A New Unsymmetrical Zinc Phthalocyanine as Photosensitizers for Dye-sensitized Solar Cells

A new unsymmetrical zinc phthalocyanine has been designed and synthesized based on the 'push-pull' and extended pi-conjugation concept for the dye-sensitized solar cells. Three tert-butoxy groups, which act as electron releasing ('push'), enhance the solubility of phthalocyanine in common organic solvents and reduce the aggregation. Hydroxy substituted 9,10-anthraquinones act as electron acceptors ('pull') for the study of photoinduced electron transfer processes as well as grafting onto nanocrystalline TiO2. The new unsymmetrical zinc phthalocyanine was fully characterized by FTIR, UV-vis, H-1 NMR, cyclic voltammetry and differential pulse voltammetry. The new sensitizer was tested in dye-sensitized solar cells, and gave a better performance.