Controlled Growth of 3R Phase Tantalum Diselenide and Its Enhanced Superconductivity

Ya Deng; Yuanming Lai; Xiaoxu Zhao; Xiaowei Wang; Chao Zhu; Ke Huang; Chao Zhu; Jiadong Zhou; Qingsheng Zeng; Ruihuan Duan; Qundong Fu; Lixing Kang; Yang Liu; Stephen J Pennycook; X Renshaw Wang; Zheng Liu

doi:10.1021/jacs.9b11673

Controlled Growth of 3R Phase Tantalum Diselenide and Its Enhanced Superconductivity

J Am Chem Soc. 2020 Feb 12;142(6):2948-2955. doi: 10.1021/jacs.9b11673. Epub 2020 Jan 28.

Authors

Ya Deng¹, Yuanming Lai^{2

3}, Xiaoxu Zhao⁴, Xiaowei Wang¹, Chao Zhu¹, Ke Huang², Chao Zhu¹, Jiadong Zhou¹, Qingsheng Zeng¹, Ruihuan Duan¹, Qundong Fu¹, Lixing Kang¹, Yang Liu⁵, Stephen J Pennycook⁴, X Renshaw Wang², Zheng Liu¹

Affiliations

¹ School of Materials Science and Engineering , Nanyang Technological University , Singapore 639798 , Singapore.
² School of Physical and Mathematical Sciences & School of Electrical and Electronic Engineering , Nanyang Technological University , Singapore 639798 , Singapore.
³ State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 610054 , China.
⁴ Department of Materials Science and Engineering , National University of Singapore , Singapore 117575 , Singapore.
⁵ School of Computer Science and Engineering , Nanyang Technological University , Singapore 639798 , Singapore.

PMID: 31961673
DOI: 10.1021/jacs.9b11673

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 (T_c) of 1.6 K in the 3R-TaSe₂, which undoubtedly breaks the traditional perception of TaSe₂ crystal as a material with T_c 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 T_c.