Tight-binding calculations of image charge effects in colloidal nanoscale platelets of CdSe

摘要

CdSe nanoplatelets show perfectly quantized thicknesses of few monolayers.They present a situation of extreme, yet well defined quantum confinement. Dueto large dielectric contrast between the semiconductor and its ligandenvironment, interaction between carriers and their dielectric images stronglyrenormalize bare single particle states. We discuss the electronic propertiesof this original system in an advanced tight-binding model, and show thatCoulomb interactions, including self-energy corrections and enhancedelectron-hole interaction, lead to exciton binding energies up to severalhundred meVs.