We report on the growth, processing, and characterization of uncoated, unpassivated GaInAsSb detector mesa photodiodes with a cutoff wavelength of 2.4 μm. We find peak room temperature specific detectivity value of 6×1010 cm Hz1/2/W and maximum zero-bias resistivity of 25 Ω cm2. The zero-bias resistivities of mesas with areas ranging from 502 μm2 to 1 mm2 were found to be limited by generation-recombination currents at mesa sidewalls. At low temperatures, devices were limited by Ohmic leakage, which is likely due to the formation of oxides on the sidewalls. After 6 months of aging, Ohmic leakage becomes the limiting factor at room temperature as well. Based on experimentally obtained material parameters in this and other studies, an upper limit D∗ and R0A were estimated for GaInAsSb materials and compared to those HgCdTe and InGaAs.