Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga koen, Kasuga, Fukuoka 816-8580, Japan.
Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsuta Midori-ku, Yokohama 226-8503, Japan.
Sci Rep. 2017 Jan 31;7:41780. doi: 10.1038/srep41780.
Thermally activated delayed fluorescence (TADF) materials emerged as promising light sources in third generation organic light-emitting diodes (OLED). Much effort has been invested for the development of small molecular TADF materials and vacuum process-based efficient TADF-OLEDs. In contrast, a limited number of solution processable high-molecular weight TADF materials toward low cost, large area, and scalable manufacturing of solution processed TADF-OLEDs have been reported so far. In this context, we report benzophenone-core carbazole dendrimers (GnB, n = generation) showing TADF and aggregation-induced emission enhancement (AIEE) properties along with alcohol resistance enabling further solution-based lamination of organic materials. The dendritic structure was found to play an important role for both TADF and AIEE activities in the neat films. By using these multifunctional dendritic emitters as non-doped emissive layers, OLED devices with fully solution processed organic multilayers were successfully fabricated and achieved maximum external quantum efficiency of 5.7%.
热致延迟荧光(TADF)材料作为第三代有机发光二极管(OLED)的有前途的光源而出现。人们投入了大量精力来开发小分子 TADF 材料和基于真空工艺的高效 TADF-OLED。相比之下,迄今为止,仅报道了少数几种可溶液加工的高分子量 TADF 材料,用于低成本、大面积和可扩展的溶液处理 TADF-OLED 的制造。在这种情况下,我们报告了苯甲酮核咔唑树状大分子(GnB,n=代),它们表现出 TADF 和聚集诱导发射增强(AIEE)特性,以及耐醇性,从而能够进一步进行基于溶液的有机材料层压。发现树枝状结构对纯膜中的 TADF 和 AIEE 活性都起着重要作用。通过将这些多功能树枝状发射器用作无掺杂发射层,成功制备了完全通过溶液处理的有机多层 OLED 器件,并实现了 5.7%的最大外量子效率。