Poly(P-Phenylenevinylene) Light-Emitting-Diodes - Enhanced Electroluminescent Efficiency Through Charge Carrier Confinement

TitlePoly(P-Phenylenevinylene) Light-Emitting-Diodes - Enhanced Electroluminescent Efficiency Through Charge Carrier Confinement
Publication TypeJournal Article
Year of Publication1992
AuthorsBrown, A. R., Bradley D. D. C., Burroughes J. H., Friend R. H., Greenham N. C., Burn P. L., Holmes A. B., and Kraft A.
JournalApplied Physics Letters
Volume61
Issue23
Pagination2793–2795
AbstractWe have fabricated light-emitting diodes with poly(p-phenylenevinylene) as the emissive layer, and with an electron-transporting layer formed from a solid state dispersion of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole in poly(methyl methacrylate), placed between this and the negative electrode. These structures show typically a tenfold improvement in efficiency in the low-voltage regime and an eightfold improvement in the high-voltage regime over devices without the electron-transporting layer. Typical efficiencies are about 0.8% photons/electron. We consider that the role of the electron-transport layer is to confine holes to the emissive layer.