Controllable Hydrothermal Synthesis of 1D β-Ga2O3 for Solar-Blind Ultraviolet Photodetection

Abstract

Gallium oxide (Ga2O3), an ultrawide bandgap semiconductor, is an ideal material for solar-blind photodetectors, but challenges such as low responsivity and response speed persist. In this paper, one-dimensional (1D) Ga2O3 nanorods were designed to achieve high photodetection performance due to their effective light absorption and light field confinement. Through modulating source concentration, pH value, temperature, and reaction time, 1D β-Ga2O3 nanorods were controllably fabricated using a cost-effective hydrothermal method, followed by post-annealing. The nanorods had a diameter of ~500 nm, length from 0.5 to 3 μm, and structure from nanorods to spindles, indicating that different β-Ga2O3 nanorods can be utilized controllably through tuning reaction parameters. The 1D β-Ga2O3 nanorods with a high length-to-diameter ratio were chosen to construct metal-semiconductor-metal type photodetectors. These devices exhibited a high responsivity of 8.0 × 10−4 A/W and detectivity of 4.58 × 109 Jones under 254 nm light irradiation. The findings highlighted the potential of 1D Ga2O3 nanostructures for high-performance solar-blind ultraviolet photodetectors, paving the way for future integrable deep ultraviolet optoelectronic devices.