Effect of constant electric field on electronic absorption spectra of dye-doped amorphous polymer films

Abstract

The change of an electronic absorption coefficient of polymer films, doped by symmetric cationic polymethine dye is researched in an external constant electric field. This effect are characterised by an increase of intensity on the shortwave edge of a band and its decrease at the longwave edge. The charge distribution in dye cation in the model electric field 10⁷-10⁸ V/m of point charges and capacitor was calculated by the method AM1. Based on quantum chemical calculations, the spectral regularities in the electric field is interpreted by a change of the electronic charge value on the cation. The theoretical model based on changes of the value of eigenfrequencies inherent to charged anharmonic oscillators under the operation field is offered for the description of observed effects. The experimental spectra correlate well with those calculated theoretically.