Dark Current Evolution in Irradiated MWIR HgCdTe Photodiodes

Abstract

HgCdTe detectors are a key technology for space-based infrared imagery. Radiation in the space environment affects the performance of these detectors. Gamma and protons irradiation are performed in order to assess the impact of total ionising dose and displacement damage dose on the dark current of mid-wavelength infrared HgCdTe photodiodes. Parameters such as dark current contributions, lateral collection length and activation energy are studied following irradiation. Metal–insulator–semiconductor devices were also irradiated in order to study the mechanisms of interface contributions to the dark current. A focal plane array was used to measure response evolution with irradiation. This study also analyses the impact of a post-irradiation thermal cycle on the evolution of the dark current.