INFLUENCE OF SPIN-ORBIT SPLIT-OFF BAND ON OPTICAL-PROPERTIES OF SPHERICAL SEMICONDUCTOR NANOCRYSTALS - THE CASE OF CDTE

The multiband envelope-function formalism, including the effects of fi nite spin-orbit splitting energy Delta, is used to calculate valence-b and confined states in spherical semiconductor nanocrystallites. A com pact analytical formulation of the necessary equations is proposed. In the particular case of CdTe, despite the large value of Delta, the sp lit-off band has a sizeable influence on the fundamental interband tra nsition, which is found dipole-forbidden, by symmetry. This result can not be accounted for by usual models in which the influence of the spl it-off band is a priori neglected, when Delta is large. The consequenc es of basic assumptions on this prediction, which should have importan t consequences on intrinsic luminescence, are discussed.