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ine 1 O g taining the nanostructured electron accepting component and the tential for much lower cost because it eliminates the expenses associated with high temperature and vacuum processing. Be-[3] and CVD methods [4]. These methods involve complex mers into a mesoporous, nanostructured oxide semiconductor network [9]. Increasing the growth time leads to the formation of ZnO rod array with large rod diameter, high surface area and small inter-Available online at www.sciencedirect.com 008sides, solution processing is compatible with roll-to-roll pro-cessing of flexible plastic substrates. ZnO nanorods grownelectron-donating organic semiconductor in a “bulk heterojunc-tion ” structure are promising materials for photovoltaic device [1]. Ultra-fast photoinduced charge transfer occurs between the conjugated polymers and the metal oxide semiconductor such as TiO2, or ZnO [2]. However, the overall performance of such devices is still disappointing because of limited charge transport and charge separation efficiency. Zinc oxide (ZnO) is of interest because of its availability of low temperature synthesis, the high electron mobility, and the potential for preparing the ordered nanostruc-ture by the solution process. Solution synthesis offers the po-procedures, sophisticated equipment and high temperature. Recently, O’Brien et al.[5] and Vayssieres [6] reported the low temperature growth of ZnO nanocolumns from aqueous solution. Vertically aligned ZnO nanorods were used to increase the efficiencies of these photovoltaic devices [7,8]. The ordered zinc oxide nanorods acted as electron acceptors and provided the direct path for photogenerated electrons to the collecting electrode. If the electrons diffuse through the film faster than they recombine, the majority of the charge injected into the semiconductor is collected at the transparent conducting elec-trode. Devices were prepared by infiltrating conjugated poly-of the photoluminescence spectra suggests that filling the polymer into the ZnO rod microstructure favors more planar molecular orientations of the conjugated polymers and leads to an increase in the effective conjugation length