Electronic structure and relative stability of the coherent and semi-coherent HfO2/III-V interfaces

show that interface energy depends sensitively on the type and position of the defects and the atomic structure of the interface. Various coherent interfaces are stable and have band gaps free of defect states in spite of the interfacial structural defects. The semi-coherent interfaces include harmful As dimers and As dangling bonds. If kinetics contributes via the layer by layer oxide growth, the semi-coherent interfaces are formed under the experimentally relevant O-rich growth conditions. This is explained by the basic interfacial structural motifs and the electron counting rule (ECR). An oxidized (3 × 1) substrate has previously been used to decrease interface defect gap state density. A scenario, which explains why the oxidized substrate leads to a relatively small interface defect density, is presented.