4H-SiC PIN Recessed Window Avalanche Photodiode

We report 4H-SiC p-i-n recessed window avalanche photodiodes with low dark current and high quantum efficiency. For a circular device of 250 mum diameter, the device demonstrated a responsivity of ~135.5 mW/A (external quantum efficiency = ~64%), a dark current ~90 pA (~0.183 mum/cm²) at a photocurrent gain of 1000, and an excess noise factor k of slightly less than 0.1.