• Title/Summary/Keyword: crystalline

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Dielectric Properties of Liquid Crystalline Polymer (고분자액정의 유전특성)

  • Kang, Dae-Ha;Lee, Jae-Hoon;Park, Sang-Ho;Choi, Phil-Soo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1266-1267
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    • 2008
  • Liquid crystalline polymer BB-3(1-methyl) takes two kinds of glass phases which are liquid crystalline glass and liquid glass below the glass temperature. This study is aimed to analyze the phase transitions of those samples with variation of temperature. For the analyzing temperature dispersion of dielectric constants was measured and the results were analyzed.

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Synthesis and Properties of Liquid Crystalline Y-shaped Molecules Containing 1,3,4-Oxadiazole

  • Kwon, Eun-Kyoung;Choi, E-Joon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.542-544
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    • 2007
  • New liquid crystalline Y-shaped molecules containing 1,3,4-oxadizoles have been synthesized with variation of terminal groups (R = H, $OCH_3$ or $OC_8H_{17}$). The structures of obtained compounds were identified by FT/IR and NMR spectrometry, and their thermal and liquid crystalline properties were investigated by DSC and polarizing optical microscope.

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Preparation of Self-Assembled Crystalline Microparticles with Bispyridyl Zn-Porphyrin

  • Lee, Da-Hee;Lee, Suk-Joong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.4
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    • pp.1317-1320
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    • 2012
  • Well-defined solid-state microcrystalline structures from bispyridyl Zn-porphyrin have been successfully synthesized. The coordinative interactions between pyridine and Zn are main responsible for this translation of porphyrin molecular building blocks to crystalline microscopic objects. The hexagonal plates are obtained from acetonitrile and rhombus plates are grown from toluene solution. With a simple manipulation during the microcrystal growth, such as growth temperature and time, the morphologies can be controlled by adopting different molecular packing. Consequently, morphologies of microcrystals have been diversified.

Fiber Laser를 이용한 다결정 태양전지 Surface Texturing

  • Kim, Tae-Hun;Kim, Seon-Yong;Go, Ji-Su;Park, Hong-Jin;Kim, Gwang-Yeol;Choe, Byeong-Deok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.270-270
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    • 2009
  • The surface texturing technology is one of the methods to improve the efficiency of crystalline silicon solar cell. This process reduced the reflectance at the surface by the so-called double bounce effect and increased the light trapping. Among these surface texturing technology, the laser texturing is effective for multi-crystalline silicon solar cells which have random crystallographic directions. We investigated the characteristics of laser processing on the surface of the multi-crystalline silicon solar cells using the fiber laser.

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Investigation of Ni Silicide formation for Ni/Cu contact formation crystalline silicon solar cells (Ni/Cu 금속 전극이 적용된 결정질 실리콘 태양전지의 Ni silicide 형성의 관한 연구)

  • Lee, Ji-Hun;Cho, Kyeong-Yeon;Lee, Soo-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.434-435
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    • 2009
  • The crystalline silicon solar cell where the solar cell market grows rapidly is occupying of about 85% or more. high-efficiency and low cost endeavors many crystalline silicon solar cells. the fabrication processes of high-efficiency crystalline silicon solar cells necessitate complicated fabrication processes and Ti/Pd/Ag contact, however, this contact formation processed by expensive materials. Ni/Cu contact formation is good alternative. in this paper, according to temperature Ni silicide makes, produced Ni/Cu contact solar cell and measured conversion efficiency.

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The study of recrystallization of willemite crystal in ceramic glaze (도자기용 아연 결정유의 재결정화 연구)

  • Lee, Hyun-Soo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.4
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    • pp.136-142
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    • 2020
  • Crystallization of zinc crystalline glaze requires demanding conditions such as the formation of a nucleating agent and the amount of nucleating agent, and growth of crystalline. Zinc crystalline glaze is hard to utilize in the industry because of its narrow range of the firing temperature, and the crystallization's dependency on the quality of zinc. Stimulation of zinc crystallization and formation of frit enable zinc crystalline glaze to be reconstituted in a various range of firing schedules, leading to the development of a competitive industrial glaze.

Fabrication of poly-crystalline silicon ingot for solar cells by CCCC method (CCCC법에 의한 태양전지용 다결정 실리콘 잉고트의 제조)

  • Shin J. S.;Lee D. S.;Lee S. M.;Moon B. M.
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.94-97
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    • 2005
  • For the fabrication of poly-crystalline silicon ingot, CCCC (Cold Crucible Continuous Casting) method under a high frequency alternating magnetic field, was utilized in order to prevent crucible consumption and ingot contamination and to increase production rate. In order to effectively and continuously melt and cast silicon, which has a high radiation heat loss due to the high melting temperature and a low induction heating efficiency due to a low electric conductivity, Joule and pinch effects were optimized. Throughout the present investigation, poly-crystalline Si ingot was successfully produced at the casting speed of above 1.5 mm/min under a non-contact condition.

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Properties of Single Crystalline 3C-SiC Thin Films Grown with Several Carbonization Conditions (여러 탄화조건에 따라 성장된 단결정 3C-SiC 박막의 특성)

  • Shim, Jae-Cheol;Chung, Gwiy-Sang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.11
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    • pp.837-842
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    • 2010
  • This paper describes the crystallinity, growth rate, and surface morphology of single crystalline 3C-SiC (cubic silicon carbide) thin films grown with several carbonization conditions such as temperature, $C_3H_8$ flow rate, time. In case of carbonization, an increase in the carbonization temperature caused a increase in the size and numbers of unsealed void (big black spot) which decrease the crystallinity. In addition, optimal $C_3H_8$ flow rate made carbonization layer form well and prevented the formation of voids. Also, after a period of time, the growth of carbonization layer did not increase no more. The single crystalline 3C-SiC thin films on optimal carbonized Si substrate showed an improvement on the crystallinity, the growth rate, the roughness, and the carrier concentration.

The influence of a magnetic field on a crystalline structure of carbon nitride deposition (질화탄소 박막 증기 증착 시 자장이 결정 구조 성장에 미치는 영향)

  • 김종일;배선기;박희석
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.165-169
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    • 2001
  • Carbon nitride films were grown on Si (100) substrate by a laser-electric discharge method with and without a magnetic field assistance. The magnetic field leads to vapor plume plasma expending upon the ambient arc discharge plasma area. Influence of the magnetic field has resulted in increase of a crystallite size in the films due to bombardment (heating) of Si substrates by energetic carbon and nitrogen species generated during cyclotron motion of electrons in the discharge zone. Many crystalline grains were observed in the morphology of the deposited films by scanning electron microscopy. In order to determine the structural crystalline parameters, X-ray diffraction (XRD) was used to analysis the grown films.

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A Study of low cost and high efficiency Solar Cell using SOD(spin on doping) (SOD(Spin On Doping)법을 이용한 저가 고효율 태양전지에 관한 연구)

  • Park, Sung-Hyun;Kim, Kyoung-Hae;Mon, Sang-Il;Kim, Dae-Won;Yi, Jun-Sin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1054-1056
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    • 2002
  • High temperature Kermal diffusion from $POCl_3$ source usually used for conventional process through put of a cell manufacturing line and potentially reduce cell efficiency through bulk like time degradation. To fabricate high efficiency solar cells with minimal thermal processing, spin-on-doping(SOD) technique can be employed to emitter diffusion of a silicon solar cell. A technique is presented to emitter doping of a mono-crystalline solar cell using spin-on doping (SOD). Moreover it is shown that the sheet resistance variation with RTA temperature and time fer mono-crystalline and multi-crystalline silicon samples. This novel SOD technique was successfully used to produces 11.3% efficiency l04mm by 104mm size mono-crystalline silicon solar cells.

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