氟取代联蒽类双极性深蓝光材料的合成及光电性能研究

White organic light-emitting devices (WOLEDs) have received considerable interest due to their potential application in full color displays and solid-state lighting, and to saving a significant amount of energy. However, the highly stable and efficient blue materials always keep as one of the most challenging targets of WOLEDs research compared to red and green materials, and have thus become the bottleneck of commercialization of organic electroluminescent technology, especially the defect of single carrier transport in blue hosts. Fluorinated organic compounds may play a primary role as active materials in organic light-emitting devices because of their optoelectronic and charge transfer properties. Similarly, anthracene derivatives are important building blocks to construct blue luminescent dyes due to their merits such as outstanding photoluminescence and electroluminescence properties. This project proposes to combine the electron-withdrawing fluorine substituent and the attractive anthracene moiety, to discuss the electronic effects and space effects resulting from effects of substitute groups, and to design and synthesize a novel class of excellent bipolar deep-blue emitters based on fluorinated bianthracene derivatives, and to study systematically the effect of different fluorine groups on the thermal stability as well as the charge transporting and luminescent ability of the materials in experiment and theory, especially by density functional theory employing the B3LYP functional, and finally to achieve substantial increase of colour purity and thermal stability of ideal efficient deep-blue organic light-emitting devices. This project has practical significance for the development of highly efficient bipolar deep-blue emitters based on fluorinated organic materials in WOLEDs.

白色有机电致发光器件（WOLEDs）因其在显示和照明领域的潜在应用以及在降低全球能源消耗方面的重要作用，已经成为当前研究的热点。相对于绿光和红光材料，WOLEDs所必需的高性能蓝光材料的开发比较滞后，特别是作为蓝光主体存在单载流子传输的缺陷。因此本项目提出将氟取代有机材料独特的电荷传输特性和光电性能与蒽类材料优异的发光性能相结合，综合考虑分子的几何构型、取代基的电子效应和空间效应等因素，设计并合成出一类具有非给-受体结构的氟取代联蒽类材料，得到双极性电荷传输、发光性能和稳定性均优异的深蓝色发光材料，以制备出高效率和理想色纯度的深蓝色发光器件。并利用密度泛函理论计算和实验测试相结合的方法，系统研究该类材料的分子结构与发光性能、电荷传输性能以及稳定性之间的内在关系，揭示分子结构对材料性能的调控规律。本项目的研究对更好地开发氟取代有机材料在高性能WOLEDs中的应用具有重要的价值和现实意义。

为达到平板显示和固态光源所要求的蓝光色纯度要求（欧洲广播联盟（EBU）制定的蓝光标准为CIE (0.15, 0.06)），人们对高效深蓝色有机电致发光材料和器件进行了大量的研究。但是现有的深蓝色荧光OLED的外量子效率很少超过5%。.本项目基于非给-受体结构设计思想，合成了大量新型氟取代联蒽类深蓝光材料，运用密度泛函理论分析与实验研究相结合的方法，通过改变吸电子基团（氟和三氟甲基）的取代模式，进而调节该类材料的光物理性能、热稳定性、能级和载流子传输性能，得到双极性电荷传输、发光性能和稳定性均优异的深蓝色发光材料和器件。在以氟取代联蒽类材料为发光层的非掺杂器件中实现了高达6.11%的外量子效率，CIE色坐标为(0.15, 0.058)，完全满足EBU蓝光标准。在以氟取代联蒽类材料为掺杂剂的器件中实现了高性能的深蓝光（CIE (0.154 - 0.156, 0.055 - 0.087)），特别是以MBA-(4)-F为发光材料的器件效率高达6.65%，是目前满足EBU蓝光标准中最好的深蓝光器件之一。此外，以氟取代联蒽类材料为主体材料可实现高效稳定的蓝色发光器件（器件效率为5.78 - 9.46%）。因此，这些具有扭曲的分子内电荷转移态的氟取代联蒽类材料可增加荧光电致发光器件的单线态激子比例，从而实现高效率和理想色纯度的深蓝色发光器件。