Design, Synthesis And Properties Of Alternative Copolymers Based On Donor-Accepter Hetero-Junction

Organic electroluminescent materials have attracted much attention in the research of optoelectronic information materials for the various advantages compared with inorganic light-emitting diodes. Polymers with donor and accepter (p-n copolymers) can adjust to charge transfer between the molecules and the optical and electrical properties, these materials may improve the electron and hole injection balance, improve electron and hole transmission performance, control carrier transport properties, which help to improve device performance. Therefore, the materials with donor-accepter were applied in organic optoelectronic devices, such as organic light emitting diodes, organic thin-film transistors, organic photovoltaic cells. In this thesis, based on the previous work mentioned above, a new serious of polymers with donor-accepter were developed. The content of this thesis could be divided into two parts.Part 1:Star-shaped polymers were synthesized and characterized. A series of triphenylamine as the core of the star polymer (TPACzB, TPACzBT) were designed and synthesized by Suzuki coupling reaction. The compounds were examined by UV-visible absorption spectrum, photoluminescent spectrum. Cyclic voltammetry illustrated that HOMO orbital energy, the further LUMO energy level were calculated through that and Optical band gap, which indicated that the compound has good hole injection transport performance. TG and DTA thermal performance curve indicates stable compounds were highly amorphous.Part 2:Star-shaped oligomer was synthesized and characterized. Conjugated oligomers possess regular conjugation lengths and structure, absence of chain defects, and the purification and characterization are easy, which make them more favorable than the conjugated polymer for exploring the relationship between structure and properties. In this part, in order to regulate and improve the input balance of carriers, avoid the formation of excime, a star star-shaped oligomer molecule was designed. As an electron-deficient unit, TBTs was connected to the three-arm of triphenylamine through Suzuki coupling reaction, and the target oligomer molecule was successfully synthesized. And the UV-visible absorption spectrum, photoluminescent spectrum were studied. The electrochemical and thermal performance analysis indicated that the star-shaped copolymer compound possesed the lower band gap and better hole injection transport performance. While the oligomer’s TG and DTA curves illusioned that this material has fine thermal stability.