Flexible multilayer inverted polymer light-emitting diodes with a gravure contact printed Cs2 CO3 electron injection layer

Dae Young Chung, Dong Seok Leem, Donal D.C. Bradley, Alasdair J. Campbell

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Here we demonstrate high efficiency, flexible inverted polymer light-emitting diodes in which the bottom-contact cesium carbonate electron injection layer is gravure contact printed. The poly(9,9-dioctylfluorene-alt- benzothiadiazole) emissive/electron transport layer, the poly(9,9- dioctylfluorene-alt- N -(4-butylphenyl)-diphenylamine) hole transport/electron blocking layer and the poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) hole injection layer were sequentially spin-coated from solution using orthogonal solvent formulations with appropriate wetting properties. By switching from indium-tin-oxide (ITO) on glass to ITO on poly(ethylene terephthalate) and using gravure contact printing instead of spin-coating, Cs2 CO3 smoothness and morphology was optimized, resulting in an approximately fivefold increase in current efficiency and power efficiency at 100 cd/m2. © 2011 American Institute of Physics.
Original languageEnglish (US)
JournalApplied Physics Letters
Issue number10
StatePublished - Mar 7 2011
Externally publishedYes

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