Spectral variation of light-emitting diodes based on organic molecules doped polymer

Organic light-emitting diodes based on naphthylimine-gallium complexes doped into a PPV derivative have been fabricated by a spin coating method. Color variation from green to blue with increase of the applied voltage has been observed. And the electroluminescent intensity of the blend samples is much stronger than that of the samples containing the complexes only. The results have been attributed to the variation of the recombination zone and the charge transfer between the materials. The process of the charge transport has been analyzed in detail.