We fabricated the CuPc and C

60

heterojunction organic photovoltaic devices by vacuum deposition and investigated the effects of CuPc deposition rate on photovoltaic device performance. We found that the photovoltaic devices with high CuPc deposition rate exhibited larger short circuit current and higher power conversion efficiencies. X-ray diffraction and atomic force microscopy studies show that the CuPc thin films with high deposition rates are smooth and amorphous

which may correlated with improvements of the charge transport and exciton diffusion for obtaining higher performance of organic photovoltaic devices.