Refractive index of doped polymers modified by electrical field

Polymethylmethacrylate (PMMA) and polystyrene (PS) were doped from a solution with 3-(1,2-dimethyl imidazole)-borane dipolar compound to 0-10 wt.%. From the pristine and doped polymers, 200-nm thick films were prepared by spin coating onto a silicon substrate. The film deposition proceeded either without external electrical field or under DC electrical field of 2.5 W cm(-1). Refractive index (n) of the from 200-1100 nm was determined by a refractometer. It was demonstrated that, under the external electrical field, films in spectral region both polymer composites behave differently. While for PS based composite the refractive index increases, for doped polar PMMA, application of an external electrical field results in refractive index declination. (C) 2004 Elsevier B.V. All rights reserved.