Enhanced optical absorption of Poly(3-hexylthiophene) films deposited on the gold nanoparticle arrays was investigated. Highly dense arrays of gold nanoparticles were produced using the amphiphilic poly (styrene-block-4-vinylpyridine) diblock copolymer. The local electric field enhancement due to the localized surface plasmon resonance excitation of novel metal nanoparticles can increase the absorption of light from nearby photoactive materials. This result can be applicable to improve the solar harvesting in organic photovoltaics. (C) 2010 Elsevier B.V. All rights reserved.