Comparing the emissive dipole orientation of two similar phosphorescent green emitter molecules in highly efficient organic light-emitting diodes

被引：117

作者：

Liehm, Philipp ^{[1
]}

Murawski, Caroline ^{[1
]}

Furno, Mauro ^{[2
]}

Luessem, Bjoern ^{[1
]}

Leo, Karl ^{[1
]}

Gather, Malte C. ^{[1
]}

机构：

[1] Tech Univ Dresden, Inst Angew Photophys, D-01062 Dresden, Germany

[2] Novaled AG, D-01307 Dresden, Germany

来源：

APPLIED PHYSICS LETTERS | 2012年 / 101卷 / 25期

关键词：

Light - Organic light emitting diodes (OLED);

D O I：

10.1063/1.4773188

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We investigate the average orientation of the transition dipole moments of two green phosphorescent emitters Ir(ppy)(3) and Ir(ppy)(2)(acac) embedded in a CBP matrix, using in-situ angle resolved electroluminescence spectroscopy and optical simulations. The dipole orientation of Ir(ppy)(3) is nearly isotropic while 77% of the dipoles are horizontally aligned for Ir(ppy)(2)(acac). Optimized organic light-emitting diodes based on these emitters achieve external quantum efficiencies of 18.3% (Ir(ppy)(3)) and 21.7% (Ir(ppy)(2)(acac)). This difference is partially explained by the different dipole orientations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773188]

引用

页数：4

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