Application And Theoretical Study On Novel Self-Assembled Coordination Porphyrins In Dye-Sensitized Solar Cells

It is necessary to study renewable energy,as the demand for energy is increasing,non-renewable energy is constantly used,non-renewable energy has an adverse impact on the environment all over the world.The dye-sensitized solar cell has become a promising mass-produced battery in the future because of its low price,simple manufacturing process and stable battery performance.Sensitizers are an important part of dye-sensitized solar cells.Among various sensitizers,porphyrins have become a research hotspot because of their strong absorption in the visible region and easy modification of structures.In this paper,we synthesized the antenna molecules ZnPi?i=1-3?,ZnPMnx?x=1-4?,anchoring molecule ZnPA,and axially coordinating self-assembled porphyrins ZnPi-ZnPA?i=1-3?,ZnPMnx-ZnPA?x=1-4?were completed during cell preparation,and these self-assembled porphyrins were bonded to titanium dioxide to make solar cells to study their photoelectric properties.Their photoelectric behavior was also studied theoretically by density functional theory.We used nuclear magnetic,mass spectrometry and other characterization methods to characterize the synthesized molecules.UV-visible absorption spectroscopy and impedance technique were used to study the factors affecting the cell performances on the aspects of optics and electrochemistry.The stable ground state geometry,frontier molecular orbital and UV-visible absorption spectroscopy of sensitizers were studied by density functional theory.The photoelectron excitation and electron injection process of sensitizers were deeply understood.The results show that the self-assembled porphyrin-sensitized cell has better ability to capture sunlight,relatively larger absorption range,and higher J_SC,which lead to higher efficiency of self-assembled porphyrin-sensitized cell comparing with monomer-anchored molecule ZnPA-sensitized solar cell.However,compared with the monomeric porphyrin-sensitized solar cell,the V_OC of the self-assembled porphyrin-sensitized cell is lower,because the self-assembled porphyrin increases the charge recombination on the electrode surface and the titanium dioxide conduction band energy level decreases.In ZnPi-ZnPA?i=1-3?sensitized cells,the cell efficiency of ZnP3-ZnPA is higher.Among ZnPMnx-ZnPA?x=1-4?sensitized cells,ZnPMn2-ZnPA has a higher battery efficiency.These mean that the trifluoromethyl substituent in the antenna porphyrins of ZnP3,ZnPMn2 is more suitable group.