【Epitaxy Papers】Self-Powered Deep-Ultraviolet Detection via High-Photovoltage Open-Circuit Mode in Nanoporous Ga₂O₃ Thin Films

      Researchers from Gachon University have published a dissertation titled " Self-Powered Deep-Ultraviolet Detection via High-Photovoltage Open-Circuit Mode in Nanoporous Ga₂O₃ Thin Films " in Surfaces and Interfaces.

Abstract

      Detection of ultraviolet C (UVC) radiation has enabled state-of-the-art applications, including flame alarming, missile tracking, partial-discharge detection, and wireless communication. Although wide-bandgap Ga₂O₃ is an excellent candidate for solar-blind UVC detection, the requirement for complex and ultrahigh-vacuum fabrication processes remains an obstacle to the industrial and cost-effective production of high-performance Ga₂O₃-based UVC detectors. Additionally, light scattering on the photoabsorber surface causes a loss of incident light, leading to poor device sensitivity for weak-intensity UV detection. To address these issues, we propose a facile process for preparing a highly nanoporous Ga₂O₃ thin film as an efficient photoabsorber layer using a sol–gel spin-coating method. The intrinsic porosity of the Ga₂O₃ film enhances the UVC absorption coefficient by up to 70% compared with a compact Ga₂O₃ control film prepared using an analogous sol–gel spin-coating process. As a result, the nanoporous Ga₂O₃-based photodetector (PD) exhibits an outstanding on/off ratio (>10³) and a large open-circuit voltage (V_OC = 0.82 V) under 254 nm UV illumination without a power supply. As a proof of concept, the PD can be conveniently connected to a simple digital multimeter to monitor weak-intensity UVC light without interference from solar light.

DOI：

https://doi.org/10.1016/j.surfin.2026.109646