Solution-processable π-conjugated dendrimers with hole-transporting, electroluminescent and fluorescent pattern properties
作者:Zhong'an Li、Zuoquan Jiang、Shanghui Ye、Cathy K. W. Jim、Gui Yu、Yunqi Liu、Jingui Qin、Ben Zhong Tang、Zhen Li
DOI:10.1039/c1jm11176k
日期:——
In this paper, four new Ï-conjugated dendrimers G1 and G2-1âG2-3, constructed by triphenylamine and carbazole moieties, have been successfully prepared via a simple synthetic route. This molecular design imparts the materials with good solution-processability, high thermal and morphological stabilities, and low oxidation potential, all of which are promising properties for optoelectronic materials. The double-layer OLEDs fabricated using these materials through solution processing demonstrate that they can exhibit dual functions, hole-transporting and light-emitting. Devices using G1 or G2-1 as the hole-transporting layer present good stability during the passage of current, with a maximum efficiency of 1.70 and 1.59 cd Aâ1, respectively. Moreover, devices using these dendrimers as the emitting layer show moderate performance, and the device of G2-2 gives a maximum luminance and efficiency of 1190 cd mâ2 and 1.67 cd Aâ1, respectively, thanks to three-dimensional building of the dendritic system, which might suppress the inherent reductive or aggregation-caused quenching that usually happens for triphenylamine/carbazole derivatives to some degree. Also, the photo-cross-linking property of triple bonds enables ready fabrication of highly fluorescent photoresist patterns of these dendrimers.
本文通过简单的合成路线成功制备了由三苯胺和咔唑部分构建的四种新型α-共轭树枝状大分子G1和G2-1~G2-3。这种分子设计赋予材料良好的溶液加工性、高热稳定性和形态稳定性以及低氧化电位,所有这些对于光电材料来说都是有前途的特性。使用这些材料通过溶液加工制造的双层OLED表明它们可以表现出空穴传输和发光的双重功能。采用G1或G2-1作为空穴传输层的器件在电流通过过程中表现出良好的稳定性,最高效率分别为1.70和1.59 cd A·1。此外,使用这些树枝状聚合物作为发光层的器件表现出中等的性能,并且由于三维构建,G2-2的器件的最大亮度和效率分别为1190 cd m-2和1.67 cd A-1。树枝状系统的结构,这可能会在一定程度上抑制三苯胺/咔唑衍生物通常发生的固有还原或聚集引起的猝灭。此外,三键的光交联特性使得可以容易地制造这些树枝状聚合物的高荧光光致抗蚀剂图案。