Zinc Porphyrin Sensitized Solar Cell Containing Fluorophenyl/Polypyridine Ruthenium Coordination Group

Dye-sensitized solar cells(DSSC)are easy to manufacture,have low production costs,have relatively high photovoltaic efficiency and good stability,and become a promising cell that can be mass-produced.In DSSC,the sensitizer has the function of light trapping and is an important part of the cell.Among various sensitizers,porphyrin sensitizers have excellent full-color light collection ability,easy modification of the structure,and excellent photoelectric properties,which has attracted wide attention from researchers.First,we have designed and synthesized three kinds of zinc porphyrins ZnFi(i=1-3)containing different numbers of fluorine atoms,which were characterized by¹H NMR,mass spectrometry,and ultraviolet-visible absorption spectroscopy.Density functional theory is used to calculate the stable ground state geometric configuration and frontier molecular orbital of the dye,in order to understand the electron excite and inject process of the dye.The dye is made into a dye-sensitized solar cell device,and its photoelectric performance and electrochemical impedance spectroscopy are tested.We also applied the co-sensitization of three porphyrin dyes and chenodeoxycholic acid(CDCA)to DSSC to study the changes in photoelectric properties.After that,we have designed and synthesized three zinc porphyrins JPx(x=1-3)containing ruthenium complexes,which were characterized by mass spectrometry and ultraviolet-visible absorption spectroscopy.JPx(x=1-3)was co-sensitized with ZnPA or ZnH1 in dye-sensitized solar cells,and different ratios were used.The photoelectric performance and electrochemical impedance test were carried out to explore which ratio of the co-sensitized cell has the best performance.The experimental results show that among the three kinds of zinc porphyrins ZnFi(i=1-3)containing different numbers of fluorine atoms,the porphyrin Zn F1 with less fluorine atoms shows better cell performance.After co-sensitizing the porphyrin dye ZnFi(i=1-3)and CDCA,the photoelectric conversion efficiency of the cell has been improved.The cell based on Zn F1+CDCA shows a maximum efficiency of2.71%and a short-circuit current density of 5.17 m A·cm^-2,the open circuit voltage is0.651 V,and the fill factor is 80.41.The photoelectric performance research results of the three sets of co-sensitized cells based on JP1+ZnPA,JP2+ZnPA and JP3+ZnH1show that the cell performance after co-sensitization is better than that of a single dye-sensitized cell.This is because the two dyes co-adsorbed on the surface of TiO₂can inhibit the recombination of charges on the surface of TiO₂,and accelerate the electron conduction,so that the open circuit voltage and short-circuit current density of the cell are improved.The three groups of sensitized cells have the highest efficiency when the ratio is 0.05:0.15,reaching 3.39%,3.57%and 2.94%respectively.The above results indicate that dye co-sensitization is an effective strategy to improve the photoelectric performance of the cell.