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 Cs 3 Cu 2 I 5 and Li-doped Cs 3 Cu 2 I 5 :Li single crystals are grown by the Bridgman method. The Li + dopant enhances the photoelectric properties of the Cs 3 Cu 2 I 5 single crystal by extending the carrier life time, improving the carrier mobility from 6.49 to 9.52 cm 2 V -1 s -1 , and increasing the mobility-lifetime (μτ) product from 1.4×10 -4 to 2.9×10 -4 cm 2 V –1 . The sensitive direct X-ray detector with a vertical device configuration of Au/Cs 3 Cu 2 I 5 :Li single crystal/PCBM/Au is fabricated and demonstrated to have a high sensitivity of 831.1 µC Gy air -1 cm -2 and low detection limit of 34.8 nGy air s -1 . Furthermore, the detector shows fast response, negligible baseline current drift and excellent stability upon X-ray illumination.