EXCITON SPECTRA OF AG1-XCUXI SOLID-SOLUTI ONS

The composition dependence of some parameters (spectral position, half width) of the excitonic bands in thin films of gamma-Ag1-xCuxI solid s olutions prepared by vacuum evaporation of AgI:CuI mixture on NaCl cry stal substrates, is studied in the range x = 0 divided-by 0.5. It is f ound that the compositions dependence of the energy of spin-orbital sp litting does not correlate with Chadi's theory, which takes into consi deration the mixing of s - and p - states of conduction and valence zo nes by the aperiodic part of the crystal potential. An anomalous decre ase of the excitonic band halfwidth is observed in the range x = 0 div ided-by 0.25. It is mainly caused by a decrease of the position disord er with an increase of the Cu concentration.