Synthesis, characterization and electrochemical properties of a compact titanium dioxide layer

In this paper, we report on the synthesis, characterization, and electrochemical properties of a compact titanium dioxide layer as well as its application in dye-sensitized solar cells (DSCs). The compact TiO2 layer, which was prepared via a facile approach by the hydrolysis of TiCl4 aqueous solution, has been characterized by XRD, SEM, UV-vis absorption spectroscopy, voltammetry, and electrochemical impedance spectroscopy (EIS). Experimental results show that the compact TiO2 layer with the thickness of about 100 nm is composed of anatase-phase nanoparticles with the particle size of 10-15 nm. Impedance measurements display that the compact layer of TiO2 can prevent the back reaction of electrons with triiodide ions under low applied potentials, increase the open circuit voltage (V-oc) and fill factor (FF), and finally improve the conversion efficiency (eta) for the DSCs from 7.5 to 8.1%. (C) 2008 Elsevier Masson SAS. All rights reserved.