Fig. 6 also indicates that the addition of benzoic acid to the PL dyes increased the amount of –OH groups and Cdouble bond; length as m-dashO stretching and reduced the amount of C–N stretching. Consequently, the Jsc of the DSSCs with a small pH (more acid) increased sharply. In contrast, the amount of –OH groups and Cdouble bond; length as m-dashO stretching in the dye with pH 3.0 again decreased, which might be due to the destruction of the groups because of the high acidity conditions. The smaller amounts of –OH groups and Cdouble bond; length as m-dashO stretching found in the dyes, the lower Jsc was generated from the DSSCs.