Highly Efficient Electrophosphorescence from a Grafted Biscyclometalated Iridium Complex with Triarylamine Unit in Polymer Light-Emitting Devices
ZHU Mei-Xiang1, WU Zhong-Lian1, JIANG Chang-Yun2, LIU Jian1, LI Jian-Ren1, XING Kong-Qiang3, YANG Yu-Ping1, GAN Quan1,
CAO Yong2, ZHU Wei-Guo1
1College of Chemistry, Xiangtan University, Xiangtan 411105
2IPOMD, South China University of Technology, Guangzhou 510640
3Department of Chemistry, Qiongzhou University, Wuzhishan 572200
Highly Efficient Electrophosphorescence from a Grafted Biscyclometalated Iridium Complex with Triarylamine Unit in Polymer Light-Emitting Devices
1College of Chemistry, Xiangtan University, Xiangtan 411105
2IPOMD, South China University of Technology, Guangzhou 510640
3Department of Chemistry, Qiongzhou University, Wuzhishan 572200
Abstract： The electroluminescence performance from a novel grafted cyclometalated iridium complex (BuPhNPPy)$_{2}$Ir(acac) with triarylmine unit, where BuPhNPPy is N,N-di(4-tert-butylphenyl)-4-(2-pyridyl) phenylamine and Hacac is acetylacetone, is demonstrated in the double-layered polymer light-emitting devices (PLEDs). The PLEDs emit intense green phosphorescence at 533nm with a shoulder peak of 566nm employing 4wt.% (BuPhNPPy)2Ir(acac) doped a blend of poly(vinylcarbazole) (PVK) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) as the emitting layer. A maximum luminance of 14610cd/m2 at voltage of 24V and a maximum external quantum efficiency Eext of 10.4% photons per electron (ph/el) at current density of 32mA/cm2 are achieved. When the current density is raised to 100mA/cm2, Eext of the device still remained to 8.3% ph/el. This indicates that the triplet--triplet annihilation is restrained more effectively at high current density. The improvement of electrophosphorescence performances of the iridium complex may be contributed to an ortho-substituent effect of grafted triarylmine unit.
ZHU Mei-Xiang;WU Zhong-Lian;JIANG Chang-Yun;LIU Jian;LI Jian-Ren;XING Kong-Qiang;YANG Yu-Ping;GAN Quan;
CAO Yong;ZHU Wei-Guo. Highly Efficient Electrophosphorescence from a Grafted Biscyclometalated Iridium Complex with Triarylamine Unit in Polymer Light-Emitting Devices[J]. 中国物理快报, 2005, 22(7): 1793-1796.
ZHU Mei-Xiang, WU Zhong-Lian, JIANG Chang-Yun, LIU Jian, LI Jian-Ren, XING Kong-Qiang, YANG Yu-Ping, GAN Quan,
CAO Yong, ZHU Wei-Guo. Highly Efficient Electrophosphorescence from a Grafted Biscyclometalated Iridium Complex with Triarylamine Unit in Polymer Light-Emitting Devices. Chin. Phys. Lett., 2005, 22(7): 1793-1796.
2005, Vol. 22 
