电致发光液晶聚合物的合成设计及其偏振发光器件研究

The improvement in brightness, lifetime and quantum efficiency of the LED's is the key for their application. The aim of the present project are: (1) improving the ability of electron transfer of PPV derivatives by introduction of 1,3,4-oxadiazole side group through chemical modification.(2) orienting of PPV polymer backbone by appropriate method in order for its application as backlight of LCD. Several structural different 1,3,4-oxadiazole liquid crystalline compounds were designed and prepared and both nematic and smectic liquid crystalline were found in some of the compounds. PPV derivatives containing 1,3,4-oxadiazole side chains (COPE6) were synthesized and their PL study showed that small red-shift of the emission (8nm) of COPE6 film(564) compared to that in solution（556nm） and this is attributed to the introduction of the large side chains, which decrease the tendency of backbone aggregation. The I-V curves of COPE6 and MEHPPV showed that relatively larger current for the LED based on COPE6 than that of MEHPPV at the same voltage, indicating that the introduction of 1,3,4,-oxadiazole could improve the electron mobility of PPV derivatives. Backbone of COPE6 could be aligned parallel to the mechanical field according to the polarized FTIR spectroscopy study on the oriented COPE6 films.

合成兼有电致发光性、液晶性与电子、空穴传输性的多功能聚合物，弄清分子结构对其液晶性和发光性的影响规律；研究取向结构对电致发光液晶聚合物的载流子迁移率及其偏振电致、光致发光行为影响的微观机制；探索偏振发光二极管的性能优化方案，为发光材料的分子设计提供新的设计思想，为该类材料LCD背照明及信息处理领域的应用提供科学依据。.