Low-noise photodiodes based on GaSb/GaInAsSb/AlGaAsSb double heterostructures for the 1–4.8 μm spectral range

Photodiode heterostructures n-GaSb/n-GaInAsSb/p-AlGaAsSb with a red cutoff at 4.8 μm are studied. It is shown that making higher the content of In and Al in the narrow-gap and wide-gap layers, respectively, improves the photoelectric parameters of a structure via elimination of the tunnel leakage across the n-GaInAsSb/p-AlGaAsSb junction. A detectivity D λ * = 1.1 × 109 cm Hz1/2 W−1 at room temperature was obtained.