Efficient carbon-doped nanostructured TiO2 (anatase) film for photoelectrochemical solar cells

In this paper, we have demonstrated that carbon-doped nanostructured TiO 2 (CD ns-TiO 2 ) films could be prepared simply and cheaply with oxalic acid and tetrabutylammonium bromide (Bu 4 N·Br) as the carbon sources. The surface morphology of the films was a multiple-porous network structure.The average size of nanoparticle was about 40 nm. Carbon doped into substitutional sites of TiO 2 has also proven to be indispensable for band-gap narrowing and photovoltaic effect. Carbon doping lowered the band gap of n-TiO 2 to 1.98, 1.64, and 1.26 eV. The CD ns-TiO 2 film was first used as photoanode for solar cells, exhibiting high photocurrent densities (l.34 mA/cm 2 ) and yielding an overall conversion efficiency ( η ) of 4.42 %.