三苯胺-芴类共聚物的合成及发光性能

Synthesis and Luminescencent Properties of TPA-Fluorene Copolymers

在主链上嵌入三苯胺基团来改善聚芴的空穴传输能力、平衡载流子的注入是目前改善聚芴材料发光效率的一种好方法。本文用 Suzuki缩聚法合成了芴 -三苯胺类共聚物。实验结果表明 ,在聚芴主链上引入少量的 TPA(10 %～ 2 0 % )时 ,不仅提高了 EL效率 ,而且可以改善光谱的色纯度。TPA含量为 2 0 %时 ,共聚物的 EL效率为 1.2 8%。

A series of high molecular weight, readily soluble copolymers of 9,9-di-2-ethylhexylfluorene with triphenylamine (TPA) (less than or equal to 50(mol)%) are synthesized by Suzuki polycondensation. The introduction of TPA unit into polyfluorene backbone improves the hole transfer ability and depresses the excimer formation. Narrow blue EL emission is obtained for copolymer with TPA content of 20(mol)%. External quantum efficiency is moderately high (1 28%) for such a blue emitter. The threshold voltages of devices from copolymers with TPA content of less than 20(mol)% are low in the range of 4～5V based on the device configuration: ITO/PEDOT/polymer/Ba/Al. The results indicate that fluorene-co-triphenylamine copolymers are promising blue-emitting electroluminescent materials.