Short-wave infrared barriode detectors using InGaAsSb absorption material lattice matched to GaSb

Abstract

Short-wave infrared barriode detectors were grown by molecular beam epitaxy. An absorption layer composition of In 0.28 Ga 0.72 As 0.25 Sb 0.75 allowed for lattice matching to GaSb and cut-off wavelengths of 2.9 μm at 250 K and 3.0 μm at room temperature. Arrhenius plots of the dark current density showed diffusion limited dark currents approaching those expected for optimized HgCdTe-based detectors. Specific detectivity figures of around 7 × 10 10 Jones and 1 × 10 10 Jones were calculated, for 240 K and room temperature, respectively. Significantly, these devices could support focal plane arrays working at higher operating temperatures.