Electronic Band Structures of I-III-VI2 Compounds

Abstract

Electronic band structures of CuGaS2 and CuAlS2 are selfconsistently calculated by using the discrete variational Xα method and the results are compared with the optical data. The contents of the valence and core bands are reasonably coincident with the XPS mesurements. The top of the valence bands is an admixture state of Cu3d and S3 p orbitals. The crystal-field splitting of the uppermost valence band is about 0.2 eV. The fundamental energy gaps are direct transitions from \\varGamma4 to \\varGamma1.