The fine structure of excitonic levels in CdSe nanocrystals

The fine structure of the exciton ground level in a spherical nanocrystal o f a zincblende or a wurtzite structure semiconductor was calculated with th e inclusion of short- and long-range (nonanalytical), exchange-interaction components. The band-parameter dependence of the long-range exchange-intera ction contribution to the spin Hamiltonian describing the exciton ground-le vel splitting was found. A study was made of the effect exerted on the exci ton-level fine structure by the difference between the background dielectri c permittivities of the nanocrystal and of the dielectric host in which it was grown. (C) 2000 MAIK "Nauka/Interperiodica".