THEORETICAL APPROACH TO DELTA-DOPING OF GAAS WITH IN

A systematic study of the electronic structure at In-delta-doping layers embedded into GaAs or into the well region of AlAs/GaAs quantum wells is presented. The electronic structure is calculated within the framework of a tight-binding scheme using surface Green-function techniques. We describe the Koster-Slater approach to delta-doping and discuss the behavior of deep levels induced near the conduction-band edge for single and double delta-doping of GaAs with In. It is shown that the trends in level position are connected with the quasi-one-dimensional nature of the Green function near the conduction-band edge. In the case in which the delta-doping layer is arranged inside the GaAs well region of an AlAs/GaAs quantum well, it is shown that the level positions are sensitive to the distance between the delta-doping layer and the interfaces but show no dependence on the changed local electronic structure in GaAs.