VALENCE-BAND PARAMETERS OF WURTZITE MATERIALS

We deduced the valence band parameters of several wurtzite materials ( ZnS, CdS, CdSe, and GaN) by matching the results of existing full-band calculations of the energy spectrum with analytical expressions of th e envelope-function formalism. The calculated A-, B-, and C-type hole dispersion relations show strongly anisotropic characteristics and ant i-crossing features in spectrum due to band mixing effects. We demonst rated that for all materials considered except CdSe, the spherical cub ic approximation for six Luttinger-like parameters holds with good acc uracy, so that the anisotropy arises mainly owing to the crystal field splitting term. Thus, the top valence band may be described with (in addition to crystal held and spin-orbit splitting energies) only two L uttinger-like parameters, gamma(1) and gamma(2). Copyright (C) 1996 Pu blished by Elsevier Science Ltd