Metastable 1T′-phase group VIB transition metal dichalcogenide crystals

• Main Authors: Lai, Zhuangchai, He, Qiyuan, Tran, Thu Ha, Repaka, D. V. Maheswar, Zhou, Dong-Dong, Sun,Ying, Xi, Shibo, Li, Yongxin, Chaturvedi, Apoorva, Tan, Chaoliang, Chen, Bo, Nam, Gwang-Hyeon, Li, Bing, Ling, Chongyi, Zhai, Wei, Shi, Zhenyu, Hu, Dianyi, Sharma, Vinay, Hu, Zhaoning, Chen, Ye, Zhang, Zhicheng, Yu, Yifu, Wang, Renshaw Xiao, Ramanujan, Raju V., Ma, Yanming, Hippalgaonkar, Kedar, Zhang, Hua
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Materials::Metallic materials; Electronic Devices; Two-Dimensional Materials
• Online Access: https://hdl.handle.net/10356/156006
• Institution: Nanyang Technological University

Metastable 1T′-phase transition metal dichalcogenides (1T′-TMDs) with semi-metallic natures have attracted increasing interest owing to their uniquely distorted structures and fascinating phase-dependent physicochemical properties. However, the synthesis of high-quality metastable 1T′-TMD crystals, especially for the group VIB TMDs, remains a challenge. Here, we report a general synthetic method for the large-scale preparation of metastable 1T′-phase group VIB TMDs, including WS2, WSe2, MoS2, MoSe2, WS2xSe2(1−x) and MoS2xSe2(1−x). We solve the crystal structures of 1T′-WS2, -WSe2, -MoS2 and -MoSe2 with single-crystal X-ray diffraction. The as-prepared 1T′-WS2 exhibits thickness-dependent intrinsic superconductivity, showing critical transition temperatures of 8.6 K for the thickness of 90.1 nm and 5.7 K for the single layer, which we attribute to the high intrinsic carrier concentration and the semi-metallic nature of 1T′-WS2. This synthesis method will allow a more systematic investigation of the intrinsic properties of metastable TMDs.