Centimeter‐Sized Single Crystal of Two‐Dimensional Halide Perovskites Incorporating Straight‐Chain Symmetric Diammonium Ion for X‐Ray Detection
Yue Shen, Yucheng Liu, Haochen Ye, Yiting Zheng, Qi Wei, Yingdong Xia, Yonghua Chen, Kui Zhao, Wei Huang, Shengzhong Liu
Abstract
Abstract Two‐dimensional (2D) AA′ n −1 M n X 3 n +1 type halide perovskites incorporating straight‐chain symmetric diammonium cations define a new type of structure, but their optoelectronic properties are largely unexplored. Reported here is the synthesis of a centimeter‐sized AA′ n −1 M n X 3 n +1 type perovskite, BDAPbI 4 (BDA=NH 3 C 4 H 8 NH 3 ), single crystal and its charge‐transport properties under X‐ray excitation. The crystal shows a staggered configuration of the [PbI 6 ] 4− layers, a band gap of 2.37 eV, and a low trap density of 3.1×10 9 cm −3 . The single‐crystal X‐ray detector exhibits an excellent sensitivity of 242 μC Gy air −1 cm −2 under the 10 V bias (0.31 V μm −1 ), a detection limit as low as 430 nGy air s −1 , ultrastable response current, a stable baseline with the lowest dark current drift of 6.06×10 −9 nA cm −1 s −1 V −1 , and rapid response time of τ rise =7.3 ms and τ fall =22.5 ms. These crystals are promising candidates for the next generation of optoelectronic devices.