【Epitaxy Papers】Sol–Gel Spin-Coated Nanoporous β-Ga₂O₃ Thin Films for High-Performance and Scalable UVC Photodetectors

      Researchers from Vietnam Academy of Science and Technology have published a dissertation titled " Sol–Gel Spin-Coated Nanoporous β-Ga₂O₃ Thin Films for High-Performance and Scalable UVC Photodetectors " in Optical Materials.

Abstract

      In this study, we propose a cost-effective, solution-processed strategy to fabricate nanoporous β-Ga₂O₃ thin film via a sol–gel spin-coating method. The as-prepared film exhibits a crystal monoclinic β-phase, interconnected porous morphology, and strong UVC absorption. The nanoporous β-Ga₂O₃ film was integrated into a vertical n–p heterojunction with p-type silicon to construct UVC photodetector. Under 254 nm illumination, the device exhibits a high responsivity of 558.7 mA/W, a high specific detectivity of 1.07 × 10¹² Jones, and a fast photo response under a moderate reverse bias of −2.5 V. The performance metrics are attributed to the synergistic effects of the porous morphology, which facilitates deep light absorption and short diffusion paths, and the built-in electric field at the β-Ga₂O₃/p-Si interface, which promotes efficient carrier separation and collection. Furthermore, the device demonstrates excellent photostability and operational reproducibility over 500 continuous on/off cycles. The simplicity, scalability, and effectiveness of this fabrication route suggest significant promise for the practical deployment of UVC photodetectors in low-cost and high-reliability applications.

DOI：

https://doi.org/10.1016/j.optmat.2026.118166