Weak Signals Detection and Single Photon Counting with Ultraviolet SiC-based Avalanche Photodiodes

We report on the responsivity measurement of these devices in the linear regime with quantum efficiency of up to 45%. Responsivity attenuation is significant at wavelengths longer than 400nm and thin film dielectric stack filters may be used to tailor the wavelength response of the SiC APDs for various applications, including those requiring their use in the UV-A, UV-B and UV-C ranges with very good blocking in the visible or solar spectrum.