Anisotropies of energy bands in GaSe and InSe

Abstract

Energy level diagrams at the Γ point of 2H(β)-GaSe and InSe have been analyzed on the basis of the LCAO-MO scheme with reference to the experimental information obtained from optical absorption and photoemission measurements. The LCAO wavefunctions thus deduced give effective mass values in terms of the k · p perturbation method. The results show that dispersions of the lowest conduction band, the uppermost valence band, and spin-orbit split-off valence bands have in fact three-, one- and two-dimensional features, respectively, near the Γ point, in quantitative agreement with the experimental results of resonant Raman, photoemission and transport phenomena.