We conducted an extensive study on poly(3-hexylthiophene) (P3HT) in combination with titanium dioxide (TiO(2)) nanorods hybrid material for polymer solar cell applications. The device performance critically depends on the morphology of the hybrid film that will be determined by the molecular weight of P3HT, the solvent type, the hybrid compositions, the surface ligand on the TiO(2) nanorods, film thickness, process conditions, and so on. The current-voltage characteristic of the device fabricated in air has shown a power conversion efficiency of 0.83% under air mass (AM) 1.5 illumination using high molecular weight (65,000 D) P3HT. high boiling point solvent trichlorobenzene, and pyridine-modified TiO(2) nanorods with a film thickness of about 100 nm. The Kelvin probe force microscopy (KPFM) study of hybrid films shows large-scale phase separation with domain size greater than 10 nm, which may be the main factor limiting device performance. (C) 2008 Elsevier B.V. All rights reserved.