Short‐period InAs/GaSb superlattices for mid‐infrared photodetectors

Using a newly developed envelope function approximation model that includes interface effects, several InAs/GaSb type‐II superlattices (SLs) were designed for uncooled mid‐infrared detector applications. The 4 micron cutoff could be achieved with several SL designs. Superlattices with shorter periods have larger intervalence band separations than larger‐ones, which could increase the optical signal and reduce the detector noise, thus making room temperature operation possible. To test these possibilities, several short‐period SLs were grown by molecular‐beam epitaxy and their optical properties with reducing SL period were studied by band‐edge absorption, photoconductivity and photoluminescence measurements. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)