Extended short-wave infrared linear and Geiger mode avalanche photodiodes, based on 6.1 Å materials

Extended short-wave infrared (SWIR) avalanche photodiodes based on III–V quaternary alloys were grown on GaSb. An InGaAsSb absorber allowed for cut-off wavelengths of 2.2 μm and 2.75 μm, at 77 K and 300 K, respectively. A multiplication layer of AlGaAsSb with Al = 0.9 mole fraction was used, a material recently characterized by our group, allowing for a breakdown voltage of less than 15 V. Linear and 2D arrays were fabricated using BCl3 dry and HF wet-chemical etching, and dielectric passivation layers were tested. These results indicate that extended SWIR single photon detectors can be developed.