• Title/Summary/Keyword: HOMO

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New Fluorene-Based Polyquinoxalines with Ether-Linkage in The Main Chain: Synthesis and Light-Emitting Properties

  • Jung, Sung-Hyun;Kim, Dong-Young;Cho, Hyun-Nam;Won, You-Tae;Suh, Dong-Hack
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.937-939
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    • 2003
  • We synthesized and characterized new fluorene-based polyquinoxalines with ether-linkage in the main chain, which have luminescent properties. Cyclic voltammetry reveals that these polymers have a low-lying LUMO and HOMO energy levels. Therefore, the polymers would be attractive candidates for electron-tansporting or hole-blocking materials in LEDs.

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Models of Possible Trapping Sites in Homo-Charged PVF (호모로 대전된 PVF박막에서 트랩위치의 제시)

  • 김광영;김기준;황병호;홍진웅;이준웅
    • Electrical & Electronic Materials
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    • v.3 no.2
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    • pp.99-104
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    • 1990
  • 두께 30[.mu.m]의 코로나 대전된 포리비닐후로라이드 박막에 전압 -3~-6[kV]를 인가한 후, 온도범위 -100~200[.deg.C]에서 열자격 전류를 측정하였다. 결과로 .betha., .alpha. 그리고 .delta. 피크가 온도 -40, 40 그리고 90[.deg.C] 부근에서 각각 나타났다. 이들 피크의 기원으로 첫째 .betha. 피크는 카보닐기의 기여로 둘째로 .alpha. 피크는 주쇄와 비정질 영역의 측쇄에 트랩된 캐리어의 탈트랩의 기여로 나타났고 끝으로 .delta. 피크는 비정질 영역 또는 비정질과 결정질 영역 사이의 경계에 트랩된 캐리어의 탈트랩에 기여로 사료된다.

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양자계산을 통한 CuPC의 전자구조 특성 분석

  • Gang, Yeong-Ho
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.467-471
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    • 2014
  • 유기 반도체 물질로서 활발히 연구되고 있는 CuPC의 기체 및 고체상에 대한 전자구조 분석을 진행하였다. CuPC는 기체상에서는 4 eV 이상의 큰 HOMO-LUMO gap을 가지고 있지만 고체가 되면 ~2 eV 정도의 gap을 나타내게 된다는 것을 밝혔다. 특히 GW 계산을 이용하여 고체에서 전자의 screening 효과는 IP와 EA를 기체에 비해 상당히 변화시킨다는 것을 알아냈고 이는 CuPC와 같은 유기 분자로 이루어진 고체의 전자구조 결정에 polarizable medium을 잘 기술하는 것이 중요한 역할을 한다는 것을 발견하였다.

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Poly(fluorene)s for LED Applications

  • Lee, Jeong-Ik;Zyung, Tae-Hyoung;Klaerner, Gerrit;Miller, Robert D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.129-130
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    • 2000
  • The emission color stability of poly(fluorene) derivatives upon thermal annealing or passage of current in an electroluminescent device is affected by the structure of the main chain polymer unit and particularly by the polymer chain end substituents. Proper attention to these features leads to colorfast blue emission in both photo- and electoluminescence. Furthermore, the spectral emission characteristics can be tuned by the incorporation of various comonomers. Preliminary single layer device studies validate the potential utility of poly(fluorene) homo and copolymers for OLED applications.

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Investigation on Contact Resistance of Amorphous Indium Gallium Zinc Oxide Thin Film Transistors with Various Electrodes by Transmission Line Method

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.3
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    • pp.139-141
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    • 2015
  • Contact resistance of interface between the channel layers and various S/D electrodes was investigated by transmission line method. Different electrodes such as Ti/Au, a-IZO, and multilayer of a-IGZO/Ag/a-IGZO were compared in terms of contact resistance, using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes showed good performance and low contact resistance due to the homo-junction with channel layer.

BioCovi: A Visualization Service for Comparative Genomics Analysis

  • Lee, Jungsul;Park, Daeui;Bhak, Jong
    • Genomics & Informatics
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    • v.3 no.2
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    • pp.52-54
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    • 2005
  • Visualization of the homology information is an important method to analyze the evolutionary and functional meanings of genes. With a database containing model genomes of Homo sapiens, Mus muculus, and Rattus norvegicus, we constructed a web­based comparative analysis tool, BioCovi, to visualize the homology information of mammalian sequences on a very large scale. The user interface has several features: it marks regions whose identity is greater than that specified, it shows or hides gaps from the result of global sequence alignment, and it inverts the graph when total identity is higher than the threshold specified.

유통경로구조의 결정요인에 관한 연구 - 주요산업별(석유, 가전, 간이음식, 주류, 자동차) 비교 연구 -

  • 오세조;임영균;박종희;이승창
    • Journal of Distribution Research
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    • v.1 no.1
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    • pp.147-196
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    • 1996
  • The objective of this study is th analyse the determinant factors of the marketing channel structures in the five industries, including homo-electronics, automobile, oil, liquors, and fast-food industries, on the basis of the transaction cost TCA and to develop the complementary and exensive conceptuai model for understanding the determinants of the channel structures. TCA is relatively weak and besides of the TCA varkables other environmental or relational variables are more likely to dorminate the channel structuring.

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Synthesis of Diaryl $\alpha$-Diketones via Palladium Catalyzed Double Carbonylative Homo Coupling of Aryl Iodides with Carbon Monoxide

  • Kim Jin Il;Kim Nam Jung;Ryu Cheol Mo
    • Bulletin of the Korean Chemical Society
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    • v.9 no.1
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    • pp.30-32
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    • 1988
  • Symmetrical diaryl ${\alpha}-diketones$ were synthesized in moderately good yields through the palladium catalyzed reaction of aryl iodides with carbon monoxide. The reaction was tolerant of a wide variety of fuctionalities($OCH_3,\;CH_3,\;NO_2,\;OH,\;COOH$) on the aryl iodide. On the other hand, the similar reaction of aryl bromides or chlorides with carbon monoxide did not proceed.