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 .

Keywords: X-ray detectors; perovskite CsPbBr3; solution-grown materials; ultrahigh flux.