Quenching of persistent photocurrent in an oxide UV photodetector

Abstract

The sensitivity to weak light signal is a key parameter for UV photodetectors. However, highly sensitive device has to suffer slow response speed (with photoconductive gain) or large noise current (with avalanche gain). In this work, a new type photoconductive gain with controllable response speed is discovered in Ga2O3 photodetector. The persistent photocurrent can be quenched by a 500-μs zero-voltage pulse. The photoconductive gain and the quenching of persistent photocurrent are respectively attributed to the forming and breaking of conductive filament composed of oxygen vacancies. UV illumination is demonstrated to accelerate the forming of filament. This work combines fast speed with high sensitivity for a detector with photoconductive gain.