AlGaAsSb superlattice buffer layer for p-channel GaSb quantum well on GaAs substrate

Metamorphic Al0.7Ga0.3AsySb1−y buffers on GaAs substrates to reduce defect density in the strained GaSb QW p-channels were developed by employing superlattice (SL) consisting of alternating 10 nm-thick layers with different As-contents. The maximum hole mobility of 1070 cm2/V s was obtained in a sample with As-, Sb-valves toggled, and Al-, Ga-shutters constantly open. The p-channel hole mobility strongly depended on the As average composition in AlGaAsSb SL and the resulting strain in GaSb QW. The integral room temperature photoluminescence (PL) intensity was found to decrease monotonically with increasing of biaxial strain in the GaSb QW p-channel.