Abstract

Monodisperse TiO₂ anatase hierarchical microspheres with a diameter of 320-750 nm were produced in a sol-gel synthesis from titanium tetraisopropoxide in ethanol. The nanoporous spheres in the wide diameter range displayed the high abilities of scattering light efficiently from 400 nm to 800 nm and of dye adsorption with large surface area. The films prepared from nanoporous spheres had higher incident monochromatic photo-to-current conversion efficiency (IPCE)L values over the entire wavelength region for dye-sensitized solar cell (DSC) and larger diffusion constants for electrolyte due to larger voids among the spheres, compared to that of the nanoparticles. DSCs based on TiO₂ hierarchical spheres obtained the efficiency of 9.24%, which was enhanced by 20.96% compared to 7.64% of DSC-NP under simulated AM 1.5 sunlight.

© 2013 Optical Society of America