Exciton Binding Energies in Cd0.11Zn0.89S/Mg0.22Zn0.78S Quantum Wells Lattice-Matched to GaP Substrates

The exciton binding energy in Cd 0.11 Zn 0.89 S/Mg 0.22 Zn 0.78 S single quantum wells (SQWs) is calculated to study their exciton properties in detail. The heavy-hole exciton binding energy is larger than the light-hole exciton binding energy in narrow wells, because the degree of confinement of heavy-hole excitons is larger than that of light-hole excitons in these SQWs. The heavy- and light-hole exciton binding energies are found to increase owing to the image-charge effect when the well width is less than 5 nm.