The effect of light-scattering layer on the performance of dye-sensitized solar cell assembled using TiO2 double-layered films as photoanodes

Abstract

Dye-sensitized solar cells (DSSCs) are fabricated based on double-layered films of TiO2 nanospheres and TiO2 nanorod arrays (NRAs). TiO2 nanospheres, including TiO2 hollow spheres (HSs) and TiO2 solid spheres (SSs), were served as light-scattering layers on TiO2 NRAs as composite photoanodes. The as-prepared TiO2 NRAs, TiO2 HSs and TiO2 SSs have been characterized by field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The photoelectric properties of DSSCs were investigated by UV–vis reflectance spectra, current–voltage curves and electrochemical impedance spectroscopy. Owing to the synergic effects of the TiO2 HSs (SSs) and NRAs, including large specific surface area of HSs (SSs) as light-scattering layer for effective dye adsorption and harvesting light and rapid electron transport in one dimensional TiO2 NRAs, the optimal energy conversion efficiency of DSSCs with as-prepared double-layered films as nanocomposite photoanode (5.40%) were far higher than the ones using single-layered NRAs films (1.56%).