# Mitigating Ion Migration with Alternating Voltage for Stable Perovskite Image Sensors

## TL;DR

A new method using alternating voltage improves the stability of perovskite image sensors by reducing ion migration.

## Contribution

A novel technique using forward voltage pulses to mitigate ion migration in perovskite photodetectors is introduced.

## Key findings

- Applying forward voltage pulses after each signal cycle enables stable operation for over 180 hours.
- Constant reverse bias causes perovskite photodetector degradation within 10 minutes.
- Stable imaging is demonstrated using 8 × 8 crossbar arrays with alternating voltage.

## Abstract

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.