Room‐Temperature Ferroelectric Material Composed of a Two‐Dimensional Metal Halide Double Perovskite for X‐ray Detection

• DOI: 10.1002/ange.202004235
• Publication Date: 2020-05-08T11:49:26Z
• Authors: Wuqian Guo; Xitao Liu; Shiguo Han; Yi Liu; Zhiyun Xu; Maochun Hong; Junhua Luo; Zhihua Sun

Abstract Although two‐dimensional (2D) metal–halide double perovskites display versatile physical properties due to their huge structural compatibility, room‐temperature ferroelectric behavior has not yet been reported for this fascinating family. Here, we designed a material composed of 2D halide perovskites, (chloropropylammonium) 4 AgBiBr 8 , using an organic asymmetric dipolar ligand. It exhibits concrete ferroelectricity, including Curie temperature 305 K and notable spontaneous polarization ≈3.2 μC cm −2 triggered by dynamic ordering the cation tilting motion heterometallic AgBr 6 /BiBr octahedra. Besides, alternating array inorganic perovskite sheets cations endows large mobility‐lifetime product ( μτ =1.0×10 −3 2 V −1 ) detecting X‐ray photons, which is almost tenfold higher than that CH 3 NH PbI wafers. As far as know, first study on X‐ray‐sensitive perovskites. Our findings afford promising platform exploring new materials toward further device applications.