided by band-to-band tunneling (BTBT), have been proposed as an alternative electronics architecture to decrease the energy loss in bias operation and to achieve steep switching at room temperature. Very recently, the BTBT behavior has been demonstrated in van der Waals heterostructures by using unintentionally doped semiconductors. The reason of the BTBT formation is attributed to a significant band bending near the heterointerface, resulting in carrier accumulations. In this work, to investigate charge transport in type-III transistors, we adopted the same band-bending concept to fabricate van der Waals BP/MoS2 heterostructures. Through analyzing the temperature dependence of their electrical properties, we carefully ruled out the contribution of metal-semiconductor contact resistances and improved our understanding of carrier injection in 2D type-III transistors. The BP/MoS2 heterostructures showed both negative differential resistance and 1/f 2 current fluctuations, strongly demonstrating the BTBT operation. Finally, we also designed a TFET based on this heterostructure with an ionic liquid gate, and this TFET demonstrated an subthreshold slope can successfully surmount the thermal limit of 60 mV/decade. This work improves our understanding of charge transport in such layered heterostructures and helps to improve the energy efficiency of next-generation nanoscale electronics.
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Affiliation(s)
- Shih-Hsien Yang
- Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
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20
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Aftab S, Iqbal MW, Afzal AM, Khan MF, Hussain G, Waheed HS, Kamran MA. Formation of an MoTe2 based Schottky junction employing ultra-low and high resistive metal contacts. RSC Adv 2019; 9:10017-10023. [PMID: 35520896 PMCID: PMC9062468 DOI: 10.1039/c8ra09656b] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/18/2019] [Indexed: 12/03/2022] Open
Abstract
Schottky-barrier diodes have great importance in power management and mobile communication because of their informal device technology, fast response and small capacitance. In this research, a p-type molybdenum ditelluride (p-MoTe2) based Schottky barrier diode was fabricated using asymmetric metal contacts. The MoTe2 nano-flakes were mechanically exfoliated using adhesive tape and with the help of dry transfer techniques, the flakes were transferred onto silicon/silicon dioxide (Si/SiO2) substrates to form the device. The Schottky-barrier was formed as a result of using ultra-low palladium/gold (Pd/Au) and high resistive chromium/gold (Cr/Au) metal electrodes. The Schottky diode exhibited a clear rectifying behavior with an on/off ratio of ∼103 and an ideality factor of ∼1.4 at zero gate voltage. In order to check the photovoltaic response, a green laser light was illuminated, which resulted in a responsivity of ∼3.8 × 103 A W−1. These values are higher than the previously reported results that were obtained using conventional semiconducting materials. Furthermore, the barrier heights for Pd and Cr with a MoTe2 junction were calculated to be 90 meV and 300 meV, respectively. In addition, the device was used for rectification purposes revealing a stable rectifying behavior. Schottky-barrier diodes have great importance in power management and mobile communication because of their informal device technology, fast response and small capacitance.![]()
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Affiliation(s)
- Sikandar Aftab
- Department of Physics and the Astronomy and Graphene Research Institute
- Sejong University
- Seoul 05006
- Korea
| | - Muhammad Waqas Iqbal
- Department of Physics
- Riphah Institute of Computing and Applied Sciences (RICAS)
- Riphah International University
- Lahore
- Pakistan
| | - Amir Muhammad Afzal
- Department of Physics and the Astronomy and Graphene Research Institute
- Sejong University
- Seoul 05006
- Korea
| | - M. Farooq Khan
- Department of Physics and the Astronomy and Graphene Research Institute
- Sejong University
- Seoul 05006
- Korea
| | - Ghulam Hussain
- Department of Physics
- Riphah Institute of Computing and Applied Sciences (RICAS)
- Riphah International University
- Lahore
- Pakistan
| | - Hafiza Sumaira Waheed
- Department of Physics
- Riphah Institute of Computing and Applied Sciences (RICAS)
- Riphah International University
- Lahore
- Pakistan
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21
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Li M, Lin CY, Yang SH, Chang YM, Chang JK, Yang FS, Zhong C, Jian WB, Lien CH, Ho CH, Liu HJ, Huang R, Li W, Lin YF, Chu J. High Mobilities in Layered InSe Transistors with Indium-Encapsulation-Induced Surface Charge Doping. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1803690. [PMID: 30589465 DOI: 10.1002/adma.201803690] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/13/2018] [Indexed: 06/09/2023]
Abstract
Tunability and stability in the electrical properties of 2D semiconductors pave the way for their practical applications in logic devices. A robust layered indium selenide (InSe) field-effect transistor (FET) with superior controlled stability is demonstrated by depositing an indium (In) doping layer. The optimized InSe FETs deliver an unprecedented high electron mobility up to 3700 cm2 V-1 s-1 at room temperature, which can be retained with 60% after 1 month. Further insight into the evolution of the position of the Fermi level and the microscopic device structure with different In thicknesses demonstrates an enhanced electron-doping behavior at the In/InSe interface. Furthermore, the contact resistance is also improved through the In insertion between InSe and Au electrodes, which coincides with the analysis of the low-frequency noise. The carrier fluctuation is attributed to the dominance of the phonon scattering events, which agrees with the observation of the temperature-dependent mobility. Finally, the flexible functionalities of the logic-circuit applications, for instance, inverter and not-and (NAND)/not-or (NOR) gates, are determined with these surface-doping InSe FETs, which establish a paradigm for 2D-based materials to overcome the bottleneck in the development of electronic devices.
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Affiliation(s)
- Mengjiao Li
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Che-Yi Lin
- Department of Electrophysics, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Shih-Hsien Yang
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Yuan-Ming Chang
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Jen-Kuei Chang
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Feng-Shou Yang
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Chaorong Zhong
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Wen-Bin Jian
- Department of Electrophysics, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Chen-Hsin Lien
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Ching-Hwa Ho
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 106, Taiwan
| | - Heng-Jui Liu
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Rong Huang
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Wenwu Li
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Yen-Fu Lin
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Junhao Chu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
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22
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Shekhar S, Cho D, Cho DG, Yang M, Hong S. Mapping nanoscale effects of localized noise-source activities on photoconductive charge transports in polymer-blend films. NANOTECHNOLOGY 2018; 29:205204. [PMID: 29488470 DOI: 10.1088/1361-6528/aab2dd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We develolped a method to directly image the nanoscale effects of localized noise-source activities on photoconducting charge transports in domain structures of phase-separated polymer-blend films of Poly(9,9-di-n-octylfluorenyl-2,7-diyl) and Poly(9,9-di-n-octylfluorene-alt-benzothiadiazole). For the imaging, current and noise maps of the polymer-blend were recorded using a conducting nanoprobe in contact with the surface, enabling the conductivity (σ) and noise-source density (N T) mappings under an external stimulus. The blend-films exhibited the phase-separation between the constituent polymers at domains level. Within a domain, high σ (low N T) and low σ (high N T) regions were observed, which could be associated with the ordered and disordered regions of a domain. In the N T maps, we observed that noise-sources strongly affected the conduction mechanism, resulting in a scaling behavior of σ ∝ [Formula: see text] in both ordered and disordered regions. When a blend film was under an influence of an external stimulus such as a high bias or an illumination, an increase in the σ was observed, but that also resulted in increases in the N T as a trade-off. Interestingly, the Δσ versus ΔN T plot exhibited an unusual scaling behavior of Δσ ∝ [Formula: see text] which is attributed to the de-trapping of carriers from deep traps by the external stimuli. In addition, we found that an external stimulus increased the conductivity at the interfaces without significantly increasing their N T, which can be the origin of the superior performances of polymer-blend based devices. These results provide valuable insight about the effects of noise-sources on nanoscale optoelectronic properties in polymer-blend films, which can be an important guideline for improving devices based on polymer-blend.
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23
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Mitra R, Jariwala B, Bhattacharya A, Das A. Probing in-plane anisotropy in few-layer ReS 2 using low frequency noise measurement. NANOTECHNOLOGY 2018; 29:145706. [PMID: 29457965 DOI: 10.1088/1361-6528/aaac03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
ReS2, a layered two-dimensional material popular for its in-plane anisotropic properties, is emerging as one of the potential candidates for flexible electronics and ultrafast optical applications. It is an n-type semiconducting material having a layer independent bandgap of 1.55 eV. In this paper we have characterized the intrinsic electronic noise level of few-layer ReS2 for the first time. Few-layer ReS2 field effect transistor devices show a 1/f nature of noise for frequency ranging over three orders of magnitude. We have also observed that not only the electrical response of the material is anisotropic; the noise level is also dependent on direction. In fact the noise is found to be more sensitive towards the anisotropy. This fact has been explained by evoking the theory where the Hooge parameter is not a constant quantity, but has a distinct power law dependence on mobility along the two-axes direction. The anisotropy in 1/f noise measurement will pave the way to quantify the anisotropic nature of two-dimensional (2D) materials, which will be helpful for the design of low-noise transistors in future.
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Affiliation(s)
- Richa Mitra
- Department of Physics, Indian Institute of Science, Bangalore 560012, India
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24
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Ma N, Jiang XY, Zhang L, Wang XS, Cao YL, Zhang XZ. Novel 2D Layered Molybdenum Ditelluride Encapsulated in Few-Layer Graphene as High-Performance Anode for Lithium-Ion Batteries. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1703680. [PMID: 29488317 DOI: 10.1002/smll.201703680] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 01/18/2018] [Indexed: 05/17/2023]
Abstract
Molybdenum ditelluride nanosheets encapsulated in few-layer graphene (MoTe2 /FLG) are synthesized by a simple heating method using Te and Mo powder and subsequent ball milling with graphite. The as-prepared MoTe2 /FLG nanocomposites as anode materials for lithium-ion batteries exhibit excellent electrochemical performance with a highly reversible capacity of 596.5 mAh g-1 at 100 mA g-1 , a high rate capability (334.5 mAh g-1 at 2 A g-1 ), and superior cycling stability (capacity retention of 99.5% over 400 cycles at 0.5 A g-1 ). Ex situ X-ray diffraction and transmission electron microscopy are used to explore the lithium storage mechanism of MoTe2 . Moreover, the electrochemical performance of a MoTe2 /FLG//0.35Li2 MnO3 ·0.65LiMn0.5 Ni0.5 O2 full cell is investigated, which displays a reversible capacity of 499 mAh g-1 (based on the MoTe2 /FLG mass) at 100 mA g-1 and a capacity retention of 78% over 50 cycles, suggesting the promising application of MoTe2 /FLG for lithium-ion storage. First-principles calculations exhibit that the lowest diffusion barrier (0.18 eV) for lithium ions along pathway III in the MoTe2 layered structure is beneficial for improving the Li intercalation/deintercalation property.
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Affiliation(s)
- Ning Ma
- Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Xiao-Yu Jiang
- Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Lu Zhang
- Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Xiao-Shuang Wang
- Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Yu-Liang Cao
- Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
- Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan, 430072, China
| | - Xian-Zheng Zhang
- Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
- Key Laboratory of Biomedical Polymers of Ministry of Education & Institute for Advanced Studies (IAS), Wuhan University, Wuhan, 430072, P. R. China
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25
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Chang YM, Yang SH, Lin CY, Chen CH, Lien CH, Jian WB, Ueno K, Suen YW, Tsukagoshi K, Lin YF. Reversible and Precisely Controllable p/n-Type Doping of MoTe 2 Transistors through Electrothermal Doping. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1706995. [PMID: 29430746 DOI: 10.1002/adma.201706995] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Indexed: 06/08/2023]
Abstract
Precisely controllable and reversible p/n-type electronic doping of molybdenum ditelluride (MoTe2 ) transistors is achieved by electrothermal doping (E-doping) processes. E-doping includes electrothermal annealing induced by an electric field in a vacuum chamber, which results in electron (n-type) doping and exposure to air, which induces hole (p-type) doping. The doping arises from the interaction between oxygen molecules or water vapor and defects of tellurium at the MoTe2 surface, and allows the accurate manipulation of p/n-type electrical doping of MoTe2 transistors. Because no dopant or special gas is used in the E-doping processes of MoTe2 , E-doping is a simple and efficient method. Moreover, through exact manipulation of p/n-type doping of MoTe2 transistors, quasi-complementary metal oxide semiconductor adaptive logic circuits, such as an inverter, not or gate, and not and gate, are successfully fabricated. The simple method, E-doping, adopted in obtaining p/n-type doping of MoTe2 transistors undoubtedly has provided an approach to create the electronic devices with desired performance.
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Affiliation(s)
- Yuan-Ming Chang
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Shih-Hsien Yang
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu, 30071, Taiwan
| | - Che-Yi Lin
- Department of Electrophysics, National Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Chang-Hung Chen
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Chen-Hsin Lien
- Department of Electrical Engineering and Institute of Electronic Engineering, National Tsing Hua University, Hsinchu, 30071, Taiwan
| | - Wen-Bin Jian
- Department of Electrophysics, National Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Keiji Ueno
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Yuen-Wuu Suen
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Kazuhito Tsukagoshi
- WPI Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
| | - Yen-Fu Lin
- Department of Physics, National Chung Hsing University, Taichung, 40227, Taiwan
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26
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Liao W, Wei W, Tong Y, Chim WK, Zhu C. Low-Frequency Noise in Layered ReS 2 Field Effect Transistors on HfO 2 and Its Application for pH Sensing. ACS APPLIED MATERIALS & INTERFACES 2018; 10:7248-7255. [PMID: 29388427 DOI: 10.1021/acsami.8b00193] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Layered rhenium disulfide (ReS2) field effect transistors (FETs), with thickness ranging from few to dozens of layers, are demonstrated on 20 nm thick HfO2/Si substrates. A small threshold voltage of -0.25 V, high on/off current ratio of up to ∼107, small subthreshold swing of 116 mV/dec, and electron carrier mobility of 6.02 cm2/V·s are obtained for the two-layer ReS2 FETs. Low-frequency noise characteristics in ReS2 FETs are analyzed for the first time, and it is found that the carrier number fluctuation mechanism well describes the flicker (1/f) noise of ReS2 FETs with different thicknesses. pH sensing using a two-layer ReS2 FET with HfO2 as a sensing oxide is then demonstrated with a voltage sensitivity of 54.8 mV/pH and a current sensitivity of 126. The noise characteristics of the ReS2 FET-based pH sensors are also examined, and a corresponding detection limit of 0.0132 pH is obtained. Our studies suggest the high potential of ReS2 for future low-power nanoelectronics and biosensor applications.
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Affiliation(s)
- Wugang Liao
- Department of Electrical and Computer Engineering, National University of Singapore , 4 Engineering Drive 3, 117583, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, 117546, Singapore
| | - Wei Wei
- Department of Electrical and Computer Engineering, National University of Singapore , 4 Engineering Drive 3, 117583, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, 117546, Singapore
| | - Yu Tong
- Department of Electrical and Computer Engineering, National University of Singapore , 4 Engineering Drive 3, 117583, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, 117546, Singapore
| | - Wai Kin Chim
- Department of Electrical and Computer Engineering, National University of Singapore , 4 Engineering Drive 3, 117583, Singapore
| | - Chunxiang Zhu
- Department of Electrical and Computer Engineering, National University of Singapore , 4 Engineering Drive 3, 117583, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, 117546, Singapore
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27
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Molybdenum Dichalcogenides for Environmental Chemical Sensing. MATERIALS 2017; 10:ma10121418. [PMID: 29231879 PMCID: PMC5744353 DOI: 10.3390/ma10121418] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/04/2017] [Accepted: 12/05/2017] [Indexed: 11/17/2022]
Abstract
2D transition metal dichalcogenides are attracting a strong interest following the popularity of graphene and other carbon-based materials. In the field of chemical sensors, they offer some interesting features that could potentially overcome the limitation of graphene and metal oxides, such as the possibility of operating at room temperature. Molybdenum-based dichalcogenides in particular are among the most studied materials, thanks to their facile preparation techniques and promising performances. The present review summarizes the advances in the exploitation of these MoX₂ materials as chemical sensors for the detection of typical environmental pollutants, such as NO₂, NH₃, CO and volatile organic compounds.
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28
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Ji H, Joo MK, Yi H, Choi H, Gul HZ, Ghimire MK, Lim SC. Tunable Mobility in Double-Gated MoTe 2 Field-Effect Transistor: Effect of Coulomb Screening and Trap Sites. ACS APPLIED MATERIALS & INTERFACES 2017; 9:29185-29192. [PMID: 28786660 DOI: 10.1021/acsami.7b05865] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
There is a general consensus that the carrier mobility in a field-effect transistor (FET) made of semiconducting transition-metal dichalcogenides (s-TMDs) is severely degraded by the trapping/detrapping and Coulomb scattering of carriers by ionic charges in the gate oxides. Using a double-gated (DG) MoTe2 FET, we modulated and enhanced the carrier mobility by adjusting the top- and bottom-gate biases. The relevant mechanism for mobility tuning in this device was explored using static DC and low-frequency (LF) noise characterizations. In the investigations, LF-noise analysis revealed that for a strong back-gate bias the Coulomb scattering of carriers by ionized traps in the gate dielectrics is strongly screened by accumulation charges. This significantly reduces the electrostatic scattering of channel carriers by the interface trap sites, resulting in increased mobility. The reduction of the number of effective trap sites also depends on the gate bias, implying that owing to the gate bias, the carriers are shifted inside the channel. Thus, the number of active trap sites decreases as the carriers are repelled from the interface by the gate bias. The gate-controlled Coulomb-scattering parameter and the trap-site density provide new handles for improving the carrier mobility in TMDs, in a fundamentally different way from dielectric screening observed in previous studies.
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Affiliation(s)
- Hyunjin Ji
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Republic of Korea
| | - Min-Kyu Joo
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Hojoon Yi
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Homin Choi
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Hamza Zad Gul
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Mohan Kumar Ghimire
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Seong Chu Lim
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
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29
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Ahmed S, Yi J. Two-Dimensional Transition Metal Dichalcogenides and Their Charge Carrier Mobilities in Field-Effect Transistors. NANO-MICRO LETTERS 2017; 9:50. [PMID: 30393745 PMCID: PMC6199053 DOI: 10.1007/s40820-017-0152-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/11/2017] [Indexed: 05/26/2023]
Abstract
Two-dimensional (2D) materials have attracted extensive interest due to their excellent electrical, thermal, mechanical, and optical properties. Graphene has been one of the most explored 2D materials. However, its zero band gap has limited its applications in electronic devices. Transition metal dichalcogenide (TMDC), another kind of 2D material, has a nonzero direct band gap (same charge carrier momentum in valence and conduction band) at monolayer state, promising for the efficient switching devices (e.g., field-effect transistors). This review mainly focuses on the recent advances in charge carrier mobility and the challenges to achieve high mobility in the electronic devices based on 2D-TMDC materials and also includes an introduction of 2D materials along with the synthesis techniques. Finally, this review describes the possible methodology and future prospective to enhance the charge carrier mobility for electronic devices.
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Affiliation(s)
- Sohail Ahmed
- School of Materials Science and Engineering, UNSW, Kensington, Sydney, 2052 Australia
| | - Jiabao Yi
- School of Materials Science and Engineering, UNSW, Kensington, Sydney, 2052 Australia
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30
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Recent Advances in Electronic and Optoelectronic Devices Based on Two-Dimensional Transition Metal Dichalcogenides. ELECTRONICS 2017. [DOI: 10.3390/electronics6020043] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two-dimensional transition metal dichalcogenides (2D TMDCs) offer several attractive features for use in next-generation electronic and optoelectronic devices. Device applications of TMDCs have gained much research interest, and significant advancement has been recorded. In this review, the overall research advancement in electronic and optoelectronic devices based on TMDCs are summarized and discussed. In particular, we focus on evaluating field effect transistors (FETs), photovoltaic cells, light-emitting diodes (LEDs), photodetectors, lasers, and integrated circuits (ICs) using TMDCs.
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31
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Amit I, Octon TJ, Townsend NJ, Reale F, Wright CD, Mattevi C, Craciun MF, Russo S. Role of Charge Traps in the Performance of Atomically Thin Transistors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1605598. [PMID: 28295639 DOI: 10.1002/adma.201605598] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/06/2017] [Indexed: 06/06/2023]
Abstract
Transient currents in atomically thin MoTe2 field-effect transistors (FETs) are measured during cycles of pulses through the gate electrode. The curves of the transient currents are analyzed in light of a newly proposed model for charge-trapping dynamics that renders a time-dependent change in the threshold voltage as the dominant effect on the channel hysteretic behavior over emission currents from the charge traps. The proposed model is expected to be instrumental in understanding the fundamental physics that governs the performance of atomically thin FETs and is applicable to the entire class of atomically thin-based devices. Hence, the model is vital to the intelligent design of fast and highly efficient optoelectronic devices.
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Affiliation(s)
- Iddo Amit
- Centre for Graphene Science, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Tobias J Octon
- Centre for Graphene Science, Department of Engineering, University of Exeter, Stocker Road, Exeter, EX4 4QF, UK
| | - Nicola J Townsend
- Centre for Graphene Science, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Francesco Reale
- Department of Materials, Imperial College London, London, SW7 2AZ, UK
| | - C David Wright
- Centre for Graphene Science, Department of Engineering, University of Exeter, Stocker Road, Exeter, EX4 4QF, UK
| | - Cecilia Mattevi
- Department of Materials, Imperial College London, London, SW7 2AZ, UK
| | - Monica F Craciun
- Centre for Graphene Science, Department of Engineering, University of Exeter, Stocker Road, Exeter, EX4 4QF, UK
| | - Saverio Russo
- Centre for Graphene Science, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
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32
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Joo MK, Moon BH, Ji H, Han GH, Kim H, Lee G, Lim SC, Suh D, Lee YH. Understanding Coulomb Scattering Mechanism in Monolayer MoS 2 Channel in the Presence of h-BN Buffer Layer. ACS APPLIED MATERIALS & INTERFACES 2017; 9:5006-5013. [PMID: 28093916 DOI: 10.1021/acsami.6b15072] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
As the thickness becomes thinner, the importance of Coulomb scattering in two-dimensional layered materials increases because of the close proximity between channel and interfacial layer and the reduced screening effects. The Coulomb scattering in the channel is usually obscured mainly by the Schottky barrier at the contact in the noise measurements. Here, we report low-temperature (T) noise measurements to understand the Coulomb scattering mechanism in the MoS2 channel in the presence of h-BN buffer layer on the silicon dioxide (SiO2) insulating layer. One essential measure in the noise analysis is the Coulomb scattering parameter (αSC) which is different for channel materials and electron excess doping concentrations. This was extracted exclusively from a 4-probe method by eliminating the Schottky contact effect. We found that the presence of h-BN on SiO2 provides the suppression of αSC twice, the reduction of interfacial traps density by 100 times, and the lowered Schottky barrier noise by 50 times compared to those on SiO2 at T = 25 K. These improvements enable us to successfully identify the main noise source in the channel, which is the trapping-detrapping process at gate dielectrics rather than the charged impurities localized at the channel, as confirmed by fitting the noise features to the carrier number and correlated mobility fluctuation model. Further, the reduction in contact noise at low temperature in our system is attributed to inhomogeneous distributed Schottky barrier height distribution in the metal-MoS2 contact region.
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Affiliation(s)
- Min-Kyu Joo
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Byoung Hee Moon
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Hyunjin Ji
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Gang Hee Han
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Hyun Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Gwanmu Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Seong Chu Lim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Dongseok Suh
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea
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33
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Ji H, Joo MK, Yun Y, Park JH, Lee G, Moon BH, Yi H, Suh D, Lim SC. Suppression of Interfacial Current Fluctuation in MoTe2 Transistors with Different Dielectrics. ACS APPLIED MATERIALS & INTERFACES 2016; 8:19092-19099. [PMID: 27362461 DOI: 10.1021/acsami.6b02085] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
For transition metal dichalcogenides, the fluctuation of the channel current due to charged impurities is attributed to a large surface area and a thickness of a few nanometers. To investigate current variance at the interface of transistors, we obtain the low-frequency (LF) noise features of MoTe2 multilayer field-effect transistors with different dielectric environments. The LF noise properties are analyzed using the combined carrier mobility and carrier number fluctuation model which is additionally parametrized with an interfacial Coulomb-scattering parameter (α) that varies as a function of the accumulated carrier density (Nacc) and the location of the active channel layer of MoTe2. Our model shows good agreement with the current power spectral density (PSD) of MoTe2 devices from a low to high current range and indicates that the parameter α exhibits a stronger dependence on Nacc with an exponent -γ of -1.18 to approximately -1.64 for MoTe2 devices, compared with -0.5 for Si devices. The raised Coulomb scattering of the carriers, particularly for a low-current regime, is considered to be caused by the unique traits of layered semiconductors such as interlayer coupling and the charge distribution strongly affected by the device structure under a gate bias, which completely change the charge screening effect in MoTe2 multilayer. Comprehensive static and LF noise analyses of MoTe2 devices with our combined model reveal that a chemical-vapor deposited h-BN monolayer underneath MoTe2 channel and the Al2O3 passivation layer have a dissimilar contribution to the reduction of current fluctuation. The three-fold enhanced carrier mobility due to the h-BN is from the weakened carrier scattering at the gate dielectric interface and the additional 30% increase in carrier mobility by Al2O3 passivation is due to the reduced interface traps.
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Affiliation(s)
- Hyunjin Ji
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Korea
| | - Min-Kyu Joo
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Yoojoo Yun
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Ji-Hoon Park
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Gwanmu Lee
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Byoung Hee Moon
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
- Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Hojoon Yi
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Dongseok Suh
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
| | - Seong Chu Lim
- Department of Energy Science, Sungkyunkwan University (SKKU) , Suwon 16419, Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea
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Nakaharai S, Yamamoto M, Ueno K, Tsukagoshi K. Carrier Polarity Control in α-MoTe2 Schottky Junctions Based on Weak Fermi-Level Pinning. ACS APPLIED MATERIALS & INTERFACES 2016; 8:14732-14739. [PMID: 27203118 DOI: 10.1021/acsami.6b02036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The polarity of the charge carriers injected through Schottky junctions of α-phase molybdenum ditelluride (α-MoTe2) and various metals was characterized. We found that the Fermi-level pinning in the metal/α-MoTe2 Schottky junction is so weak that the polarity of the carriers (electron or hole) injected from the junction can be controlled by the work function of the metals, in contrast to other transition metal dichalcogenides such as MoS2. From the estimation of the Schottky barrier heights, we obtained p-type carrier (hole) injection from a Pt/α-MoTe2 junction with a Schottky barrier height of 40 meV at the valence band edge. n-Type carrier (electron) injection from Ti/α-MoTe2 and Ni/α-MoTe2 junctions was also observed with Schottky barrier heights of 50 and 100 meV, respectively, at the conduction band edge. In addition, enhanced ambipolarity was demonstrated in a Pt-Ti hybrid contact with a unique structure specially designed for polarity-reversible transistors, in which Pt and Ti electrodes were placed in parallel for injecting both electrons and holes.
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Affiliation(s)
- Shu Nakaharai
- WPI Center for Materials Nanoarchitechtonics, National Institute for Materials Science , Tsukuba 305-0044, Japan
| | - Mahito Yamamoto
- WPI Center for Materials Nanoarchitechtonics, National Institute for Materials Science , Tsukuba 305-0044, Japan
| | - Keiji Ueno
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University , Saitama 338-8570, Japan
| | - Kazuhito Tsukagoshi
- WPI Center for Materials Nanoarchitechtonics, National Institute for Materials Science , Tsukuba 305-0044, Japan
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Kolobov AV, Tominaga J. Emerging Applications of 2D TMDCs. TWO-DIMENSIONAL TRANSITION-METAL DICHALCOGENIDES 2016. [DOI: 10.1007/978-3-319-31450-1_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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