NOVELTY - 5,10,15-20-tetrakis(4-(imidazolyl)benzimidazolyl)porphyrinato Zn(II) complex, is new.    USE - As photosensitizer in preparation of sensitized solar cell electrode (claimed).    ADVANTAGE - Porphyrin is stable and adjustable with the redox potential, has strong absorption at visible light area, can promote sensitized semiconductor material in the visible light range, easy to design and chemical modification and low cost. The porphyrin dye sensitizing the solar battery has photo-electric conversion efficiency of 11%. Compared with multi-pyridine ruthenium complex and other organic dye sensitizer, a porphyrin dye sensitizer photo-electric conversion efficiency is without a comparable initial degree. Therefore the corresponding modified porphyrin compound as the electron donor is artificial light reaction system, and is connected with the electron acceptor, comprising artificial photo-electric conversion system, for searching solar application, and it has important theoretical and practical significance.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for synthesizing the zinc porphyrin comprising heterocyclic ring, involving refluxing the pyrrole and 4-bromobenzaldehyde for 1-3 hours at 80-160 degrees C in mole ratio of 1:0.5 to 1:3 in the mixed solvent of glacial acetic acid and nitrobenzene; cooling into room temperature, agitating for 1-24 hours, filtering, performing column chromatography separation to obtain 4-bromophenyl porphyrin; making the 4-bromophenyl porphyrin and zinc acetate react for 1-8 hours at 40-80 degrees C in mole ratio of 1:1 to 1:10 to obtain 4-bromophenyl zinc porphyrin; under the protection of nitrogen, taking dimethylformamide (DMF) as solvent, taking copper powder as catalyst and taking potassium carbonate to provide the alkaline environment, making 4-bromophenyl zinc porphyrin and benzimidazole or imidazole react for 1-48 hours at 100-180 degrees C in mole ratio of 1:1 to 1:10; and vaporizing the DMF, performing Soxhlet extraction by using trichloromethane, and then drying the organic phase with anhydrous sodium sulfate, subjecting the rough product to silica column separation to obtain the target product, where in the mixed solvent of glacial acetic acid and nitrobenzene, mole ratio of the glacial acetic acid to the nitrobenzene is 1:1 to 1:3; where the dosage of copper powder and potassium carbonate is 1-10 times of mole amount of 4-bromophenyl zinc porphyrin.