Progress on 2D topological insulators and potential applications in electronic devices**Project supported by the Beijing Natural Science Foundation, China (Grant Nos. Z190006 and 4192054), the National Natural Science Foundation of China (Grant Nos. 61971035, 61901038, and 61725107), Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB30000000), and Beijing Institute of Technology Research Fund Program for Young

Abstract

Two-dimensional topological insulators (2DTIs) have attracted increasing attention during the past few years. New 2DTIs with increasing larger spin–orbit coupling (SOC) gaps have been predicted by theoretical calculations and some of them have been synthesized experimentally. In this review, the 2DTIs, ranging from single element graphene-like materials to bi-elemental transition metal chalcogenides (TMDs) and to multi-elemental materials, with different thicknesses, structures, and phases, have been summarized and discussed. The topological properties (especially the quantum spin Hall effect and Dirac fermion feature) and potential applications have been summarized. This review also points out the challenge and opportunities for future 2DTI study, especially on the device applications based on the topological properties.