Proton-Implantation-Isolated 4H-SiC Avalanche Photodiodes

We report 4H-SiC p-i-n structure avalanche photodiodes (APDs) isolated by proton implantation. These APDs achieved low dark current (670 nA/cm
²
at a gain of 1000) and gains as high as 105. The external quantum efficiency was 44% at 278 nm.