Mechanochemical Synthesis of High-Entropy Perovskite toward Highly Sensitive and Stable X-ray Flat-Panel Detectors.

Wu, Haodi; Chen, Xu; Song, Zihao; Zhang, Ao; Du, Xinyuan; He, Xin; Wang, Hanqi; Xu, Ling et al. · Adv Mater · 2023

basic_science · Level V

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Abstract

Perovskites are attracting attention for optoelectronic devices. Despite their promise, the large-scale synthesis of perovskite materials with exact stoichiometry, especially high-entropy perovskites, has been a major challenge. Moreover, the difficulty in stoichiometry control also hinders the development of perovskite X-ray flat-panel detectors. Previous reports all employed simple MAPbI<sub>3</sub> as the active layer, while the performance still falls short of optimized single-crystal-based single-pixel detectors. Herein, a scalable and universal strategy of a mechanochemical method is adopted to synthesize stoichiometric high-entropy perovskite powders with high quality and high quantity (>1 kg per batch). By utilizing these stoichiometric perovskites, the first FA<sub>0.9</sub> MA<sub>0.05</sub> Cs<sub>0.05</sub> Pb(I<sub>0.9</sub> Br<sub>0.1</sub> )<sub>3</sub> -based X-ray flat-panel detector with low trap density and large mobility-lifetime product (7.5 × 10<sup>-3</sup> cm<sup>2</sup> V<sup>-1</sup> ) is reported. The assembled panel detector exhibits close-to-single-crystal performance (high sensitivity of 2.1 × 10<sup>4</sup> µC Gy<sub>air</sub> <sup>-1</sup> cm<sup>-2</sup> and ultralow detection limit of 1.25 nGy<sub>air</sub> s<sup>-1</sup> ), high spatial resolution of 0.46 lp/pixel, as well as excellent thermal robustness under industrial standards. The high performance in the high-entropy perovskite-based X-ray FPDs has the potential to facilitate the development of new-generation X-ray-detection systems.