Gradient Passivation of Oxygen Vacancy Boosts Ga 2 O 3 Solar‐Blind UV Detector

Abstract Ultra‐wide bandgap semiconductor gallium oxide (Ga 2 O 3 ) is rising as a promising candidate for the applications in solar‐blind UV detectors, radio frequency devices, and power electronics. However, the randomly distributed oxygen vacancy (V O ) defects result in the disorganized local energy level, limiting the carrier transport and device performance. Here we report the energy level alignment based on the Gradient Passivation of Oxygen Vacancy (GPVO), enabled by the migration of shallower oxygen interstitial defects (O i ) toward Ga 2 O 3 film surface, and the recombination of deeper O i with V O through vacuum annealing. We construct the gradually increased E f of Ga 2 O 3 film along the direction from surface to bulk, and improve the built‐in electric field of Ga 2 O 3 vertical Schottky diode. Therefore, we fabricate the Ga 2 O 3 Solar‐blind UV detectors with enhanced responsivity and specific detectivity of 8.6 A W −1 and 1.5 × 10 15 Jones under 254 nm illumination, at bias voltage of −1.7 V, as well as the shorter response time of 1.04 s/16 ms. Moreover, we report the first 64 × 64 Ga 2 O 3 image sensor and demonstrate the solar‐blind UV video imaging of complex images.