Electric poling of 4-(dimethylamino)-4'-nitrostilbene in poly(methyl methacrylate) studied by polarized absorption spectroscopy

The inversion symmetry of chromophores doped in thin organic polymer films can be eliminated by electric poling. Polarized absorption spectroscopy (PAS) is used to study the electric poling of a guest-host system of poly(methyl methacrylate) doped with 4-(dimethylamino)-4'-nitrostilbene. Orientational order parameters induced by electric poling are obtained by angle-resolved PAS. The electric field inside the polymer film during poling is estimated from the order parameters obtained. PAS also suggests that there might be another electronic transition in the long wavelength part of the charge-transfer band. The order parameter decay may be fitted by a biexponential function, suggesting two different relaxation mechanisms might exist.