The fine structure of excitonic levels in CdSe nanocrystals

The fine structure of the exciton ground level in a spherical nanocrystal of a zincblende or a wurtzite structure semiconductor was calculated with the inclusion of short-and long-range (nonanalytical), exchange-interaction components. The band-parameter dependence of the long-range exchange-interaction contribution to the spin Hamiltonian describing the exciton ground-level splitting was found. A study was made of the effect exerted on the exciton-level fine structure by the difference between the background dielectric permittivities of the nanocrystal and of the dielectric host in which it was grown.