Optimizing the internal electric field distribution of alternating current driven organic light-emitting devices for a reduced operating voltage
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Date
17/02/2014Keywords
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Abstract
The influence of the thickness of the insulating layer and the intrinsic organic layer on the driving voltage of p-i-n based alternating current driven organic light-emitting devices (AC-OLEDs) is investigated. A three-capacitor model is employed to predict the basic behavior of the devices, and good agreement with the experimental values is found. The proposed charge regeneration mechanism based on Zener tunneling is studied in terms of field strength across the intrinsic organic layers. A remarkable consistency between the measured field strength at the onset point of light emission (3-3.1 MV/cm) and the theoretically predicted breakdown field strength of around 3 MV/cm is obtained. The latter value represents the field required for Zener tunneling in wide band gap organic materials according to Fowler-Nordheim theory. AC-OLEDs with optimized thickness of the insulating and intrinsic layers show a reduction in the driving voltage required to reach a luminance of 1000 cd/m2 of up to 23% (8.9 V) and a corresponding 20% increase in luminous efficacy.
Citation
Fröbel , M , Hofmann , S , Leo , K & Gather , M C 2014 , ' Optimizing the internal electric field distribution of alternating current driven organic light-emitting devices for a reduced operating voltage ' , Applied Physics Letters , vol. 104 , no. 7 , 071105 . https://doi.org/10.1063/1.4865928
Publication
Applied Physics Letters
Status
Peer reviewed
ISSN
0003-6951Type
Journal article
Rights
© 2014 AIP Publishing LLC
Description
This work was funded with financial means of the European Social Fund and the Free State of Saxony through the OrthoPhoto project.Collections
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