Poly(p phenylene vinylene)/porous silicon composites

Composites made by mixing porous silicon grains with poly(p phenylene vinylene) or PPV were studied by optical and electrical characterization. Infrared, UV–vis absorption, Raman and photoluminescence measurements were performed on films with different silicon concentrations and the results were compared to those obtained separately from porous and PPV samples. The optical spectra showed that porous silicon was incorporated into the polymer without significant change in the polymer structure. In contrast, porous silicon was oxidized and aged by the conversion process of the polymer. Light emitting diodes fabricated with the composites have low turn-on voltage as compared to devices using PPV. The improvement was explained by the enhancement of the conductivity and by the increase in the contact area between the film and the electrode due to the change in morphology of the surface of the film.