Yan Zhou, Xiaoqiang Tao, Tianyi Li, Dong Zhou, Weizong Xu, Feng Zhou, Fangfang Ren, Dunjun Chen, Rong Zhang, Youdou Zheng, Hai Lu
In this work, an ultraviolet (UV) 4H-SiC single-photon avalanche photodiode (SPAD) with a separated absorption-charge-multiplication structure is designed and fabricated, by which the electric field distribution within the device is optimized to enhance effective light absorption and reliability. The SiC SPAD exhibits a high single photon detection efficiency of 26.8%@270 nm and a low dark count rate of ~8.75 Hz/μm2at room temperature. For the first time, the reliability behavior of SiC SPADs under continuous Geiger-mode operation conditions is evaluated. The SPAD exhibits no performance degradation after over 10,000 hours of operation and a cumulative avalanche count exceeding 1014, which demonstrates significant potential of SiC SPADs in practical UV photon counting applications.