Insight into the high-voltage stability of perovskite ionizing radiation detector: From interfacial reaction to performance degradation.

This article focuses on the stability challenges of perovskite-based ionizing radiation detectors, specifically those using CsPbBr₃ (CPB) single crystals with indium (In) or bismuth (Bi) anodes forming Schottky contacts. It identifies that operational instability at high voltage arises from chemical and electrochemical reactions between the anode metal and perovskite, driven by ion migration within the crystals, which degrades charge collection efficiency (CCE). The study demonstrates that using CPB crystals with high ion migration activation energy (0.42 eV) combined with a low-reactivity Bi anode significantly suppresses interface reactions, resulting in stable pulse height spectra and energy resolution under high electric fields over extended periods. The degradation mechanism involves interfacial reactions altering energy levels and electric field distribution, thereby impairing carrier transport and detector performance. These findings contribute to improving the reliability and commercial viability of perovskite radiation detectors.