Photovoltaic properties of devices using fullerene and copper-phthalocyanine doped with poly(3-hexylthiophène)

We have fabricated organic solar cells, with an active layer of fullerene (C60) and Copper-phthalocyanine (CuPc) doped with poly(3-hexylthiophène) (P3HT) deposited by spin-coating. This layer is sandwiched between the anode, an indium tin oxide film and the C60 layer. We have studied the effect of CuPc doping using P3HT in order to improve the efficiency of the photovoltaic devices. The thin films have been characterized by infrared absorption measurements (I-R), Atomic force microscope (AFM) and ultraviolet/visible spectroscopy in order to study the influence of P3HT doping on the properties of the solar cells. We have also compared the I-V characteristics of two different structures: ITO/PEDOT:PSS/ C60-CuPc/Al and ITO/PEDOT:PSS/ C60-CuPc-P3HT/Al. Both structures show weak but significant photovoltaic behaviour. Indeed, doping CuPc with P3HT improves the efficiencies of the solar cells. We have also seen that the diffusion of species from the indium tin oxide (ITO) anode into the active layer causes a decrease in overall photovoltaic characteristics of C60-CuPc-P3HT based solar cell.