Stable Hard X-ray Detectors by High-Charge-Mobility Two-Dimensional Cu(Gly)2Pb2Br4 Single Crystal

Abstract

Two-dimensional (2D) perovskites have better long-term stability, better ion migration inhibition ability, and lower dark current in X-ray detection due to the hindrance effect of organic cations. However, this also limits the charge carrier transport and lowers the device sensitivity. Here, we report a new trans-copper glycinate lead bromide (Cu(Gly)₂Pb₂Br₄) perovskite-like single crystal. Through the cross-linking strategy of metal ions, the charge carrier transport ability of Cu(Gly)₂Pb₂Br₄ along the out-of-plane direction was greatly improved. The record high hole mobility of 54.1 cm² V^–1 s^–1 enables a high sensitivity of 26 589 μC Gy_air^–1 cm^–2. The cross-linking structure of the organic interlayer also inhibits ion migration paths and enhances stability with a small dark current drift as low as 4.93 × 10^–18 A cm^–1 V^–1 s^–1. The Cu(Gly)₂Pb₂Br₄ single crystal also shows good stability and X-ray imaging capability as a potential candidate for X-ray detection.