Aspects of the band structure of CuGaS2and CuGaSe2

Abstract

The spin-orbit splitting has been determined in the sulfur-rich section of the system $\mathrm{CuGa}{\mathrm{S}}_{2-2x}{\mathrm{Se}}_{2x}$, which demonstrates that the spin-orbit splitting is negative in CuGa${\mathrm{S}}_2$. A model which provides adjustable coupling and separation between the $p$- and $d$-like valence band can account for the main features of the band structure of CuGa${\mathrm{S}}_2$ and CuGa${\mathrm{Se}}_2$.