Improvement of efficiency in solar cells based on vertically grown copper phthalocyanine nanorods

We have fabricated efficient organic photovoltaic cells using copper phthalocyanine (CuPc) nanorods as donor and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) as the acceptor material. Highly dense randomly oriented and vertically aligned nanorods with diameters of about 30–50 nm have been achieved from vacuum-deposited CuPc films by simple surface solvent treatment. X-ray diffraction confirms the polycrystalline nature of the CuPc nanorods. Significantly improved cell performance was observed with the change in shape and orientations of the nanorods. Maximum power conversion efficiency of 2.57% was obtained from the vertically aligned nanorods, which is a result of an increment in the donor–acceptor interface area and efficient photogenerated charge carrier transports.