TiO2 coated SnO2 nanosheet films for dye-sensitized solar cells

TiO₂-coated SnO₂ nanosheet (TiO₂-SnO₂ NS) films about 300 nm in thickness were fabricated on fluorine-doped tin oxide glass by a two-step process with facile solution-grown approach and subsequent hydrolysis of TiCl₄ aqueous solution. The as-prepared TiO₂-SnO₂ NSs were characterized by scanning electron microscopy and X-ray diffraction. The performances of the dye-sensitized solar cells (DSCs) with TiO₂-SnO₂ NSs were analyzed by current-voltage measurements and electrochemical impedance spectroscopy. Experimental results show that the introduction of TiO₂-SnO₂ NSs can provide an efficient electron transition channel along the SnO₂ nanosheets, increase the short current density, and finally improve the conversion efficiency for the DSCs from 4.52 to 5.71%.