Wafer-Scale Photolithography-Pixeled Pb-Free Perovskite X-ray Detectors.

Pb-free perovskite material is considered to be a promising material utilized in next-generation X-ray detectors due to its high X-ray absorption coefficient, decent carrier transport properties, and relatively low toxicity. However, the pixelation of the perovskite material with an industry-level photolithography processing method remains challenging due to its poor structural stability. Herein, we use CsAgBiBr perovskite material as the prototype and investigate its interaction with photolithographic polar solvents. Inspired by that, we propose a wafer-scale photolithography patterning method, where the pixeled perovskite array devices for X-ray detection are successfully prepared. The devices based on pixeled Pb-free perovskite material show a high detection sensitivity up to 19118 ± 763 μC Gy cm, which is comparable to devices with Pb-based perovskite materials and superior to the detection sensitivity (∼20 μC Gy cm) of the commercial a-Se detector. After pixelation, the devices achieve an improved spatial resolution capacity with the spatial frequency from 2.7 to 7.8 lp mm at modulation-transfer-function (MTF) = 0.2. Thus, this work may contribute to the development of high-performance array X-ray detectors based on CsAgBiBr perovskite material.