Mitigating Ion Migration with Alternating Voltage for Stable Perovskite Image Sensors

Perovskite photodetectors have emerged as a potential replacement for silicon photodiodes in modern cameras due to their high sensitivity to visible light and ability to be easily integrated into existing electronics. However, the use of perovskite photodetectors in conventional CMOS image sensors requires the application of reverse bias, which can lead to unstable detector performance due to ion migration effects. In this article, we propose a new approach that involves the application of forward voltage pulses to attenuate ion migration while still enabling the capture of photocurrent under reverse bias. Our results show that using this technique after each cycle of signal integration allows for stable operation of perovskite photodetectors for over 180 h, while applying a constant reverse bias leads to degradation within just 10 min. Additionally, we demonstrate stable imaging using alternating voltage and 8 × 8 crossbar arrays of perovskite photodetectors.