Blue organic light-emitting diodes based on diphenylamino dibenzo[g,p]chrysene derivatives

Three blue materials based on diphenylamino dibenzo[g,p]chrysene were designed and synthesized via Buchwald-Hartwig amination. To characterize their electroluminescent properties, multilayered organic light emitting diodes (OLEDs) were fabricated with the following device structure: indium tin oxide (ITO) (180 nm)/4,4′,4″-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA) (40 nm)/N,N′-diphenyl-N,N′-(1-napthyl)-(1,1′-phenyl)-4,4′-diamine (NPB) (10 nm)/2-methyl-9,10-di(naphthalen-3-yl)anthracene (mADN): 3 or 7% blue dopants (20 nm)/tris-(8-hydroxyquinoline)aluminum (Alq3) (30 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm). All the devices showed blue emission with high electroluminescent efficiencies. Particularly, a device using 2-methyl-9,10-di(naphthalen-3-yl)anthracene as the host material and 3,6-di[4′-(1-di(tert-butyl))phenyl]-11,14-bis(diphenylamino) dibenzo[g,p]chrysene (2) as the dopant material at 3% doping exhibited highly efficient blue emission with an external quantum efficiency of 4.72% at 20 mA/cm2.