Cs3Cu2I5 Single Crystal for Efficient Direct X-ray Detection

Abstract Low-dimensional copper-based halide perovskite single crystals are considered excellent scintillators for indirect X-ray detection, but their potential in direct X-ray detection has not been investigated. Herein, high-quality pure Cs3Cu2I5 and Li-doped Cs3Cu2I5:Li single crystals are grown by the Bridgman method. The Li+ dopant enhances the photoelectric properties of the Cs3Cu2I5 single crystal by extending the carrier life time, improving the carrier mobility from 6.49 to 9.52 cm2V-1s-1, and increasing the mobility-lifetime (μτ) product from 1.4×10-4 to 2.9×10-4 cm2V–1. The sensitive direct X-ray detector with a vertical device configuration of Au/Cs3Cu2I5:Li single crystal/PCBM/Au is fabricated and demonstrated to have a high sensitivity of 831.1 µC Gyair -1 cm-2 and low detection limit of 34.8 nGyair s-1. Furthermore, the detector shows fast response, negligible baseline current drift and excellent stability upon X-ray illumination.