Low-temperature chemical synthesis of rutile and anatase mixed phase TiO₂nanostructures for DSSCs photoanodes

Wet chemical deposition method by using copper salt doping approach is used to synthesize mixed phase (rutile and anatase) titanium dioxide (TiO₂) nanostructures. Pristine and Cu-doped TiO₂photoanodes are analyzed for their physical properties. The results showed a significant influence of Cu-salt concentration in tuning the TiO₂properties in terms of structural, morphological, porosity, optical and electrochemical properties. The Cu-free TiO₂photoanode is rutile in structure whereas when Cu-doping level is increased, beyond 0.003 M, is transformed to mixed rutile-anatase structure. Presence of copper (Cu) in different weight percentages was confirmed from the surface energy dispersive X-ray analysis. Effect of Cu-doping on the power conversion efficiency of TiO₂-based dye-sensitized solar cells is investigated. At 0.005 M Cu-doping level, both power conversion and incident-photon-to-current-conversion efficiencies of TiO₂electrode are optimal i.e. 3.32% and 46% respectively; consistent to electron life time measurement where with increase in Cu-doping level from 0.001 to 0.005 M an electron life time of TiO₂photoanode is increased from 0.1893 ms to 0.5967 ms.