새로운 청색의 인광 물질을 어용한 유기 발광 소자의 전기적 특성 및 수명에 대한 연구

The Characteristics of Organic Light-emitting Diodes With a New Blue Phosphorescent Material

A new blue phosphorescent material for organic light emitting diodes (OLEDs), Iridium(III)bis[2-(4-fIuoro-3-benzonitrile)-pyridinato-N,C2 ] picolinate (Firpic-CN), was synthesized and studied. We compared characteristics of Firpic-CN and Bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium III (FIrpic) which has been used for blue dopant materials frequently. The devices structure were indium tin oxide (ITO) (1000 {AA})/N,N -diphenyl-N,N -(2-napthyl)-(1,1 -phenyl)-4,4 -diamine (NPB) (500 {AA})/4,4 -N,N -dicarbazole-biphyenyl (CBP) : FIrpic and FIrpic-CN (X wt%)/4,7-diphenyl-1,10-phenanthroline (BPhen) (300 {AA})/lithum quinolate (Liq) (20 {AA})/Al (1000 {AA}). 15 wt% FIrpic-CN doped device exhibits a luminance of 1450;cd/m^2 at 12.4 V, luminous efficiency of 1.31 cd/A at 3.58mA/cm^2, and Commission Internationale d Eclairage (CIE_{x,y}) coordinates of (0.15, 0.12) at 12 V which shows a very deep blue emission. We also measured lifetime of devices and was presented definite difference between devices of FIrpic and FIrpic-CN. Device with FIrpic-CN as a dopant presented lower longevity due to chemical effect of CN ligand.