• Title/Summary/Keyword: electroluminescence (EL)

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On the Synthesis of Zn-doped GaN Fine-Powders (Zn가 첨가된 GaN 미세 분말의 합성에 관하여)

  • 이재범;이종원;박인용;김선태
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.95-95
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    • 2003
  • 최근, 대면적 평판표시소자 제작을 위한 전기발광 (EL; electroluminescence)소자용 소재로서 GaN 분말을 적용하고자 하는 연구가 진행되고 있다. 이와 같이 GaN 분말을 EL 소재로 사용하기 위해서는 원하는 파장의 빛을 발광할 수 있도록 특정의 불순물을 첨가하여야 할 필요가 있다. Mg이 첨가된 GaN 분말의 합성과 특성에 대한 연구가 있었으며, 희토류 원소가 첨가된 GaN 분말의 특성이 보고된바 있다. 본 논문에서는 GaOOH 분말을 출발물질로 채택하여 Zn가 첨가된 GaN 분말을 합성하고 광학적인 특성을 조사하였다. Zn가 첨가된 GaN 분말을 합성하기 위하여, 우선 CaOOH 분말 1g과 일정량의 ZnO 또는 Zn(NO$_3$)$_3$를 함께 섞어 유발에서 습식 혼합한 후 건조시켰다. Ga에 대한 Zn의 몰 비는 0.1부터 30 까지 변화시켰다. 반응온도는 900~110$0^{\circ}C$의 범위에서 변화시켰고, 반응시간은 1~4시간 범위에서 변화시켰으며, NH$_3$의 유량은 400 sccm으로 하였다. X선 회절분석장치를 사용하여 결정구조를 확인하였고, Zn의 첨가에 따른 광학적 특성은 10 K의 온도에서 광루미네센스(PL; photoluminescence)를 측정하여 평가하였다.

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Powder Type Electroluminescence Display with Good Uniformity for LCD Backlighting (LCD 후면 광원용으로 우수한 Uniformity를 갖는 분산형 EL)

  • Kwon, S.S.;Lim, M.S.;Lim, K.J.;Park, S.G.;Ryu, B.H.
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.776-778
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    • 1998
  • Electrical and optical characteristics of Powder type EL display(P-ELD) in this study are described, In experimental results of V-J, current are increased with increasing the frequency and voltage. Luminance was increased with frequency. This is due to the positive space charge formed to cathode region. Lumiance at 150V, 20 kHz has $840\;cd/m^2$. This tendency is due to the decrease of capacitive reactance in insulator layer. Uniformity of P-ELD shows 97%. CIE chromaticity with increasing frequency are shifted toward blue color. It can be explained in tenn of the difference of recombination energy.

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Synthesis and Luminescent Properties of Light Harvesting Dendrimers Encapsulated Fluorescent Dyes

  • Choi, Dong-Hoon;Kim, Hong-Suk;Kim, Go-Woon;Cho, Min-Ju;Jin, Jung-Il
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.980-983
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    • 2006
  • New blue light emitting branched molecules were synthesized by reacting 3,5-bis-(3,5-bis-benzyloxy)- benzoic moiety or 3,5-bis-(3,5-bis-benzyloxy-benzyloxy)- benzoic moiety with biscarbazolyl vinyl biphenyl moiety by dicyclohexylcarbodiimide (DCC) catalyzed esterification. Similar synthetic strategy was also applied to prepare a red light emitting dendrimer. In this paper, we described two blue emitting dendrimers for investigating the effect of the dendronized structures on photoluminescence (PL) and electroluminescence (EL). EL properties of the dendrimers were investigated using heterostructured samples in detalil.

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Stable blue light emitting polyfluorenes with good solution processibility

  • Hwang, Do-Hoon;Lee, Ji-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1057-1059
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    • 2003
  • New polyfluorene derivatives, poly[9,9-bis(4' n-octyloxyphenyl)] fluorene (PAPF-8) and poly[9,9-bis(4'-(2",7"-dimethylocyloxy)phenyl)] fluorene (PAPF-10) were synthesized from the monomers, 2,7-dibromo-9,9-bis[4' (2"-ethylhexyloxy)benzene] fluorene and 2,7-dibromo-9,9-bis[4' (2", 7"-dimethyloctyloxybenzene)] fluorene through the Ni(0) mediated polymerization. The copolymers were characterized using FT-IR spectroscopy, UV-vis spectroscopy, TGA, photoluminescence (PL) & electroluminescence (EL) spectroscopy, elementa analysis, and molecular weight studies. The synthesized POPF-8 and POPF-10 showed a pure blue emission without any spectral change upon thermal annealing and EL device operation.

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적층 양자점을 포함한 초발광 다이오드의 광대역 출력 파장 특성 연구

  • Park, Mun-Ho;Im, Ju-Yeong;Park, Seong-Jun;Song, Jin-Dong;Choe, Won-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.156-156
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    • 2011
  • InAs와 InGaAs 양자점(Quantum Dot: QD)을 이용한 광대역 초발광 다이오드(Superluminescent Diode: SLD) 시료가 분자선증착법(Molecular Beam Epitaxy)을 이용하여 성장되었다. 광대역 파장대 출력을 얻기 위해 각기 다른 종류의 양자점과 다른 크기의 양자점을 적층하였다. 시료는 광발광(Photoluminescence: PL) 측정과 전계발광(Electroluminescence: EL) 측정을 통해 분석 되었으며, PL 측정결과 1222 nm와 1321 nm 파장에서 최대치(peak)를 나타냈으며 EL 측정결과 900mA 전류 주입시 131 nm의 반치폭(Full Width at Half Maximum: FWHM)을 얻었다.

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Synthesis of Red, Green, Blue Light Emitting Polymers and Their Electroluminescence Properties

  • Park, Lee-Soon;Han, Yoon-Soo;Kim, Sang-Dae;Kim, Dong-Uk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.123-124
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    • 2000
  • Three types of conjugated polymer, poly(DFPZ-AV), poly(MEHPV-PV) and poly(BFMP12-BPV), were obtained by Honer-Emmons condensation using potassium tert-butoxide from the synthesized monomers in anhydrous tetrahydrofurane. The Honer-Emmons reaction was found to be a useful synthetic method for the preparing a wide range of EL polymers. The EL devices using poly(DFPZ-AV), poly(MEHPV-PV) and poly(BFMP12-BPV) as light emitting layer gave red, green and blue emission, respectively, which were in close chromaticity with the CIE 1931 NTSC standard.

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Preparation and characterization of $Alq_3$/TPD EL devices ($Alq_3$/TPD EL소자의 제작과 그 특성에 관한 연구)

  • Chai, Su-Gil;Kim, Tae-Wan;Kang, Dou-Yol
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1469-1471
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    • 1997
  • In this study, Organic electroluminescent(EU devices with multilayer structures were fabricated using tris (8-hydroxy quinolinate) aluminum($Alq_3$) as an electron-tran sporting emitting layer and TPD(N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[1,1'-biphenyl]-4,4'-diamine : aromatic diamine) as a hole-transporting layer. A cell with a structure of glass substrate/indium-tin-oxide(ITO)/$Alq_3$/TPD/Mg:In exhibited bright green electroluminescence from the TPD layer. The peak intensity of TPD and $Alq_3$ different from spin coating and vacuum evaporation. The peak emission energy shifts to a higher energy with deposition technique. An emission peak at 500nm was achieved at a driving voltage of 30V.

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Emission Properties of Electroluminescent Device Using Poly(3-hexylthiophene) as Emilting Material (The Poly(3-hexylthiophene)을 발광층으로 사용한 전계 발광소자의 발광특성)

  • 김주승;구할본;조재철
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.263-266
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    • 1999
  • Electrolunlinescent devices based on conjugated polymer emitting materials have been much attracted possible applications for multicolor flat panel display, since the conjugated polymers have a small band gap emitting obtained at a low driving voltage. In this paper, we fabricated the single layer EL device using poly(3-hexylthiophene) as emitting material Electroluminescence(EL) and I-V-L characteristics of indium-tin-oxide[ITO]P3HT/AI device with a various thickness were investigated. It was demonstrate that the I-V characteristics depend, not the voltage but the electric- field strength, The current is dependent on the electric filed and not on the applied voltage, indicating that the carriers are injected by a tunneling process. In the device, the barrier to hole injection is only 0.5eV and the barrier to electron injection is 1.5eV.

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Transferred charge density and Optical Property on Powder Electroluminescent device (후막 EL 소자의 광학 및 이동전하밀도 특성)

  • 오주열;이종찬;박대희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.286-290
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    • 1999
  • Electroluminescence is occurred when phosphor is located in electric field. In this paper, we made powder electroluminescent device (PELD) with structured ITO film/Phosphor/Insulator/Silver paste. The transparent electrode was ITO film and green(2704-01), orange(2702-02) and blue-green(2703-01) were used as phosphor. The insulator was BaTiO$_3$ and $Y_2$O$_3$, back electrode was silver paste. To investigate electrical and optical properties of PELDs, EL spectrum, Brightness, Transferred charge density using Sawyer-Tower\`s circuit was measured.

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Properties of Powder Electroluminescent Device with $Y_2O_3 and BaTiO_3$ (유전체 종류에 따른 후막 전계발광(EL) 소자의 특성)

  • 이종찬;박춘배;박대희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.582-585
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    • 1999
  • Electroluminescence is occurred when phosphor is located in electric field. In this paper, we made powder electroluminescent device (PELD) with structured ITO film/Phosphor/Insulator/Silver paste. The transparent electrode was ITO film and green(2704-01) and orange(2702-02) and blue-preen(2703-01) were used as phosphor. The insulator was BaTiO$_3$ and $Y_2$O$_3$, bark electrode was silver paste. To investigate electrical and optical properties of PELDs, EL spectrum, Brightness . Transferred charge density using Sawyer-Towers circuit was measured.

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