We report on the growth, fabrication and characterization of GaInAsSb <i>p-i-n</i> photodiodes with a high sensitivity in the short-wave infrared. Uniquely these photodiodes are grown on a GaAs substrate using the interfacial misfit array technique, which accommodates the lattice mismatch at an abrupt GaAs/GaSb interface. Top illuminated mesa
photodiodes with varying area were fabricated and characterized at room temperature. A zero bias resistance area
product of 260 Ωcm<sup>2</sup> is measured, together with a responsivity of up to 0.8 AW<sup>-1</sup> without an anti-reflection coating. The D* at zero bias is estimated to be 4.5x10<sup>10</sup> Hz<sup>1/2</sup>W<sup>-1</sup> which is approaching the best results reported for GaInAsSb photodiodes. Hence this work presents a promising alternative to GaInAsSb detectors grown lattice matched on GaSb substrates, strained InGaAs detectors grown on InP substrates or HgCdTe detectors. Making use of cheaper GaAs substrates, available in larger diameters and dry etch chemistry, the GaInAsSb photodiode technology reported here is particularly well placed to support future lower cost, larger area focal plane arrays approaching gigapixel resolution.