Energy-band structure of CdTe and Si: a sp3(s∗)2 k.p model

The energy bands of the direct-band-gap semiconductor (CdTe) as well as the indirect-band-gap semiconductor (Si), throughout the entire Brillouin zone, have been obtained by diagonalizing a 24×24 k.p Hamiltonian referred to basis states at k=0. We extend the sp3s∗ basis functions by the inclusion of sV∗ orbitals. We find that the sp3‘d’(s∗)2 k.p model is fairly sufficient to describe the electronic structure of these systems over a wide energy range, obviating the use of any d orbitals. Finally, the comparison with available theoretical results shows that the present model reproduces known results for bulk CdTe and Si, that is, their band structure, including s and p valence bands and the lowest two conduction bands.