Molecularly thin, two-dimensional all-organic perovskites
Hwa Seob Choi, Jun Lin, Gang Wang, Walter P. D. Wong, In‐Hyeok Park, Fang Lin, Jun Yin, Kai Leng, Junhao Lin, Kian Ping Loh
Abstract
Recently, the emergence of all-organic perovskites with three-dimensional (3D) structures has expanded the potential applications of perovskite materials. However, the synthesis and utilization of all-organic perovskites in 2D form remain largely unexplored because the design principle has not been developed. We present the successful synthesis of a metal-free 2D layered perovskite, denoted as the Choi-Loh van der Waals phase (CL-v phase), with the chemical formula A 2 B 2 X 4 , where A represents a larger-sized cation compared to B and X denotes an anion. The CL-v phase exhibits a van der Waals gap enabled by interlayer hydrogen bonding and can be exfoliated or grown as molecularly thin 2D organic crystals. The dielectric constants of the CL-v phase range from 4.8 to 5.5 and we demonstrate their potential as gate dielectrics for thin-film transistors.