Doping effect on exciton binding energy in semiconductor quantum well

Abstract

By solving the Schrödinger equation and Poisson’s equation self-consistently, we have calculated the electronic structure for Si-doped GaAs/Al[Formula: see text]Ga[Formula: see text]As quantum well system at [Formula: see text] K in the effective mass approximation. We obtain the self-consistent potentials, eigen-envelope functions and the subband energies for different doping concentrations and for different thicknesses of the doping layer. The binding energies of exciton in GaAs/Al[Formula: see text]Ga[Formula: see text]As quantum wells under different doping conditions are calculated by using a variational method. And the variation of the binding energy with the thickness of the doped layer and the doping concentration is analyzed. It is found that at a given doping concentration, with the increase of thickness of the doping layer, the self-consistent potential becomes wider and more shallow, the binding energy of exciton decreases. At a given thickness of the doping layer, with the increase of the doping concentration, the self-consistent potential becomes narrower and deeper, the binding energy of exciton increases.