Surface plasmon-enhanced dye-sensitized solar cells based on double-layered composite films consisting of TiO2/Ag and TiO2/Au nanoparticles

Abstract

We have fabricated silver and gold colloid particles, and used them to fabricate surface plasmon-enhanced dye-sensitized solar cells (DSSCs) based on N719 dye. N719 dye, which is the most heavily used dye in DSSCs, has two strong visible absorption bands centered at 393 and 533 nm. The localized surface plasmon absorption band of Ag nanoparticles (NPs) was well matched with the higher energy band of N719 dye, while that of Au NPs matched with the lower one. The energy conversion efficiency was significantly improved from the DSSCs based on double-layered composite films; the bottom layer consisted of TiO₂ and Ag NPS, while the top one consisted of TiO₂ and Au NPs. The efficiency was 10.0%, which was almost the same as the highest value reported for the surface plasmon-enhanced DSSCs. The high efficiency might be due to a good energy matching between the extinction bands of Ag and Au NPs and absorption bands of N719 dye.