Effect of size-selective photoetching on the absorption and photoluminescence spectra of CdSe nanoparticles

Abstract

Peculiarities of the absorption and photoluminescence (PL) spectra of colloidal solution of CdSe nanoparticles have been studied in the process of size-selective photoetching. The values of homogeneous broadening and lifetime of resonantly excited exciton states in nanoparticles of definite sizes have been estimated. A model explaining the nature of Stokes shift has been suggested, which takes into account inhomogeneity of energy of the electron-hole pair in the volume of nanoparticle. The Stokes shift values have been determined for different samples. Different changes in the PL spectra observed during the process of photoetching could be caused by the influence of different initial defect structures of the samples.