6533b82bfe1ef96bd128d50b

RESEARCH PRODUCT

A deep-blue emitting charged bis-cyclometallated iridium(iii) complex for light-emitting electrochemical cells

Wiebke SarfertFlorian KesslerJosé M. Junquera-hernándezM. Khaja NazeeruddinEtienne BaranoffEtienne BaranoffHenk J. BolinkMichael GrätzelSebastian MeierSebastian MeierManuel DelgadoEnrique OrtíRosario ScopellitiDaniel Tordera

subject

Materials scienceLigandIntermolecular forceCationic polymerizationAnalytical chemistrychemistry.chemical_elementGeneral ChemistryPhotochemistryElectrochemical cellLight intensitychemistryMaterials ChemistryConstant currentIridiumDeep blue

description

We report here a new cationic bis-cyclometallated iridium(III) complex, 1, with deep-blue emission at 440 nm and its use in Light-emitting Electrochemical Cells (LECs). The design is based on the 2′,6′-difluoro-2,3′-bipyridine skeleton as the cyclometallating ligand and a bis-imidazolium carbene-type ancillary ligand. Furthermore, bulky tert-butyl substituents are used to limit the intermolecular interactions. LECs have been driven both at constant voltage (6 V) and constant current (2.5 mA cm−2). The performances are significantly improved with the latter method, resulting overall in one of the best reported greenish-blue LECs having fast response (17 s), light intensity over 100 cd m−2 and a reasonable efficiency of almost 5 cd A−1.

https://doi.org/10.1039/c2tc00251e