TiO2 Nanofibers Based Dye-Sensitized Solar Cells

Abstract

Dye sensitized solar cells (DSSCs) are promising photovoltaic devices as they offer advantages such as low cost and easy for fabrication et al. The key part of the original DSSC is a sintered film of nanoparticles which has a large surface area for the absorption of dyes. It has been reported that boundaries of nanoparticles diminish the efficiency of charge transport in the nanoparticle network, and lead to charge–carrier recombination. The one dimensional morphology of the nanofiber is believed to improve electron transport efficiency without sacrificing the high specific surface area for the adsorption of dyes. In this paper, TiO2 nanofibers are used to replace TiO2 nanoparticles in the DSSC. The film of nanofibers was synthesized by electrospinning process and collected on the transparent conductive glass substrate. The precursor used for the electrospinning of the nanofiber consists of titanium (IV) isopropoxide, acetate acid, ethanol and polyvinylpyrrolidone(PVP). After the electrospinning process, nanofibers were pretreated at 120°C for 2 hours and annealed at 500°C in atmosphere for another 2 hours. Then DSSC with the film of TiO2 nanofibers were assembled and characterized through electrical measurements. Open circuit voltage of 0.7V and short circuit current densities of 0.45mA/cm2 were achieved.