Markedly Enhanced Performance of Dye Sensitized TiO$_{2}$ Nanoparticle Solar Cells via Rational Surface Treatment

Dye sensitized solar cell (DSSC) was fabricated with the P-25 TiO$_{2}$ nanoparticle film sensitized with N719 dye. TiCl$_{4}$ treatment was found to increase the power conversion efficiency of DSSC. More importantly, subsequent treatment with O$_{2}$ plasma further enhanced the efficiency, while the O$_{2}$ plasma processing of an untreated TiO$_{2}$ photoanode resulted in a lower efficiency. With TiCl$_{4}$ and O$_{2}$ plasma treatments, dye sensitized TiO$_{2}$ nanoparticle solar cell with 21 $\mu $m thick active layer illuminated under 100 mW/cm$^{2}$ exhibited a markedly enhanced power conversion efficiency of 8.35{\%} as compared to 3.86{\%} for untreated cells.