Suppressing dark current in self-powered perovskite photodetectors: a review of origins, strategies, and applications.

Self-powered perovskite photodetectors (PDs), capable of operating without an external bias, offer a compelling pathway toward low-power and integrated optoelectronic applications. Nevertheless, dark current remains a key factor severely restricting device performance, leading to high noise, low sensitivity, as well as undesired specific detectivity of PDs. In recent years, considerable efforts have been made to identify the origins of dark current and to develop effective suppression strategies. Therefore, this review explores the origins and generation mechanisms of dark current in self-powered perovskite PDs and summarizes recent suppression strategies, including film-deposition engineering, interface engineering, additive engineering, and quantum-dot engineering. Moreover, this review discusses different applications of low-dark-current self-powered perovskite PDs in wearable optoelectronic devices, imaging, and optical communication. Finally, we conclude and outline future challenges and prospects, highlighting material screening assisted by machine learning and the development of lead-free perovskite systems with improved stability. This review aims to provide theoretical guidance for the development of self-powered perovskite PDs with low dark current and to present the great potential of PDs in various practical applications.