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Guo J, Dai X, Zhang L, Li H. Electron Transport Properties of Graphene/WS 2 Van Der Waals Heterojunctions. Molecules 2023; 28:6866. [PMID: 37836709 PMCID: PMC10574387 DOI: 10.3390/molecules28196866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
Van der Waals heterojunctions of two-dimensional atomic crystals are widely used to build functional devices due to their excellent optoelectronic properties, which are attracting more and more attention, and various methods have been developed to study their structure and properties. Here, density functional theory combined with the nonequilibrium Green's function technique has been used to calculate the transport properties of graphene/WS2 heterojunctions. It is observed that the formation of heterojunctions does not lead to the opening of the Dirac point of graphene. Instead, the respective band structures of both graphene and WS2 are preserved. Therefore, the heterojunction follows a unique Ohm's law at low bias voltages, despite the presence of a certain rotation angle between the two surfaces within the heterojunction. The transmission spectra, the density of states, and the transmission eigenstate are used to investigate the origin and mechanism of unique linear I-V characteristics. This study provides a theoretical framework for designing mixed-dimensional heterojunction nanoelectronic devices.
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Affiliation(s)
- Junnan Guo
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, China;
| | - Xinyue Dai
- Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai 200444, China;
| | - Lishu Zhang
- Peter Grünberg Institut (PGI-1) and Institute for Advanced Simulation (IAS-1), Forschungszentrum Jülich, Jülich 52428, Germany;
| | - Hui Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, China;
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Chen W, Pan J, Jing S, Li W, Bian B, Liao B, Wang G. Influence of contact interface on electric transport in in-plane graphene/MoSSe heterojunction. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Song S, Gong J, Jiang X, Yang S. Influence of the interface structure and strain on the rectification performance of lateral MoS 2/graphene heterostructure devices. Phys Chem Chem Phys 2022; 24:2265-2274. [PMID: 35014641 DOI: 10.1039/d1cp04502d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We systematically study the influence of interface configuration and strain on the electronic and transport properties of lateral MoS2/graphene heterostructures by first-principles calculations and quantum transport simulations. We first identify the favorable heterostructure configurations with C-S and/or C-Mo bonds at the interfaces. Strain can be applied to graphene or MoS2 and would not change the relative stabilities of different heterostructures. Band alignment calculations show that all the lateral heterostructures have n-type Schottky contacts. The current-voltage characteristics of the lateral MoS2/graphene heterostructure diodes exhibit good rectification performance. Too strong and too weak interface interactions do not benefit electronic transport. The MoS2/graphene heterostructures with moderate C-S bonds at the interface have larger currents through the junctions than those with C-Mo bonds at the interface. The maximal rectification ratio of the lateral diode with strain applied to MoS2 can reach up to 105. With strain applied to graphene, the currents through the heterostructures can increase by 1-2 orders of magnitude due to the reduced Schottky barrier heights at the interface, but the rectification ratio is reduced with a maximal value of 104. Our calculations can serve as a theoretical guide to design rectifier and diode devices based on two-dimensional lateral heterostructures.
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Affiliation(s)
- Shun Song
- School of Physics and Technology, Inner Mongolia University, Hohhot 010021, P. R. China. .,State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China.
| | - Jian Gong
- School of Physics and Technology, Inner Mongolia University, Hohhot 010021, P. R. China.
| | - Xiangwei Jiang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China.
| | - Shenyuan Yang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P. R. China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Gber TE, Louis H, Owen AE, Etinwa BE, Benjamin I, Asogwa FC, Orosun MM, Eno EA. Heteroatoms (Si, B, N, and P) doped 2D monolayer MoS 2 for NH 3 gas detection. RSC Adv 2022; 12:25992-26010. [PMID: 36199611 PMCID: PMC9468912 DOI: 10.1039/d2ra04028j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/29/2022] [Indexed: 11/21/2022] Open
Abstract
2D transition metal dichalcogenide MoS2 monolayer quantum dots (MoS2-QD) and their doped boron (B@MoS2-QD), nitrogen (N@MoS2-QD), phosphorus (P@MoS2-QD), and silicon (Si@MoS2-QD) surfaces have been theoretically investigated using density functional theory (DFT) computation to understand their mechanistic sensing ability, such as conductivity, selectivity, and sensitivity toward NH3 gas. The results from electronic properties showed that P@MoS2-QD had the lowest energy gap, which indicated an increase in electrical conductivity and better adsorption behavior. By carrying out comparative adsorption studies using m062-X, ωB97XD, B3LYP, and PBE0 methods at the 6-311G++(d,p) level of theory, the most negative values were observed from ωB97XD for the P@MoS2-QD surface, signifying the preferred chemisorption surface for NH3 detection. The mechanistic studies provided in this study also indicate that the P@MoS2-QD dopant is a promising sensing material for monitoring ammonia gas in the real world. We hope this research work will provide informative knowledge for experimental researchers to realize the potential of MoS2 dopants, specifically the P@MoS2-QD surface, as a promising candidate for sensors to detect gas. 2D transition metal dichalcogenide MoS2 monolayer quantum dots (MoS2-QD) and their doped boron (B@MoS2-QD), nitrogen (N@MoS2-QD), phosphorus (P@MoS2-QD), and silicon (Si@MoS2-QD) counterparts are proposed as selective sensors for NH3 gas.![]()
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Affiliation(s)
- Terkumbur E. Gber
- Computational and Bio-Simulation Research Group, University of Calabar, Calabar, Nigeria
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar, Calabar, Nigeria
| | - Hitler Louis
- Computational and Bio-Simulation Research Group, University of Calabar, Calabar, Nigeria
- Department of Chemistry, Akwa-Ibom State University, Uyo, Nigeria
| | - Aniekan E. Owen
- Computational and Bio-Simulation Research Group, University of Calabar, Calabar, Nigeria
- Department of Chemistry, Akwa-Ibom State University, Uyo, Nigeria
| | - Benjamin E. Etinwa
- Computational and Bio-Simulation Research Group, University of Calabar, Calabar, Nigeria
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar, Calabar, Nigeria
| | - Innocent Benjamin
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar, Calabar, Nigeria
| | - Fredrick C. Asogwa
- Computational and Bio-Simulation Research Group, University of Calabar, Calabar, Nigeria
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar, Calabar, Nigeria
| | | | - Ededet A. Eno
- Computational and Bio-Simulation Research Group, University of Calabar, Calabar, Nigeria
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar, Calabar, Nigeria
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Wang X, Long R. Photoinduced Anomalous Electron Transfer Dynamics at a Lateral MoS 2-Graphene Covalent Junction. J Phys Chem Lett 2021; 12:7553-7559. [PMID: 34351765 DOI: 10.1021/acs.jpclett.1c02169] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Photoinduced charge separation significantly affects the optoelectronic performance of the lateral MoS2-graphene junctions. Generally, an adiabatic mechanism governs electron transfer (ET) at a chemically binding interface. Counterintuitively, we demonstrate, using nonadiabatic (NA) molecular dynamics, that an NA mechanism dominates the ET from MoS2 to graphene in the lateral MoS2-graphene covalent junction. The anomalous ET mechanism arising from the built-in electric field formed at the interface that decreases the donor-acceptor interaction by driving electrons and holes moving to opposite directions. Driven by both graphene and MoS2 vibrations, the photoexcited electrons on MoS2 rapidly transfer into graphene by the NA mechanism within 200 fs, which is faster than electron-phonon energy relaxation and ensures that "hot" electrons can be successfully extracted before they cool and lose energy to heat. The study establishes a mechanistic understanding of the complex charge-phonon dynamics in the lateral MoS2-graphene junctions that are key to optoelectronic and photovoltaic applications.
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Affiliation(s)
- Xiaoli Wang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
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