Facile preparation of anatase-stabilised gels using niobium chloride for efficient dye-sensitized solar cells

In this study, we reported a facile straightforward process for the deposition of uniform photoanode electrodes by a novel TiO2 gel for dye-sensitized solar cells (DSSCs) applications. Highly crystalline anatase-TiO2 phase is stabilised by niobium chloride at 500 A degrees C. The electrodes are composed of uniform spherical particles with diameter around 3 A mu m, containing small nanoparticles with the average grain size of 40 nm, deposited by dip coating method. X-ray photoelectron spectroscopy revealed that 0.7 at.% Nb5+ was incorporated into titania crystal lattice and stabilised anatase phase by limiting the transformation from anatase to rutile phase. UV-Visible spectra showed that the stabilised-film had lower band gap energy than that of undoped-TiO2, extending the absorption of TiO2 into visible region. The anatase-stabilised DSSC had higher power conversion efficiency of 7.09 % than that of unstabilised cell (6.21 %) as a result of less recombination, which is demonstrated by electrochemical impedance spectroscopy.