Discovery of a 2D Hybrid Silver/Antimony-Based Iodide Double Perovskite Photoferroelectric with Photostrictive Effect and Efficient X-Ray Response

摘要

2D hybrid halide double perovskites (HHDPs) have been demonstrated tobe a promising alternative to conventional lead-based halide perovskites asa new system of photoferroelectrics, due to their unique characteristics ofenvironmental friendliness, favorable stability, and fascinating optoelectronicproperties. Herein, for the first time, a 2D iodide double perovskite photoferroelectricis reported based on Ag/Sb ions, (4,4-DFPD)_4AgSbI_8 (4,4-DFPD =4,4-difluoropiperidinium), which possesses a high Curie temperature of414 K (above BaTiO_3), a large spontaneous polarization of 9.6 μC cm~(?2), ferroelectricphotovoltaic effect, and photostrictive effect. Notably, to the best ofthe authors’ knowledge, the discovery of photostriction in HHDP photoferroelectricsis unprecedented. Moreover, (4,4-DFPD)_4AgSbI_8 exhibits an impressiveX-ray responsivity, with a sensitivity as high as 704.8 μC Gyair~(?1) cm~(?2) at100 V bias and a detection limit as low as 0.36 μGy_(air) s~(?1) at 10 V bias, bothof which outperform the current all HHDP photoferroelectrics. This workenriches the photoferroelectric family, and proves that Ag/Sb-based HHDPphotoferroelectrics are a promising candidate for the next-generation optoelectronicdevices.