Numerical analysis of impact ionization in HOT HgCdTe avalanche photodiodes

Semiconductor avalanche photodiodes enable individual photons to be detected when the incident flux of light is very low. This is possible thanks to the use of the avalanche multiplication phenomenon. Consequently, the obtained gain of photocurrent is from a few to several million times. The avalanche multiplication effect in semiconductors is determined by the generation rate caused by impact ionization. This paper describes the results of research aimed at investigation of the impact ionization mechanism in HgCdTe photodiodes operating at 230 K and in the medium-wave infrared range. Numerical analyses were used for the study using a computer program in which the modeling and consideration of all the possible generation and recombination mechanisms were included.