High-Performance and Stable Perovskite X-ray Detection and Imaging Based on a Ti Cathode

High-energy radiation detectors with a good imaging resolution, fast response, and high sensitivity are desired to operate at a high electric field. However, strong ion migration triggered by electrochemical reactions at the interface between a high-potential electrode and an organic-inorganic hybrid perovskite limits the stability of radiation detectors under a high electric field. Herein, we demonstrate that such ion migration could be effectively suppressed in devices with a Ti cathode, even at a high electric field of 50 V mm^-1, through time-of-flight secondary-ion mass spectrometry. X-ray photoelectron spectroscopy illustrates that Ti-N bonds formed at the interface of MAPbBr₃ perovskite single crystals/Ti electrode effectively inhibit the electrochemical reaction in organic-inorganic hybrid perovskite devices and ultimately improve the operating stability under a high electric field. The device with a Ti electrode reaches a high sensitivity of 96 ± 1 mC Gy_air^-1 cm^-2 and a low detection limit of 2.8 ± 0.3 nGy s^-1 under hard X-ray energy.