Advanced Materials (FRG) 2012-06-05

N-heterocyclic carbazole-based hosts for simplified single-layer phosphorescent OLEDs with high efficiencies.

Zachary M Hudson, Zhibin Wang, Michael G Helander, Zheng-Hong Lu, Suning Wang

Index: Adv. Mater. 24(21) , 2922-8, (2012)

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Abstract

Highly efficient single-layer organic light-emitting diodes (OLEDs) are demonstrated using new N-heterocyclic carbazole-based host materials. Phosphorescent OLEDs with a structure of ITO/MoO(3) /host/host:dopant/host/Cs(2) CO(3) /Al are fabricated in which the new materials act simultaneously as electron-transport, hole-transport, and host layer. Devices with maximum current and external quantum efficiencies of 92.2 cd A(-1) and 26.8% are achieved, the highest reported to date for a single-layer OLED.Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.