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Sayyad M, Kopaczek J, Gilardoni CM, Chen W, Xiong Y, Yang S, Watanabe K, Taniguchi T, Kudrawiec R, Hautier G, Atatüre M, Tongay SA. The Defects Genome of Janus Transition Metal Dichalcogenides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2403583. [PMID: 38743929 DOI: 10.1002/adma.202403583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/02/2024] [Indexed: 05/16/2024]
Abstract
2D Janus Transition Metal Dichalcogenides (TMDs) have attracted much interest due to their exciting quantum properties arising from their unique two-faced structure, broken-mirror symmetry, and consequent colossal polarization field within the monolayer. While efforts are made to achieve high-quality Janus monolayers, the existing methods rely on highly energetic processes that introduce unwanted grain-boundary and point defects with still unexplored effects on the material's structural and excitonic properties Through high-resolution scanning transmission electron microscopy (HRSTEM), density functional theory (DFT), and optical spectroscopy measurements; this work introduces the most encountered and energetically stable point defects. It establishes their impact on the material's optical properties. HRSTEM studies show that the most energetically stable point defects are single (VS and VSe) and double chalcogen vacancy (VS -VSe), interstitial defects (Mi), and metal impurities (MW) and establish their structural characteristics. DFT further establishes their formation energies and related localized bands within the forbidden band. Cryogenic excitonic studies on h-BN-encapsulated Janus monolayers offer a clear correlation between these structural defects and observed emission features, which closely align with the results of the theory. The overall results introduce the defect genome of Janus TMDs as an essential guideline for assessing their structural quality and device properties.
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Affiliation(s)
- Mohammed Sayyad
- Materials Science and Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona, AZ 85287, USA
| | - Jan Kopaczek
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, Wroclaw, 50-370, Poland
| | - Carmem M Gilardoni
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Weiru Chen
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Yihuang Xiong
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Shize Yang
- Aberration Corrected Electron Microscopy Core, Yale University, New Haven, CT 06516, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, 305-0044, Japan
| | - Robert Kudrawiec
- Department of Semiconductor Materials Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Stanisława Wyspiańskiego 27, Wroclaw, 50-370, Poland
| | - Geoffroy Hautier
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | - Mete Atatüre
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Seth Ariel Tongay
- Materials Science and Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona, AZ 85287, USA
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2
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Wang Y, Zhai W, Ren Y, Zhang Q, Yao Y, Li S, Yang Q, Zhou X, Li Z, Chi B, Liang J, He Z, Gu L, Zhang H. Phase-Controlled Growth of 1T'-MoS 2 Nanoribbons on 1H-MoS 2 Nanosheets. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2307269. [PMID: 37934742 DOI: 10.1002/adma.202307269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 10/31/2023] [Indexed: 11/09/2023]
Abstract
2D heterostructures are emerging as alternatives to conventional semiconductors, such as silicon, germanium, and gallium nitride, for next-generation electronics and optoelectronics. However, the direct growth of 2D heterostructures, especially for those with metastable phases still remains challenging. To obtain 2D transition metal dichalcogenides (TMDs) with designed phases, it is highly desired to develop phase-controlled synthetic strategies. Here, a facile chemical vapor deposition method is reported to prepare vertical 1H/1T' MoS2 heterophase structures. By simply changing the growth atmosphere, semimetallic 1T'-MoS2 can be in situ grown on the top of semiconducting 1H-MoS2, forming vertical semiconductor/semimetal 1H/1T' heterophase structures with a sharp interface. The integrated device based on the 1H/1T' MoS2 heterophase structure displays a typical rectifying behavior with a current rectifying ratio of ≈103. Moreover, the 1H/1T' MoS2-based photodetector achieves a responsivity of 1.07 A W-1 at 532 nm with an ultralow dark current of less than 10-11 A. The aforementioned results indicate that 1H/1T' MoS2 heterophase structures can be a promising candidate for future rectifiers and photodetectors. Importantly, the approach may pave the way toward tailoring the phases of TMDs, which can help us utilize phase engineering strategies to promote the performance of electronic devices.
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Affiliation(s)
- Yongji Wang
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Wei Zhai
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Yi Ren
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yao Yao
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Siyuan Li
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Qi Yang
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Xichen Zhou
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Zijian Li
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Banlan Chi
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Jinzhe Liang
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Zhen He
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Lin Gu
- Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Hua Zhang
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
- Hong Kong Branch of National Precious Metals Material Engineering Research Center (NPMM), City University of Hong Kong, Hong Kong, China
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen, 518057, China
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3
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Dai B, Su Y, Guo Y, Wu C, Xie Y. Recent Strategies for the Synthesis of Phase-Pure Ultrathin 1T/1T' Transition Metal Dichalcogenide Nanosheets. Chem Rev 2024; 124:420-454. [PMID: 38146851 DOI: 10.1021/acs.chemrev.3c00422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
The past few decades have witnessed a notable increase in transition metal dichalcogenide (TMD) related research not only because of the large family of TMD candidates but also because of the various polytypes that arise from the monolayer configuration and layer stacking order. The peculiar physicochemical properties of TMD nanosheets enable an enormous range of applications from fundamental science to industrial technologies based on the preparation of high-quality TMDs. For polymorphic TMDs, the 1T/1T' phase is particularly intriguing because of the enriched density of states, and thus facilitates fruitful chemistry. Herein, we comprehensively discuss the most recent strategies for direct synthesis of phase-pure 1T/1T' TMD nanosheets such as mechanical exfoliation, chemical vapor deposition, wet chemical synthesis, atomic layer deposition, and more. We also review frequently adopted methods for phase engineering in TMD nanosheets ranging from chemical doping and alloying, to charge injection, and irradiation with optical or charged particle beams. Prior to the synthesis methods, we discuss the configuration of TMDs as well as the characterization tools mostly used in experiments. Finally, we discuss the current challenges and opportunities as well as emphasize the promising fields for the future development.
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Affiliation(s)
- Baohu Dai
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Yueqi Su
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Yuqiao Guo
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Changzheng Wu
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Yi Xie
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
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4
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Li S, Ouyang D, Zhang N, Zhang Y, Murthy A, Li Y, Liu S, Zhai T. Substrate Engineering for Chemical Vapor Deposition Growth of Large-Scale 2D Transition Metal Dichalcogenides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211855. [PMID: 37095721 DOI: 10.1002/adma.202211855] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 04/17/2023] [Indexed: 05/03/2023]
Abstract
The large-scale production of 2D transition metal dichalcogenides (TMDs) is essential to realize their industrial applications. Chemical vapor deposition (CVD) has been considered as a promising method for the controlled growth of high-quality and large-scale 2D TMDs. During a CVD process, the substrate plays a crucial role in anchoring the source materials, promoting the nucleation and stimulating the epitaxial growth. It thus significantly affects the thickness, microstructure, and crystal quality of the products, which are particularly important for obtaining 2D TMDs with expected morphology and size. Here, an insightful review is provided by focusing on the recent development associated with the substrate engineering strategies for CVD preparation of large-scale 2D TMDs. First, the interaction between 2D TMDs and substrates, a key factor for the growth of high-quality materials, is systematically discussed by combining the latest theoretical calculations. Based on this, the effect of various substrate engineering approaches on the growth of large-area 2D TMDs is summarized in detail. Finally, the opportunities and challenges of substrate engineering for the future development of 2D TMDs are discussed. This review might provide deep insight into the controllable growth of high-quality 2D TMDs toward their industrial-scale practical applications.
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Affiliation(s)
- Shaohua Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Decai Ouyang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Na Zhang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Yi Zhang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Akshay Murthy
- Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL), Batavia, IL, 60510, USA
| | - Yuan Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, 518057, P. R. China
| | - Shiyuan Liu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, 518057, P. R. China
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5
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Li X, Yang J, Sun H, Huang L, Li H, Shi J. Controlled Synthesis and Accurate Doping of Wafer-Scale 2D Semiconducting Transition Metal Dichalcogenides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2305115. [PMID: 37406665 DOI: 10.1002/adma.202305115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/24/2023] [Accepted: 07/04/2023] [Indexed: 07/07/2023]
Abstract
2D semiconducting transition metal dichalcogenide (TMDCs) possess atomically thin thickness, a dangling-bond-free surface, flexible band structure, and silicon-compatible feature, making them one of the most promising channels for constructing state-of-the-art field-effect transistors in the post-Moore's era. However, the existing 2D semiconducting TMDCs fall short of meeting the industry criteria for practical applications in electronics due to their small domain size and the lack of an effective approach to modulate intrinsic physical properties. Therefore, it is crucial to prepare and dope 2D semiconducting TMDCs single crystals with wafer size. In this review, the up-to-date progress regarding the wafer-scale growth of 2D semiconducting TMDC polycrystalline and single-crystal films is systematically summarized. The domain orientation control of 2D TMDCs and the seamless stitching of unidirectionally aligned 2D islands by means of substrate design are proposed. In addition, the accurate and uniform doping of 2D semiconducting TMDCs and the effect on electronic device performances are also discussed. Finally, the dominating challenges pertaining to the enhancement of the electronic device performances of TMDCs are emphasized, and further development directions are put forward. This review provides a systematic and in-depth summary of high-performance device applications of 2D semiconducting TMDCs.
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Affiliation(s)
- Xiaohui Li
- The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, P. R. China
| | - Junbo Yang
- The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, P. R. China
| | - Hang Sun
- The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, P. R. China
| | - Ling Huang
- The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, P. R. China
| | - Hui Li
- The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, P. R. China
| | - Jianping Shi
- The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, P. R. China
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6
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Montblanch ARP, Barbone M, Aharonovich I, Atatüre M, Ferrari AC. Layered materials as a platform for quantum technologies. NATURE NANOTECHNOLOGY 2023:10.1038/s41565-023-01354-x. [PMID: 37322143 DOI: 10.1038/s41565-023-01354-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 02/17/2023] [Indexed: 06/17/2023]
Abstract
Layered materials are taking centre stage in the ever-increasing research effort to develop material platforms for quantum technologies. We are at the dawn of the era of layered quantum materials. Their optical, electronic, magnetic, thermal and mechanical properties make them attractive for most aspects of this global pursuit. Layered materials have already shown potential as scalable components, including quantum light sources, photon detectors and nanoscale sensors, and have enabled research of new phases of matter within the broader field of quantum simulations. In this Review we discuss opportunities and challenges faced by layered materials within the landscape of material platforms for quantum technologies. In particular, we focus on applications that rely on light-matter interfaces.
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Affiliation(s)
- Alejandro R-P Montblanch
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Matteo Barbone
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Cambridge Graphene Centre, University of Cambridge, Cambridge, UK
- Munich Center for Quantum Science and Technology, (MCQST), Munich, Germany
- Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universität München, Garching, Germany
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, New South Wales, Sydney, Australia
- Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Ultimo, New South Wales, Sydney, Australia
| | - Mete Atatüre
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| | - Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, Cambridge, UK.
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7
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Feuer MG, Montblanch ARP, Sayyad MY, Purser CM, Qin Y, Alexeev EM, Cadore AR, Rosa BLT, Kerfoot J, Mostaani E, Kalȩba R, Kolari P, Kopaczek J, Watanabe K, Taniguchi T, Ferrari AC, Kara DM, Tongay S, Atatüre M. Identification of Exciton Complexes in Charge-Tunable Janus W SeS Monolayers. ACS NANO 2023; 17:7326-7334. [PMID: 37058341 PMCID: PMC10134503 DOI: 10.1021/acsnano.2c10697] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 03/29/2023] [Indexed: 06/17/2023]
Abstract
Janus transition-metal dichalcogenide monolayers are artificial materials, where one plane of chalcogen atoms is replaced by chalcogen atoms of a different type. Theory predicts an in-built out-of-plane electric field, giving rise to long-lived, dipolar excitons, while preserving direct-bandgap optical transitions in a uniform potential landscape. Previous Janus studies had broad photoluminescence (>18 meV) spectra obfuscating their specific excitonic origin. Here, we identify the neutral and the negatively charged inter- and intravalley exciton transitions in Janus WSeS monolayers with ∼6 meV optical line widths. We integrate Janus monolayers into vertical heterostructures, allowing doping control. Magneto-optic measurements indicate that monolayer WSeS has a direct bandgap at the K points. Our results pave the way for applications such as nanoscale sensing, which relies on resolving excitonic energy shifts, and the development of Janus-based optoelectronic devices, which requires charge-state control and integration into vertical heterostructures.
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Affiliation(s)
- Matthew
S. G. Feuer
- Cavendish
Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
| | | | - Mohammed Y. Sayyad
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Carola M. Purser
- Cavendish
Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - Ying Qin
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Evgeny M. Alexeev
- Cavendish
Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - Alisson R. Cadore
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - Barbara L. T. Rosa
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - James Kerfoot
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - Elaheh Mostaani
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - Radosław Kalȩba
- Cavendish
Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
| | - Pranvera Kolari
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Jan Kopaczek
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Andrea C. Ferrari
- Cambridge
Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, U.K.
| | - Dhiren M. Kara
- Cavendish
Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
| | - Sefaattin Tongay
- Materials
Science and Engineering, School for Engineering of Matter, Transport
and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Mete Atatüre
- Cavendish
Laboratory, University of Cambridge, 19 J. J. Thomson Avenue, Cambridge, CB3 0HE, U.K.
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8
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Li C, An Y. Two-dimensional ferromagnetic semiconductors of rare-earth Janus 2H-GdIBr monolayers with large valley polarization. NANOSCALE 2023; 15:8304-8312. [PMID: 37082903 DOI: 10.1039/d2nr06654h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Based on a rare-earth Gd atom with 4f electrons, through first-principles calculations, we demonstrate that a Janus 2H-GdIBr monolayer exhibits an intrinsic ferromagnetic (FM) semiconductor character with an indirect band gap of 0.75 eV, a high Curie temperature Tc of 260 K, a significant magnetic moment of 8μB per f.u. (f.u. = formula unit), in-plane magnetic anisotropy (IMA) and a large spontaneous valley polarization of 118 meV. The MAE, inter-atomic distance or angle, and Tc can be efficiently modulated by in-plane strains and charge carrier doping. Under a strain range from -5% to 5% and charge carrier doping from -0.3 e to 0.3 e per f.u., the system still retains its FM ordering and the corresponding Tc can be modulated by strains from 233 K to 281 K and by charge carrier doping from 140 K to 245 K. Interestingly, under various strains, the matrix element differences (dz2, dyz), (dx2-y2, dxy) and (px, py) of Gd atoms dominate the MAE behaviors, which originates from the competition between the contributions of the Gd-d orbitals, Gd-p orbitals, and p orbitals of halogen atoms based on the second-order perturbation theory. Inequivalent Dirac valleys are not energetically degenerate due to the time-reversal symmetry breaking in the Janus 2H-GdIBr monolayer. A considerable valley gap between the Berry curvature at the K and K' points provides an opportunity to selectively control the valley freedom and states. External tensile (compressive) strain further increases (decreases) the valley gap up to a maximum (minimum) value of 158 (37) meV, indicating that the valley polarization in the Janus 2H-GdIBr monolayer is robust to external strains. This study provides a novel paradigm and platform to design spintronic devices for next-generation quantum information technology.
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Affiliation(s)
- Cunquan Li
- Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, National Demonstration Center for Experimental Function Materials Education, School of Material Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
| | - Yukai An
- Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, National Demonstration Center for Experimental Function Materials Education, School of Material Science and Engineering, Tianjin University of Technology, Tianjin, 300384, China.
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9
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Jiang J, Mi W. Two-dimensional magnetic Janus monolayers and their van der Waals heterostructures: a review on recent progress. MATERIALS HORIZONS 2023; 10:788-807. [PMID: 36594899 DOI: 10.1039/d2mh01362b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
A magnetic Janus monolayer, a special type of material which has asymmetric arrangements of its surface at the nanoscale, has been shown to present rather exotic properties for applications in spintronics and its intersections. This review aims to offer a comprehensive review of the emergent physical properties of magnetic Janus monolayers and their van der Waals heterostructures from a theoretical point of view. The review starts by introducing the theoretical methodologies composed of the state-of-the-art methods and the challenges and limitations in validations for the descriptions of the magnetic ground states and thermodynamic properties in magnetic materials. The built-in polarization field induced physical phenomena of magnetic Janus monolayers are then presented. The tunable electronic and magnetic properties of magnetic Janus monolayer-based van der Waals heterostructures are discussed. Finally, the conclusions and future challenges in this field are prospected. This review serves as a complete summary of the two-dimensional magnetic Janus library and emergent electronic and magnetic properties in magnetic Janus monolayers and their heterostructures, and provides guidelines for the design of electronic and spintronic devices based on Janus materials.
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Affiliation(s)
- Jiawei Jiang
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin 300354, China.
| | - Wenbo Mi
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin 300354, China.
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10
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Harris SB, Lin YC, Puretzky AA, Liang L, Dyck O, Berlijn T, Eres G, Rouleau CM, Xiao K, Geohegan DB. Real-Time Diagnostics of 2D Crystal Transformations by Pulsed Laser Deposition: Controlled Synthesis of Janus WSSe Monolayers and Alloys. ACS NANO 2023; 17:2472-2486. [PMID: 36649648 DOI: 10.1021/acsnano.2c09952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Energetic processing methods such as hyperthermal implantation hold special promise to achieve the precision synthesis of metastable two-dimensional (2D) materials such as Janus monolayers; however, they require precise control. Here, we report a feedback approach to reveal and control the transformation pathways in materials synthesis by pulsed laser deposition (PLD) and apply it to investigate the transformation kinetics of monolayer WS2 crystals into Janus WSSe and WSe2 by implantation of Se clusters with different maximum kinetic energies (<42 eV/Se-atom) generated by laser ablation of a Se target. Real-time Raman spectroscopy and photoluminescence are used to assess the structure, composition, and optoelectronic quality of the monolayer crystal as it is implanted with well-controlled fluxes of selenium for different kinetic energies that are regulated with in situ ICCD imaging, ion probe, and spectroscopy diagnostics. First-principles calculations, XPS, and atomic-resolution HAADF STEM imaging are used to understand the intermediate alloy compositions and their vibrational modes to identify transformation pathways. The real-time kinetics measurements reveal highly selective top-layer conversion as WS2 transforms through WS2(1-x)Se2x alloys to WSe2 and provide the means to adjust processing conditions to achieve fractional and complete Janus WSSe monolayers as metastable transition states. The general approach demonstrates a real-time feedback method to achieve Janus layers or other metastable alloys of the desired composition, and a general means to adjust the structure and quality of materials grown by PLD, addressing priority research directions for precision synthesis with real-time adaptive control.
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Affiliation(s)
- Sumner B Harris
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Yu-Chuan Lin
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania16802, United States
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Ondrej Dyck
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Tom Berlijn
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Gyula Eres
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Christopher M Rouleau
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - David B Geohegan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
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