Electrical Characterization of Type II Superlattice Midwave Infrared Photodetectors Irradiated by Protons

This article reports the influence of proton irradiation on the dark current of Ga-free InAs/InAsSb type II superlattice (T2SL) midwave infrared barrier photodetectors, with a cutoff wavelength of 4.8~\mu m at 150 K. The proton irradiation is performed with 60-MeV protons and fluence up to 8~\boldsymbol {\times } 10^{11} H+/cm2 on a T2SL detector kept at its operating temperature (150 K) in a cryostat or at room temperature (300 K). Degradation in dark current is observed under proton irradiation due to displacement damage dose (DDD) effects, with the presence of trap-assisted tunneling (TAT) current at -1 V. Trap carrier density, absorbing layer (AL) doping, and minority carrier lifetime are extracted from the measured J-V characteristics.