Impact ionization threshold energy of trigonal selenium: An ab initio study

Impact ionization coefficient is a critical parameter that determines the multiplication gain in avalanche photodiodes. The impact ionization coefficient is closely related to the ionization threshold, E th , which is determined by the band dispersion of the semiconducting material used in detectors. The ionization threshold energy is commonly calculated based on a parabolic band assumption, which provides only a crude approximation. Here we …