Effect of electric field on the photoluminescence of polymer-inorganic nanoparticles composites

摘要

We report on the effect of electric field on the photoluminescence, PL, froma composite consisting of a conjugated polymer mixed with zinc oxidenanoparticles. We have found that in the absence of electric field PL emissionfrom the composite film has two maxima in the blue and green-yellow regions.Application of a voltage bias to planar gold electrodes suppresses thegreen-yellow emission and shifts the only PL emission maximum towards the blueregion. Current-voltage characteristics of the polymer-nanoparticles compositeexhibit the non-linear behavior typical of non-homogeneous polymer-inorganicstructures. Generation of excited states in the composite structure implies thepresence of several radiative recombination mechanisms including formation ofpolymer-nanoparticle complexes including exciplex states and charge transferbetween the polymer and nanoparticle that can be controlled by an electricfield.