Improved photovoltaic performance of hybrid solar cells based on silicon nanowire and P3HT

The properties of organic/inorganic poly(3-hexylthiophene) (P3HT): silicon nanowires nanocomposite films and nanocomposite based solar cells as a function of SiNWs concentration and the solvent used for the film fabrication were studied. We demonstrate that the performance of these devices is highly dependent on these parameters. A detailed study of the effects that active layer thickness has on the photovoltaic performances has also been performed for bulk heterojunction hybrid solar cells. Photoluminescence spectroscopy (PL) shows the existence of a critical SiNWs concentration of about 15 wt% for PL quenching corresponding to the most efficient charge pair separation. Photoluminescence responses were correlated with the topography (AFM) of the thin films. The photovoltaic effect of ITO/PEDOT:PSS/SiNWs:P3HT/Al was studied by current-voltage (I-V) measurements under illumination and interpreted on the basis of the charge transfer differences resulting from the morphologies. By optimizing all the physical parameters listed above we fabricated devices with PCE of 0.08%, which is the highest efficiency reported so far for this system.