Bias-Tuned Selective Spectral Response High-Performance Ga₂O₃/GaN Heterojunction Ultraviolet Photodetector

Abstract

$\beta $ -Ga2O3 films were successfully fabricated using the GaN thermal oxidation method, and Ga2O3/GaN heterojunction ultraviolet photodetectors were constructed with varying electrode parameters, including length, width, and electrode spacing. Under optimized electrode parameters, the detector demonstrates an exceptionally low dark current, with a value of just 63.2 fA at a 10V bias. Under $33~\mu $ W/cm2 ultraviolet light illumination, the detector demonstrates a high light-to-dark current ratio exceeding 106. By adjusting the thickness of the $\beta $ -Ga2O3 light-absorbing layer to enhance ultraviolet light absorption and reduce carrier recombination, the detector achieves a responsivity of up to 3061 A/W and a detectivity exceeding $10^{{15}}$ Jones. Additionally, by tuning the applied bias, the detector enables adjustable control over both the solar-blind ultraviolet single-band and solar-blind-near ultraviolet dual-band response spectra. These research findings provide important theoretical support and experimental basis for the optimized design and application of high-performance ultraviolet photodetectors.