Matching of electronic wavefunctions and envelope functions at GaAs/AlAs interfaces

A method to calculate electronic wavefunctions and energies in AlGaAs heterostructures is developed and applied to some typical configurations. The method is based on the use of empirical pseudopotentials and the applicability of the flat-band approximation. Coupling of Gamma - and X-like conduction-band electrons is explicitly dealt with. Emphasis is put on the precise matching of wavefunctions at interfaces as well as on the connection rules for the related envelope functions. Among other things, the authors do not find evidence for boundary conditions for derivatives of envelope functions involving effective mass ratios.