Design, Synthesis And Characterization Of Azo-functionalized Heterofluorenes Toward Optical Electric Device Applications

Heterofluorenes are widely used in the field of organic electronics and have achieved much progress,but there are still many problems to be solved and much further work need to do,such as the multi-functionation of heterofluorenes and applications in other areas. This thesis included the research on a serious of heterofluorenes that multi-functionzed by incorporating azo-group into heterofluorene molecules,and how does the molecule structure regulate the properties of materials. The specific contents are summarized as follows:1.We designed and synthesized four kinds of single-azo-functional heterofluorenes and characterized the absorption spectrum of the materials with both solution state and film state, while the electrochemical properties, Thermodynamics properties were studied too. The application in memory device of four kinds materials are also studied. The threshold voltage of devices are 8-10 V, the on/off current ratio is about 104, the type of organic memory device are all WORM. We also studyed the Cis and trans isomers changes of four molecules when they were excited under UV light;2.We introducing Azo group into diphenyl molecule, then use different two hetero atoms substituted reagents to synthesize heterofluorenes. we did a large number of exploration work, we tested different solvents, temperatures and other conditions to synthesize heterofluorenes. We get the important precursor molecule. The computer simulation shows that the material can not only maintains good flatness, but also can extended the π-conjugated structure, and we will obtain the multi-level memory device a if we incorporating these materials into organic memory device;3.We designed and synthesized five kinds of single-azo-functional and double-azo-functional heterofluorenes and characterized the absorption spectrum of the materials with both solution state and film state, while the electrochemical properties were studied too. The application in memory device of four kinds materials are also studied. When without the electron-withdrawing groups in molecule, The threshold voltage of devices are 8-10 V, the on/off current ratios are about 103, after incorporating the electron-withdrawing groups into molecules, The threshold voltage of devices are reduced to 4-6V, the on/off current ratios are about 104,this research shows how does the molecule structure affect the properties of materials and the type of organic memory device are all WORM. We also studied the Cis and trans isomers changes of four molecules when they were excited under UV light.