Low-temperature fabrication of flexible TiO2 electrode for dye-sensitized solar cells

A novel method for preparing flexible porous titania electrode from commercial TiO2 particles at low temperature for dyesensitized solar cells (DSSCs) was introduced. In this method, hydroxypropyl methyl cellulose (HPMC) as an additive was added to form a good-quality TiO2/HPMC film on indium-tin- oxide-coated polyethylene naphthalate flexible substrate (PEN/ITO). The additive was subsequently decomposed via the TiO2 photocatalytic degradation process under 365 nm UV-light illumination at room temperature to form flexible multiporous TiO2 electrode film. Electrochemistry impedance spectroscopy (EIS) analysis indicated that the resistance of TiO2 film markedly decreased, and photocurrent-voltage curves showed that the photocurrent dramatically increased when the additive (HPMC) was removed from the flexible titania electrode film. The photocurrent conversion efficiency was estimated at 3.25% under 100 mW/cm 2 illuminations using this flexible film as the DSSC photoanode. [GRAPHICS] Photocurrent versus voltages of the as-prepared flexible DSSCs under AM 1.5 at 100 mW/cm(2) illumination: photoanode made from HPMC-free TiO2 paste (&) and photoanodes made from HPMC/TiO2 paste with UV-light illumination from 0 to 10h. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim