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

Area of Science:

• Materials Science
• Electronics Engineering
• Optoelectronics

Background:

• Perovskite photodetectors are promising alternatives to silicon photodiodes for camera applications due to their high sensitivity and integration capabilities.
• Conventional CMOS image sensor integration requires reverse bias, which causes performance instability in perovskite photodetectors due to ion migration.

Purpose of the Study:

• To develop a method to stabilize perovskite photodetector performance in CMOS image sensors.
• To overcome the ion migration issue that limits the operational stability of perovskite photodetectors.

Main Methods:

• Applying forward voltage pulses after each signal integration cycle to counteract ion migration.
• Operating perovskite photodetectors under alternating voltage pulses.
• Fabricating and testing 8x8 crossbar arrays of perovskite photodetectors.

Main Results:

• The proposed forward voltage pulse technique enabled stable operation of perovskite photodetectors for over 180 hours.
• Constant reverse bias resulted in detector degradation within 10 minutes.
• Stable imaging was demonstrated using the developed perovskite photodetector arrays.

Conclusions:

• Forward voltage pulsing is an effective strategy to stabilize perovskite photodetectors against ion migration.
• This technique significantly enhances the operational lifetime and reliability of perovskite photodetectors for imaging applications.
• Perovskite photodetectors are viable for stable, high-performance imaging sensors.