Adsorption of 4-tert-Butylpyridine on TiO2 Surface in Dye-Sensitized Solar Cells

4-tert-Butylpyridine (4-TBP) has been widely used as additive in dye-sensitized solar cells (DSC), owing to its improvement of the fill factor and the open circuit voltage of DSC. In this paper, the adsorption of 4-TBP on the rutile TiO2(110) surface in DSC was studied by using the density functional theory at DFT/B3LYP level. By comparing the results with those attained from experiments, it was concluded that the 4-TBP could chemiadsorb on the incompletely covered surface Ti atoms in the electrode. The probable mechanism of compressed recombination by coordinated 4-TBP in DSC was proposed.