| 초록 |
White organic light-emitting devices (WOLEDs) with phosphorescent multiple emissive layers (EML) were fabricated. 4,4-bis(carbazol-9-yl)biphenyl (CBP) was used as host and iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2’]picolinate (FIrpic), fac tris(2-phenylpyridine) iridium [Ir(ppy)3], and bis[2-(2’-benzothienyl)-pyridinato-N,C3’] iridium (acetylacetonate) [btp2Ir(acac)] were used as blue, green, and red dopant, respectively. We fabricated three types of WOLEDs with different hole blocking layers (HBLs) and electron transport layers (ETLs), and found that the color stability of the WOLEDs varied depending on the hole blocking property of HBL and ETL. Among these devices, a WOLED using bis(2-methyl-8-quinolinolato)(p-phenylphenolato) aluminum (BAlq) which has low hole blocking property showed the highest color stability. This WOLED showed white emission with CIE chromaticity coordinates from (0.31,0.39) to (0.29,0.43) at the luminance ranges of 10 ~ 5000 cd/m2. |
