Lead‐Free Perovskite Single Crystal Linear Array Detector for High‐Resolution X‐Ray Imaging

Abstract 0D Bi‐based 329‐type halide perovskite is demonstrated as a promising semiconductor for X‐ray detection due to its strong X‐ray absorption, superior stability, availability of large single crystals (SCs) and solution processibility at low temperature. However, its low mobility‐lifetime product (µτ) limits its further improvement in detection sensitivity. Based on the first‐principles calculations, this work designs a new 2D Bi‐based 329‐type halide perovskite using a mixed‐halide‐induced structural dimension regulation strategy. By using a continuous supply of a precursor solution, this work successfully grows inch‐sized high‐quality SCs. These SCs exhibit large µτ product, high resistivity, and low ion migration. The detectors fabricated using the SCs show X‐ray detection sensitivity as high as 24,509 µC Gy_air⁻¹ cm⁻², short response time of 315 µs, low detection limit of 4.3 nGy s⁻¹, and superior stability. These properties are the best among all lead‐free perovskite detectors and are comparable to those of the best lead‐based perovskite detectors. The linear array detector assembled on the SCs for the first time also shows a high spatial resolution of 10.6 lp mm⁻¹ during X‐ray imaging. The high performance combined with superior stability of these new 329‐type lead‐free halide perovskite SCs is expected to promote a new generation of X‐ray detection technologies.