Surface-Treated TiO2 Nanoparticles for Dye-Sensitized Solar Cells with Remarkably Enhanced Performance

Dye-sensitized solar cells (DSSCs) were prepared by capitalizing on mesoporous P-25 TiO2 nanoparticle film sensitized with N719 dyes. Subjecting TiO2 nanoparticle films to TiCl4 treatment, the device performance was improved. More importantly, O-2 plasma processing of TiO2 film that was not previously TiCl4-treated resulted in a lower efficiency; by contrast, subsequent O-2 plasma exposure after TiCl4 treatment markedly enhanced the power conversion efficiency, PCE, of DSSCs. Remarkably, with TiCl4 and O-2 plasma treatments dye-sensitized TiO2 nanoparticle solar cells produced with 21 mu m thick TiO2 film illuminated under 100 mW/cm(2) exhibited a PCE as high as 8.35%, twice of untreated cells of 3.86%.