Single-Photon-Counting Performance of 4H-SiC Avalanche Photodiodes With a Wide-Range Incident Flux

Abstract

In this letter, high-performance 4H-SiC ultraviolet (UV) single-photon avalanche diodes (SPADs) with a large diameter of $300~\mu \text{m}$ were designed and fabricated. For the first time, the influence of an incident UV photon flux on the single-photon-counting performance of 4H-SiC SPADs is investigated. With the UV photon flux increasing from ~100 photons/ $\text{s}\cdot \mu \text{m}^{2}$ to $2.3\times 10^{4}$ photons/ $\text{s}\cdot \mu \text{m}^{2}$ , the ratio of photon count rate (PCR) to dark count rate (DCR) exhibits a non-monotonic variation while the single-photon detection efficiency (SPDE) is monotonically decreased. A maximum SPDE of 9.8% with a DCR of 10 Hz/ $\mu \text{m}^{2}$ is obtained for our large-area 4H-SiC SPAD with a photon flux of 209 photons/ $\text{s}\cdot \mu \text{m}^{2}$ at the wavelength of 280 nm. In addition, the stability of our 4H-SiC SPAD is also preliminarily proved by the high-temperature storage test at 150 °C for more than 200 hours in N2 ambient, which indicates the potential capability of our 4H-SiC SPADs to operate in harsh environment for UV single-photon detection.