Device physics of white polymer light-emitting diodes
article
The charge transport and recombination in white-emitting polymer light- emitting diodes (PLEDs) are studied. The PLED investigated has a single emissive layer consisting of a copolymer in which a green and red dye are incorporated in a blue backbone. From single-carrier devices the effect of the green- and red-emitting dyes on the hole and electron transport is determined. The red dye acts as a deep electron trap thereby strongly reducing the electron transport. By incorporating trap-assisted recombination for the red emission and bimolecular Langevin recombination for the blue emission, the current and light output of the white PLED can be consistently described. The color shift of single-layer white-emitting PLEDs can be explained by the different voltage dependencies of trap-assisted and bimolecular recombination. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Topics
charge transportconjugated polymersorganic light-emitting diodesBimolecular recombinationBlue emissionCharge transport and recombinationColor shiftsDeep electron trapsDevice physicsElectron transportLangevin recombinationLight outputRed emissionsSingle carrierSingle emissive layersSingle layerVoltage dependenciesWhite polymer light-emitting diodesCharge transferConjugated polymersElectron transitionsElectron transport propertiesLight emitting diodes
TNO Identifier
461308
ISSN
1616301X
Source
Advanced Functional Materials, 22(10), pp. 2040-2047.
Collation
8 p.
Pages
2040-2047
Files
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