Cs3Cu2I5 Single Crystal for Efficient Direct X-Ray Detection

Low-dimensional copper-based halide 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 lifetime, improving the carrier mobility from 6.49 to 9.52 cm(2) V-1 s(-1), and increasing the mobility-lifetime (& mu;& tau;) product from 1.4 x 10(-4) to 2.9 x 10(-4) cm(2) V-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 & mu;C Gy(air)(-1) cm(-2) and low detection limit of 34.8 nGy(air) s(-1). Furthermore, the detector shows negligible baseline current drift and excellent stability upon X-ray radiation.