Spin orbital angular momentum coupling effects on the electronic structure of nanocrystalline semiconductor clusters Original Research Article

The effects of crystal structure and spin-orbital angular momentum coupling on spectroscopic transitions in CdS, CdSe, and CdTe semiconductor clusters are investigated using accurate pseudopotentials. These calculations reveal that spin-orbit coupling splits the exciton peak into A, B, and C transitions. The C transitions exhibit much greater blueshift with cluster size than the A and B transitions. Furthermore, the C transitions exhibit stronger quantum confinement effect in zinc-blende than in wurtzite clusters of the same size. The calculated transition energies are in good agreement with the experimental data and spin-orbit coupling is able to reveal many of the trends in the experimental spectral shifts.