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Zheng B, Sun X, Zheng W, Zhu C, Ma C, Pan A, Li D, Li S. Vapor growth of V-doped MoS 2 monolayers with enhanced B-exciton emission and broad spectral response. FRONTIERS OF OPTOELECTRONICS 2023; 16:42. [PMID: 38060145 DOI: 10.1007/s12200-023-00097-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/03/2023] [Indexed: 12/08/2023]
Abstract
Dynamically engineering the optical and electrical properties in two-dimensional (2D) materials is of great significance for designing the related functions and applications. The introduction of foreign-atoms has previously been proven to be a feasible way to tune the band structure and related properties of 3D materials; however, this approach still remains to be explored in 2D materials. Here, we systematically demonstrate the growth of vanadium-doped molybdenum disulfide (V-doped MoS2) monolayers via an alkali metal-assisted chemical vapor deposition method. Scanning transmission electron microscopy demonstrated that V atoms substituted the Mo atoms and became uniformly distributed in the MoS2 monolayers. This was also confirmed by Raman and X-ray photoelectron spectroscopy. Power-dependent photoluminescence spectra clearly revealed the enhanced B-exciton emission characteristics in the V-doped MoS2 monolayers (with low doping concentration). Most importantly, through temperature-dependent study, we observed efficient valley scattering of the B-exciton, greatly enhancing its emission intensity. Carrier transport experiments indicated that typical p-type conduction gradually arisen and was enhanced with increasing V composition in the V-doped MoS2, where a clear n-type behavior transited first to ambipolar and then to lightly p-type charge carrier transport. In addition, visible to infrared wide-band photodetectors based on V-doped MoS2 monolayers (with low doping concentration) were demonstrated. The V-doped MoS2 monolayers with distinct B-exciton emission, enhanced p-type conduction and broad spectral response can provide new platforms for probing new physics and offer novel materials for optoelectronic applications.
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Affiliation(s)
- Biyuan Zheng
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China
| | - Xingxia Sun
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China
| | - Weihao Zheng
- College of Advanced Interdisciplinary Studies and Hunan Provincial Key Laboratory of Novel Nano Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha, 410073, China
| | - Chenguang Zhu
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China
| | - Chao Ma
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China
| | - Anlian Pan
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China
| | - Dong Li
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China.
| | - Shengman Li
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Institute of Optoelectronic Integration, College of Materials Science and Engineering, Hunan University, Changsha, 410082, China.
- Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
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Aly MA, Enakerakpor EO, Koch M, Masenda H. Tuning Interlayer Exciton Emission with TMD Alloys in van der Waals Heterobilayers of Mo 0.5W 0.5Se 2 and Its Binary Counterparts. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2769. [PMID: 37887920 PMCID: PMC10609229 DOI: 10.3390/nano13202769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/12/2023] [Accepted: 10/14/2023] [Indexed: 10/28/2023]
Abstract
Semiconductor heterostructures have been the backbone of developments in electronic and optoelectronic devices. One class of structures of interest is the so-called type II band alignment, in which optically excited electrons and holes relax into different material layers. The unique properties observed in two-dimensional transition metal dichalcogenides and the possibility to engineer van der Waals heterostructures make them candidates for future high-tech devices. In these structures, electronic, optical, and magnetic properties can be tuned through the interlayer coupling, thereby opening avenues for developing new functional materials. We report the possibility of explicitly tuning the emission of interlayer exciton energies in the binary-ternary heterobilayer of Mo0.5W0.5Se2 with MoSe2 and WSe2. The respective interlayer energies of 1.516 eV and 1.490 eV were observed from low-temperature photoluminescence measurements for the MoSe2- and WSe2- based heterostructures, respectively. These interlayer emission energies are above those reported for MoSe2/WSe2 (≃1.30-1.45 eV). Consequently, binary-ternary heterostructure systems offer an extended energy range and tailored emission energies not accessible with the binary counterparts. Moreover, even though Mo0.5W0.5Se2 and MoSe2 have almost similar optical gaps, their band offsets are different, resulting in charge transfer between the monolayers following the optical excitation. Thus, confirming TMDs alloys can be used to tune the band-offsets, which adds another design parameter for application-specific optoelectronic devices.
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Affiliation(s)
- Mohammed Adel Aly
- Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany
- Department of Physics, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
| | | | - Martin Koch
- Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Hilary Masenda
- Faculty of Physics and Materials Sciences Center, Philipps-Universität Marburg, 35032 Marburg, Germany
- School of Physics, University of the Witwatersrand, Johannesburg 2050, South Africa
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