The synthesis and application of TiO2 microspheres as scattering layer in dye-sensitized solar cells

Abstract

Mesoporous TiO2 microspheres have been synthesized via a simple one-plot hydrothermal method and were used as the light scattering layer on top of the P25 TiO2 compact layer to form a double-layer film based photoanode for the dye-sensitized solar cell (DSSC). Characteristics and light scattering properties were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen sorption analysis and ultraviolet–visible spectroscopy. Photovoltaic performance of the fabricated DSSC was also investigated. It showed that photoelectric conversion efficiency of the double-layer film based DSSC was increased to 5.61% compared with single P25 compact layer film based (2.67%) and single TiO2 microspheres layer film based (2.14%) DSSC. Improvement of DSSC performance can be attributed to excellent light scattering capability given by mesoporous TiO2 microspheres. Electrochemical impedance spectra analysis also proved that double-layered structure can result in prolonged exciton lifetime, improved charge collection efficiency and decreased charge recombination.