• Title/Summary/Keyword: 열다이오드

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Thermal Effect of a Diode Side-Pumped Yb:YAG Laser Using a Diffusive Reflector (난반사체를 이용한 다이오드 횡여기 Yb:YAG 레이저의 열유도 효과 연구)

  • 이성만;김선국;윤미정;문희종;김현수;고도경;차병헌;이종민
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.46-47
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    • 2001
  • 난반사체를 이용한 다이오드 횡여기 Yb:YAG 레이저에서 레이저 결정의 반경과 레이저 결정의 도핑 농도 등을 매개변수로 하여 이들 매개변수의 변화가 열초점거리에 미치는 영향을 분석해 보았다. 이 때 결정의 굴절률은 1.826, 결정의 투과율은 90%, 결정의 길이는 10mm로 하였으며, 냉각수의 굴절률은 1.33, 냉각튜브의 두께는 1.5 mm로 하였다. 또 렌즈를 통과한 황선의 divergence는 5도, 난반사 공동체의 반사율은 95.7%로 계산하였다. 다이오드의 전체 출력은 600 W이다. 펌프헤드의 구조도를 그림1에 보였다. (중략)

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Control of Heat Temperature in Light Emitting Diodes with Thermoelectric Device (열전소자를 이용한 발광다이오드의 발열 온도 제어)

  • Han, S.H.;Kim, Y.J.;Kim, J.H.;Kim, D.J.;Jung, J.Y.;Kim, S.;Cho, G.S.
    • Journal of the Korean Vacuum Society
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    • v.20 no.4
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    • pp.280-287
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    • 2011
  • The heat temperature of a light emitting diode (LED) is investigated with the thermoelectric device (TED). The Peltier effect of the thermoelectric device is used to control the heat radiation and the junction temperature of high-power LEDs. For the typical specific current (350 mA) of high-power (1 W) LEDs, the LED temperature and the p-n junction temperature become $64.5^{\circ}C$ and $79.1^{\circ}C$, respectively. For 0.1~0.2 W driving power of TED, the LED temperature and the junction temperature are reduced to be $54.2^{\circ}C$ and $68.9^{\circ}C$, respectively. As the driving power of the TED increases over 0.2 W, the temperature of LED itself and the junction temperature are increased due to the heat reversed from the heat-sink to LED. As the difference of temperature between LED and the heat-sink is increased, the quantity of reversed heat becomes larger and it results to degrade the cooling capability of TED.

An Experimental Study on the Thermal Performance of Air Filled Thermal Diode (공기를 작동 유체로 하는 열다이오드의 열성능에 관한 실험적 연구)

  • Pak, Ee-Tong;Jang, Young-Geun;Hwang, In-Ju
    • Solar Energy
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    • v.17 no.2
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    • pp.35-42
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    • 1997
  • Thermal diode is a device which allows heat to be transferred in one direction by convection due to difference of density of fluid, and blocks heat flow in the opposite direction. Vertical plate for heat collection and radiation are of utility for design of thermal diode. It was considered the transient and steady state of air filled thermal diode with guide vane which combined rectangular and parallelogrammic shape enclosures. $Gr^*$ was kept constantly on $1.11{\times}10^{10}{\sim}1.4{\times}10^{10}$ and error range was ${\pm}3%$ during the experiment. Nu was examined when inclined angle are $15^{\cir\c}\;and\;45^{\circ}$ and, also the experiments was carried out with and without guide vane as well. Specially, Nu was linearly increased due to increase of $Gr^*$, and the effect of guide vane and dimensionless channel depth was sensitive. Developed state of temperature began at dimensionless time $0.5{\sim}0.6$ due to variation of inclined angle, which is characteristic of system.

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Properties of the Phosphorous Polymer Light Emitting Diodes with PVK:Ir(ppy)$_3$ Emission layer (PVK:Ir(ppy)$_3$ 발광부를 갖는 고분자 인광 발광다이오드의 특성평가)

  • Baek, Seung-Jun;Gong, Su-Cheol;Lee, Ho-Sub;Jang, Seong-Kyu;Chang, Ho-Jung
    • Proceedings of the KAIS Fall Conference
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    • 2010.05a
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    • pp.363-365
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    • 2010
  • 고분자 발광다이오드(polymer light emitting diode, PLED)는 초박막화, 초경량화가 가능하며 간단한 용액공정 으로 향후 휨성(flexible) 디스플레이로의 응용이 가능할 것으로 기대되고 있다. 본 연구에서는 녹색 고분자 유기 발광다이오드를 제작하고, 효율을 향상 시키고자 이중 발광층을 두어 전기 광학적 특성을 평가하였다. ITO/Glass기판 위에 정공주입층으로 PEDOT:PSS [poly(3,4-ethylenedio xythiophene):poly(styrene sulfolnate)]를 발광물질로는 형광 발광물질인 PVK(poly-vinylcarbazole)와 인광 발광 물질인 Ir(ppy)$_3$[tris(2-phenylpyridine) iridium(III)]를 각각 host와 dopant로 사용하였다. 정공 차단층 및 전자 수송층 두 개의 역할로 사용 가능한 TPBI(1,3,5-tris(2-N-phenylbenzimidazolyl) benzene)를 진공 열증착법으로 막을 형성하였다. 전자주입층으로 LiF(lithium flouride)와 음극으로 Al(aluminum)을 증착하여 최종적으로 ITO/PEDOT:PSS/PVK:Ir(ppy)$_3$/TPBI/LiF/Al 구조를 갖는 녹색 형광:인광 혼합 유기 발광 다이오드를 제작하였다.

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Fabrication of silicon Voltage Variable Capacitance Diode-II (VVC 다이오드의 시작연구(II))

  • 정만영;박계영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.7 no.2
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    • pp.33-42
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    • 1970
  • This report is concerned with the fahrication with the falricationof silicon VVC diode by the double diffusion planer technique. At first, some design charts for VVC diode were derived by considering the voltage-capacitance relations, the critical field intensity at the metallurgical junction, and the cut-off frequency of the diode. These charts enables the fabrication engineers to design VVC diode easily without going into the sophisticated design theory. We started with a 2.5 ohm-cm n-type epitaxial silicon wafer. The phosphorous was diffused by POCl3 impurity source. Then boron diffusion followed make hyperabrupt p-n junction by BN source. The maximum to minimum capacitance ratio of the diode as a tuning diode for a TV tuner made in these experiments was 4:1. Measured electrical characteristics of the sample diodes showed in good agreement with the theoretical expectations. Slicing and polishing technique of the silicon wafer and diffusion technique of the impurity atoms, which were employed in our study, are also stated briefly in this report.

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Development of Energy Efficient Smart Module with Variable Direction of Heat Flow, Heat Capacity and Surface Absorptivity (Thermo-Diode식 태양열 이용 모듈(Smart Module)개발)

  • Lee, K.J.;Chun, W.G.
    • Solar Energy
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    • v.18 no.3
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    • pp.119-128
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    • 1998
  • This study has been carried out to develop a thermo-diode system capable of adjusting heat flow direction, solar absorptivity and thermal capacity. What we call "Smart Module" here has emerged from a series of repeated processes involving design, construction and test. In all, it is found that liquid thermo-diode systems are viable in harnessing the sun's energy. The module can be applied for space heating in winter and reduce the cooling load of buildings in summer.

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