Experimental results on single-walled carbon nanotubes (SWCNTs) and nanocomposite materials ITO/SWCNTs/Al, Au/SWCNTs/n-Si/Al, Al/SWCNTs/P3OT/ITO and Au/SWCNTs/P3OT/n-Si/Al, where P3OT is conducting polymer with conjugated bonds poly-3-oxythiophene have been reported. Composite films were obtained by spin-casting from a solution on indium-tin oxide (ITO) and glass substrates and studied using absorption spectroscopy and electrical characterization methods. The carbon nanotubes are photosensitive and all solar cells structures show photovoltaic behavior, with different open circuit voltages. It is proposed that the main reason of photosensitivity is the photoinduced electron transfer at the nanotube/polymer interface. The results show that the composite on SWCNTs base represents a new class of organic semiconducting material that is promising for organic photovoltaic cells.