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 (E-dp) and built-in electric field (E-ZnO/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 x 10(10) 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 tau(r) = 0.04 s, decay time tau(d) = 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 E-dp and E-ZnO/PLZT. This work offers a feasible and effective strategy for the performance improvement of ferroelectric-based self-powered UV detectors.

Automated summary

This study successfully achieved high-performance ZnO/PLZT heterojunction-based self-powered UV photodetectors by efficiently coupling E-dp and E-ZnO/PLZT, leading to a remarkable responsivity (R = 3.96 mA W-1) and detectivity (D* = 6.6 x 10(10) Jones) two orders of magnitude higher than previous reports, with a faster response time.