Enhancement of dye-sensitized solar cells using Zr/N-doped TiO2 composites as photoelectrodes

Abstract
In this study, the effect of Zr doping on the performance of dye-sensitized solar cells (DSSCs) based on Zr/N-doped TiO2 photoelectrodes was investigated. Zr/N-doped TiO2 nanoparticles were synthesized with various Zr doping contents using the sol–gel method. The Zr/N-doped TiO2 nanoparticles had high surface areas, uniform particle sizes, and a strong red shift of their absorption into the visible region as compared with P25 nanoparticles. DSSCs fabricated with a 0.01 M Zr/N-doped TiO2 photoelectrode achieved a maximum power conversion efficiency of 12.62% with a short-circuit current (Jsc) of 26.37 mA cm−2, open-circuit voltage (Voc) of 738 mV, and fill factor (FF) of 67.3% after TiCl4 treatment. The increased energy conversion efficiency was attributed to the higher dye loading, reduced charge recombination, and enhanced charge transport.