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%. (C) 2011 Elsevier B.V. All rights reserved.