Calculated dispersion of surface excitons

We have calculated the dispersion of surface excitons from the frequency- and wavevector-dependent contribution to the dielectric function ε{lunate}(ω, k) by free excitons. The calculation is based on the surface impedance method by Fuchs and Kliewer. Numerical results are given for the case of CdS. We discuss possibilities for the experimental excitation of surface excitons. © 1975.