Ferroelectric Polarization Field Enhanced CsPbBr ₃ /ZnO Heterojunction Broadband Photodetector

ABSTRACT Perovskite‐based photodetectors are widely used in automation control, optical communication, video imaging, and other fields due to their excellent photoelectric properties. However, due to the low photogenerated carrier separation efficiency of heterojunction detectors formed by perovskite, it is necessary to introduce new strategies to improve the photoelectric conversion efficiency. In this study, a high‐performance photodetector based on CsPbBr ₃ &P(VDF‐TrFE)/ZnO heterojunction is fabricated by promoting the separation and transportation of photogenerated carriers via ferroelectric polarization field. Adding 0.4wt.% P(VDF‐TrFE) into CsPbBr ₃ can boost the photodetector performance significantly. The responsivity and detectivity reach 473.5 mA/W and 8.71 × 10 ¹² Jones, respectively, as well as the fast response/recovery time of 48 ms/51 ms. Compared with the initial device, the responsivity and detectivity are increased by 193% and 1065%, respectively. Whereas the dark current decreases from 11.13 to 0.365 nA. The optical detection range extends from ultraviolet to visible light. This work demonstrates that the ferroelectric polarization field is an effective way to improve the performance of a photodetector.