Molecular Crystals and Liquid Crystals, Vol.444, 95-101, 2006
Effective electrophosphorescence emitting devices by using new type Ir(III) complex with bluky substistuent spacers
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 (MLCT)-M-1. The EL devices with configuration of ITO/CuPc(10 nm)/alpha-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 (MLCT)-M-3 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 CH2Cl2 shows slightly higher than that of reported Ir(ppy)(3) (phi = 0.40).