Reduced interfacial recombination in dye-sensitized solar cells assisted with NiO:Eu(3+),Tb(3+) coated TiO(2) film

Eu(3+),Tb(3+) doped and undoped NiO films were deposited on TiO(2) by a sol-gel spin-coating method as the photoanodes of dye sensitized solar cells (DSSCs). A comparative study with different structures including TiO(2), TiO(2)/NiO and TiO(2)/NiO:Eu(3+),Tb(3+) as the photoanodes was carried out to illustrate the photovoltaic performance of solar cells. NiO could enhance the performance of DSSCs ascribed to acting as a barrier for the charge recombination from the fluorine doped tin oxide (FTO) to electrolyte and forming a p-n junction (NiO/TiO(2)). Moreover, Eu(3+), Tb(3+) co-doped NiO could accelerate the electron transfer at TiO(2)/dye/electrolyte interface, which further benefited the performance of solar cells. The solar cells assembled with the photoelectrodes consisting of NiO:Eu(3+),Tb(3+) and TiO(2) exhibited short-circuit current density (J(SC)) of 17.4 mA cm(−2), open-circuit voltage (V(OC)) of 780 mV and conversion efficiency of 8.8%, which were higher than that with TiO(2)/NiO and pure TiO(2). The mechanisms of the influence of NiO and NiO:Eu(3+),Tb(3+) on the photovoltaic performance of DSSCs were discussed.