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 mu m and 2.75 mu m, 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. (C) 2019 Author(s).