Low-Drift and High-Sensitivity Perovskite X-ray Detector through Proactive Healing of Bulk Ion Migration

The radiation detection performances of perovskites have significantly outperformed those of many traditional semiconductors. However, achieving high-quality perovskite detectors remains challenging due to bias-induced ion migration. The primary concern is the lack of recovery strategies to promptly heal migrated ions during operation, realizing high device stability and exceptional optoelectronic performance. Herein, we proposed a proactive healing strategy of migrated ions by alternating current voltage (ACV) to achieve a low current drift and high optoelectronic sensitivity. Under the ACV, bulk ion migration can be effectively controlled to maintain the long-term stability of perovskite devices. The as-grown defects would annihilate during the ACV post-treatment, decreasing defect density and improving crystal quality. Therefore, more stable and balanced hole and electron photoresponses are harvested after the ACV post-treatment. The treated MAPbBr₃ detector exhibits a low dark current drift (∼10^-6 nA cm^-1 V^-1 s^-1) and excellent sensitivity [5.43 × 10⁴ (hole) and 4.78 × 10⁴ (electron) μC Gy_air^-1 cm^-2]. This work not only demonstrates a deep insight into device healing but also provides an effective post-treatment and operation strategy for perovskite detectors.