• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.599-601
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• 2004

A new blue electroluminescent conjugated polymer, poly(BP-alt-BCV), was prepared by Hornor-Emmons polycondensation and used as a host polymer for the phosphorescent dopant, $(bsn)_2Ir(acac)$. Poly(N-vinylcarbazole) (PVK), known as a blue EL material, was also used for comparison with poly(BP-alt-BCV). Electrophosphorescence of PLEDs with these dopant/host systems was investigated in terms of luminescence, efficiency, emission color, and energy transfer.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1433-1436
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• 2007

Using a blue emitting DPVBi material and red dopant DCJTB, WOLEDs with and without green emitter C6 added in ETL or HTL have been fabricated. The chromaticity color index of WOLEDs without C6 depends strongly on the doping concentration. In addition, manipulating thickness of emitting layer is similar effect such as controlling weight concentration of dopant. While the white color of WOLEDs with C6 added in ETL or HTL depend on position of C6. WOLED of three colors added green dye have been shown turn-on voltage of 3.25V, and EL efficiency 3.05cd/A @9V, $8102\;cd/m^2$, CIE coordinates (0.30, 0.32).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.612-615
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• 2004

We present an extremely high efficient red organic light-emitting diodes (OLEDs) using a fluorescent dye 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped into an emitting region which consists of multiple pairs of a doped and an undoped layer. An emitting region of OLEDs composes of a tris-(8-hydroxyquinolinato) aluminum (Alq3) codoped with rubrene of 5% wt. or a mixture of Alq3 and rubrene (1:1). The luminance yield of the codoped device and the mixed device are 6.5 cd/A and 9.2 cd/A at 10 mA/$cm^2$, respectively. We have considerably improved the luminance yields of red OLEDs as much as ${\sim}$90% at 10 mA/$cm^2$ compared with that of the device doped with only DCJTB. We attribute it to both the emitting assist dopant (rubrene) and the dotted-line doping structure in an emitting region of OLED.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1034-1037
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• 2002

In this study, we fabricated red organic electrolu-minescent device with a doping material (DCJTB), and The cell structure used ITO:indium tin oxide $[20{\Omega}]$/CuPc:Hole injection layer 20nm/NPB: Hole transfer layer 40nm/$Alq_3$ (host) + DCJTB(1% or 3%) (guest) Emitting layer 40nm/$Alq_3$ : Electron transfer layer 30nm/Al :Cathode layer 150nm. the luminescent layer consisted of a host material. 8-hydrozyquinoline aluminum $(Alq_3)$, and DCJTB dye as the dopant. a stable red emission (chromaticity coordinates : x=0.64, y=0.36) was obtained in this cell with the luminance range of $100-600cd/m^2$. we study the electrical and optical properties of devices.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2477-2480
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• 2007

MgAl2O4:Eu3+ red-light emitting powder phosphor was prepared at temperature as low as 500 oC within a few minutes by using the combustion route. The prepared powder was characterized by X-ray diffraction, scanning electron microscopy and Fourier-transform infrared spectrometry. The luminescence of Eu3+-activated MgAl2O4 shows a strong red emission dominant peak around 611 nm, which can be attributed to the 5D0-7F2 transition of Eu3+ ions from the synthesized phosphor particles under excitation (394 nm). Electron paramagnetic resonance (EPR) measurements at the X-band showed that no signal could be attributed to Eu2+ ions in MgAl2O4.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.178-180
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• 2003

We performed semiempirical (AMl and ZINDO) and ab initio (HF and DFT) calculations, to investigate molecular structures and optical properties of DCM and its derivatives. DCM and its derivatives are used as a red fluorescent dopant of the organic electroluminescent host materials, $Alq_3$. We have studied the relationship between the molecular structure and the optical properties of these molecules for the improvement of EL efficiencies. Wavelength at the absorption maximum was found to be red-shifted when the molecule is substituted with both strong electron donating and withdrawing functional groups. A new red fluorescent dye was predicted by QSPR study based on calculations and experimental data.

• Transactions on Electrical and Electronic Materials
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• 제6권3호
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• pp.91-96
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• 2005

We report the efficient red light-emitting diodes based on the fluorescent dye 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTI) and 5,6,11,12-tetraphenyl naphthacene (rubrene) codoped in the tris(8-hydroxyquinoline)aluminum $(Alq_3)$. Luminance efficiency of 2.2 cd/A with a Commission International De L'Eclairage (CIE) chromaticity coordinate of x, y = (0.640, 0:350) are achieved at the driving current density of $20\;mA/cm^2$. Adding the rubrene to the DCJTI in tris(8-hydroxyquinoline)aluminum $(Alq_3)$, the red color purity and luminance efficiency improved comparing to the DCJTI only doped devices because the rubrene molecules assist the polarization effect of DCJTI by molecular interaction and enhance the energy transfer from $(Alq_3)$ to DCJTI.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.939-942
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• 2001

We fabricated Red Organic light-emitting devices(OLED). The Basic Device Structure is ITO/hole transfer layer, TPD(50nm)/red emitting layer, Alq3 doped with DCM2 or DCM2:rubrene(xnm)/electorn transfer layer, Alq3(50-xnm)/LiF(0.8nm)/Al(8nm) . The thickness of emitting layer(xnm) changed 5, 10, 20nm. we demonstrate red emitting OLED with dependent on the thickness and concentrators of Alq3 layer doped with DCM2 or co-doped with DCM2:ruberene. The Emission color and Brightness are changed with doping or co-doping condition, dopant concentarton. In the case of rubrene:DCM2 co-doped layer structure, the red color Purity and device efficiency is improved. The CIE index of rubrene co-doped OLED is x=0.67, y=0.31. By co-doping the Alq3 layer with DCM2, rubrene, EL efficiency improved from 0.38cd/A to 0.44cd/A in comparison whit DCM2 doped Alq3 layer.

• Transactions on Electrical and Electronic Materials
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• 제3권2호
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• pp.16-19
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• 2002

In this study, a novel red emitting organic electroluminescent (EL) device was fabricated with the bis(8-oxyquinolino)zinc II (Znq2) doped dye as an emitting layer. The Znq2 was synthesized successfully from zinc chloride (ZnC1$_2$) as an initial material. Then, we fabricated the red organic EL device with a dye (DCJTB) doped and inserted Znq2 between emission layer and cathode for increasing EL efficiency. The hole transporting layer is a N,N'-diphenyl-N,N'-bis-(3-methylphenyl)-1,1'-diphenyl-4,4-diamine (TPD), and the host material of emission layer is Znq2. And the electrical and luminance characteristics of the device were measured. We found that the EL device with Znq2 inserting layer results in the increasing luminance efficiency.

• 한국결정성장학회지
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• 제1권1호
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• pp.5-16
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• 1991

희토류 금속 산화물(RE=Ce, Pr, Nd, Eu, Er)을 1wt% 첨가한 큐빅 $ZrO_2(10 mol% Y_2O_3)$단결정을 스컬법으로 육성하였다. 육성된 단결정의 (111) 면에서의 임피던스 분석에 의한 전기적 성질을 조사하였다. 낮은 온도($500^{\circ}C$)에서 온도와 전기전도도와의 관계를 plot하였으며 $약300-400^{\circ}C$ 사이에서 전이를 관찰하였다. 저온 (전이전)과 고온(전이후 $50^{\circ}C$까지)산소 vacancy 이동에 관한 활성화 에너지를 구하였으며 전이로 인한 활성화 에너지의 차이는 안정제로 첨가한 이트륨 이온과 희토류 dopant 그리고 산소 vacancy와의 defect complexes를 붕괴하고 이온전도에 참여하게되는 산소 vacancy 형성에 관한 활성화 에너지로 볼 수 있다. yttria가 첨가됨에 따라, 또 희토류 산화물들의 첨가에 따른 활성화 에너지를 구하였으면 이온전도기구를 논의하였다. 육성된 단결정들은 첨가된 dopantdp 기인하여 Ce은 orang-red, Pr은 golden-yellow, Nd는 lilac, Eu는 옅은 pink, Er은 pink색으로 발현하였으며 가시광선 영역에서 광흡수 결과로서 나타내었다.