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Title: Influence of PEDOT:PSS on the effectiveness of barrier layers prepared by atomic layer deposition in organic light emitting diodes

Organic light emitting diodes (OLEDs) are well suited for energy saving lighting applications, especially when thinking about highly flexible and large area devices. In order to avoid the degradation of the organic components by water and oxygen, OLEDs need to be encapsulated, e.g., by a thin sheet of glass. As the device is then no longer flexible, alternative coatings are required. Atomic layer deposition (ALD) is a very promising approach in this respect. The authors studied OLEDs that were encapsulated by 100 nm Al{sub 2}O{sub 3} deposited by ALD. The authors show that this coating effectively protects the active surface area of the OLEDs from humidity. However, secondary degradation processes still occur at sharp edges of the OLED stack where the extremely thin encapsulation layer does not provide perfect coverage. Particularly, the swelling of poly(3,4-ethylenedioxythiophene) mixed with poly(styrenesulfonate), which is a popular choice for the planarization of the bottom electrode and at the same time acts as a hole injection layer, affects the effectiveness of the encapsulation layer.
Authors:
 [1] ;  [2] ;  [3]
  1. Siemens AG, Corporate Technology, Guenther-Scharowsky-Strasse 1, 91058 Erlangen, Germany and Center for Medical Physics and Engineering, University of Erlangen-Nuremberg, Henkestrasse 91, 91052 Erlangen (Germany)
  2. Siemens AG, Corporate Technology, Guenther-Scharowsky-Strasse 1, 91058 Erlangen (Germany)
  3. Center for Medical Physics and Engineering, University of Erlangen-Nuremberg, Henkestrasse 91, 91052 Erlangen (Germany)
Publication Date:
OSTI Identifier:
22392120
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 1; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; COATINGS; DEPLETION LAYER; DEPOSITS; ELECTRODES; ENCAPSULATION; GLASS; HUMIDITY; LIGHT EMITTING DIODES; OXYGEN; SHEETS; SURFACE AREA