Anatase-stabilised Al Ti1−O2 photoanodes containing uniform spherical particles for efficient dye-sensitized solar cells

Abstract This paper reports a facile straightforward process for the deposition of uniform photoanode electrodes by a novel Al x Ti 1− x O 2 gel for dye-sensitized solar cells (DSCs) applications. Highly crystalline anatase-TiO 2 phase is stabilised by aluminium chloride at 500 °C. The electrodes are composed of uniform spherical particles with diameter around 3 μm, containing small nanoparticles with the average grain size of 40 nm, deposited by dip coating method. X-ray photoelectron spectroscopy (XPS) reveals that 0.5 at.% Al 3+ was incorporated into titania crystal lattice and stabilised anatase phase by limiting the transformation from anatase to rutile phase. UV–vis spectra show that the stabilised-film has lower band gap energy than that of undoped-TiO 2 , extending the absorption of TiO 2 into visible region. Electrochemical impedance spectroscopy (EIS) demonstrates that the anatase-stabilised DSC enjoys less recombination and internal resistances, improving the photovoltaic performance of the cell. The anatase-stabilised DSC has higher power conversion efficiency of 7.52% than that of unstabilised cell (6.40%).