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

• Published in: Nature materials Vol. 20; no. 8; pp. 1113 - 1120
• 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, Renshaw Wang, Xiao, Ramanujan, Raju V., Ma, Yanming, Hippalgaonkar, Kedar, Zhang, Hua
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2021; Nature Publishing Group
• Subjects: 119/118; 140/133; 140/146; 639/301/1005/1007; 639/301/357/1018; 639/925/357/1018; 639/925/927/1007; Biomaterials; Carrier density; Chalcogenides; Chemistry and Materials Science; Condensed Matter Physics; Crystal structure; Crystals; Materials Science; Metal concentrations; Molybdenum compounds; Molybdenum disulfide; Nanotechnology; Optical and Electronic Materials; Phase transitions; Physicochemical properties; Single crystals; Superconductivity; Synthesis; Thickness; Transition metal compounds; Transition temperatures; Tungsten disulfide; X-ray diffraction
• ISSN: 1476-1122; 1476-4660; 1476-4660
• DOI: 10.1038/s41563-021-00971-y

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 WS 2 , WSe 2 , MoS 2 , MoSe 2 , WS 2 x Se 2(1− x ) and MoS 2 x Se 2(1− x ) . We solve the crystal structures of 1T′-WS 2 , -WSe 2 , -MoS 2 and -MoSe 2 with single-crystal X-ray diffraction. The as-prepared 1T′-WS 2 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′-WS 2 . This synthesis method will allow a more systematic investigation of the intrinsic properties of metastable TMDs. A general method for the synthesis of high-purity crystals of metastable 1T′-phase transition metal dichalcogenides is reported, providing a source of phase-engineered materials that can be used to systematically explore their intrinsic properties.