Nanosilver-Decorated TiO2 Nanofibers Coated with a SiO2 Layer for Enhanced Light Scattering and Localized Surface Plasmons in Dye-Sensitized Solar Cells

Enhanced harvesting of visible light is vital to the development of highly efficient dye-sensitized solar cells (DSSCs). Nanosilver-decorated TiO2 nanofibers (Ag@TiO2 NFs) were synthesized by depositing chemically reduced Ag ions onto the surface of electrospun TiO2 nanofibers (TiO2 NFs). The prepared Ag@TiO2 NFs were coated with SiO2 (SiO2@Ag@TiO2 NFs) by using PVP as coupling agent for protecting corrosion of Ag nanoparticle by I-/I-3(-) solution. The fabricated SiO2@Ag@TiO2 NFs demonstrated a synergistic effect of light scattering and surface plasmons, leading to an enhanced light absorption. Moreover, an anode consisting of SiO2@Ag@TiO2 NFs incorporating TiO2 nanoparticles (NPs) increased light harvesting without substantially sacrificing dye attachment. The power conversion efficiency increased from 6.8 to 8.7% for a thick film (10 mm), that is, 28%. These results suggest that SiO2@Ag@TiO2 NFs are promising materials for enhanced light absorption in dye-sensitized solar cells.