Synthesis And Photoelectrochemical Properties Of Novel Organic Dyes With 4,5,9,10-Tetramethoxypyrene

The development of the economy and the progress of society have brought unfavorable wealth to human development,and they have also had a negative impact on humanity.These negative effects are mainly reflected in environmental pollution and resource depletion.In order to adapt to sustainable development strategies,human beings have to explore new energy sources to replace non-renewable resources.With the gradual deepening of human research,various new energy sources have been developed and utilized successively.Among them,solar energy has become a research hotspot because of its cheap,clean and huge development potential.In the development of solar energy,researchers have designed a new type of device based on the principle of photoelectric conversion,dye-sensitized solar cells(DSSCs).In order to improve the photoelectric conversion efficiency of DSSCs,various types of dye sensitizers have been reported.In this paper,a new pyrene dye,FBD-1,FBD-2,FBD-3 and FBD-4,using acetylene-4,5,9,10-tetramethoxypyrene-phenothiazine as donor,was designed and synthesized according to the related literatures and the basic requirements of dye design.In donors,on the one hand,the introduction of three bonds extends the conjugated structure of FBD series new dyes,on the other hand,because both methoxy and phenothiazine contain electron-rich atoms,the donor's electron-donating ability is improved.The methoxy-modified pyrene can be used as a sensitizing unit better by coupling three bonds with electron-rich groups.In order to evaluate the performance of FBD series dyes,this thesis not only theoretically calculated,but also tested its spectral properties,electrochemical properties and other properties.In addition,we also tested the photovoltaic performance of DSSCs based on dyes FBD-1 and FBD-2.Based on the test results of photovoltaic performance,we found that the performance of FBD-2 is better than that of FBD-1.The main reasons for this result are as follows:First,according to the theoretical calculation results,when the triple bond is located at the 1-position,the charge density of the dye molecule donor moiety is larger,which is beneficial to its charge transfer;secondly,according to the spectral results,the dye molecule with the triple bond at the1-position has a broader absorption spectrum;again,the HOMO level and the LUMO level of the dye molecule at the 1-position are more closely matched with the redox potential of the electrolyte and the conduction band level of the semiconductor.Therefore,under the illumination condition of AM 1.5,the performance of FBD-2 is still relatively good,its short-circuit current density is 11.29 mA/cm~2,the open circuit voltage is 0.90 V,the fill factor is 0.57,and its photoelectric conversion efficiency is as high as 5.74%.