Strategies for suppressing dark current of perovskite photodiodes towards reliable optoelectronic applications

Photodetection is crucial for advancements in next-generation technologies, including Internet of Things, intelligent perception, augmented and virtual reality, and human-machine interactions. Metal halide perovskites (MHPs) show unique properties that allow for the creation of straightforward diode structures, enabling efficient photogeneration and charge collection across a broad spectrum of wavelengths, from ionizing radiation to near-infrared. However, the presence of dark current (I_d) poses a significant challenge, affecting the performance of these devices. This review commences by outlining the essential performance measures impacted either directly or indirectly by I_d. Subsequently, it investigates the adjustable MHP materials employed in photodiodes, with a focus on their structural and morphological characteristics. We then explore the origins of I_d and highlight the crucial factors that impact the performance of MHP-based photodiodes (MHPPDs). Additionally, we examine various strategies to mitigate I_d, thereby improving device efficacy. Finally, we provide insights into future directions for reducing I_d in MHPPDs, potentially leading to further enhancements in photodetection technologies.