【Device Papers】High-Responsivity Self-Powered Photoelectrochemical Solar-Blind Ultraviolet Detector Based on (104)-Oriented Ga₂O₃ Nanorods

      Researchers from the South China University of Technology have published a dissertation titled "High-Responsivity Self-Powered Photoelectrochemical Solar-Blind Ultraviolet Detector Based on (104)-Oriented Ga₂O₃ Nanorods" in Surfaces and Interfaces.

Abstract

      As an ultrawide-bandgap semiconductor, Ga₂O₃ is highly promising for solar-blind ultraviolet detection. Traditional preparation methods are often complicated and costly. In this study, α-Ga₂O₃ nanorods were synthesized via a hydrothermal method and employed to construct a photoelectrochemical ultraviolet PD (PEC UV PD). We investigated the influence of hydrothermal parameters on the Ga₂O₃ thin films. It was observed that extending the hydrothermal reaction time led to an increase in film thickness, whereas elevating the precursor concentration resulted in a reduction in nanorod dimensions. Notably, the introduction of ammonia induced preferential orientation of the nanorods. On the basis of these findings, a Ga₂O₃-based PEC PD with a preferential (104) crystal-plane orientation was successfully fabricated, demonstrating excellent solar-blind detection performance. Under 267 nm deep ultraviolet light, it achieved a maximum responsivity (R) of 27.8 mA W⁻¹ and detectivity (D*) of 2.80 × 10¹⁰ Jones, with a solar-blind to near-ultraviolet rejection ratio (R_267nm/R_365nm) of 11,949. The rise time (τ_rise) was 36.2 ms, and the delay time (τ_delay) was 20.1 ms. By combining experiments with density functional theory (DFT) calculations, the study indicates the (104) surface facilitates H₂O adsorption, enhancing the oxidation reaction at the PEC PD photoanode-electrolyte interface. This work offers a new approach for developing cost-effective, high-performance solar-blind ultraviolet detectors.

DOI：

https://doi.org/10.1016/j.surfin.2025.107844