Plasmonic metallic nanoparticles are coupled to the organic solar cells to overcome the trade-off between the light absorption and carrier collection. They are usually located inside or outside of the active layers. However, no detailed comparison was reported on the light absorption difference when nanoparticles are located inside or outside of the active layers. In this paper, we compare light-trapping abilities of Ag nanospheres in organic solar cells when they are located inside and outside of the photoactive layer. We show that large-sized nanoparticles are preferred when they are placed outside of the active layer while small-sized nanoparticles are favored in the case of embedding nanoparticles in the homogenous active layer.
Keywords: FDTD; Field enhancement; Nanoparticle; Organic solar cell; Plasmonic; Scattering.