High efficiency flexible dye-sensitized solar cells by multiple electrophoretic depositions

A multiple electrophoretic deposition (EPD) of binder-free TiO2 photoanode has been developed to successfully fill the crack occurring after air-drying on the first EPD-TiO2 film surface. With the slow 2nd EPD, high quality TiO2 thin films are acquired on flexible ITO/PEN substrates at room temperature and the device efficiency of the dye-sensitized solar cell achieved 5.54% with a high fill factor of 0.721. Electrochemical impedance spectroscopy measurements analyze the great enhancement of the photovoltaic performance through multiple EPD. The electron diffusion coefficient improved by about 1 order of magnitude in crack-less multiple-EPD TiO2 films. With the scattering layer, the device reveals a high conversion efficiency of up to 6.63% under AM 1.5 G one sun irradiation, having a short circuit current density, open circuit voltage, and filling factor of 12.06 mA cm(-2), 0.763 V and 0.72, respectively. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.