the NSFC (51522206, 11574151, 11774173 and 51790492), and the fundamental research funds for the central universities
(30915011203, 30918011334, 30919011403 and 30920021152).
Wan Yi, Kan Er-jun. Room-temperature stable two-dimensional ferroelectric materials: CuInS2P6 and heterostructures[J]. Progress in Physics, 2020, 40(4): 107-128.