Design And Synthesis Of New Pyrene-based Organic Semiconductors

Organic semiconductors have attracted considerable academic and commercial interest in recent years for their potential in constructing low cost,stretchable and solution processed large-area electronics.It can be used flexible active displays,rf-ID tags,smart cards,and logic circuits flat panel displays,organic light-emitting displays(OLED),memory components,solar cell,OFET and so on.Great numbers of excellent p-type organic semiconductor materials have been obtained and applied in organic electronic devices.Many reports have illustrated the characteristics of OFETs using pentacene,a well-known material,as the p-type organic transistor.In general,the development of n-type organic semiconductors has largely lagged behind the p-type counterparts,which has limited the development of practical organic electronicsHere,pyrene consists of four-ring-fused planar electron-enriched skeleton,which is well-known for high photoluminescence efficiency,and cheaper price.So we choose pyrene as the skeleton,through the chemical modification to change the compounds' energy level and photo electricity character.1.A series of new t-PyDI derivatives were synthesized by introducing different electron-withdrawing groups into the N-position of 2,7-ditert-butyl-4,5,9,10-phthalimide(t-PyDI).And we studied its optical and electrical properties systematically.We used electrochemistry,Z-Scan and other methods to characterize and explore the photoelectric properties.The morphology and crystal packing of the thin films were investigated by GI-XRD,XRD and SEM.We will explore the electron-withdrawing groups how to influence on the energy levels and band gaps of the main skeleton.At the same time,the effects of the functional side-chain groups on the fluorescence,phosphorescence,molecular morphology,and solid accumulation of the molecules were also examined.We also fabricated bottom-gate top-contact transistor device.2.We have synthesized a series of symmetrical and asymmetric PyDI-imidazoles,with introducing the imidazole groups into the compounds of 2,7-di-tert-butyl-4,5,9,10-pyrene tetracarboxylic acid dianhydride.The electronic structures of the obtained molecules were investigated by means of UV-visible spectroscopy and theoretical calculations.The data shows that the introduction of imidazole structure can increase the conjugation system of PyDI-imidazoles derivatives and reduce the band gap of the system,providing ideas for the further design of new organic semiconductor materials.