Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes

	Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes
	Qiao XF ; Tao YT ; Wang QA ; Ma DG ; Yang CL ; Wang LX ; Qin JG ; Wang FS
刊名	journal of applied physics
	2010
卷号	108 期号:3 页码:文献编号：034508
关键词	TRIPHENYLAMINE-BENZIMIDAZOLE DERIVATIVES HOLE-TRANSPORT MATERIALS ELECTROLUMINESCENT DEVICES PHOSPHORESCENT OLEDS ELECTRON-INJECTION LEVEL ALIGNMENT SMALL MOLECULES METAL-OXIDES EFFICIENCY POLYMER
ISSN号	0021-8979
通讯作者	ma dg
中文摘要	highly efficient single-layer organic light-emitting diodes with reduced efficiency roll-off are demonstrated by using a bipolar host material of 2,5-bis(2-(9ii-carbazol-9-yl)phenyl)-1,3,4-oxadiazole (o-czoxd) doped with iridium complexes as the emissive layer. for example, the green single-layer device, employing fac-tris(2-phenylpyridine) iridium ir(ppy)3 as dopant, shows a peak current efficiency of 45.57 cd a(-1), corresponding to external quantum efficiency (eqe) of 12.42%, and still exhibits efficiencies of 45.26 cd a(-1) and 40.42 cd a(-1) at luminance of 1000 and 10 000 cd m(-2), respectively. in addition, the yellow and red single-layer devices, with bis(2-(9,9- diethyl-9h-fluoren-2-yl)-1-phenyl-1h-benzoimidazol-n, c-3) iridium (acetylacetonate) (fbi)(2)ir(acac) and bis(1-phenylisoquinolinolato-c-2, n)iridium(acetylacetonate) (piq)(2)ir(acac) as emitter, also show high eqe of 7.04% and 7.28%, respectively. the transport properties of o-czoxd film are well investigated by current-voltage measurement, from which both hole and electron mobility are determined. it is found that the o-czoxd shows appealing bipolar transport character, which is favor for the balanced charge distribution in the whole doped zone. more importantly, the multifunctional role of hole trapping and electron transporting of the iridium complex in o-czoxd further balances the charge carriers and broadens the recombination zone. as a result, the recombination of electrons and holes is significantly improved and the triplet-triplet annihilation and triplet-polaron quenching processes are effectively suppressed, eventually leading to the high efficiency as well as the reduced efficiency roll-off. (c) 2010 american institute of physics. [doi: 10.1063/1.3457672]
收录类别	SCI收录期刊论文
语种	英语
WOS记录号	WOS:000280941000125
公开日期	2012-04-26
内容类型	期刊论文
源URL	[http://ir.ciac.jl.cn/handle/322003/43516]
专题	长春应用化学研究所_长春应用化学研究所知识产出_期刊论文
推荐引用方式 GB/T 7714	Qiao XF,Tao YT,Wang QA,et al. Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes[J]. journal of applied physics,2010,108(3):文献编号：034508.
APA	Qiao XF.,Tao YT.,Wang QA.,Ma DG.,Yang CL.,...&Wang FS.(2010).Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes.journal of applied physics,108(3),文献编号：034508.
MLA	Qiao XF,et al."Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes".journal of applied physics 108.3(2010):文献编号：034508.