Abstract
The optical properties in the UV-visible region of poly(ethylene oxide) thin films containing 0, 10, 20,40 and 50% by weight Dead Sea salts are reported. The obtained optical results are analyzed in terms of absorption formula for non-crystalline materials. From the optical spectra of the given polymeric system, the absorption coefficients have been calculated at room temperature. The values of the optical band width (EOP) have been obtained from direct allowed transitions in k-space. The width of the tail of localized states in the band gap (AE) was evaluated from Urbach-edges. It was found that both energy quantities (E,,P,) and (AE) vary with the concentration of Dead Sea salts dispersed in the polymer matrix. Furthermore, correlation between the energy gaps and the ac conductivity as a function of salt complex concentration is reported.