Plasmon-enhanced efficient dye-sensitized solar cells using core-shell-structured β-NaYF4:Yb,Er@SiO2@Au nanocomposites

Core-shell-structured beta-NaYF4:Yb,Er@SiO2@Au nanocomposites have been successfully prepared and applied for the first time as a multifunctional layer on top of a transparent TiO2 layer in dye-sensitized solar cells (DSSCs). Structural characterizations indicate that NaYF4:Yb,Er@SiO2 nanoparticles (NPs) have an average size of 300 nm in length and 230 nm in width. By adding these large dimension NPs as effective light scattering centers and upconversion centers, the performance of DSSCs was enhanced and an energy conversion efficiency of 7.56% was achieved. Furthermore, attachment of similar to 20 nm Au NPs on the surface of NaYF4:Yb,Er@SiO2 NPs could further improve the performance of DSSCs, resulting in an efficiency of 8.23%, which is a noticeable enhancement of 14.78% compared to the cell without the multifunctional layer. Therefore, this work provides an insight into possible further optimization of the efficiency of DSSCs.