Zhao Fu, Jia‐Bao Liu, Meng Yuan, Jiafa Cai, Rongdun Hong, Xiaping Chen, Dingqu Lin, Shaoxiong Wu, Yuning Zhang, Zhengyun Wu, Zhanwei Shen, Zhijie Wang, Jicheng Wang, Mingkun Zhang, Zhilin Yang, Deyi Fu, Feng Zhang, Rong Zhang
Abstract Sensitive avalanche photodetectors (APDs) that operate within the ultraviolet spectrum are critically required for applications in detecting fire and deep-space exploration. However, the development of such devices faces significant challenges, including high avalanche breakdown voltage, the necessity for complex quenching circuits, and thermal runaway associated with Geiger-mode avalanche operation. To mitigate these issues, we report on a 4H-SiC APD design utilizing micro-holes (MHs) structures and Al nano-triangles (NTs) to enhance surface electric field driven by strong localized surface plasmon excitations and lightning-rod effect. The device demonstrates a low avalanche breakdown voltage of approximately 14.5 V, a high detectivity of 2 × 10 13 Jones, a nanosecond-level response time, and repeated stable detections without the requirement of a quenching circuit. Collectively, when compared with the conventional wide-bandgap-based APDs, this device achieves a reduction in avalanche breakdown voltage by an order of magnitude. Consequently, the proposed APD configuration presents a promising candidate for ultraviolet detection and integrated optoelectronic circuits.