INTERPLAY OF COULOMB, EXCHANGE, AND SPIN-ORBIT EFFECTS IN SEMICONDUCTOR NANOCRYSTALLITES

Size-selective spectroscopic techniques and a tight-binding calculatio n with restricted configuration interaction have been used to study th e relative effects of Coulomb, exchange, and spin-orbit coupling terms on the size dependence of the lowest optical transitions in CdS nanoc rystallites. Quantitative agreement is obtained for the magnitude of t he corresponding dominant transitions. The nature of the states is ana lyzed on the basis of a simple model. A brief comparison to other semi conductor nanocrystallites like CdSe is finally presented. [S0163-1829 (98)02604-6].