Identifying and understanding the positive impact of defects for perovskites optoelectronic devices

TL;DR

This paper explores how defects in perovskite optoelectronic devices can be beneficial, demonstrating that defect-induced carrier trapping can enhance photodetector performance and challenge the traditional view of defects as solely harmful.

Contribution

It introduces a novel perspective that defects can positively impact device performance, specifically by increasing photoconductive gain in perovskite photodetectors.

Findings

Achieved record photoconductive gain and detection limit

Demonstrated defect trapping enhances photodetector performance

Challenged the traditional view of defects as purely detrimental

Abstract

Defects are generally regarded to have negative impacts on carrier recombination, charge-transport and ion migration in materials, which thus lower the efficiency, speed and stability of optoelectronic devices. Meanwhile, lots of efforts which focused on minimizing defects have greatly improved the performances of devices. Then, can defects be positive in optoelectronic devices? Herein, relying on in-depth understanding of defect-associated effects in semiconductors, trapping of photo-generated carriers by defects is applied to enlarge photoconductive gain in photodetection. Therefore, the record photoconductive gain, gain-bandwidth product and detection limit were achieved in this photodetector. Exceeding the general concept that defects are harmful, we identify a new view that the defects can be positive in photodetection, which may guide us to design high-performance photodetectors.