Abstract
Uncontrolled ion migration has been well-known in perovskite-based semiconductor devices. Here, we show that instead of being detrimental, ion migration can be used to enhance the performance of perovskite CsPbBr3 semiconductor gamma-ray detectors. Through deliberate application of electrical biasing, we actively control ion migration to modify the metal-CsPbBr3 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 CsPbBr3 results in a reduction in electron traps. As a result, record-breaking performance of 57Co gamma ray spectrum for CsPbBr3 detector was achieved by intentionally biasing the detector. As biasing at elevated temperatures expedites ion migration, preconditioning the CsPbBr3 crystals through reverse biasing is a promising strategy for enhancing their performance.