Electronic Structure of O-D Exciton Ground State in CdSe Nanocrystals

We present results on photoluminescence excitation spectra (PLE) of wurtzite CdSe nanocrystals (NCs) embedded in a glass with effective radii in the range 15–35 A. Information on the near band-gap absorption of an assembly of NCs is obtained by selecting a narrow energy range in the inhomogeneously broadened photoluminescence band. The size and shape dependence of the lowest exciton states are calculated for slightly non-spherical wurtzite NCs. The experimental results are in good agreement with the theoretical predictions when both shape and size dispersions are taken into account.