Ag@TiO2 Nanowires-Loaded Dye-Sensitized Solar Cells and Their Effect on the Various Performance Parameters of DSSCs

Abstract

In the search for sustainable alternative energy sources the dye-sensitized solar cell (DSSC) has proven a viable contender in photovoltaics with core advantages of facile and low-cost fabrication; and record cell power conversion efficiency (PCE) between 11–14%. This is competitively low; compared to that of the more common Si-based cells of 14–26%. Plasmonic DSSCs, with the potential of highly concentrating optical energy in cells from the localized surface plasmon resonance effect, were predicted to attain very high PCEs. However, the record plasmonic DSSC PCE is only 10.8%, attributed to, mainly, the secondary effects of plasmonic nanostructures not well understood yet. This study employed Ag@TiO2 plasmonic nanowires (PNWs), a systematic approach, wide-range PNW loadings and extended characterization to study their effects on the performance of DSSCs. They enhanced PCE from 4.63% to 5.03% from a balance of the negative and positive effects of the PNWs; most uniquely via efficient charge transport. The PNWs exhibited electron-sink effect causing upward shift of the TiO2 Fermi level with poor charge injection efficiency, at high concentrations. They improved charge collection and resistance against recombination. These results will serve as valuable guide in the field of plasmonic DSSCs and related fields.