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We report a new electron transport material, 1,6-di(pyridin-3-yl)-3,8-di(phenyl)pyrene (PPP). It has a very good electron mobility of 4.1 × 10−3 cm2/Vs at the 0.1 MV/cm. This PPP is evaluated along with other electron transport materials such as Alq3 (tris-(8-hydroxyquinoline)aluminum) and Bphen (4,7-diphenyl-1,10-phenanthroline) in green phosphorescent organic light-emitting diodes. The maximum external quantum efficiency is increased by 43.5% compared with a reference Alq3 device. Operating voltage to reach 1000cd/m2 also is reduced to 1.2 V. Such high efficiency and low driving voltage are mainly attributed to the fast electron mobility and good LUMO (lowest unoccupied molecular orbital) level of the PPP material. [ABSTRACT FROM PUBLISHER]

The new green Ir(III) complex, fac -tris[4-methyl-2-(4'-trimethylsilylph-enyl)pyridine] [Ir(msippy) 3 ], is synthesized and phosphorescent light emitting devices fabricated by using them as triplet emissive dopants. Ir(dsippy) 3 in UV-Vis. spectra showed absorption band at 395 nm originating from 1 MLCT. The EL devices with configuration of ITO/CuPc (10 nm)/a -NPD (40 nm)/CBP-Ir(msippy) 3 (20 nm)/BCP (10 nm)/Alq 3 (40 nm)/LiF (1 nm)/Al (100 nm).showed the emission maximum at 516 nm, due to the radiative decay from 3 MLCT state to ground state. The 6% doped devices showed the maximum efficiency of 49.9 cd/A and power efficiency 25.3 lm/W. The observed PL quantum efficiency (0.43) of the [Ir(msippy) 3 ] in CH 2 Cl 2 shows slightly higher than that of reported Ir(ppy) 3 (F = 0.40). [ABSTRACT FROM AUTHOR]