Sensitization of various structured polyimides in the wavelength range 400-750 nm has been studied. Injection sensitization with thin films of nanocrystal CdSe, structural-chemical sensitization with active acceptors (flullerenes), as well as spectral sensitization with various dyes have been investigated. It has been concluded that the application of polyimides as a photosensitive medium allows characteristics ofnumerous devices to be improved.

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We report on the investigation of the electrical and optical properties of hybrid active layers for organic devices consisting of a conjugated polymer MEH-PPV mixed with ZnO and Si nanoparticles. The effect of an electric field on the photoluminescence (PL) from a MEH-PPV : ZnO composite film is studied. We have found that in the absence of an electric field PL emission from the MEH-PPV : ZnO composites have two main maxima in the blue–red regions. Three additional minor PL maxima attributed to the exciplex states were found at ∼420–480 nm. Application of a voltage bias to planar electrodes significantly suppresses the blue emission. Generation of excited states in the MEH-PPV : ZnO structures implies the presence of several radiative recombination mechanisms with the formation of polymer–nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticles that can be controlled by an electric field. This effect provides the possibility to tune by an electric field the emission colour of organic light emitting diodes by combining an efficient emission from both organic/inorganic materials involved.

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