Study On Electrospun TiO₂for Dye-Sensitized Solar Cells

Dye-sensitized solar cell （DSC） has been regarded as one kind of promising newgeneration solar cells with its low cost, simple fabrication and excellent efficiency.The utilization of1-D semiconductor nanostructures instead of TiO₂nanoparticles isthought to improve its photovoltaic performance as a result of faster electron transfer.Electrospinning is a versatile, convenient and efficient technique for the fabrication of1-D nanostructures. However, the application of electrospun ceramic nanofibers islimited in DSC, due to their poor adhesion on conductive substrates and relativelysmall surface area. The present study aims at solving these two problems and usingelectrospun nanofibers into DSC effectively.P25powder and tetraisopropyl titanate were used for electrospinning TiO₂nanofibers. The influences of solution composition and electrospinning parameters onits microstructures were investigated. Several methods were used to increase thesurface area of final product, such as electrospinning together with P25, posttreatment with P25or tetraisopropyl titanate solution, and use of parallel metal piecesor cylinder as product-collectors.Calcined electrospun TiO₂nanofibers was transferred onto FTO glass, which hadbeen thinly screen-printed with TiO₂nanoparticle paste before. DSC with5.03%energy conversion efficiency was prepared with a thickness of9.7μm. Moreover, TiO₂nanowire/nanoparticle composite anode was obtained by mixing TiO₂noncrystallinepaste with calcined electrospun TiO₂nanofibers. Efficiency of3.27%was achievedwhile the thickness was only2μm. EIS results showed that electron transfer resistancein the TiO₂anode might be decreased as a result of TiO₂nanowire.