A review of recent progress in Ga₂O₃-based solar-blind ultraviolet photodetectors

Solar-blind ultraviolet (UV) photodetectors, functioning within the 200–280 nm spectral range, benefit from atmospheric absorption, which significantly suppresses background noise and enhances detection sensitivity. These advantages make them highly suitable for critical applications including missile threat warning, ozone layer surveillance, and secure ultraviolet communications. Among the candidate materials, gallium oxide (Ga₂O₃) stands out as a promising wide-bandgap semiconductor for solar-blind UV detection, owing to its large bandgap, high breakdown electric field strength, low dark current, and remarkable thermal and chemical stability. This review provides a systematic overview of recent progress in Ga₂O₃-based solar-blind UV photodetectors. It begins with a concise introduction to the crystal structures and physical characteristics of Ga₂O₃, followed by an in-depth discussion of advances categorized into four structural types: nanostructures, single crystals, thin films, and heterojunctions. For each type, representative device performance and key technical challenges are examined. Finally, based on current research trends, future research priorities are outlined, emphasizing material engineering, novel device structures, application diversification, and interdisciplinary collaboration to support the continued development and practical deployment of Ga₂O₃-based solar-blind UV detection technologies.