A method to determine the presence of oxygen in organic light-emitting diodes (OLEDs)

dc.contributor.advisor Joseph Shinar
dc.contributor.author Smith, Alexander
dc.contributor.department Electrical and Computer Engineering
dc.date 2018-08-11T13:50:29.000
dc.date.accessioned 2020-06-30T02:38:39Z
dc.date.available 2020-06-30T02:38:39Z
dc.date.copyright Fri Jan 01 00:00:00 UTC 2010
dc.date.embargo 2013-06-05
dc.date.issued 2010-01-01
dc.description.abstract <p>Organic light emitting diodes (OLEDs) have great potential to replace current commercial display offerings. However, most of the materials comprising the OLEDs suffer degradation effects from the presence of environmental oxygen and water, as both compounds can penetrate into the device. Much research and effort have been put into fabrication methods and proper device encapsulation to help mitigate these environmental effects.</p> <p>A new approach for assessing the level of molecular oxygen (O<sub>2</sub>) in OLEDs is presented. As a first step, organic films that serve as the emitting layers in OLEDs were fabricated and exposed to known levels of gas-phase O<sub>2</sub>. By doping such layers with a photoluminescent, oxygen sensitive dye molecule, measurements of the oxygen level under different gas-phase O<sub>2</sub> concentrations were made using a voltage pulsed LED as an excitation source and a photomultiplier tube that monitored the decaying photoluminescence (PL). The PL decay time is related to the O<sub>2</sub> level in the organic layer.</p> <p>Next, devices were made by similarly doping the emitting layers with the aforementioned oxygen sensitive molecule and the devices' electroluminescence (EL) decay following a voltage pulse was observed; the EL decay times were compared with those obtained from the PL experiments of the same emitting layers. By comparing these two sets of data, the oxygen contained within a specific layer of the device can be measured by simply applying a brief voltage pulse to the device, collecting and then analyzing the resultant EL decay curve. This method is inexpensive and easy to introduce to the fabrication process and could have repercussions as the quest for longer device lifetimes continues since the oxygen level in the emitting layer of the device can then be related to its long-term stability.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/11854/
dc.identifier.articleid 2904
dc.identifier.contextkey 2808102
dc.identifier.doi https://doi.org/10.31274/etd-180810-2850
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/11854
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/26060
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/11854/Smith_iastate_0097M_11640.pdf|||Fri Jan 14 18:59:47 UTC 2022
dc.subject.disciplines Electrical and Computer Engineering
dc.subject.keywords degradation
dc.subject.keywords OLED
dc.subject.keywords organic
dc.subject.keywords oxygen
dc.subject.keywords PdOEP
dc.title A method to determine the presence of oxygen in organic light-emitting diodes (OLEDs)
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
relation.isOrgUnitOfPublication a75a044c-d11e-44cd-af4f-dab1d83339ff
thesis.degree.level thesis
thesis.degree.name Master of Science
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