Wang Hui, Ryu Jeong-Tak, Cao Chao, Shin Younghwan, Kwon Younghwan
College of Information and Communication Engineering, Daegu University, Gyeongsan, Gyeongbuk 712-714, Korea.
J Nanosci Nanotechnol. 2009 Dec;9(12):7240-4. doi: 10.1166/jnn.2009.1642.
Solution-processable carbazole/triarylamine-based polyfluorene (CT-PF) was designed and synthesized by Suzuki coupling reaction. CT-PF was originally designed to have multiple functions at the same polymer backbone; blue emission and large band gap energy by fluorine group as well as good hole transporting property and tunable ionization potential by excellent electron donating triarylamine and carbazole moieties. It was confirmed from TGA measurement that the synthesized CT-PF had thermal stability up to 379 degrees C. The UV-Visible absorption spectra of CT-PF had absorption maxima at 292 nm and 351 nm in dilute solution, and 332 nm and 400 nm in film state, which might be originated from fluorene and arylamine moieties. PL emission maxima were also measured in the blue range at 425 nm in dilute solution and 468 nm in film state. Turn-on voltage of double-layered OLED with CT-PF as HTL was reduced to 7 V, and the luminescence were enhanced up to 1,397 cd/m2 with maximum current efficiency of 0.32 lm/W and power efficiency of 1.1 cd/A, which were over 3 times higher than those of single-layered device without HTL. PhOLED with CT-PF as a host material for Ir(ppy)3 phosphorescent dopant showed bright green emission with CIE color coordinates as (x = 0.31, y = 0.57).
通过铃木偶联反应设计并合成了可溶液加工的咔唑/三芳基胺基聚芴（CT-PF）。CT-PF最初设计为在同一聚合物主链上具有多种功能；通过氟基团实现蓝色发射和大带隙能量，以及通过优异的给电子三芳基胺和咔唑部分实现良好的空穴传输性能和可调电离势。热重分析（TGA）测量证实合成的CT-PF具有高达379℃的热稳定性。CT-PF的紫外-可见吸收光谱在稀溶液中292nm和351nm处有吸收最大值，在薄膜状态下332nm和400nm处有吸收最大值，这可能源于芴和芳胺部分。在稀溶液中425nm和薄膜状态下468nm处的蓝光范围内也测量到了PL发射最大值。以CT-PF作为空穴传输层（HTL）的双层有机发光二极管（OLED）的开启电压降至7V，发光增强至1397cd/m²，最大电流效率为0.32lm/W，功率效率为1.1cd/A，比没有HTL的单层器件高出3倍以上。以CT-PF作为Ir(ppy)3磷光掺杂剂的主体材料的磷光有机发光二极管（PhOLED）发出亮绿色光，CIE色坐标为（x = 0.31，y = 0.57）。
