High‐Performance Self‐Powered Ultraviolet Photodetector based on Coupled Ferroelectric Depolarization Field and Heterojunction Built‐In Potential

Ferroelectric materials have aroused increasing interest in the field of self‐powered ultraviolet (UV) photodetectors for their polarization electric field induced photovoltaic (PV) effect. However, the device performance of currently reported ferroelectric‐based self‐powered UV detectors remains to be improved. Herein, achievement of high‐performance ZnO/Pb0.95La0.05Zr0.54Ti0.46O3 (PLZT) heterojunction‐based self‐powered UV photodetectors is demonstrated by coupling the ferroelectric depolarization electric field (Edp) and built‐in electric field (EZnO/PLZT) at the ZnO/PLZT interface with a II‐type energy band alignment. The ZnO/PLZT heterojunction‐based self‐powered UV photodetector shows a remarkable responsivity (R = 3.96 mA W−1) and detectivity (D* = 6.6 × 1010 Jones), which are by two orders of magnitude larger than those of the device that are produced under similar conditions without ZnO layer. Moreover, the ZnO/PLZT heterojunction‐based device exhibits a rapid response (rise time τr = 0.04 s, decay time τd = 0.05 s), which is faster than most of previous reports. The excellent device performance of the ZnO/PLZT heterojunction‐based device can be attributed to the efficient separation and transport of photogenerated carriers caused by the constructive coupling of Edp and EZnO/PLZT. This work offers a feasible and effective strategy for the performance improvement of ferroelectric‐based self‐powered UV detectors. High‐performance ZnO/PLZT heterojunction‐based self‐powered ultraviolet photodetectors are achieved by coupling the ferroelectric depolarization electric field and built‐in electric field at the ZnO/PLZT interface with a II‐type energy band alignment. The photodetectors show a remarkable responsivity (R = 3.96 mA W−1) and detectivity (D* = 6.6 × 1010 Jones) under zero bias. Moreover, they exhibit a rapid response time (τr = 0.04 s, τd = 0.05 s).