ELECTRIC-FIELD EFFECTS ON HOLE SPECTRA - METHOD FOR STUDYING DYE MATRIX INTERACTIONS IN DOPED POLYMERS

The magnitude of matrix-induced electric dipole moments of centrosymmetric dye molecules increases from the blue to the red edge of the inhomogeneous absorption band in a number of dye-matrix systems. For the polymer polyvinyl butyral doped with a symmetrically substituted zinc tetrabenzoporphyrin this behavior is analyzed with a microscopic stochastic theory of dye-matrix interaction. Moreover, it is shown how electric-field measurements on hole spectra performed at different optical frequencies can be interpreted as a sort of two-dimensional optical spectroscopy. The two frequency scales are given by the inhomogeneous and the homogeneous linewidths. The technique is best suited for investigating amorphous systems, in which the two scales differ most strongly.