Carbazole-containing polyphenylquinolines as a basis for optoelectronic materials with white luminescence

The photophysical properties of poly-2,2'-(1-dodecyl carbazole-4,7-yl)-6,6'-(oxy)-bis-(4-phenylquinoline) in a solution, as a film, and in a poly(methyl methacrylate) or poly-N-vinylcarbazole host matrix have been studied. Considerable positive solvatochromism in the photoluminescence spectra, compared with solvatochromism in the absorption spectra, indicates that the dipole moment of the donor-acceptor complex increases in the excited state. Calculations show that the dipole moments of the complex in the ground and excited states differ by more than an order of magnitude. Upon transition to films, photoluminescence is observed in the entire visible spectral range (white luminescence). The intensity of the white luminescence grows by an order of magnitude when the polymer is dispersed in a poly(methyl methacrylate) matrix. The integrated photosensitivity and parameters of the photogeneration process (quantum yield of carrier photogeneration, quantum yield of free carrier formation, and thermalization radii) have been determined.