Discovery of a 2D Hybrid Silver/Antimony‐Based Iodide Double Perovskite Photoferroelectric with Photostrictive Effect and Efficient X‐Ray Response
Changfeng Wang, Haojin Li, Qun Ji, Chuang Ma, Lang Liu, Heng‐Yun Ye, Bo Cao, Guoliang Yuan, Hai‐Feng Lu, Da‐Wei Fu, Ming‐Gang Ju, Jinlan Wang, Kui Zhao, Yi Zhang
Abstract
Abstract 2D hybrid halide double perovskites (HHDPs) have been demonstrated to be a promising alternative to conventional lead‐based halide perovskites as a new system of photoferroelectrics, due to their unique characteristics of environmental friendliness, favorable stability, and fascinating optoelectronic properties. Herein, for the first time, a 2D iodide double perovskite photoferroelectric is reported based on Ag/Sb ions, (4,4‐DFPD) 4 AgSbI 8 (4,4‐DFPD = 4,4‐difluoropiperidinium), which possesses a high Curie temperature of 414 K (above BaTiO 3 ), a large spontaneous polarization of 9.6 μC cm −2 , ferroelectric photovoltaic effect, and photostrictive effect. Notably, to the best of the authors’ knowledge, the discovery of photostriction in HHDP photoferroelectrics is unprecedented. Moreover, (4,4‐DFPD) 4 AgSbI 8 exhibits an impressive X‐ray responsivity, with a sensitivity as high as 704.8 μC Gy air −1 cm −2 at 100 V bias and a detection limit as low as 0.36 μGy air s −1 at 10 V bias, both of which outperform the current all HHDP photoferroelectrics. This work enriches the photoferroelectric family, and proves that Ag/Sb‐based HHDP photoferroelectrics are a promising candidate for the next‐generation optoelectronic devices.