Haifeng Zhu, Hui Tong, Yongyang Gong, Shiyang Shao, Chunmei Deng, Wang Zhang Yuan and Yongming Zhang
A conjugated polymer based on 9,9′-dioctylfluorene and N-octyl substituted 2,2′-(1,4-phenylene)-bis(benzimidazole) moieties (PFBI8) was synthesized. Its solutions emit blue light efficiently, with the quantum yield up to 99% in chloroform. It is also morphologically and thermally stable, with glass transition temperature and decomposition temperature as high as 103 and 428 °C, respectively. The polymer light-emitting diode using PFBI8 as the active emitting layer exhibits blue emission (448 nm) with the maximum luminance, current efficiency and power efficiency of 1534 cd/m2, 0.67 cd/A, and 0.20 lm/W, respectively.