Degradation of minority carrier lifetime and performance of mid-wave infrared GaInAsSbBi <i>n</i>B<i>n</i> photodetectors as a function of 63 MeV proton irradiation

Alloys of GaInAsSbBi are grown by molecular beam epitaxy with various Bi compositions and subjected to a collimated beam of 63 MeV protons. Photoluminescence structures are used to evaluate the material’s minority carrier lifetime damage factor, and nBn structures are produced to investigate the detector’s rate of performance degradation. The lifetime damage factors of the photoluminescence structures containing 0.35% and 0.30% Bi are comparable at 2.4 × 10−6 and 2.2×10−6cm2/p+s, respectively, whereas the Bi-free counterpart sample exhibits a significantly higher lifetime damage factor of 3.8×10−6cm2/p+s. Two mid-wave infrared nBn detectors with 0.30% Bi absorbing regions, exhibiting a cutoff wavelength of 4.8 μm, are characterized in situ between step doses for dark current and quantum efficiency, and the dark-current-limited shot-noise-equivalent irradiance is calculated as a function of proton fluence. The noise-equivalent irradiance damage factor for both nBn structures is found to be 3.6 × 10−2 photons/p+, roughly 2.7× lower than other mid-wave infrared superlattice-based nBn detectors.