• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.651-654
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• 2009

Novel compounds with rod and disc mesogens were synthesized and characterized. The molecular structures were confirmed by FT-IR, $^1H$-NMR spectroscopy and elemental analysis. The optical properties of these molecules were investigated by UV-vis absorption spectroscopy and photo-luminescence spectroscopy. We found that they are a novel series of blue light-emitting molecules. The absorption spectra peaks of these compounds varied from 336 nm-341 nm, while the maximum emissions centered form 410 nm-450 nm in chloroform solution. However, unexpectedly we could not found their biaxiality and mesomorphic properties by POM, conoscopy and DSC method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.56-58
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• 2000

We have synthesized the new blue electroluminescent material, Bis(3-N-ethylcarbazolyl)cyanoisophthalidene(BECCIP), and characterized its properties by UV/visible absorption, photoluminescent(PL) and electroluminecent(EL) spectrum. This material is well vacuum-deposited for thin film and has dear surfaced thin film property. The BECCIP shows blue PL and EL spectra at around at 485nm.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.317-321
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• 2012

Poly[4,4'(3,3')-biphenylenevinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-vinylene], 4,4'(3,3')-PBPMEH-PPV, and poly[4,4'(3,3')-biphenylenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene], 4,4'(3,3')-PBPCAR-PPV, of varying effective conjugation lengths, were synthesized by the well-known Wittig condensation polymerization between the appropriate biphenyl diphosphonium salts and dialdehyde monomers such as carbazole or dialkoxyphenyl dialdehyde. The conjugation lengths of the polymers were controlled by biphenyl linkages (4,4' or 3,3'). The resulting polymers were highly soluble in common organic solvents and exhibited good thermal stability up to $300^{\circ}C$. The synthesized polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 314-400 nm and 430-507 nm, respectively. Carbazole and 3,3'-biphenyl containing 3,3'-PBPCAR-PPV showed a blue PL peak at 430 nm. A single-layer light-emitting diode was fabricated in a configuration of ITO/polymer/Al. Electroluminescence (EL) emission of 3,3'-PBPCAR-PPV was shown at 455 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.174-176
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• 2000

We have synthesized the new blue electroluminescent material, Bis(3-N-ethylcarbazolyl)cyanoisophthalidene(BECCIP), and characterized its properties by UV/visible absorption, photoluminescent(PL) and electroluminecent(EL) spectrum. This material is well vacuum-deposited far thin film and has clear surfaced thin film property. The BECCIP shows blue PL and EL spectra at around at 485nm.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.736-739
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• 2002

We report on white light emission from a light emitting diode(LED) prepared by blending a red emitting copolymer, m-SiPh PPV-co-MEH PPV, and a blue emitting polyvinylcarbazole (PVK). White light emission was realized when the weight ratio of the m-SiPh PPV-co-MEH PPV : PVK equals to 1 : 30, in which the commission Internationale de L'Eclairage coordinates were x=0.3266 and y=0.3438.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.767-770
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• 2009

We synthesized a spirobenzofluorene type phosphine oxide (SPPO2) as a new triplet host and an universal electron transport material for phosphorescent organic light-emitting diodes(PHOLEDs). Red PHOLEDs with the SPPO2 host material showed a high quantum efficiency of 14.3 % with a current efficiency of 20.4 cd/A. In addition, the SPPO2 could be applied as an electron transport material which can be matched with any host material due to the lowest unoccupied molecular orbital of 2.4 eV. Electron injection from a cathode to the SPPO2 electron transport layer was better than common electron transport materials. In particular, the SPPO2 was effective as the electron transport material in blue PHOLEDs and the quantum efficiency was more than doubled and driving voltage was lowered by more than 3 V using the SPPO2 instead of common electron transport material.

• 한국정보디스플레이학회:학술대회논문집
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• 2001.08a
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• pp.157-158
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• 2001

We synthesized Bis(3-N-ethylcarbazolyl) terephthalidene(BECP) and Bis(3-N-ethylcarbazolyl) cyanoterephthalidene (BECCP) and characterized EL properties of these materials. Our device shows a strong blue emission at 472 nm with a luminance efficiency of 0.9 lm/Wat a voltage, a current density. and a brightness of 8 V, 5.7 $mA/cm^2$, and 130 $cd/m^2$, respectively.

• Polymer(Korea)
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• v.26 no.4
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• pp.543-550
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• 2002

We have synthesized a novel carrier transporting copolymer having triphenylamine moiety as a hole transporting unit and triazine moiety as an electron transporting unit in the polymer side chain. Single-layered organic electroluminescent (EL) devices consisted of ITO/copolymer and emitting materials (DCM, coumarin 6, DPvBi)/Al exhibited maximum external quantum efficiency when the ratio of hole transporting unit and electron transporting unit is 6:4 and the content of emitting material is 30 wt%. Especially, the devices emitted the light of red (620 nm), green (520 nm) and blue (450 nm) corresponding to the emitting materials, respectively. A maximum luminance of ITO/copolymer (6:4) and DCM (30 wt%)/Al EL device was about 500 cd/$m^2$ at a DC drive voltage of 12V.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1639-1646
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• 2014

A series of novel fused-ring spiro compounds, spiro[benzo[ij]tetraphene-7,9'-fluorene] (SBTF) derivatives containing an end-capping aryl substituent at both the C3 and C10-positions hasbeen designed and synthesized via multi-step Suzuki coupling reactions. 3-(1-Naphthyl)-10-phenylSBTF (1N-PSBTF), 3-(2-naphthyl)-10-phenylSBTF (2N-PSBTF) and 3-[4-(1-naphthyl)phenyl]-10-phenylSBTF (NP-PSBTF) showed improved glass transition temperatures ($T_g$) with good thermal stability. Their photophysical, electrochemical, and electroluminescent properties were investigated and were used to construct blue organic light emission diodes (OLEDs). The typical OLED devices showed excellent performance; the NP-PSBTF-based device exhibited highly efficient deep blue-light emission with a maximum efficiency of 5.27 cd/A (EQE, 4.63%) with CIE (x = 0.133, y = 0.144). According to these characteristics, these deep-blue light emitting materials have sufficient potential for fluorescent OLED applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.331-334
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• 2000

The organic electroluminescent(EL) device has gathered much interest because of its large potential in materials and simple device fabrication. We fabricated EL devices which have a blended single emitting layer containg poly(Nvinylcarbazole)[PVK] and poly(3-dodecylthiophene)[P3DoDT]. The molar ratio between P3DoDT and PVK changed with 1:0, 2:1 and 1:1. To improve the external quantum efficiency of EL devices, we applied insulating layer, LiF layer between polymer emitting layer and AI electrode. All of the devices emit orange-red light and it's can be explained that the energy transfer occurs from PVK to P3DoDT. Within the molar ratio 1:0, 2:1 and 1:1, the energy transfer was not saturated, which results in the not appearance of PVK emission in the blue region. In the voltage-current and voltage-light power characteristics of devices applied LiF layer, current and light power drastically increased with increasing with applied voltage. In the consequence of the result, the light power of the device have a molar ratio 1:1 with LiF layer was about 10 times larger than that of the device without PVK at 6V.