Size dependence of electroluminescence of nanoparticle (rutile-TiO2) dispersed MEH-PPV films

Polymer/nanoparticle composites show the enhanced optical and electronic properties. In this study, poly(2-methoxy-5-ethylhexyloxy-1,4-phenylene vinylene) (MEH-PPV)/rutile-TiO2 composite films were made with various sizes from 7 to 23 nm and their electroluminescent characteristics were investigated, where the device structure of indium tin oxide (ITO)/nanoparticle dispersed MEH-PPV/Alq3/Li:Al was used. It was found that the luminance efficiency increases from 7 to 23 nm. In comparison with single polymer device, the brightness and luminescence efficiency of multi-layer device improved five times under 9 V dc.