We report on highly efficient polymer light-emitting devices (PLEDs) achieved using a phosphorescent polymer, which is a copolymer that has bis(2-phenylpyridine)iridium (acetylacetonate) [Ir(ppy)2(acac)], N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine (TPD) and 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as a side group. The phosphorescent polymer has an ambipolar charge-transport ability. An increase in PBD unit concentration allows an improvement in the efficiency of the PLEDs. Ba and Cs were used for electron-injection layers as well as Ca, to improve the electron injection. An external quantum efficiency of 11.8% and a power efficiency of 38.6lm∕W were obtained by using Cs. The results indicate that this can be attributed to an improvement in the charge balance of electrons and holes.
A unique method of material synthesis based on vacuum co‐deposition is reported. A Eu complex was formed by co‐deposition of bis(dipivaloymethanato)europium (Eu(DPM)3) and 2,9‐dimethyl‐4,7‐diphenyl‐1,10‐phenanthroline (BCP), which both showed excellent volatility during vacuum deposition. Photoexcitation of the BCP led to intense emission from the Eu3+ ions, verifying efficient exciton energy transfer and therefore complex formation.
Articles you may be interested inStudy on copper phthalocyanine and perylene-based ambipolar organic light-emitting field-effect transistors produced using neutral beam deposition method Electron mobility in tris(8-hydroxyquinoline)aluminum ( Al q 3 ) films by transient electroluminescence from single layer organic light emitting diodes
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.