双氮杂环卡宾硼深蓝光中性铱配合物的设计合成及发光性能研究

The development of blue phosphorescent dyes is more fragile than that of red and green phosphorescent dyes, which have been successfully applied in organic light-emitting diode (OLED). The insufficient color purity of previous reported blue phosphorescent dyes hindered OLED applications in the field of lighting and display. This project aims to design and synthesis of a series of highly efficient deep blue-emitting neutral iridium(III) complexes with high-energy compounds as main ligands and bis-heterocyclic carbene borates as ancillary ligands. The influence of ancillary ligand double-heterocyclic carbene borate to the blueshift the iridium(III) complexes will be discussed. The electron deficient boron atoms of ancillary ligands can make iridium(III) complexes keep neutral and increase their volatilities. With these new iridium(III) complexes, blue phosphorescent OLEDs are fabricated. The project will provide theoretical basis for the development of deep-blue phosphorescent materials and electroluminescent devices with high luminous efficiency and excellent color purity.

与成功应用于有机发光二极管(OLED)的红光和绿光磷光染料相比，蓝光磷光染料的发展较为滞后，其主要问题在于其发光色纯度明显不足，严重阻碍了OLED在照明和显示领域的应用。本项目拟以高发光能级的化合物为主配体、以双氮杂环卡宾硼为辅助配体合成系列深蓝中性铱配合物磷光材料，探讨双氮杂环卡宾硼作为辅助配体对调控铱配合物发光蓝移的作用规律。辅助配体中硼原子的缺电子特点可使配合物呈电中性，提高其挥发性，采用真空蒸镀法制备此类新材料的蓝光PhOLED器件。为开发发光效率高、色纯度优异的深蓝光磷光材料及其电致发光器件提供理论依据。

有机发光二极管（OLED）具有自发光、宽视角、对比度高、重量轻、色彩鲜艳、柔性和面发光等优点，被认为新一代的绿色节能显示及照明技术。发光染料是OLED器件的核心，在众多发光染料中，铱配合物因其具有发光效率高、发光寿命短和光色可调等优点而备受关注。然而铱配合物发光染料仍存在着诸如蓝光色纯度不高、器件效率滚降严重、离子型配合物热稳定性差等问题亟待解决。本项目正式基于此系列问题开展研究，其主要成果包括：通过改变配体实现了磷光铱配合物发光颜色由深蓝光到红光的有效调控；通过在配合物中引入载流子传输基团提高了发光器件的发光效率，改善了因发光层载流子传输性能差所导致的效率滚降效应；通过在配合物中引入大位阻的配体提高离子型铱配合物的热稳定性，实现了离子型铱配合物采用蒸镀成膜制备发光器件的可能性；同时，还合成了具有双极传输和热活化延迟荧光（TADF）性能亚铜发光配合物，并获得了优异的器件性能。通过核磁、质谱、元素分析和X-射线单晶衍射等手段对这些发光染料的结构和组成进行了表征，探讨了不同配体对配合物发光性能的影响，并研究了其发光器件的光电性能。本项目的研究，不仅丰富了OLED用发光染料的结构，而且为开发新型高效的发光材料提供了理论基础。