Degradation of InP-based Geiger-mode avalanche photodiodes due to proton irradiation.

Degradation of InGaAs/InP Geiger-mode avalanche photodiodes caused by proton irradiation is reported for the first time. The devices are found to be very sensitive to displacement damage. Substantial changes in the dark count rate, and the after-pulse count rate are observed following room temperature irradiation and characterization at -50°C. The device detection efficiency is unaffected by irradiation. Following 51 MeV proton fluences in the mid 109 protons/cm2 range, the dark count rate becomes so large that the devices are rendered essentially unusable. This is a very low fluence at which to observe device failure. [ABSTRACT FROM AUTHOR]