Effi ciency of dye sensitized solar cells with various compositions of TiO2 based screen printed photoactive electrodes

Abstract

Abstract The TiO2 electrode has a key role in dye sensitized solar cell (DSSC) technology in the charge generation and charge transportation. The properties of TiO2 layer affect resulting efficiency of DSSC and can be controlled by printing process and chemical composition of printing paste. TiO2 pastes with different compositions of TiO2 nanoparticles, ethanol, ethyl cellulose, water, acetic acid, α-terpineol were prepared and screen printed onto the glass substrate with fluorine doped tin oxide (FTO). The TiO2 pastes for screen printing were characterized by rheological measurements and screen printed TiO2 electrodes by atomic force microscopy and UV-Vis spectroscopy. The photocurrent - voltage characteristics and efficiencies of DSSC were evaluated and compared. All prepared TiO2 pastes were suitable for screen printing with ideal rheological characteristics. The highest efficiency 0.68 % and current density ISC = 1.21 mA/cm2 reached by the DSSC based on TiO2 electrode with thickness 1.5 μm, with amount of absorbed dye 1.1 × 10-8 mol/cm2 and without visible cracks and particles aggregation. This TiO2 electrode was prepared from the paste containing 5.4 wt. % of TiO2, 65.3 wt. % of ethanol, 1.8 wt. % of ethyl cellulose, 23 wt. % of H2O and 4.5 wt. % of CH3COOH.