Performance Improvement in Ga₂O₃ Schottky Photodiode With Pyroelectric Effect

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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$499~\mu $ </tex-math></inline-formula>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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.26\times 10^{{6}}$ </tex-math></inline-formula>, a high specific detectivity <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D} ^{\ast } $ </tex-math></inline-formula> of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.38\times 10^{{13}}$ </tex-math></inline-formula> 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.