Effect of hole transporting materials on the emission characteristics of soluble processed organic light-emitting devices on the plastic substrate

Abstract

We have fabricated solution processed organic light-emitting devices (OLEDs) with various hole transporting materials (HTMs) on the plastic substrate. The device structure was ITO/HTM: Ir(2-phq) 3 1wt%: FIrpic 5wt % (50 nm)/TAZ (50 nm)/LiF (0.5 nm)/Al (100 nm). 4,4'-bis(carbazol9-yl) biphenyl (CBP), di-[ 4-(N, N-ditolyl- amino)-phenyl] cyclohexane (TAP C), poly[ N, N'-bis(4- butylphenyl)-N, N'-bis(phenyl)- benzidine] (poly-TPD), and poly(9-vinylcarbazole) (PVK)were used for HTM. Phosphorescent orange-red emitting Ir(2-phq)(3) and blue emitting FIrpic guest molecules were mixed with the HTMs and solvents. OLED with TAPC exhibited the maximum current efficiency of 17.4 cd/A at 0.42 mA/cm(2).