• 제목/요약/키워드: Optical conductivity

검색결과 380건 처리시간 0.035초

A Development of Coatable Conductive Polymer (코팅가능한 전도성 고분자 개발)

  • 김종은;심재훈;서광석;윤호규;구자윤;박영인
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.223-226
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    • 1998
  • Organic conducting N-methyl phenazinium TCNQ (7,7,8,8-tetracyanoquinonedimethane) ion radical salt was synthesized and characterized by FTIR, EA. After blending this material with PMMA using NMP/DMF, the solution was bar-coated on a PET film and dried at 40$^{\circ}C$. The optical micrograph showed the fibril crystals. The surface resistivity was 10$\^$5/ $\Omega$/$\square$. The conductivity decreased considerably at temperatures above 80$^{\circ}C$, although it decreased slightly at RT and 4$^{\circ}C$.

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A photoswitch from conjugative aromatic polymers

  • Kwon, Tae-Chang;Kim, Yong-Jung;Kim, Yu-Na;Lee, Hyo-Jin;Rameshbabu Krishnamurthy;Sarwade Bhimrao D.;Kim, Eun-Kyoung
    • Proceedings of the Polymer Society of Korea Conference
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.174-174
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    • 2006
  • By condensing two different functional monomers, highly fluorescent aromatic polymers were prepared to produce a conjugated- conjugated spacer-type copolymer or conjugated-non-conjugated spacer-type copolymer. As synthesized polymers were soluble in an organic solvent and showed significantly enhanced optical properties compared to its monomer. Variation in the monomer composition afforded polymers having multifunctionaility such as photochromic-fluorescent polymers. Transparent thin films of the polymer as a solid medium were prepared using spin coating method and fabricated as a photoswitch, which showed photo-induced conductivity switching properties depending on the core monomeric unit in the polymers.

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A brief review on graphene applications in rechargeable lithium ion battery electrode materials

  • Akbar, Sameen;Rehan, Muhammad;Liu, Haiyang;Rafique, Iqra;Akbar, Hurria
    • Carbon letters
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    • 제28권
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    • pp.1-8
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    • 2018
  • Graphene is a single atomic layer of carbon atoms, and has exceptional electrical, mechanical, and optical characteristics. It has been broadly utilized in the fields of material science, physics, chemistry, device fabrication, information, and biology. In this review paper, we briefly investigate the ideas, structure, characteristics, and fabrication techniques for graphene applications in lithium ion batteries (LIBs). In LIBs, a constant three-dimensional (3D) conductive system can adequately enhance the transportation of electrons and ions of the electrode material. The use of 3D graphene and graphene-expansion electrode materials can significantly upgrade LIBs characteristics to give higher electric conductivity, greater capacity, and good stability. This review demonstrates several recent advances in graphene-containing LIB electrode materials, and addresses probable trends into the future.

A Backlight Feedback Control System with Integrated Color Sensor on LCD

  • Lee, Ki-Chan;Park, Yun-Jae;Ko, Hyun-Seok;Moon, Seung-Hwan;Park, Jin-Hyeok;Berkeley, Brian;Kim, Sang-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1550-1551
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    • 2005
  • In this paper, to improve the well-known photo conductivity degradation of amorphous silicon, a new LASER immersion treatment has been applied. The optical feedback control LED backlighting system with integrated LCD panel sensor increased the color variation less than 0.008 ${\Delta}u'v'$ compared to 0.025 for a non-feedback system.

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Plastic Substrate for Flexible TFT LCD

  • Hwang, Hee-Nam;Choi, Jae-Moon;Yeom, Eun-Hee;Park, Yong-Ho;Kim, Lee-Ju;You, Ho-Young;Lee, Ki-Ho;Kim, In-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1406-1408
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    • 2006
  • Plastic substrate for flexible TFT LCD is developed. The gas barrier, optical properties and conductivity in the substrate is improved through depositing silicon oxide/nitride layer and ITO layer, coating polymer layer on plastic film by sputtering process and wet coating process. The whole production process of the plastic substrate is guaranteed the productivity by using roll to roll process.

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Controlling Preferred Orientation of ITO Thin Films by RF-Magnetron Sputtering Method

  • Park, Ju-O;Kim, Jae-Hyung;Lee, Joon-Hyung;Kim, Jeong-Joo;Cho, Sang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.818-821
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    • 2003
  • Sn-doped $In_{2}O_{3}$ (ITO) thin film is one of the materials widely on research not only in the academic fields but also in industrial fields because of their transparency, high conductivity and good adhesion characteristics on substrate. ITO thin films are usually preferred oriented to one of the (222), (400), and (440) planes during crystallization process, which is dependent on processing variables. The preferred orientation affects electrical, optical and etching properties of the films. In this study, thin films of preferred oriented in different orientation were fabricated by controlling processing variables. The crystallization behavior, grain size, surface roughness, transparency and electrical properties of the thin films in different orientation were examined.

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Preparation of Carbon Fiber from Heavy Oil Residue through Bromination

  • Park, Young-Ok;Yang, Kap-Seung
    • Fibers and Polymers
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    • 제2권4호
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    • pp.178-183
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    • 2001
  • A pitch precursor for a general purpose carbon fiber was prepared by condensation of pyrolized fuel oil (petroleum residual oil) with bromine under nitrogen blowing. such a condensation raised the softening point of the pitch from 4$0^{\circ}C$ to $265^{\circ}$ with a yield of 43%. The pitch precurosr showed an enhanced aromaticity and enlarged molecular size, which led to a reduction in molecular mobility and optical isotropy. The precursor was spun into fibers of $20\mu\textrm{m}$ diameter at a take-up speed of 700m/min. The fiber was stepwise stabilized in air and carbonized in Ar gas to obtain an isotropic carbon fiber. The carbon fiber exhibited tensile strengths of 500-800 ㎫though the fiber was formed via a crude method. The electric conductivity of the carbon fiber was relatively high, 2.2$\times$$10^2$S/cm, sufficient to be used as electrode materials.

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Carbon nanotube antennas analysis and applications: review

  • El-sherbiny, Sh.G.;Wageh, S.;Elhalafawy, S.M.;Sharshar, A.A.
    • Advances in nano research
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    • 제1권1호
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    • pp.13-27
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    • 2013
  • Carbon nanotube characterized by additional inductive effect as compared with the traditional conductors like copper wires of the same size. Consequently, carbon nanotubes have high characteristic impedance and slow wave propagation in comparison with traditional conductors. Due to these characteristics, carbon nanotubes can be used as antenna. In view of this, we describe and review the present research progress on carbon nanotube antennas. We present different analysis models and results which are developed to investigate the characteristics of CNT antennas. Then we conclude by summarizing the characteristics of CNT antennas and specifying the operating frequency limit.

Annealing Effect on Structural, Electrical and Optical Properties of CdS Films Prepared by CBD Method

  • Haider, Adawiya J.;Mousa, Ali M.;Al-Jawad, Selma M.H.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제8권4호
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    • pp.326-332
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    • 2008
  • In this work CdS films were prepared by using chemical bath deposition, which is simple and inexpensive technique suitable for large deposition area. Annealing in air at different temperatures (300, 350, 400, 450 and $500^{\circ}C$) at constant time of 30 min, also for different times (15, 30, 45, 60 and 90 min) at constant temperature ($300^{\circ}C$) is achieved. X-Ray analysis has confirmed the formation of cadmium oxide (CdO) with slight increase in grain size, shift towards lower scattering angle due to relaxation in the tensile strain for deposition films, and structure change from cubic and hexagonal to the hexagonal. From electrical properties, significant increase in electrical conductivity appeared in samples annealed at $300^{\circ}C$ for 60 min, and at $350^{\circ}C$ for 30 min.

A Study on Combined Heat Transfer in a Enclosure with a Block (밀폐공간내의 피가열체 존재시 복합열전달에 관한 연구)

  • Hong, Seong-Kook;Ryou, Hong-Sun;Hong, Ki-Bae;Chae, Soo
    • Journal of the Korean Society of Safety
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    • 제15권1호
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    • pp.19-27
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    • 2000
  • This paper numerically deals with combined heat transfer in a enclosure with a block. The block affected by hot wall is located centrally in the enclosure with a radiating gray gas. The discrete ordinate method(DOM) was used for solving the radiative transfer equation. Both laminar and turbulent cases were investigated for various Rayleigh number and standard k-$\varepsilon$ model was adopted to turbulent case. The effects of optical thickness, wall emissivity and fluid-solid thermal conductivity ratio are investigated on the flow and temperature fields. This study shows that as the wall emissivity decreases, the temperature distribution gradually becomes uniform and the heat transfer is reduced in enclosure. It is expected that this study can help to design the energy system related to the combined heat transfer and operate it safely.

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