Structure des bandes des halogenures de cuivre: CuCl, CuBr et CuI

According to a recent band calculation the highest valence band of CuCl is of 3d of Cu origin. Taking this fact into consideration, the second valence band, of 3p of Cl origin, is regarded as the valence band in comparing the calculated interband energies of CuCl to those of the isoelectronic compounds; Ge-Si, GaP and ZnS. The theory of Herman and Callaway on the interband energies of zinc blend type semi-conductors is shown to apply very satisfactorily to I-VII compounds too. Guided by this agreement with Herman-Callaway's theory the ultra-violet spectra of CuCl, CuBr and CuI are reinterpreted in a coherent way. This is also in satisfactory agreement with the calculated band scheme for CuCl. Band schemes of CuBr and CuI are proposed which are similar to that of CuCl.