Impact of the substrate on the transport parameters of InAs/In$_{\mathrm{1-x}}$Ga$_{\mathrm{x}}$Sb Superlattices

It is shown that n-type InAs/InGaSb superlattices can be electrically isolated from lightly doped n-type GaSb substrates at much higher temperatures than from the more common p-type GaSb substrates without the use of a large bandgap insulating layer. Transport measurements show superlattice conduction up to near room temperature. It is argued that the isolation is due to the n/p/n junction created by the substrate/buffer layer superlattice structure.