Study On Print-processable And Long-range Ordered Semiconductor Materials Based On Self-assembled Benzoperylene Imides

Over the past 20 years,the practical needs of solution-processing organic semiconductor materials has given birth to the ideas and goals of using printed electronic technology to manufacture various electronic thin-film devices for reducing processing costs.Although printed electronics has been rapidly developed,the outstanding problem that the printable processing suitability of organic materials and the semiconductor characteristics of the obtained films are difficult to be compatible with each other has not been fundamentally solved,which largely limits the further development of printed electronics.Discotic liquid crystal material with excellent self-assembly properties are considered as one of the potential materials to solve the above compatibility problems.In addition,most of the existing self-assembled long-range ordered semiconductor material systems that can be solution print-processing are hole transport materials such as Hexa-peri-Hexabenzocoronene,it is particularly important to develop electron transport semiconductor materials that can also be print-processable and long-range ordered.The main idea of this study is to design and synthesize a series of novel self-assembled electron transport semiconductor materials based on benzoperylene-imide structure,and its solubility,absorption spectrum,thermal stability,the phase transition behavior,the molecules energy level of the aggregate state,carrier mobility and solution processing capability of thin film have been systematically studied,and the correlation between the above properties and the molecular structure and molecular packing state was explored.It is expected to provide useful ideas and exploration for the development of self-assembled long-range and printable electronic transmission semiconductor materials that can be printable processing.The main contents of the thesis are as follows:1)The synthesis route of the intermediate products of benzo[ghi]perylene and coronene?dibenzoperylene?by dehydrogenate Diels-Alder reactions and the conditions of cycloaddition reactions were studied.The above compounds are obtained by primary cycloaddition and two cycloaddition,respectively.By optimizing the reaction route and conditions,the yield of coronene structure molecules can reach more than 28%.2)The synthesis and molecular properties of a series of N-substituted benzo[ghi]perylenetriimides were studied.Four benzo[ghi]perylenetrimide molecules were synthesized and characterized.The above compounds have very strong self-assembly properties,the thermotropic liquid crystal phase transition behavior of benzo[ghi]perylenetrimides containing long chain branches was confirmed by DSC,POM and XRD.In addition,the LUMO energy level of benzo[ghi]perylenetriimides are about-3.98eV,indicating that it is a new type of electron transport materials.Such compound materials with a long-chain generally have good solubility,can be conveniently prepared into a film by solution processing of an organic electronic ink.3)A series of N-substituted coronenetetraimides compounds with?-branched alkyl long chains were synthesized and their molecular properties were studied.Five N-substituted coronenetetraimides molecules were efficiently synthesized and characterized.The above compounds UV-vis absorption peaks mainly appear at 374 nm and 413 nm in a dichloromethane solution.These coronenetetraimides containing?-branched long chain has a high thermal decomposition temperature,and its thermal phase transition behavior is obtained by DSC and POM tests,and it has been confirmed that it is a kind of material having only solid-liquid phase transition.The HOMO and LUMO energy levels of these compounds are respectively around-6.40 eV and-4.03 eV,which are a class of electron transporting semiconductor materials that are relatively stable in air.All of compounds have very good solubility,and can also be prepared as organic electronic inks.4)The synthesis method and molecular characteristics of a series of N-substituted coronentetraimides compounds containing?-branched alkyl long chains were studied.Five kinds of coronenetetraimides were efficiently synthesized and characterized.The obtained compound molecules have good thermal stability,and the thermotropic liquid crystal phase transition behavior of the coronenetetraimides containing?-branched long chains is obtained by DSC,POM and XRD,indicating a typical hexagonal columnar phase discotic liquid crystal.The carrier mobility of the above liquid crystal compound was tested by time-of-flight,and the electron mobility?_e of the compound was generally in the range of 8.7×10^-3-4.4×10^-2cm²V^-1s^-1.The above compounds are an electron transport type material having stable transmission characteristics in air,because the LUMO energy levels are respectively about-4.2 eV.The obtained compound has very good solubility and can be prepared as an organic electronic ink,and the film obtained by the solution processing has excellent long-range order by heat treatment.