Enhanced DSSC performance with high surface area thin anatase TiO2 nanoleaves

Thin anatase TiO2 nanoleaves (NLs) with high surface area (∼93 m2/g) are synthesized by hydrothermal route and dye-sensitized solar cells (DSSC) made using such NLs are compared with those made with hydro-thermally synthesized TiO2 nanoparticles and the Degussa P25 powder. The NLs-based DSSCs show increment of 16% and 24% in the total conversion efficiency over the cells made with NPs and P25 respectively. Interestingly, the highest increment in the conversion efficiency (∼35%) is achieved for cells made using a 50:50 (wt/wt) mixture of NLs and NPs. In this case the dye loading is found to be >50% higher than the case of NP films. Moreover the DC resistance of diffusion of I3- in electrolyte (as revealed by the electrochemical impedance spectroscopy) is substantially lower than the NP film case, other cell parameters being nominally comparable.

► High surface area TiO2 Nanoleaves synthesized by hydrothermal method.
► Current-perpendicular-to-plane (CPP) conductivity measurements showed higher conductivity for Nanoleaves.
► Concurrent higher dye loading and improved transport in the specific NL + NP architecture.
► The charge transport properties are revealed by electrochemical impedance spectroscopy.