Valence Band Offset in AlAs/GaAs Heterojunctions and the Empirical Relation for Band Alignment.

摘要

The valence band offset in AlAs/GaAs heterojunctions is found to be 0.45 + or - 0.05 eV from analysis of charge transfer versus undoped spacer layer thickness. This result and several recent experiments on Al(x)Ga(1-x)As/GaAs heterojunctions indicate that the valence band offset is approximately linear in AlAs fraction x over the entire alloy composition range and more than twice the previously accepted value. The relation between heterojunction band offsets and Fermi level pinning for metals on semiconductors is discussed. Keywords included: Valence band offset, AlGaAs, GaAs, and Heterojunction. (Reprints)