Inverted‐Structural Self‐Powered Gan/PZT/ITO UV Photodetector Enhanced by Ferroelectric Modulation

Abstract Ferroelectric materials with remnant polarization can effectively modulate the built‐in electric field of semiconductor devices and hold great promise for the development of high‐performance self‐powered optoelectronic devices. However, the low depolarization and low separation efficiency of photo‐generated carriers limit the performance of existing ferroelectric/semiconductor‐based self‐powered photodetectors. In this study, a n‐GaN/Pb(Zr0.2Ti0.8)O3 (PZT)/ITO self‐powered ultraviolet (UV) photodetector with an inverted structure and GaN as the optical absorption material is fabricated. By coupling the strong depolarization field (Edp) of PZT with the enhanced built‐in electric field (EPZT/GaN) of GaN/PZT heterojunction, this device exhibits outstanding performances with an ultra‐high light‐to‐dark current (Ilight/Idark) ratio of 3.07 × 107, a high responsivity of 176 mA W−1, a high detectivity of 2.36 × 1013 Jones, and a fast response time of 0.52/0.58 ms. Its comprehensive detection performance surpasses most reported advanced ferroelectric/semiconductor‐based UV photodetectors. The proposed strategy provides a simple and feasible approach for the design of high‐performance GaN‐based self‐powered UV photodetectors.