Calculation of exciton suppression in quantum well filled by 2D electrongas and resultant modification of modulation spectra,

摘要

Abstract: We present an algorithm and results of calculation of the binding energy and the oscillator strength of an exciton in a GaAs/InGaAs/GaAs single strained quantum well taking into account self consistency effects and phase space filling. We assume that the well is placed in a depletion region and the well filling by free carriers is governed by a surface voltage. The wave functions of the charge carriers motion in the direction transverse to the well plane were calculated via self-consistent solution of Schreodinger and Poisson equations. The exciton binding energy, wave functions of in-plane motion and oscillator strength were found by a variational approach. The variational function of the exciton was chosen in the form that explicitly includes the phase space filling. It is found that the dependence of the binding energy and oscillator strength of the exciton versus the surface voltage is not monotonic. This is explained by a competition of the self consistency effects and the phase space filling. !7