Highly efficient plasmon-enhanced dye-sensitized solar cells through metal@oxide core-shell nanostructure

摘要

We have investigated the effects of localized surface plasmons (LSPs) on the performance of dye-sensitized solar cells (DSSCs). The LSPs from Ag nanoparticles (NPs) increase the absorption of the dye molecules, allowing us to decrease the thickness of photoanodes, which improves electron collection and device performance. The plasmon-enhanced DSSCs became feasible through incorporating core-shell Ag@TiO_2 NPs into conventional TiO _2 photoanodes. The thin shell keeps the photoelectrons from recombining on the surface of metal NPs with dye and electrolyte and improves the stability of metal NPs. With 0.6 wt % Ag@TiO_2 NPs, the power conversion efficiency of DSSCs with thin photoanodes (1.5 μm) increases from 3.1% to 4.4%. Moreover, a small amount of Ag@TiO_2 NPs (0.1 wt %) improves efficiency from 7.8% to 9.0% while decreasing photoanode thickness by 25% for improved electron collection. In addition, plasmon-enhanced DSSCs require 62% less material to maintain the same efficiency as conventional DSSCs.