Controlled Growth of 3R Phase Tantalum Diselenide and Its Enhanced Superconductivity
Ya Deng, Yuanming Lai, Xiaoxu Zhao, Xiaowei Wang, Xiaowei Wang, Chao Zhu, Ke Huang, Chao Zhu, Jiadong Zhou, Qingsheng Zeng, Ruihuan Duan, Qundong Fu, Lixing Kang, Yang Liu, Stephen J. Pennycook, Xiao Renshaw Wang, Xiao Renshaw Wang, Zheng Liu
Abstract
Transition metal dichalcogenides (TMDs) have become a playground for exploring rich physical phenomena like superconductivity and charge-density-waves (CDW). Here, we report the synthesis of the atom-thin TaSe2 with a rare 3R phase and enhanced superconductivity. The 3R phase is achieved by an ambient pressure chemical vapor deposition (CVD) strategy and confirmed by the high-resolution aberration-corrected STEM. Low-temperature transport data reveal an enhanced superconducting transition temperature (Tc) of 1.6 K in the 3R-TaSe2, which undoubtedly breaks the traditional perception of TaSe2 crystal as a material with Tc close to 0 K. This work demonstrates the strength of ambient pressure CVD in the exploration of crystal polymorphism, highlights a decisive role of layer stacking order in the superconducting transition, and provides fresh insights on manipulating crystal structures to gain access to enhanced Tc.