摘要
热活性延迟荧光(TADF)材料具有小的单重态-三重态能级差(?EST),因此三重态激子可以通过反向系间窜越(RISC)转变成单重态激子发光.该类材料能够充分利用电激发下形成的单重态激子和三重态激子,使其器件的内量子效率理论上可以达到100%,媲美磷光材料,远远高于传统荧光材料的25%,成为继有机荧光材料和有机磷光材料之后发展的第3代有机发光材料,近年来受到广泛关注.本文介绍了TADF的机理和材料设计的基本原则,综述了近年来国内外学者在TADF材料的设计合成及其在有机发光二极管(OLED)上应用的研究进展,重点介绍了绿光、蓝光、红光、黄光、白光TADF材料的合成与性能.高效的TADF材料经过缜密设计、精确制备和系统研发,将会陆续进入实际应用并在照明和显示领域发挥重要作用.
Thermally activated delayed fluorescence （TADF） materials possess many advantages, such as the controllable molecular structures, stable performance and low cost. In recent years, it has attracted wide attention in organic light-emitting diodes （OLEDs） field. TADF materials are promising for the next generation of organic light emitters. TADF molecules offer unique optical and electronic properties. Because of small energy gap （AEsT） between the lowest singlet （$1） and triplet （T1） excited states, TADF moleculers have an efficient way to harvest triplet excitons for fluorescence through facilitated reverse inter system crossing （RISC） （Tl^S1）. This approach harvests light from both triplet and singlet excitons, allowing the internal quantum efficiency of the device to reach nearly 100%, which clearly breaks 25% efficiency limitation of fluorescent emitters and is comparable to the rare metal-complex phosphorescence emitters. In this review, the mechanisms and fundamental principles on design strategies of TADF have been presented. The main progresses on the recent development of TADF materials and their applications are briefly reviewed. In particular, we will address the synthsis and applications for OLEDs of the differnet kinds of color TADF materials. We are convinced that, with rationale design, precision preparation, and systematic research and development, various highly efficient TADF materials will soon play an indispensable role in illumination and display device.
出处
《科学通报》
EI
CAS
CSCD
北大核心
2015年第31期2989-3004,共16页
Chinese Science Bulletin
基金
国家自然科学基金(21104002,51221002)
北京市高等学校“青年英才计划”(YETP0491)资助
关键词
电致发光
有机发光二极管
发光材料
热活性延迟荧光
electroluminescence, organic light emitting diodes, luminescent material, thermally activated delayed fluorescence
