| 초록 |
Green phosphorescent organic light-emitting diodes (PHOLEDs) with a mixed hole transporting layer (HTL) were developed and device performances were studied depending on the composition of mixed HTL materials with different type of host materials. N, N’-di(1-naphthyl)-N,N’-diphenylbenzidine (NPB) and 4,4’,4”-tris(N-carbazolyl)triphenylamine (TCTA) as used in the mixed hole transport layer were combined two type of host materials with hole-transport-type material, (4,4’-N,N’-dicarbazole)biphenyl (CBP) and electron-transport-type material, PH1, respectively. CBP host device with mixed HTL showed reduced efficiency roll-off due to broad recombination zone and little charge leakage compared with that of PH1 host devices. |
