Photonic-Electronic Dual-Passivated Ultrafast β-Ga₂O₃ 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-Ga₂O₃-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 × 10⁴, rejection ratio (R_{200 nm}/R_{350 nm}) of 1.12 × 10⁴, 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.