The valence band structure in chalcopyrite Cu(In,Ga)Se-2 films

The structure of the valence band at the Gamma point of the Brillouin zone of Cu(In,Ga)Se-2 films is investigated on the basis of interference spectrophotometry data and an analysis of the structure of edge absorption within the framework of the quasicubic model of valence-band p-d hybridization in chalcopyrite compounds. The fundamental parameters of the quasicubic model associated with splitting of the valence band under the action of the tetragonal lattice field (Delta(cf)), the spin-orbit interaction (Delta(so)), and the degree of adulteration (hybridization) of the upper p-levels of the chalcogen by copper d states in Cu(In,Ga)Se-2 chalcopyrite films are determined. The dependence of the direct allowed transitions E-A, E-B, E-C On the composition of CuInxGa1-xSe2 solid solutions (for 0 less than or equal to x less than or equal to 1) is established. (C) 1997 American Institute of Physics.