Simulation on high-performance Ga₂O₃ photodetectors with the synergism of nanohole and nanograting

The Sun serves as the primary source of ultraviolet radiation on Earth. The UVC band, 200–280 nm, is strongly absorbed by atmospheric ozone, thereby establishing a naturally low-background-noise “solar-blind region.” Solar-blind UV photodetectors operating within this spectral range exhibit significant potential in applications such as flame detection, missile early warning systems, and ozone monitoring. With its ultra-wide bandgap of 4.7–4.9 eV, β-Ga₂O₃ has emerged as a highly promising material for the fabrication of such detectors. To further enhance device performance, this study introduces a dual-layer light-trapping architecture that incorporates surface nanopores and a bottom aluminum grating. Simulations conducted using the Finite Difference Time Domain (FDTD) method reveal that this composite structure achieves an absorption efficiency of 63.7% at a wavelength of 250 nm, representing a 247% improvement compared to unstructured devices. Additionally, the device’s responsivity increases from 0.55 A/W to 7.08 A/W, with more than 50% responsivity retained even at incident angles as large as 60°, demonstrating exceptional angular robustness. These simulation results confirm the synergistic interaction between light-scattering enhancement from nanopores and plasmonic resonance in metal gratings, offering a robust theoretical foundation for the design and fabrication of high-performance Ga₂O₃-based solar-blind ultraviolet detectors.