• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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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.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.156-156
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• 2011

Nanocrystalline $Ca_2Gd_8Si_6O_{26}$ (CGS) : $Sm^{3+}$ and CGS : $Tb^{3+}/Sm^{3+}$ phosphors were prepared by solvothermal reaction method for light emitting diode (LED) and field emission display (FED) applications. The XRD patterns of these phosphors confirmed their oxyapatite structure in the hexagonal lattice. The visible luminescence properties of these phosphors were investigated by exciting with ultraviolet (UV) or near-UV light and low voltage electron beam. The photoluminescence (PL) properties of $Ca_2Gd_8Si_6O_{26}$ (CGS) : $Sm^{3+}$ and CGS : $Tb^{3+}/Sm^{3+}$ phosphors were investigated as a function of $Sm^{3+}$ concentration. Cathodoluminescence (CL) properties were examined by changing the acceleration voltage. The CGS : $Sm^{3+}$ showed the dominant orange emission due to the $^4G_{5/2}{\rightarrow}^6H_{7/2}$ transition. The CGS : $Tb^{3+}/Sm^{3+}$ phosphor showed the green, white and orange emissions when excited with 275, 378, and 405 nm wavelengths, respectively. The chromaticity coordinates of these phosphors were comparable to or better than those of standard phosphors for LED or FED devices.

• 반도체디스플레이기술학회지
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• 제4권3호
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• pp.17-22
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• 2005

LED lamp was designed by the serial-parallel integration of LED chips in metal-interconnection. The 7 $4.5{\times}4.5\;in^{2}$ masks were designed with the contact type of chrome-no mirror?dark. The white epitaxial thin film was grown by metal-organic chemical vapor deposition. The active layers were consisted with the serial order of multi-quantum wells for blue, green and red lights. The fabricated LED chip showed the electroluminescence peaked at 450, 560 and 600 nm. For the current injection of 20 mA, the operating voltage was measured to 4.25 V and the optical emission power was obtained to 0.7 $\mu$W.

• 한국세라믹학회지
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• 제43권3호
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• pp.169-172
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• 2006

We have synthesized a $Eu^{2+}-activated\;{(Sr,Ba)}_2SiO_4$ yellow phosphor and investigated the development of blue LEDs by combining the phosphor with a InGaN blue LED chip (${\lambda}_{em}$=405 nm). The InGaN-based ${(Sr,Ba)}_2SiO_{4}:Eu$ LED lamp shows two bands at 405 nm and 550 nm. The 405 nm emission band is due to a radiative recombination from a InGaN active layer. This 405 nm emission was used as an optical transition of the ${(Sr,Ba)}_2SiO_{4}:Eu$ phosphor. The 550 nm emission band is ascribed to a radiative recombination of $Eu^{2+}$ impurity ions in the ${(Sr,Ba)}_2SiO_4$ host matrix. In the preparation of UV Yellow LED Lamp with ${(Sr,Ba)}_2SiO_{4}:Eu$ yellow phosphor, the highest luminescence efficiency was obtained at the epoxy-to-yellow phosphor ratio of 1:0.45. At this ratio, the CIE chromaticity was x=0.4097 and y=0.5488.

• Journal of Information Display
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• 제2권4호
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• pp.8-14
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• 2001

Three types of conjugated polymers, poly(PZ-Pi), poly(PZ-BPI) and poly(PZ-NPI) were synthesized by Schiff-base reaction. These new conjugated polymers exhibited improved solubility in common organic solvents due to the presence of alkyl side chains as well as azomethine groups, Double layer LEDs made with the synthesized polymers as emitting layer and $Alq_3$, as electron transporting layer exhibited enhanced EL emission and efficiency compared to those of single layer LEDs. Double layer LEDs exhibited gradual shift in the emission peak th the single layer LED, made of only $Alq_3$ as the emitting layer as the thickness of $Alq_3$ layer increased.

• 한국전기전자재료학회논문지
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• 제26권7호
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• pp.567-574
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• 2013

An optical model is proposed in the white LED using phosphor and LED chip. In this paper a new model that describes the absorption rate and quantum efficiency with increasing the mixing ratio of phosphor in silicone, and the allotment of the phosphor absorption optical power in the several phosphor mixing in the silicone. Single phosphor in silicone from the optical measurement data before and after molding, the solution to get the blue optical power and the phosphor emission optical power is proposed. By these solution the absorption rate and the quantum efficiency was obtained. The model with single phosphor mixing in the silicone the validity was confirmed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.84-84
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• 2008

A multidimensional ZnO light-emitting diode LEDstructure comprising film/nanorods/substrate was fabricated on a p-type Si substrate using metal organic chemical vapor deposition at relatively low growth temperature. The filmlike top layer used for the metal contact was continuously formed on the ZnO nanorods by varying the growth conditions and the resulting structure allowed us to utilize the nanorods with intense emission as an active layer. We investigated the performance of the resulting multidimensional LED. An extremely high breakdown voltage and low reverse leakage current as well as typical rectification behavior were observed in the I-V characteristics.

• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.1056-1060
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• 2005

We investigated the fabrication and characteristics of the nitride-based spin-polarized LEDs with room-temperature ferromagnetic (Ga,Mn)N layer as a spin injection source. The (Ga,Mn)N thin films having room-temperature ferromagnetic ordering were found to exhibit the negative MR and anomalous Hall resistance up to room temperature, revealing the existence of spin-polarized electrons in (Ga,Mn)N films at room temperature. The electrical characteristics in the spin LEDs did not degraded in spite of the insertion of the (Ga,Mn)N layer into the LED structure. In EL spectra of the spin LEDs, it is confirmed that the devices produce intense EL emission at 7 K as well as room temperature. These results are expected to open up new opportunities to realize room-temperature operating semiconductor spintronic devices.

• 공업화학
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• 제26권3호
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• pp.247-250
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• 2015

유기 발광 다이오드(OLED)는 학문 및 산업 분야에서 많은 관심을 받아왔다. OLED는 기존에 사용되고 있는 광원들과는 달리 면 발광, 친환경적인 에너지 사용, 대면적, 초경량, 그리고 초박형 등의 차별화된 특징을 가지고 있기 때문에 최근 조명 시장에서 많은 관심을 받고 있다. 게다가, OLED 조명은 LED 형광등을 대체할 수 있는 차세대 조명으로써 주목되고 있다. 본 논문에서는 white OLED (WOLED)에 적용되고 있는 대표적인 인광 발광 재료들을 소개하며, 특히 yellow, orange, red 인광 물질들의 화학구조와 소자효율을 정리하였다. 이러한 선행연구의 물질들을 이해하고 인광 물질들을 체계적으로 분류함으로써 새로운 발광 재료를 연구하고 개발함에 있어서 많은 도움이 되리라고 생각한다.

• 대한화학회지
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• 제47권4호
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• pp.370-375
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• 2003

보라색 발광 다이오드에 의해 여기되어 청색, 녹색, 적색을 발광하는 형광체로 각각 $BaMg_2Al_16O_27:Eu,\SrGa_2S_4:Eu$, ZnCdS:Ag,Cl 형광체를 선택하였다. 보라색 발광 다이오드의 발광에서 형광체에 의해서 완전히 흡수되지 않고 나오는 보라색 발광과 $BaMg_2Al_16O_27:Eu,\SrGa_2S_4:Eu$, ZnCdS:Ag,Cl 형광체에서 나오는 청색, 녹색, 적색 발광을 조합하여 사파장 백색 발광 다이오드를 만들었다. 사파장 백색 발광 다이오드의 발광 특성을 확인하였다.