Linearly polarised organic light-emitting diodes (OLEDs): synthesis and characterisation of a novel hole-transporting photoalignment copolymer
We describe the synthesis and characterisation of a novel hole transporting photoalignment copolymer for linearly polarised emission. The copolymer has a coumarin side-chain which undergoes (2 + 2) cycloaddition on irradiation with ultraviolet light. A fluorene side-chain, whose ionisation potential...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Published: |
Royal Society of Chemistry
2005
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| Subjects: | |
| Online Access: | http://pubs.rsc.org/en/Content/ArticleLanding/2005/JM/B506063J#!divAbstract http://pubs.rsc.org/en/Content/ArticleLanding/2005/JM/B506063J#!divAbstract |
| Summary: | We describe the synthesis and characterisation of a novel hole transporting photoalignment copolymer for linearly polarised emission. The copolymer has a coumarin side-chain which undergoes (2 + 2) cycloaddition on irradiation with ultraviolet light. A fluorene side-chain, whose ionisation potential is well matched to the work-function of indium tin oxide, provides hole transporting properties. Polarised green electroluminescence was obtained by spin coating a novel polymerisable and light-emitting liquid crystal onto the photoaligned copolymer. A polarisation ratio value of 13 : 1 and a polarised irradiance of 200 cd m−2 was obtained at 9 V. Polarised red emission is also described in a guest–host configuration. The spatial patterning of the polarisation direction is also shown. |
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