Symmetry Manipulation of Two-Dimensional Semiconductors by Janus Structure

Figure 1. Schematic diagram of structure, synthesis, properties and performance of Janus TMDCs. Reproduced with permission from refs (2−5). Copyright 2021 The Authors, 2021 American Chemical Society, 2023 The Authors, 2017 American Chemical Society. Figure 2. Structures of Janus TMDCs and their heterostructures. (a) Lattice structures of monolayer 1T’ MoSSe and 2H MoSSe. (b) Schematic illustration of the topological band inversion of 1T’ MoSSe (left) and 2H MoSSe (right). Reproduced with permission from ref (4). Copyright 2023 The Authors. (c) Schematic illustration of a monolayer lateral multi-heterostructure composed with MoS₂-Janus MoSSe-Janus MoSeS-MoSe₂. (d) Kelvin probe force microscope image of monolayer lateral multi-heterostructure composed of MoS₂–MoSSe-MoSeS-MoSe₂. Reproduced with permission from ref (2). Copyright 2021 The Authors. (e) Schematic illustration of MoSSe/MoS₂ vertical heterostructure. (f) Optical microscopy (OM) images of Janus heterostructures with AA, AB, AAA, AAB, and ABA stacking modes. Scale bars: 4 μm. Scale bars: 1.2 μm. Reproduced with permission from ref (6). Copyright 2020 American Chemical Society. Figure 3. Synthesis of Janus TMDCs and their lateral heterostructures. (a) Contrast of activation energy barriers between RT-ALS strategy (red) and conventional substitution in high temperature (blue). (b) Raman spectra of pristine monolayer MoS₂, Janus MoSSe, and converted MoSe₂. (c) Spatially resolved Raman mapping for A_1g mode intensity of a monolayer multi-heterostructure made with MoS₂–MoSSe-MoSeS-MoSe₂. Reproduced with permission from ref (2). Copyright 2021 The Authors. Figure 4. Properties and potential applications of Janus TMDCs. (a) HHG image of 1T’ MoSSe observed by CCD camera. (b) Left: schematic illustration of angle-resolved SHG setup measuring out-of-plane dipole of Janus MoSSe. Right: angle-dependent SHG intensity ratio between p and s polarization (I_p and I_s) in 1T’ MoSSe, 2H MoSSe, and 2H MoS₂. Reproduced with permission from ref (4). Copyright 2023 The Authors. (c) Calculated volcano curve of hydrogen evolution reaction (HER) of various catalysts, including Janus WSSe. Reproduced with permission from ref (13). Copyright 2018 American Chemical Society. (d) DFT calculation of shift current susceptibility tensor element σ_xzx⁽²⁾ and σ_zxx⁽²⁾. The dark (red) blue curve indicates shift current for Janus MoSeS (MoSSe) monolayer. Reproduced with permission from ref (15). Copyright 2022 American Chemical Society. Xueqiu Zheng received her B.S. Degree in Department of Chemistry in Zhejiang University in 2023. She is a Master degree candidate in Department of Chemistry in Zhejiang University currently. Her research focuses on the controllable synthesis of Janus TMDCs and their heterostructures. Yi Zhou received his B.S. Degree in Hangzhou Normal University in 2023. He is a Master degree candidate in Department of Chemistry in Zhejiang University currently. His research focuses on the investigation of catalytic performance of Janus TMDCs. Yunfan Guo received her Ph.D. Degree in College of Chemistry and Molecular Engineering, Peking University in 2016. She is currently Assistant Professor in Department of Chemistry in Zhejiang University. Her research focuses on low-dimensional electronic materials. X.Z., Y.Z., and Y.G. acknowledge the financial support from National Key R&D Program of China (2022YFA1204301), National Natural Science Foundation of China (Grant No. 22475186) and Zhejiang University. This article references 15 other publications. This article has not yet been cited by other publications.