A highly dense and uniform layer of Au nanoparticles (NPs) on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film has been produced by the pulsed laser deposition (PLD) technique toward the production of an improved efficiency photovoltaic device. The advantage of PLD over other techniques is the easy and precise control of the Au NPs size and spatial distribution, without needing of further NP surface functionalization. The efficiency enhancement factor related to Au NPs doping has been evaluated in a solar cell based on poly-(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) diffused bilayer. The short-circuit current density, J SC, increases by 18 % and the power conversion efficiency by 22 %, respectively, in comparison with an equivalent device without Au NPs. The optical and morphological properties of the Au NPs layer have been …