Preparation of TiO_2 paste using poly(vinylpyrrolidone) for dye sensitized solar cells

摘要

The surface morphology of titanium oxide (TiO_2) films as a photoanode in dye sensitized solar cells plays a vital role in converting light to electricity. Therefore, TiO_2 films were prepared using TiO_2 paste with different compositions of poly(vinylpyrrolidone) (PVP) as a binder to optimize their physico-chemical properties. The paste was prepared with commercial TiO_2 powder mixed with acetylacetone, PVP, 4-octylphenol polyethoxylate, acetic acid and ethanol. The chemical composition remains the same for all pastes except PVP. The quantity of the PVP was optimized in such a way that it provides a thick film with a good network connection. The impact of the quantity of PVP in the TiO_2 paste was analyzed. The prepared TiO_2 film struc ture was characterized by X-ray diffraction. The surface morphology was analyzed by scanning electron mi croscopy. The electrochemical performance of the prepared TiO_2 as a photoanode was also investigated. Among the four different photoanodes, the cells fabricated with a TiO_2 film prepared with 0.4 g of PVP exhibited the highest power conversion efficiency of 6.77%, short-circuit photocurrent density and open cir cuit voltage of 12.38 mA/cm~2 and 0.77 V, respectively.