Leakage mechanisms and potential performance of molecular-beam epitaxially grown GaInAsSb 2.4   μ m photodiode detectors

We report on the growth, processing, and characterization of uncoated, unpassivated GaInAsSb detector mesa photodiodes with a cutoff wavelength of 2.4 μ m . We find peak room temperature specific detectivity value of 6 × 10 10 cm Hz 1 / 2 / W and maximum zero-bias resistivity of 25 Ω cm 2 . The zero-bias resistivities of mesas with areas ranging from 50 2 μ m 2 to 1 mm 2 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 R 0 A were estimated for GaInAsSb materials and compared to those HgCdTe and InGaAs.