High‐Performance X‐Ray Detector Based on Liquid Diffused Separation Induced Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> Single Crystal
Shunyong Wei, Shujie Tie, Kai Shen, Tixian Zeng, Jihua Zou, Yixuan Huang, Hui Sun, Lingzhi Luo, Xiangyu Zhou, Aobo Ren, Xiaojia Zheng, Dewei Zhao, Jiang Wu
Abstract
Abstract The recently demonstrated Cs 3 Bi 2 I 9 single crystals (SCs) exhibit superior performance for X‐ray detection. More importantly, they do not contain any toxic lead element. However, compared with lead‐halide perovskites, one challenge for the Cs 3 Bi 2 I 9 SC for X‐ray detection application is that it is difficult to prepare large‐sized and high‐quality SCs. Here, a liquid diffused separation induced crystallization (LDSC) method is employed to grow Cs 3 Bi 2 I 9 SCs for eliminating the temperature fluctuation and convection currents caused by the thermal gradient in the growth solution. The resultant Cs 3 Bi 2 I 9 SC exhibits a microstrain of 1.21 × 10 –3 , a resistivity of 1.12 × 10 9 Ω cm, a carrier mobility of 4.57 cm 2 V –1 s –1 , and a mobility‐lifetime product of 1.87 × 10 –3 cm 2 V –1 . As a result, an X‐ray detector based on the high‐quality Cs 3 Bi 2 I 9 SC exhibits an excellent dose rate linearity, a sensitivity of 964 µC Gy air –1 cm –2 , and a limit of detection (LoD) of 44.6 nGy air s –1 .