Boosting the Efficiency of Dye‐Sensitized Solar Cells by a Multifunctional Composite Photoanode to 14.13

We report a new strategy to fabricate a multifunctional composite photoanode containing TiO2 hollow spheres (TiO2‐HSs), Au nanoparticles (AuNPs) and novel NaYF4 : Yb,Er@NaLuF4 : Eu@SiO2 upconversion nanoparticles (UCNPs). The AuNPs are grown on the photoanode film including TiO2‐HSs and UCNPs by a simple in situ plasmonic treatment. As a result, an impressive power conversion efficiency of 14.13 % is obtained, which is a record for N719 dye‐based dye‐sensitized solar cells, demonstrating great potential for the solar cells toward commercialization. This obvious enhancement is ascribed to a collaborative mechanism of the TiO2‐HSs exhibiting excellent light‐scattering ability, of the UCNPs converting near‐infrared photons into visible photons and of the AuNPs presenting outstanding surface plasmon resonance effect. Notably, a steady‐state experiment further reveals that the champion cell exhibits 95.33 % retainment in efficiency even after 180 h of measurements, showing good device stability. A new strategy to fabricate a multifunctional composite photoanode containing TiO2 hollow spheres, Au nanoparticles and upconversion nanoparticles is presented. A champion power conversion efficiency of 14.13 % is obtained, which is a record for N719 dye‐based dye‐sensitized solar cells.