Design,Synthesis,and Photovoltaic Application Of Perylene Imide Electronic Transport Materials

In recent decades,with the rapid development of organic solar cell research,a variety of device materials with excellent performance have been developed,but compared with a large number of excellent hole transport materials,the development of electron transport materials is relatively lagging behind,the research of electron transport materials with excellent photoelectric performance is of great significance.Perylene diimide with good stability,high carrier mobility,large conjugated core and low LUMO energy level have a good foundation in the field of electron transport materials.In this study,to solve the problems of electron transport materials,a series of perylene diimide semiconductor materials were designed,synthesized and applied to organic solar cells.Specific research contents are as follows:(1)Perylene diimide small molecule acceptor material with twisted conjugate near infrared absorption was designed,synthesized and applied to organic solar cells.Triazolindione was introduced to regulate the absorption of perylene diimide molecule on the basis of the design principle of three-dimensional conjugation,and the difference of the properties of two perylene diimide molecules was studied.The absorption,fluorescence,electrochemistry and thermal stability of the two compounds were tested,and they were used as electron acceptors in bulk heterojunction organic solar cells.Both compounds have good solubility,low LUMO energy levels(-3.85 e V and-3.92 e V,respectively),and good stability.When PM6 was used as the donor and Sdi PDI was used as the acceptor,the power conversion efficiency was 4.53%.While PM6 was used as the donor and Bu TADSdi PDI molecule was used as the acceptor,the power conversion efficiency was 1.09%.The introduction of triazolindione made the absorption spectrum of the molecule redshift by nearly 150 nm,which played a good role in regulating the molecular absorption.(2)Halogene-modified perylene diimide cathode interface material was designed,synthesized,and applied to organic solar cells.Perylene tetramethylene anhydride was used as the feedstock to synthesize six low LUMO energy level molecules of alcoholsoluble cathode interlayer through a 6-step reaction of hydrolysis,substitution,bromination,condensation,amidation and ionization.The LUMO energy levels of these molecules(Br PDIN:-3.91 e V,2Br PDIN:-3.85 e V,Br PDIN-Br:-3.98 e V,2Br PDIN-Br:-3.96 e V,Br PDINN:-4.06 e V,2Br PDINN:-3.82 e V)are relatively low.When 6 molecules were used as cathode interface materials for organic solar cells,Br PDINN and 2Br PDINN showed more than 16% power conversion efficiency in organic photovoltaic devices based on PM6:Y6 as active interface layers.