Deep-shallow transitions and loss of amphoterism in type-II superlattices

Abstract

The traditional rules of effective-mass theory, that a substitutional dopant is a donor (acceptor) if it lies to the right (left) in the periodic table of the atom it replaces, are shown to be broken often in type-II-misaligned superlattices such as InAs/GaSb. Impurities commonly undergo deep-shallow transitions and transitions to ‘‘false valence,’’ and group-IV substitutional dopants can lose their amphoterism as remote layer thicknesses are varied.