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Guo H, Lang X, Tian X, Jiang W, Wang G. Tunable Schottky barrier in Janus- XGa 2Y/Graphene ( X/ Y = S, Se, Te; X≠ Y) van der Waals heterostructures. NANOTECHNOLOGY 2022; 33:425704. [PMID: 35817003 DOI: 10.1088/1361-6528/ac800d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) Janus materials have attracted significant attention due to their asymmetrical structures and unique electronic properties. In this work, by using the first-principles calculation based on density functional theory, we systematically investigate the electronic properties of 6 types of Janus-XGa2Y/Graphene van der Waals heterostructures (vdWHs). The results show that the Janus-XGa2Y/Graphene vdWHs are connected by weak interlayer vdW forces and can form n-type Schottky contact, p-type Schottky contact or Ohmic contact when the spin-orbit coupling (SOC) is not considered. However, when considering SOC, only the SeGa2S/G and G/SeGa2S vdWHs show n-type Schottky contact, and other vdWHs show Ohmic contacts. In addition, the Schottky barriers and contact types of SeGa2S/Graphene and Graphene/SeGa2S vdWHs can be effectively modulated by interlayer distance and biaxial strain. They can be transformed from intrinsic n-type Schottky contact to p-type Schottky contact when the interlayer distances are smaller than 2.65 Å and 2.90 Å, respectively. They can also be transformed to Ohmic contact by applying external biaxial strain. Our work can provide useful guidelines for designing Schottky nanodiodes, field effect transistors or other low-resistance nanodevices based on the 2D vdWHs.
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Affiliation(s)
- Hao Guo
- School of Urban Construction, Hebei Normal University of Science & Technology, Qinhuangdao 066004, People's Republic of China
- Material Simulation and Computing Laboratory, Department of Physics, Hebei Normal University of Science & Technology, Qinghuangdao 066004, People's Republic of China
| | - Xiufeng Lang
- Material Simulation and Computing Laboratory, Department of Physics, Hebei Normal University of Science & Technology, Qinghuangdao 066004, People's Republic of China
| | - Xiaobao Tian
- Department of Mechanics and Engineering, Sichuan University, Chengdu 610065, People's Republic of China
| | - Wentao Jiang
- Department of Mechanics and Engineering, Sichuan University, Chengdu 610065, People's Republic of China
| | - Guangzhao Wang
- Key Laboratory of Micro Nano Optoelectronic Devices and Intelligent Perception Systems, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, School of Electronic Information Engineering, Yangtze Normal University, Chongqing 408100, People's Republic of China
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Šolajić A, Pešić J. Novel wide spectrum light absorber heterostructures based on hBN/In(Ga)Te. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:345301. [PMID: 35709717 DOI: 10.1088/1361-648x/ac7996] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Two-dimensional group III monochalcogenides have recently attracted quite attention for their wide spectrum of optical and electric properties, being promising candidates for optoelectronic and novel electrical applications. However, in their pristine form they are extremely sensitive and vulnerable to oxygen in air and need good mechanical protection and passivization. In this work we modeled and studied two newly designed van der Waals (vdW) heterostructures based on layer of hexagonal boron nitride (hBN) and GaTe or InTe monolayer. Using density functional theory, we investigate electronic and optical properties of those structures. Their moderate band gap and excellent absorption coefficient makes them ideal candidate for broad spectrum absorbers, covering all from part of IR to far UV spectrum, with particularly good absorption of UV light. The hBN layer, which can be beneficial for protection of sensitive GaTe and InTe, does not only preserve their optical properties but also enhances it by changing the band gap width and enhancing absorption in low-energy part of spectrum. Calculated binding energies prove that all three stacking types are possible to obtain experimentally, with H-top as the preferable stacking position. Moreover, it is shown that type of stacking does not affect any relevant properties and bandstructure does not reveal any significant change for each stacking type.
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Affiliation(s)
- A Šolajić
- Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - J Pešić
- Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
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Huong PT, Idrees M, Amin B, Hieu NN, Phuc HV, Hoa LT, Nguyen CV. Electronic structure, optoelectronic properties and enhanced photocatalytic response of GaN–GeC van der Waals heterostructures: a first principles study. RSC Adv 2020; 10:24127-24133. [PMID: 35517332 PMCID: PMC9055037 DOI: 10.1039/d0ra04145a] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 06/12/2020] [Indexed: 01/10/2023] Open
Abstract
In this work, we systematically studied the electronic structure and optical characteristics of van der Waals (vdW) heterostructure composed of a single layer of GaN and GeC using first principles calculations. The GaN–GeC vdW heterostructure exhibits indirect band gap semiconductor properties and possesses type-II energy band arrangement, which will help the separation of photogenerated carriers and extend their lifetime. In addition, the band edge positions of the GaN–GeC heterostructure meet both the requirements of water oxidation and reduction energy, indicating that the photocatalysts have the potential for water decomposition. The GaN–GeC heterostructure shows obvious absorption peaks in the visible region, leading to the efficient use of solar energy. Tensile and compressive strains of up to 10% are also proposed. Tensile strain leads to an increase in the blue shift of optical absorption, whereas a red shift is observed in the case of the compressive strain. These fascinating characteristics make the GaN–GeC vdW heterostructure a highly effective photocatalyst for water splitting. In this work, we systematically studied the electronic structure and optical characteristics of van der Waals (vdW) heterostructure composed of a single layer of GaN and GeC using first principles calculations.![]()
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Affiliation(s)
- Pham T. Huong
- Division of Computational Mathematics and Engineering
- Institute for Computational Science
- Ton Duc Thang University
- Ho Chi Minh City
- Vietnam
| | - M. Idrees
- Department of Physics
- Hazara University
- Mansehra 21300
- Pakistan
| | - B. Amin
- Department of Physics
- Abbottabad University of Science and Technology
- Abbottabad 22010
- Pakistan
| | - Nguyen N. Hieu
- Institute of Research and Development
- Duy Tan University
- Da Nang 550000
- Vietnam
- Faculty of Natural Sciences
| | - Huynh V. Phuc
- Division of Theoretical Physics
- Dong Thap University
- Cao Lanh 870000
- Vietnam
| | - Le T. Hoa
- Institute of Research and Development
- Duy Tan University
- Da Nang 550000
- Vietnam
- Faculty of Natural Sciences
| | - Chuong V. Nguyen
- Department of Materials Science and Engineering
- Le Quy Don Technical University
- Ha Noi 100000
- Vietnam
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Mercado E, Zhou Y, Xie Y, Zhao Q, Cai H, Chen B, Jie W, Tongay S, Wang T, Kuball M. Passivation of Layered Gallium Telluride by Double Encapsulation with Graphene. ACS OMEGA 2019; 4:18002-18010. [PMID: 31720504 PMCID: PMC6843706 DOI: 10.1021/acsomega.9b01752] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/05/2019] [Indexed: 05/25/2023]
Abstract
Layered semiconductor gallium telluride (GaTe) undergoes a rapid structural transition to a degraded phase in ambient conditions, limiting its utility in devices such as optical switches. In this work, we demonstrate that the degradation process in GaTe flakes can be slowed down dramatically via encapsulation with graphene. Through examining Raman signatures of degradation, we show that the choice of substrate significantly impacts the degradation rate and that the process is accelerated by the transfer of GaTe to hydrophilic substrates such as SiO2/Si. We find that double encapsulation with both top and bottom graphene layers can extend the lifetime of the material for several weeks. The photoresponse of flakes encapsulated in this way is only reduced by 17.6 ± 0.4% after 2 weeks, whereas unencapsulated flakes display no response after this time. Our results demonstrate the potential for alternative, van der Waals material-based passivation strategies in unstable layered materials and highlight the need for careful selection of substrates for 2D electronic devices.
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Affiliation(s)
- Elisha Mercado
- Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
| | - Yan Zhou
- Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
| | - Yong Xie
- School of Advanced Materials and Nanotechnology, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, P. R. China
| | - Qinghua Zhao
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, P. R. China
| | - Hui Cai
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Bin Chen
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Wanqi Jie
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, P. R. China
| | - Sefaattin Tongay
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Tao Wang
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, P. R. China
| | - Martin Kuball
- Center for Device Thermography and Reliability (CDTR), H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K
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