Upconversion photoluminescence enhancement by Gd-doped NaYF4:Yb,Er@SiO2 nanoparticles and their application in dye-sensitized solar cells

Introducing upconversion nanoparticles (UCNPs) onto photoanode films is an effective way to enhance the photovoltaic performance of dye-sensitized solar cells (DSSCs). In this contribution, the β-NaYGdF4:Yb, Er UCNPs and β-NaYGdF4:Yb,Er@SiO2 nanoparticles (NPs) were prepared by tuning the dopant contents of the Gd ions and the β-NaYGdF4:Yb,Er@SiO2 NPs were applied as an upconverting layer in DSSCs. Upconversion photoluminescence indicates that the UCNPs doped with 5% Gd ions exhibit the strongest green and red fluorescence emissions. Moreover, the DSSCs device incorporating the NPs with 5% Gd ion dopant can achieve an optimal photovoltaic efficiency of 5.89%, which is 20.20% enhancement in comparison to the device without NPs and 16.17% increasement with respect to the device containing β-NaYF4:Yb,Er@SiO2 nanocrystals, thus highlighting the effect of the doping of the Gd ions in nanoparticles on their upconversion photoluminescence and photoelectric performance. Accordingly, the current results offer a feasible strategy for further regulating the photoluminescence property of UCNPs and optimizing the photovoltaic performance of UCNPs-based DSSCs devices. [Display omitted] •Two kinds of Gd-doped nanoparticles are prepared and applied to dye-sensitized solar cells.•The UCNPs doped with 5% Gd ion exhibit the strongest green and red fluorescence emissions.•The DSSCs containing the UCNPs with 5% Gd dopant can achieve a best photovoltaic performance.•The current results offer a feasible strategy for further regulating the upconversion photoluminescence of UCNPs.•This work provides an insight into possible further optimization of the efficiency of UCNPs-based DSSCs.