High performance nBn detectors based on InGaAsSb bulk materials for short wavelength infrared detection

We report a low dark current, high quantum efficiency nBn photodetectors based on In0.28Ga0.72As0.25Sb0.75 bulk materials with a cut-off wavelength of 3μm at room temperature. Generation-Recombination current was suppressed using an nBn design to shift deplete region from In0.28Ga0.72As0.25Sb0.75 active region into a wide band gap AlGaSb barrier region. The Arrhenius plots of R0A-1/T show that there is no Generation-Recombination current detected in nBn device, whereas pin devices have a Generation-Recombination dominant dark current at temperatures ranging from 160K to 220K. Optical characterizations at 300K show the nBn device using InGaAsSb as an absorption material has a relative high quantum efficiency. The nBn device exhibits a peak specific detectivity of 4.8×1010 Jones under 200mV reverse bias voltage at 300K. The low dark current, high quantum efficiency and band gap tunability are expected to make InGaAsSb bulk material a competitive candidate for short wavelength infrared regime.