Excitons and Trions Modified by Interaction with a Two-Dimensional Electron Gas

Abstract

A concept of mixed exciton-trion states is formulated theoretically and proved experimentally for II–VI semiconductor quantum wells with a two-dimensional electron gas. The concept considers the resonances of neutral excitons and charged excitons (trions) as mixed (with each other) via their interaction with free electrons. Reflectivity spectra of modulation-doped ZnSe/(Zn,Mg)(S,Se) and CdTe/(Cd,Mg)Te quantum wells are analyzed. A good qualitative agreement of the experimental results with model calculations is achieved.