High responsivity solar-blind metal-semiconductor-metal photodetector based on α-Ga₂O₃

α-Ga₂O₃, with an ultra-high energy bandgap of 5.1 eV, is an attractive material for applications in solar-blind photodetectors and high-power electronics. We fabricated an α-Ga₂O₃ metal-semiconductor-metal (MSM) interdigitated solar-blind photodetector, where an epitaxial α-Ga₂O₃ thin film was grown on a sapphire substrate using a hydride vapor-phase epitaxy technique. Excellent optoelectronic device properties including high responsivity (4.24 × 10⁴ A/W), detectivity (1.77 × 10¹¹ Jones), and external quantum efficiency (2.07 × 10⁵) were demonstrated in response to ultraviolet (UV) C wavelength. Under sunlight, the α-Ga₂O₃ MSM photodetector exhibited stable solar-blind sensitivity to UVC wavelength without interference from the incoming solar spectrum. Our work proposes that α-Ga₂O₃ has great potential as a next-generation high-performance solar-blind photodetector.