• 제목/요약/키워드: Liquid crystal (LC) alignment

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바이어스 조건하에서 증착한 a-C:H 박막을 이용한 액정배향 효과 (LC Alignment Effects using a-C:H Thin Film as Working Gas at Bias Condition)

  • 황정연;조용민;서대식;노순준;백홍구
    • 한국전기전자재료학회논문지
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    • 제16권11호
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    • pp.1019-1022
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    • 2003
  • We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of a-C:H thin film as working gas at 30W rf bias condition. A high pretilt angle of about 5$^{\circ}$ by ion beam(IB) exposure on the a-C:H thin film surface was measured. A good LC alignment by the IB alignment method on the a-C:H thin film surface was observed at annealing temperature of 250$^{\circ}C$, and the alignment defect of the NLC was observed above annealing temperature of 300$^{\circ}C$. Consequently, the high LC pretilt angle and the good thermal stability of LC alignment by the IB alignment method on the a-C:H thin film surface as working gas at 30W rf bias condition can be achieved.

The Effects of Ion Beam on the Liquid Crystal Alignment Phenomena using a-C:H Thin Films

  • Rho, Soon-Joon;Chung, Doo-Han;Jeon, Baek-Kyun;Kim, Kyeong-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.1114-1117
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    • 2004
  • We investigated the liquid crystal (LC) alignment phenomena using hydrogenated amorphous carbon (a-C:H) thin films. For LC alignment, the surface of a-C:H thin films is treated with low energy ion beam. We investigated the relationship between the properties of a-C:H thin films and LC alignment phenomena.

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Homeotropic Alignment Effect of a Nematic Liquid Crystal on Oblique Deposited SiOx Thin-film with e-beam Evaporation

  • Choi, Dai-Seub
    • Transactions on Electrical and Electronic Materials
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    • 제8권6호
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    • pp.274-277
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    • 2007
  • In this study, liquid crystal(LC) aligning capabilities for homeotropic alignment on the $SiO_x$ thin film by electron beam evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the nematic liquid crystal(NLC) treated on $SiO_x$ thin film were investigated. A high pretilt angle of about $86.5^{\circ}$ was obtained, and also the suitable pretilt angle of the NLC on the $SiO_x$ thin film at $10{\sim}50nm$ thickness with e-beam evaporation can be achieved. The uniform LC alignment and good thermal stabilities on the $SiO_x$ thin film surfaces with electron beam evaporation can be achieved. It is considered that the LC alignment on the $SiO_x$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $SiO_x$ thin film surface created by evaporation.

이온빔 에너지 밀도 조절에 따른 액정 배향 효과 (Effects of LC Alignment by Controlling Ion-beam Energy Density)

  • 박홍규;이강민;오병윤;김병용;강동훈;한진우;김영환;옥철호;한정민;이상극;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.399-399
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    • 2007
  • Recently, it is widely studied to liquid crystal (LC) alignment using ion-beam exposure. Because conventional rubbing method has some problems such as defects from dust and electrostatic charges during rubbing process. Therefore rubbing-free techniques like ion-beam method are strongly required. We studied LC alignment by controlling ion-beam energy density and electro-optical (EO) characteristics of twisted nematic LC on the polyimide surface. In this experiment, a good uniform alignment of the nematic liquid crystal (NLC) with the ion-beam exposure on the polyimide (PI) surface was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned twisted nematic liquid crystal display (TN-LCD) on PI surface.

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액정분자 배향용 원스텝 브러시 코팅으로 유도된 이방성 TiSrYZrO 박막 (Anisotropic TiSrYZrO Thin Films Induced by One-step Brush Coating for Liquid Crystal Molecular Orientation)

  • 오병윤
    • 한국정보전자통신기술학회논문지
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    • 제17권3호
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    • pp.146-154
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    • 2024
  • 본 논문에서는 액정디스플레이 산업에서 러빙공정의 대안으로 브러시 모(brush hair)를 이용한 편리한 액정분자 정렬 방식을 제시합니다. 졸겔 공정을 이용해서 타이타늄 스트론튬 이트륨 지르코늄 산화물(TiSrYZrO) 용액을 제조하였고, 원스텝(one-step) 브러시 코팅 공정을 통해 TiSrYZrO 배향막 제조와 액정분자 배향을 통합하였다. 경화온도가 높아짐에 따라 액정 셀의 액정분자 정렬 상태가 향상되었고, 코팅 표면의 brush hair 움직임에 의한 전단 응력에 기인하는 물리적 표면 이방성 구조 형성으로 인해 균일한 액정분자 정렬을 유도하였다. 균일하고 균질한 액정분자 정렬은 편광 광학 현미경과 선경사 각 측정을 통해 확인하였다. X-선 광전자 분광법으로 열산화를 통해 금속산화물로 잘 형성된 TiSrYZrO 박막을 확인하였고, 우수한 광학 투명성이 있음을 검증하였다. 이러한 결과로부터 러빙공정의 대안으로 brush hair를 이용한 편리한 액정분자 정렬 방식이 실행 가능한 차세대 기술이 될 것이라고 기대된다.

Stamping-assisted Fabrication Technique of the Bidirectional Alignment Layer for Wide-Viewing Twisted-Nematic Liquid Crystal Displays

  • Koo, Kyung-Mo;Na, Jun-Hee;Kim, Yeun-Tae;Li, Hongmei;Lee, Sin-Doo
    • Journal of Information Display
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    • 제10권4호
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    • pp.180-183
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    • 2009
  • A stamping-assisted rubbing technique for generating bidirectional alignment in the fabrication of wide-viewing twistednematic (TN) liquid crystal displays (LCDs) was developed. A patterned layer of a fluorinated acrylate polymer was transferred onto the first rubbed alignment layer prepared on a substrate by stamping. The fluorinated acrylate polymer provides a protective layer that covers the first alignment layer during the second rubbing process to facilitate the bidirectional alignment of the LC molecules. The LC cell in the twisted geometry with two bidirectional-alignment layers showed stable electro-optic properties and wide-viewing characteristics. The stamping-assisted rubbing technique serves as a mask-free alignment method of producing multidomains for wide-viewing LCDs.

DLC 박막을 이용한 액정 배향 효과 (Liquid Crystal Alignment Effects using a DLC Thin Film)

  • 조용민;황정연;서대식;노순준;이대규;백홍구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.346-349
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    • 2001
  • We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of diamond like carbon (DLC) thin film. A high pretilt angle of about $4^{\circ}$ was measured by ion beam(IB) exposure on the DLC thin film surface. A good LC alignment was observed by the IB alignment method on the DLC thin film surface at annealing temperature of $200^{\circ}C$, and the alignment defect of the NLC was observed above annealing temperature of $220^{\circ}C$. Consequently, the high NLC pretilt angle and the good thermal stability of LC alignment can be achieved by the IB alignment method on the DLC thin film surface.

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DLC 박막을 이용한 액정 배향 효과 (Liquid Crystal Alignment Effects using a DLC Thin Film)

  • 조용민;황정연;서대식;노순준;이대규;백흥구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.346-349
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    • 2001
  • We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of diamond like carbon (DLC) thin film. A high pretilt angle of about 4$^{\circ}$ was measured by ion beam(IB) exposure on the DLC thin film surface. A good LC alignment was observed by the IB alignment method on the DLC thin film surface at annealing temperature of 200$^{\circ}C$, and the alignment defect of the NLC was observed above annealing temperature of 220$^{\circ}C$ . Consequently, the high NLC pretilt angle and the good thermal stability of LC alignment can be achieved by the IB alignment method on the DLC thin film surface.

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전사배향 TN-LCD의 액정배향 및 전기광학특성 (Liquid crystal alignment and EO performance of transcription-aligned TN-LCD)

  • 서대식;김진호
    • 한국전기전자재료학회논문지
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    • 제11권12호
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    • pp.1133-1138
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    • 1998
  • In this paper, we obtained the monodomain alignment of nematic liquid Crystal(NLC) in the cell fabricated by transcription alignment method on polyimide(PI) surface with side chain. It is considered that the LC alignment produced by the transcription alignment method is attributed to a memory effect of the NLC on PI surfaces. Also we observed that the generated pretilt angle of NLC is about $3.7^{\circ}$ with transcription alignment on PI surface. Next, we measured that the voltage-transmittance characteristics of transcription-aligned TN-LCD are almost same compared to rubbing-aligned TN-LCD. Also, we measured that the curve of transcription-aligned TN-LCD is less sharp than that of the rubbing-aligend TN-LCD in the decay time characteristics. It is considered that the response time characteristics of transcription-aligned TN-LCD are attributed to the weak anchoring strength between the LC molecules and the polymer surface.

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Diamond-like Carbon 박막을 이용한 액정 배향 효과 (Liquid Crystal Alignment Effects using a Diamond-like Carbon Thin Film)

  • 황정연;조용민;서대식;노순준;이대규
    • 한국전기전자재료학회논문지
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    • 제15권5호
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    • pp.419-422
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    • 2002
  • We studied the nematic liquid crystal (NLC) aligning capabilities using the new alignment material of a diamond like carbon (DLC) thin film. A high pretilt angle of about $3.5^{\circ}$ by ion beam(IB) exposure on the DLC thin film surface was measured. A good LC alignment by the IB alignment method on the DLC thin film surface was observed at annealing temperature of $200^{\circ}C$, and the alignment defect of the NLC was observed above annealing temperature of $220^{\circ}C$. Consequently, the high NLC pretilt angle and the good thermal stability of LC alignment by the IB alignment method on the DLC thin film surface can be achieved.