High‐Performance Self‐Driven MAPbI <sub>3</sub> ‐MAPbBr <sub>3</sub> Perovskite Single Crystal Heterojunction Photodetectors for Ultra‐Sensitive Weak Light Imaging
Chenyang Liu, Rui Wang, Jialin Liu, Wenli Xu, He Zhang, Xinying Liu, Xiangyu Huo, Xueying Cui, Haiqing Sun, Rui Liu, Huiling Zhu, Weiwei Zhang, Jianxu Ding
Abstract
Abstract The rapid advancement of optoelectronic devices, particularly photodetectors, demands enhanced sensitivity for detecting weak light. In this study, MAPbI 3 ‐MAPbBr 3 perovskite single crystal heterojunctions (SCHs) are fabricated via atomic force bonding using liquid‐phase epitaxy, with polydimethylsiloxane (PDMS) serving as a substrate protector. The resulting SCHs photodetector exhibits self‐driven operation, an ultra‐low dark current, and a high on‐off ratio of 5.8 × 10 4 at 0 V bias. Under weak illumination and 5 V bias, the device achieves a maximum external quantum efficiency of 414.9%. With a remarkable detection rate of 4.5 × 10 13 Jones, the device demonstrates outstanding potential for weak light imaging. Furthermore, the self‐driven SCHs photodetector enables high‐quality imaging under a 445 nm light source at a remarkably low intensity of 2.7 µW cm −2 , without the need for any external power supply.