On the origin of carrier localization on two-dimensional GaN substitution layers embedded in GaAs

The electronic properties of a nitrogen atomic layer embedded in GaAs are studied by means of the empirical pseudopotential (EPP) method in a periodic modelling approach. The electronic properties of a nitrogen atomic layer embedded in GaAs are studied by means of the empirical pseudopotential (EPP) method in a periodic modelling approach. They are found to be anomalous, compared with other A(III)–B(V)-semiconductors containing isovalent atomic substitution layers. Namely, the nitrogen layer induces not only one but two localized states in the lower conduction band region of the GaAs host material. It is shown that this anomaly originates from chemical and size effects associated with the nitrogen substitution layer. These theoretical results can be correlated with first experimental investigations on the GaN/GaAs-system.