Effect of surface on the excitonic characteristics of semiconductors

The effect of surface treatments on the main characteristics of excitons in the subsurface region of semiconductors (for GaAs), as well as the spatial distribution of main characteristics of excitons (for CdS), was studied. An analysis of experimental data showed that the deposition of insulator layers with a lower dielectric constant on the surface of the semiconductor resulted in an enhancement of the exciton-phonon interaction and an increase in the exciton binding energy. The appearance of the surface layer with a higher defect concentration increasing after some surface treatments results in the lowering of the exciton binding energy in the subsurface region and also in the weakening of the exciton-phonon interaction.