Poly(p phenylene vinylene)/porous silicon composites

Composites made by mixing porous silicon grains with poly(p phenylene vinyl ene) or PPV were studied by optical and electrical characterization. Infrar ed, UV-vis absorption, Raman and photoluminescence measurements were perfor med on films with different silicon concentrations and the results were com pared to those obtained separately from porous and PPV samples. The optical spectra showed that porous silicon was incorporated into the polymer witho ut significant change in the polymer structure. In contrast, porous silicon was oxidized and aged by the conversion process of the polymer. Light emit ting diodes fabricated with the composites have low turn-on voltage as comp ared to devices using PPV. The improvement was explained by the enhancement of the conductivity and by the increase in the contact area between the fi lm and the electrode due to the change in morphology of the surface of the film. (C) 2000 Elsevier Science S.A. All rights reserved.