Enhanced efficiency of TIO2 photoanodes modified with WO3−x nanomaterials in dye-sensitized solar cells

In the present study, non-stoichiometric tungsten oxide (WO_3-x) nanomaterials synthesized by a modified plasma arc gas condensation technique were added into anatase titanium oxide (a-TiO₂) which was used as photoanode materials in dye-sensitized solar cells (DSSC). The WO_3-x/a-TiO₂ sample was characterized by FESEM, XRD, HRTEM, XPS and UV-visible spectra techniques. The photovoltaic efficiency of the DSSC fabricated by WO_3-x/a-TiO₂ was measured under the simulated solar light system with AM1.5 filter. The results showed the enhanced cell performance by incorporation of WO_3-x and the highest efficiency acquired is 6.16 % for DSSC fabricated by 10wt% WO_3-x/TiO₂ sample. The possible explanation for the efficiency enhancement can be attributed to the additive of WO_3-x nanomaterials to form the defects in the WO_3-x/TiO₂ lattices and the imperfect structures of WO₃, accelerating the electron transport rate.