High-Performance Ga₂O₃ Solar-Blind Photodetector Based on Thermal Oxidized Ga Buffer-Layer

Abstract

High-performance Ga₂O₃ solar-blind photodetectors are critical for applications due to their selective solar-blind ultraviolet sensitivity. The quality of the Ga₂O₃ film has a significant impact on the performance of photodetectors. This study presents an innovative approach to enhancing the quality of Ga₂O₃ films through the introduction of a naturally graded buffer layer, which is formed by the oxidation of a metallic Ga film and significantly improves interface stability by accommodating lattice mismatches and reducing defects. The structural and compositional characteristics of Ga₂O₃ films were comprehensively analyzed using UV-vis (ultraviolet-visible) spectroscopy, AFM (Atomic Force Microscope), PL (Photoluminescence Spectroscopy), TEM (Transmission Electron Microscope), and XPS (X-ray Photoelectron Spectroscopy). The photodetectors fabricated from these films demonstrate responsivity of 99.8 mA/W and a solar-blind UV/UV ratio of 1.17 × 10³, with significant improvement compared to direct deposited films. This research highlights the potential of natural buffering layers to advance the performance of Ga₂O₃-based solar-blind UV detectors.