Combination of inorganic semiconductor and conjugated polymer as inorganic-organic hybrid solar cell with supra-hierarchical nano-structure such as interdigitated structure of perpendicularly oriented array of metal oxide and conductive polymer is promissing to improve the solar cell efficiencies. We prepared high aspect ratio cylindrical metal oxides, such as ZnO or TiO₂ nanorod arrays and applied them for polymer solar cells in order to improve the absorption of the solar photons and effective collection of the photogenerated charge carriers. In order to improve the light absorption, we fabricated hybrid solar cells by using metal oxide nanorod arrays modified with some dye-molecules and P3HT/PCBM. For the first stage, ordered bulk heterojunction composed of ZnO nanorod arrays vertically on the substrate and filled with conductive polymer with surface modification of ZnO with N719 was constructed and evaluated the device performance in terms of electron transportation. Modification of the surface of ZnO nanorod arrays with N719 for inorganic-organic hybrid solar cell attained short-circuit current density of 8.89 mA/cm², which is 1.5 times higher than that in the case without the dye and such surface modification resulted 1.7 times enhancement of the power conversion efficiency up to 2.00%. Supra-hierarchical nano-structured cell is also fabricated from molecular assembly of new C₆₀ analogue and dye composite for the efficient exciton splitting and charge transport and by reducing the band gap of the polymer so that a larger fraction of the solar spectrum can be absorbed.