Performance Improvement in Ga2O3 Schottky Photodiode With Pyroelectric Effect

Abstract

As a potential architecture for solar-blindness ultraviolet (SBUV) detection, a relatively small responsivity of the Ga2O3 Schottky photodiode hinders their practical usage. Subjected to the severe persistent photoconductivity (PPC) effect, most existing methods can improve the responsivity of Ga2O3 photodetectors, but at the cost of the response speed. Here, an interface pyroelectric effect, induced in the depletion region on ultraviolet illumination, has been utilized for performance improvement of Ga2O3 Schottky photodiode. The influence of optical power density (PD), incident wavelength, externally applied bias, and temperature on the basic pyroelectric properties and corresponding working mechanisms are systematically investigated. Under 254-nm illumination with $499~\mu $ W/cm2, the self-powered device exhibits an improved performance, with a decent responsivity R of 0.056 A/W, a large photodark current ratio PDCR of $3.26\times 10^{{6}}$ , a high specific detectivity ${D} ^{\ast } $ of $3.38\times 10^{{13}}$ Jones, and a rise/decay time of 1.94/2.61 ms. This work provides an effective approach to settle the long-standing tradeoff between responsivity and response speed, promoting the practical application of the Ga2O3 photodetector.