Optical properties of porous silicon/poly(p phenylene vinylene) devices

Hybrid devices formed by filling porous silicon with poly(p phenylene vinylene) or PPV have been investigated in this work. Analyses of the devices by scanning electron microscopy (SEM), infrared (IR), Raman spectroscopy demonstrated that the porous silicon layer was filled by the polymer with no significant change of the structure of the components. This suggests that there is no interaction between the materials. The photoluminescence (PL) of the devices was investigated at different temperatures (from 11 to 290 K). At low temperature, emission of both materials are observed, that of porous silicon occurs at 398 nm while PPV has two main bands located at 528 and 570 nm. As the temperature increases, the PL intensity of porous silicon decreases and the PPV spectra are blue shifted. The dominant peak of PPV at 515 nm suggests that very thin film has been formed in the pores of porous silicon in agreement with the results obtained by SEM, IR and Raman spectroscopy.