New three emitting compounds, AK-1, AK-2 and AK-3 including diazocine moiety were synthesized through Suzuki-coupling reaction. Physical properties such as optical, electroluminescent properties were investigated. UV-visible spectrum of AK-1, AK-2 and AK-3 in film state showed maximum 392, 393 and 401 nm. PL spectrum of AK-1, AK-2 and AK-3 showed maximum emission wavelength of 472, 473 and 435 nm. Three compounds were used as EML in OLED device: ITO/2-TNATA (60 nm)/NPB (15 nm)/EML (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). AK-3 OLED device showed C.I.E value of (0.18, 0.26) and luminance efficiency of 0.51 cd/A at 10 mA/cm2. New derivatives including diazocine moiety were introduced as OLED emitting material and the EL efficiency was increased by the proper combination of core and side group.

New carbazole derivatives including coumarin moiety, 7-(3-Carbazol-9-yl-phenyl)-chromen-2-one (C-PCa), 7-(9-Phenyl-9H-carbazol-3-yl)-chromen-2-one (PCa-C), 7-[9-(3-Carbazol-9-yl-phenyl)-9H-carbazol-3-yl]-chromen-2-one (PDCa-C) were synthesized by Suzuki reaction. In film state, maximum UV-Vis absorption of three synthesized compounds appeared in the range 331 to 345 nm. PL spectrum of C-PCa, PCa-C and PDCa-C showed miximum emission wavelength of 449, 467 and 467 nm, respectively. C-PCa showed white emission of current efficiency of 1.16 cd/A, power efficiency of 0.59 lm/W and C.I.E of (0.26, 0.33). PCa-C showed current efficiency of 1.13 cd/A, power efficiency of 0.62 lm/W and C.I.E of (0.19, 0.27). PDCa-C showed the highest current efficiency of 1.34 cd/A, power efficiency of 0.62 lm/W and C.I.E of (0.18, 0.23).

7-(4-([1,1-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)-4-methyl-2H-chromen-2-one (BPFA-C) including coumarin moiety was synthesized through Suzuki aryl-aryl coupling reaction. Optical and electrical properties were examined by UV-visible absorption spectra, PL spectra, and AC-2. UV-visible spectrum of BPFA-C in a film state showed maximum absorption wavelength of 367 nm. PL spectrum of BPFA-C show maximum emission wavelength of 511 nm. BPFA-C showed highly efficient luminescence property. EL spectrum of BPFA-C exhibited a maximum value of 504 nm and BPFA-C device provided luminescence efficiency of 4.59 cd/A, power efficiency of 3.17 lm/W, and CIE (x,y) of (0.25, 0.53) at a current density of 10 mA/cm².

Two emitting compounds, 9,10-bis-[1,1;3,1]terphenyl-5-yl-1,5-di-o-tolyl- anthracene [TP-DTA-TP] and 9,10-bis-phenyl[1,1;3,1]triphenyl-5-yl-1,5-di-o- tolylanthracene[ TPB-DTA-TPB] based on newtwisted core moiety were synthesized through boration, Suzuki reaction, and Sandmeyer reactions. EL performance was improved by varying the chemical structure of the side group. Physical properties such as optical, electrochemical, and electroluminescent properties were investigated. Synthesized compounds were used as an EML in OLED device: ITO/2-TNATA (60 nm)/NPB (15 nm)/TP-DTA-TP or TPB-DTA-TPB (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). It was found that TPB-DTA-TPB showed higher luminance efficiency and better C.I.E. value than TP-DTA-TP device.

본 연구는 해양 미세조류에서 추출한 물질에 대한 광 발광(Photoluminescence) 측정 및 GC-MS 분석을 통해 유기발광다이오드 소자로 이용 가능한 물질을 탐색하고자 하였다. 국내에서 주로 서식하는 해양 미세조류 14종의 추출물을 분획으로 얻었으며 광 발광 측정 결과, Nitzschia denticula, Navicula cacellata, Nannochloropsis salina 총 3종의 추출물에서 광 발광 반응이 나타났다. 광 발광 반응을 보인 물질의 특성을 알아내기 위해 GC-MS로 분석하였으며, 그 결과 3종의 추출물이 imidazole, purine 및 quinoline기를 가진다는 것을 확인하였고, 이 계열의 물질들이 광 발광에 영향을 주는 것으로 판단된다.

본 논문에서는 청색 인광 발광 물질인 bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium (III) (Flrpic)과 녹색 인광 발광 물질인 fac-tris(2-phenypyridine) irdium(III) (Ir(ppy)3)와 적색 인광 발광 물질인 his(5-benzoyl-2-phenylpyridinato-C,N)iridium(III) (acetylacetonate) ((Bzppy)2Ir(acac))를 각각 적층하여 백색 유기 발광 다이오드를 제작하였고, 각각의 발광층 사이에 혼합된 스페이서인 4,4'-N,N'-dicarbazole-biphenyl (CBP):4,7-diphenyl-1,10-phenanthroline (BPhen)을 적층하여 그 때의 영향에 대하여 연구하였다. 최적화된 구조에서의 전력 효율은 0.014 mA/cm2에서의 19.7 lm/w를 나타내었으며, 0.127 mA/cm2에서의 11.5%의 외부 양자 효율을 나타내었고, 8 V에서 Commission Internationale do I'Eclairage (CIEx,y) coordinates (x=0.36, y=0.44)의 색좌표를 나타내었다.

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 a)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (500 a)/4,4'-N,N'-dicarbazole-biphyenyl (CBP) : FIrpic and FIrpic-CN (X wt%)/4,7-diphenyl-1,10-phenanthroline (BPhen) (300 a)/lithum quinolate (Liq) (20 a)/Al (1000 a). 15 wt% FIrpic-CN doped device exhibits a luminance of 1450 cd/m2 at 12.4 V, luminous efficiency of 1.31 cd/A at 3.58mA/cm2, and Commission Internationale d'Eclairage (CIEx,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.

The tfTZ(4,4',4"-trifluoro-triazine) was used as a hole blocking material for the electroluminescent devices(ELDs) in this study. In general, the holes are outnumbered the electrons in hole transport and emitting layers because the hole transport is more efficient in most organic ELDs. The hole blocking layer are expected to control the excess holes to increase the recombination of holes and electrons and to decrease current density. The former study using the 2,4,6-triphenyl-1,3,5-triazine(TTA) as hole blocking layer showed that the TTA did not form stable films with vapor deposition technique. The tfTZ can generate stable evaporated films, moreover the fluorine group can lower the highest occupied molecular orbital(HOMO) level, which produces the energy barrier for the holes. The tfTZ has high electron affinities according to the data by the Cyclic-Voltammety(CV) method, which is developed for the measurement of HOMO and lowest occupied molecular orbital(LUMO) level of organic thin films. The lowered HOMO level is made the tfTZ to be applied for a hole blocking layer in ELDs. We fabricated multilayer ELDs with a structure of ITO/hole blocking layer(HBL)/hole transporting layer(HTL)/emitting layer/electrode. The hole blocking properties of this devices is confirmed from the lowered current density values compared with that without hole blocking layer.