Effect of proton irradiation on extended wavelength In0.83Ga0.17As infrared detector

Extended wavelength In0.83Ga0.17As infrared detectors have been irradiated with 2 MeV proton with a fluence of 1 × 1015 cm−2. Dark current-voltage characteristics, low frequency noise (LFN) and response spectra were measured before and after irradiation at room temperature (RT) to investigate the irradiation effect. The results showed that dark current and LFN increased after irradiation, and the responsivity decreased. The performance degeneration of detectors is generally related to the defects originated from the displacement effect of irradiation. The analysis of dark current mechanisms indicates that the irradiation mainly results in the increase of shunt component. The degeneration of LFN is attributed to the increase of all noise components, i.e. 1/f noise, g-r noise and white noise. The annealing behaviors of dark currents were observed at RT. The dark currents decreased by about 17% on average by the 19th hour and then hardly recovered by the 225th hour after irradiation. The InGaAs/InAlAs multilayer epitaxial material used to fabricate the detector was also irradiated. The Photoluminescence (PL) measurements at 77 K showed that PL intensity of InGaAs layer decreased much greater than that of InAlAs layer after irradiation.