Highly efficient dye-sensitized solar cells based on metal-free and copper(II) phthalocyanine bearing 2-phenylphenoxy moiety

Novel metal-free and copper (II) phthalocyanines containing tetra-(2-phenyl)phenoxy groups were synthesized and characterized. The applicability of these newly synthesised compounds in dye-sensitized solar cells (DSSCs) as photosensitizers was studied. The effect of sintering temperature of thick TiO₂ film, the sintering temperature was varied from 100 to 500 °C, on solar cells parameters has also been investigated. The measurements of the effect of sintering temperature on their performance indicated that the annealing process gives rise to a significant increase in the short current density and the photoconversion efficiency. Interesting results were obtained in TiO₂ based solar cell sensitized by 1(4),8(11),15(18),22(25)-tetra-([2-phenyl]phenoxy)phthalocyaninatocopper under optimized conditions. The DSSC devices containing this compound exhibited short-circuit current densities of 12.2 mA cm^-2 and solar energy-to-electricity conversion efficiencies of 6.81% under AM 1.5 illumination and 100 mW cm^-2 irradiation.