Self-consistent calculations of interface states and electronic structure of the (110) interfaces of Ge-GaAs and AlAs-GaAs

Self-consistent pseudopotential techniques, together with a superlattice geometry, are used to investigate the detailed electronic structure of the (110) interfaces of Ge-GaAs and AlAs-GaAs. For Ge-GaAs six types of interface states are found, all lying below the thermal gap. No interface states are found in AlAs-GaAs. For each interface the total charge density, self-consistent potential, projected band structure, and local density of states are presented. The interface states in Ge-GaAs are discussed in detail. We also present results for the conduction- and valence-band discontinuities at these interfaces, discuss superlattice states in AlAs-GaAs, and suggest possible relaxation at the Ge-GaAs (110) interface.