The effect of strong localization on the mobility of electrons in modulation-doped inverted structures

Abstract

Modulation‐doped quantum well structures grown by molecular‐beam epitaxy in which the two‐dimensional electron gas samples both interfaces, have been characterized by Hall mobility and Shubnikov–de Haas measurements. In as‐grown and annealed samples the low electron mobility associated with the inverted interface is attributed mainly to localization effects and is not influenced significantly by Si diffusion in these structures. The localization can be reduced by replacing the bulk (Al,Ga)As layers by a short period superlattice of equivalent band gap, resulting in improved mobilities.