THE EFFECT OF SCREENED COULOMB INTERACTION ON THE OPTICAL PROPERTIES OF EuS/PbS/EuS FINITE CONFINING POTENTIAL QUANTUM WELL

Abstract

We theoretically investigate excitonic effects on the optical properties of quasi-two dimensional realistic EuS/PbS/EuS finite confining potential quantum well. The strong contrast of material parameter’s across the well interfaces and the characteristic band-nonparabolicity effect of lead salt semiconductor are taken into account. In presence of medium polarization a feasibility of the screened Coulomb potential in quantum well is examined and appropriate screening radius is revealed for the first time. The screened binding energy investigated while a variational approach has been used. Depend on the realistic nanostructure specifics a monotonic decrease of the enhanced binding energy is received when in-plane carrier density/temperature ratio parameter increases. Exciton absorption spectra near the band edge within the effective-mass approximation is examined. Coulomb potential having a cutoff type is used, that efficiently represented the potential in the realistic quantum well. Screened exciton factor, which is the absorption intensity enhancement of the unbound (continuum) exciton states that are located above the band edge, is used. Plot of the dependence of the exciton factor on the exciton pair energy is given.