Photonic‐Electronic Dual‐Passivated Ultrafast β‐Ga ₂ O ₃ SBUV Photodiode

Ultrafast response is a necessary characteristic for solar‐blind ultraviolet (SBUV) photodetectors (PDs) in fault warning and aircraft exhaust plume monitoring. Here, for β‐Ga 2 O 3 ‐based SBUV PDs, we propose a novel photonic‐electronic dual‐passivation (PEDP) strategy, which simultaneously mitigates carrier diffusion in non‐depleted regions and surface trapping‐detrapping dynamics. Consequently, the PEDP‐modified PD achieves an ultrafast rise time of 5.9 ns and decay time of 86.8 ns at 0 V bias, outperforming existing SBUV PDs by 2–9 orders of magnitude. It also exhibits excellent overall performance at 0 V, including a dark current of 0.58 pA, photo‐to‐dark current ratio of 5.04 × 10 4 , rejection ratio (R 200 nm /R 350 nm ) of 1.12 × 10 4 , responsivity of 0.084 A W −1 , and external quantum efficiency of 59.9%. These results demonstrate the feasibility of the PEDP strategy for fast‐response SBUV detection and provide valuable insights for the development of fast imaging technologies.