Ultrafast and Sensitive NiO/Ga 2 O 3 Lateral Superjunction Photodetectors for Solar-Blind Ultraviolet Detection

Ultrahigh responsivity has been reported in Ga2O3 solar-blind photodetectors, but their response speed still remains a significant challenge for practical applications. Here, lateral NiO/Ga₂O₃ superjunction p-n photodetectors are demonstrated, simultaneously achieving high responsivity and fast response. The devices exhibit a record photo to dark current ratio of 8.50 × 10⁸, a high responsivity of 3.92 A/W, an excellent detectivity of 1.02 × 10¹⁵ Jones at 254 nm, and fast rise/decay times of 493/477 μs. The excellent performance is attributed to the periodically arranged NiO/Ga₂O₃ heterointerfaces, which introduce multiple localized built-in electric fields that promote efficient carrier separation, suppress recombination, and shorten the effective carrier transit distance. These results demonstrate the great potential of Ga₂O₃ superjunctions for solar-blind photodetection.