Ion Migration Enhances the Performance of Perovskite CsPbBr 3 γ‐Ray Detectors

Abstract Uncontrolled ion migration is well‐known in perovskite‐based semiconductor devices. Here, it is shown that instead of being detrimental, ion migration can be used to enhance the performance of perovskite CsPbBr 3 semiconductor gamma‐ray detectors. Through the deliberate application of electrical biasing, ion migration is actively controlled to modify the metal‐CsPbBr 3 interface barrier height in devices with asymmetric electrodes. Ion migration plays a pivotal role in reducing bulk defects, as evidenced by the contact potential difference measurement, thermally stimulated current spectroscopy and photoluminescence measurements. The evidence suggests that biasing‐induced ion migration in CsPbBr 3 results in a reduction in electron traps and significant detector improvement. As biasing at elevated temperatures expedites ion migration, preconditioning the CsPbBr 3 crystals through reverse biasing is a promising strategy for enhancing their energy‐resolving performance.