A triple-functional photoanode for light harvesting enhancement in dye sensitized solar cells

To improve the photoelectric performance of dye sensitized solar cells (DSSCs), graphene oxide (GO), upconversion luminescent material NaYbF4:Ho3+ (UC) and porous hollow titanium dioxide microspheres (PHTS) were synthesized to couple with the commercial P25 for improving the light-harvesting of DSSCs. In the composited nanostructure, the GO reduces the internal charge recombination, while the UC doping broadens the absorption spectral range, both of which were applied to the novel PHTS for improving the dye adsorption capacity and light utilization. The P25, P25/GO, P25/UC/GO, P25/UC/GO + PHTS photoanodes were fabricated and the morphology and photoelectric performance were analyzed respectively. Among them, DSSC using P25/UC/GO + PHTS photoanode showed the best performance with the power conversion efficiency (PCE) reaching as high as 9.41%. [Display omitted] •The NaYbF4:Ho3+ was mixed with commercial P25 to broaden the spectral absorption range.•The porous hollow titanium dioxide microspheres was used as light-scattering layer to improve light and dye adsorption.•Graphene oxide reduced charge recombination rate and improved electron transfer rate in DSSC.•The efficiency P25/UC/GO + PHTS-based DSSC reached as high as 9.41%.