Effects of HNO(3) treatment of TiO(2) nanoparticles on the photovoltaic properties of dye-sensitized solar cells

The effects of the nitric acid (HNO(3)) treatment of TiO(2) nanoparticles on the photovoltaic properties of the dye-sensitized solar cell (DSSC) were investigated. The HNO(3) treatment enhanced the dispersion of TiO(2) particles, increased the surface area and porosity of the sintered TiO(2) films, increased the relative proportion of the Ti(3(+ state in the Ti 2p X-ray photoelectron spectroscopy spectrum, significantly increased the amount of adsorbed dye molecules on the TiO(2) electrode, and reduced the charge-transfer resistance at the TiO(2)/dye/electrolyte interface. The short circuit photocurrent density (I(s(c) was increased due to the increased amount of adsorbed dye molecules and the reduced charge-transfer resistance. The HNO(3) pre-treatment of TiO(2) particles improved the overall conversion efficiency of the DSSC by about 14%.