Ultrahigh‐Flux X‐ray Detection by a Solution‐Grown Perovskite CsPbBr₃ Single‐Crystal Semiconductor Detector

Abstract Solution‐processed perovskites are promising for hard X‐ray and gamma‐ray detection, but there are limited reports on their performance under extremely intense X‐rays. Here, a solution‐grown all‐inorganic perovskite CsPbBr₃ single‐crystal semiconductor detector capable of operating at ultrahigh X‐ray flux of 10¹⁰ photons s⁻¹ mm⁻² is reported. High‐quality solution‐grown CsPbBr₃ single crystals are fabricated into detectors with a Schottky diode structure of eutectic gallium indium/CsPbBr₃/Au. A high reverse‐bias voltage of 1000 V (435 V mm⁻¹) can be applied with a small and stable dark current of ≈60–70 nA (≈9–10 nA mm⁻²), which enables a high sensitivity larger than 10 000 µC Gy_air⁻¹ cm⁻² and a simultaneous low detection limit of 22 nGy_air s⁻¹. The CsPbBr₃ semiconductor detector shows an excellent photocurrent linearity and reproducibility under 58.61 keV synchrotron X‐rays with flux from 10⁶ to 10¹⁰ photons s⁻¹ mm⁻². Defect characterization by thermally stimulated current spectroscopy shows a similar low defect density of a synchrotron X‐ray and a lab X‐ray irradiated device. Solid‐state nuclear magnetic resonance spectroscopy suggests that the excellent performance of the solution‐grown CsPbBr₃ single crystal may be associated with its good short‐range order, comparable to the spectrometer‐grade melt‐grown CsPbBr₃.