Noise Characterization of Geiger-Mode 4H-SiC Avalanche Photodiodes for Ultraviolet Single-Photon Detection

We present here the noise properties of the 4H-SiC avalanche photodiodes (APD) operated in Geiger mode. After-pulse events together with the dark count rate were measured at different temperatures. We found that at a certain bias voltage, the after-pulse probability of the 4H-SiC APD was dependent on the incident photon flux. This interesting observation may be useful to build a photon-number resolving detector for the UV regime. Moreover, the after-pulse and the dark counts noise decreased as the temperature dropped from room temperature to-;40 °C so that the single-photon detection performance of the 4H-SiC APD could be improved by decreasing the operation temperature.