Phosphorescent Blue Organic Light-Emitting Diodes with New Bipolar Host Materials
作者:Eun-Sun Yu、Sung-Hyun Jung、Mi-Young Chae、Woo Sik Jeon、Chandramouli Kulshreshtha、Jung-Soo Park、Jang Hyuk Kwon
DOI:10.1166/jnn.2012.4586
日期:2012.2.1
We report narrow band gap bipolar host materials, CbPr-3 (9,9′-[(3,3′-Biphenyl-3.3′-yl-bipyridine)-1,3-biphenyl]bis-9H-carbazole) and Bim-4 (9,9′-[5-(1-phenyl-1H-benzimadazol-2yl)-1,3-phenylene] bis-9H-carbazole), for blue phosphorescent OLEDs application. These two bipolar hosts have high triplet energy of ≥2.9 eV, capable of reducing the driving voltages and improving efficiencies. Significant low driving voltages of 7.4 and 6.6 V were obtained for CbPr-3 and Bim-4 hosts, compared with 9.0 V of the commonly used host, mCP (1,3-bis(9-carbazolyl)benzene). At a given constant luminance of 1000 cd/m2, the power efficiency of both the bipolar host devices was enhanced by 2.5 times.
我们报告了窄带隙双极宿主材料 CbPr-3(9,9′-[(3,3′-联苯-3.3′-基联吡啶)-1,3-联苯]双-9H-咔唑)和 Bim-4(9,9′-[5-(1-苯基-1H-苯并咪唑-2-基)-1,3-亚苯基]双-9H-咔唑),用于蓝色磷光 OLED。这两种双极宿主具有≥2.9 eV的高三重态能量,能够降低驱动电压并提高效率。与常用宿主 mCP(1,3-双(9-咔唑基)苯)的 9.0 V 电压相比,CbPr-3 和 Bim-4 宿主的驱动电压明显较低,分别为 7.4 和 6.6 V。在给定的 1000 cd/m2 恒定亮度下,两种双极主控器件的功率效率都提高了 2.5 倍。