Facile synthesis of TiO2 hierarchical microspheres assembled by ultrathin nanosheets for dye-sensitized solar cells

• TiO2 hierarchical spheres were prepared via one-pot solvothermal route.
• TiO2 hierarchical spheres based DSSCs shows a conversion efficiency of 5.56%.
• The performance of DSSC is dependence of the thickness of photoanode.

TiO2 hierarchical microspheres assembled by ultrathin nanosheets were prepared via solvothermal route for dye-sensitized solar cells (DSSCs). The performance of cells was investigated by diffuse and reflectance spectra, photocurrent–voltage measurement, incident-photon-to-current conversion efficiency and electrochemical impedance spectra. Photoanodes with different thickness of TiO2 hierarchical spheres were studied, which proves that the photoanode with thickness of 15.9 μm exhibits higher performance (short-circuit current density of 12.36 mA cm−2, open-circuit voltage of 0.73 mV, fill factor of 61.95, and conversion efficiency of 5.56%) than that of P25-based DSSC due to the excellent particle interconnections, low electron recombination and high specific surface area (78 m2 g−1).