부산대학교 도서관

Organic light-emitting diode (OLED) has been successfully commercialized in various applications such as mobile phone, OLED TV and flat display devices, etc. OLED is becoming the mainstream of next-generation displays to replace with liquid crystal display (LCD). As the one of the key issues in the emission materials, blue fluorescence materials have shown the very short lifetime, low color purity and low luminance efficiency when equipped with the commercial OLED display. Thus, growing interest has focused on the increment of the luminance efficiency, power efficiency and C.I.E coordinates of blue emitting materials which aimed to the longer lifetime, higher glass transition temperature and narrow FWHM. In this study, blue fluorescent compounds were designed and synthesized based on core-side group concept.First, 9,10-bis(-diphenylphenyl)anthracene (MAM), 9-(-diphenylbiphenyl) -10-(-diphenylbiphenyl--yl)anthracene (MAT), 9,10-bis(-diphenylbiphenyl--yl)anthracene (TAT) were synthesized by boration and Suzuki coupling reaction. TAT exhibits excellent color coordinate (0.156, 0.088) which is very close to NTSC blue standard value and has external quantum efficiency of 7.18% which is twice that of commercial blue emission materials, MADN. Second, 9,10-Bis(-diphenylbiphenyl--yl)anthracene (TAT), 2-tert-butyl-9,10-bis(-diphenylbiphenyl–-yl)anthracene (T-TAT), 2-(9- antracenyl)-9,10-bis(-diphenylbiphenyl–-yl)anthracene (A-TAT) have been synthesized and fabricated into OLED devices by solution process. The OLED devices were layered as follows: ITO / PEDOT : PSS (40 nm) / PVK (15 nm) / emission materials (45 nm) / TPBi (20 nm) / LiF (1 nm) / Al (200 nm). The luminance efficiency of the synthesized materials at 20 mA/cm2 were measured to be 0.59 cd/A for TAT and 0.84 cd/A for T-TAT, respectively. In case of the CIEs, TAT and T-TAT exhibited (0.150, 0.097) and (0.147, 0.097). However, A-TAT exhibits the greenish-blue color.Third, 1-naphthalen-1-yl-6-(10-naphthalen–1-yl-anthracen-9-yl)-yrene (Na-AP-Na) was synthesized and fabricated into white OLED devices along with commercial yellow emission material (PDY-132). White emission has been achieved by incorporating blue and yellow emitting layers in a hybrid multi-layered structure : ITO / PEDOT : PSS (40 nm) / PDY-132 (35∼80 nm) / NPB (10 nm) / Na-AP-Na (25 nm or 30 nm) / Alq3 (20 nm) / LiF (1 nm) / Al (200 nm). Luminance efficiencies of the white OLED devices at 10 mA/cm2 were measured to be from 5.96 cd/A to 6.71 cd/A at various thickness of blue and yellow emitting layers. One of WOLED devices showed the optimized white optical properties such as 6.56 cd/A and C.I.E of (0.301, 0.341) having cool-white light.Fourth, using anthracene and pyrene chromophore as core material, -bis-(4-anthracen-9-yl-phenyl)-3,8-dibutyl--diphenyl-pyrene-1,6-diamine (DAnP) was synthesized. WOLED devices were made by using red phosphorescent material of Ir(piq)3 and DAnP. Structures of the WOLED devices were as follows : ITO / NPB (30 nm) / CBP : 3 wt% Ir(piq)3 (x nm) / DAnP (y nm) / TPBi (40 nm) / LiF (1 nm) / Al (200 nm). By the optimization of thickness of the red and blue emission material, D4 device having red and biue of 10 nm and 40 nm showed excellent optical and electrical properties which has C.I.E of (0.35, 0.36), luminance efficiency of 5.08 cd/A and power efficiency of 2.55 lm/W.