Electronic structure of quantum spheres with wurtzite structure

The hole effective-mass Hamiltonian for the semiconductors with wurtzite st ructure is given. The effective-mass parameters are determined by fitting t he valence-band structure near the top with that calculated by the empirica l pseudopotential method: The energies and corresponding wave functions are calculated with the obtained effective-mass Hamiltonian for the CdSe quant um spheres, and the energies as functions of sphere radius R are given for the zero spin-orbital coupling (SOC) and finite SOC cases. The energies do not vary as 1/R-2 as the general cases, which is caused by the crystal-fiel d splitting energy and the linear terms in the Hamiltonian. It is found tha t the ground state is not the optically active S state for the R smaller th an 30 Angstrom, in agreement with the experimental results and the "dark ex citon'' theory. [S0163-1829(99)01040-1].