Synthesis, Structure And Properties Of Several Zinc Phthalocyanine Compounds

Dye-sensitized solar cells (DSSC)，which have been emerged as cheap，high-efficiencyand environmental friendly solar cells，have attracted significant attention since1990s. Theheart of DSSC system is a mesoporous oxide layer composed of nanometer-sized particleanchored by a monolayer of the charge transfer dye，Sunlight is harvested by a dye sensitizer,and then photo-excitation of the dye results in the injection of electrons into the conductionband of the oxide．Dye is one of the most important parts for DSSC to ontain high efficiencyand long lifetime．Phthalocyanines are a kind of π electronic delocalization macrocyclic conjugated system,they have excellent chemical, thermal stability, a unique optical, electrical and otherproperties. The structure of phthalocyanines molecule can be modified with substitutes toobtain the performance of different phthalocyanine derivatives. In many areas with potentialapplications, which are widely used in dye sensitized solar cell. Traditional phthalocyanines,less soluble, easy reunion. In order to enhance solubility, reduce the reunion, increases thespectral absorption range, the successful synthesis of six new zinc phthalocyanine-sensitizeddyes, through the introduction of different substituents change the molecular structure, toimprove the optical and electrical properties.Aryloxy and Schiff’s bases， two major categories of the six new zinc phthalocyanineswere synthesized by4-nitro-phthalonitrile,4-amino-Phenol, p-hydroxybenzoic acid,8-hydroxyquinoline, Benzoic aldehyde, p-hydroxybenzaldehyde and zinc acetate in1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) catalyst. Respectively is:2(3)-(4-carboxy-phenoxy)-9(10),16(17),23(24)-tri(isopropoxy) zinc phthalocyanine (IPc)、2(3)-(4-carboxy-phenoxy)-9(10),16(17),23(24)-tri(8-oxy-quinoline) zinc phthalocyanine (QPc)、2(3)-[(bis(4-nitrophenyl)amino)phenoxy]-9(10),16(17),23(24)-tri(8-oxy-quinoline) zinc phthalocyanine (TQPc)、 β-tetra-(benzylidenemino)phthtalocyaninatozinc (BPc)、β-tetra-(4-hydroxy-benzylidenemino)phthtalocyaninatozinc (HPc)、β-tetra-(4-Carboxy-benzy-lidenemino)phthtalocyaninatozinc (CPc)。By IR, UV-visible spectroscopy, elemental analysis and NMR characterization of thestructure of the six complexes. Compares the six kinds of asymmetric zinc phthalocyanines inN,N-dimethyl formamide (DMF) solution and its sensitized TiO2thin films by UV-visiblespectrum; the UV-visible spectroscopy, cyclic voltammetry curves and the differential pulsevoltammetry, determine the six complexes the ground state oxidation potential andexcited-state oxidation potential of the energy level position, and measured by the assemblyof dye-sensitized solar cells (DSSC) photovoltaic performance.The results showed that aryloxy complexes in DMF, UV-visible spectrum of Q with themaximum absorption peak around670-680nm, while schiff’s bases is710nm, the occurrenceof varying degrees of red shift, sensitized TiO2thin films by UV-visible spectral red shift ismore obvious; six kinds of asymmetric zinc phthalocyanine dye sensitizers excited state levelrange from-0.88V to-1.20V, and nanometer TiO2conduction band energy level locationmatch; total photoelectric conversion efficiency of (η) are:0.40%,0.43%,0.51%,0.70%,0.73%,0.98%, and gave a better performance.