Fast-speed self-powered PEDOT:PSS/α-Ga2O3 nanorod array/FTO photodetector with solar-blind UV/visible dual-band photodetection

Abstract

The α-Ga2O3 nanorod array is grown on FTO by hydrothermal and annealing processes. And a self-powered PEDOT:PSS/α-Ga2O3 nanorod array/FTO (PGF) photodetector has been demonstrated by spin coating PEDOT:PSS on the α-Ga2O3 nanorod array. Successfully, the PGF photodetector shows solar-blind UV/visible dual-band photodetection. Our device possesses comparable solar-blind UV responsivity (0.18 mA/W at 235 nm) and much faster response speed (0.102 s) than most of the reported self-powered α-Ga2O3 nanorod array solar-blind UV photodetectors. And it presents the featured and distinguished visible band photoresponse with a response speed of 0.136 s at 540 nm. The response time is also much faster than the other non-self-powered β-Ga2O3 DUV/visible dual-band photodetectors due to the fast-speed separation of photogenerated carries by the built-in electric field in the depletion regions of PEDOT:PSS/α-Ga2O3 heterojunction. The results herein may prove a promising way to realize fast-speed self-powered α-Ga2O3 photodetectors with solar-blind UV/visible dual-band photodetection by simple processes for the applications of multiple-target tracking, imaging, machine vision and communication.