Screening of Bound-State Excitons in Modulated Reflectance

Abstract

The influence of free-carrier screening of the Coulomb interaction on bound states of excitons in crystals is investigated. The dependences of the ground-state energy and oscillator strength of the free-carrier concentration are obtained within the effective mass formalism employing a screened Coulomb potential. The results are used to successfully predict CdS modulated reflectance line shapes as a function of free-carrier concentration.