Influence of nanocrystals on the energy levels and luminescent properties of the polymer matrix in conjugated polymer–dielectric nanocomposites

We report results of experimental investigations into the luminescent properties of conjugated polymers in which are embedded dielectric nanocrystals. In poly(p-phenylene vinylene), embedding nanocrystals results in a blue shift and broadening of luminescence spectra with a simultaneous disappearance of its vibronic structure. The same nanocrystals in poly(2-(6-cyano-6′-methylheptyloxy)-1,4-phenylene) cause a red shift and spectral broadening. The results are explained with reference to a model accounting for the change in the polarization component of carrier and exciton energy in the vicinity of nanocrystals. The polymer–dielectric nanocomposites demonstrated increased electroluminescence effectiveness compared with pure polymers.