한국정보전자통신기술학회논문지 (The Journal of Korea Institute of Information, Electronics, and Communication Technology)

  • 제17권3호
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  • Pages.146-154
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  • 2024
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  • 2005-081X(pISSN)
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  • 2288-9302(eISSN)
한국정보전자통신기술학회 (Korea Information Electronic Communication Technology)
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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
  • Byeong-Yun Oh (Research and Development Department, Cheomdanlab Inc)
  • 투고 : 2024.05.30
  • 심사 : 2024.06.17
  • 발행 : 2024.06.29
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초록

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.

In this paper, we present a convenient liquid crystal (LC) molecular alignment method using brush hairs as an alternative to the rubbing process in the LC display industry. Titanium strontium yttrium zirconium oxide (TiSrYZrO) solution was prepared using a sol-gel process, and the TiSrYZrO alignment film production and LC molecular alignment were integrated through a one-step brush coating process. As the curing temperature increased, the LC molecule alignment of the LC cell improved, and the formation of a physical surface anisotropic structure due to the shear stress caused by the movement of the brush hairs on the coating surface led to uniform alignment of the LC molecules. Uniform and homogeneous LC molecular alignment was confirmed through polarizing optical microscopy and pretilt angle measurement. Through thermal oxidation using X-ray photoelectron spectroscopy, the TiSrYZrO thin film well formed of metal oxide was confirmed and verified to have excellent optical transparency. From these results, it is expected that a convenient LC molecular alignment method using brush hairs as an alternative to the rubbing process will be a viable next-generation technology.

키워드

참고문헌

  1. J. Jung, H. Park, H. Y. Jung, S. E. Jung, S. G. Kim, T. H. Kim, Y. J. Lim, B.-C. Ku, M. Kim, and S. H. Lee, "Recent progress in liquid crystal devices and materials of TFT-LCDs", Journal of Information Display, vol. 25, no. 1, pp. 121-142, 2024. 
  2. H.-W. Chen, J.-H. Lee, B.-Y. Lin, S. Chen, and S.-T. Wu, "Liquid crystal display and organic light-emitting diode display: present status and future perspectives", Light: Science & Applications, vol. 7, pp. 17168, 2018. 
  3. I. Stoica, A. I. Barzic, and C. Hulubei, "The impact of rubbing fabric type on surface roughness and tribological properties of some semi-alicyclic polyimides evaluated from atomic force measurements", Applied Surface Science, vol. 268, pp. 442-449, 2013. 
  4. T. Seki, "New strategies and implications for the photoalignment of liquid crystalline polymers", Polymer Journal, vol. 46, pp. 751-768, 2014. 
  5. D. W. Lee, E. M. Kim, G. S. Heo, J. H. Lee, D. H. Kim, J. Y. Oh, J. I. Jang, S. J. Eom, H.-C. Jeong, and D.-S. Seo, "Uniformly aligned liquid crystal molecules on reformed poly(ethylene-co-vinyl acetate) layers driven by ion beam exposure", Liquid Crystals, vol. 49, no. 2, pp. 172-181, 2021. 
  6. P. Roy, R. Mukherjee, D. Bandyopadhyay, and P. S. G. Pattader, "Electrodynamic-contact-line-lithography with nematic liquid crystals for template-less E-writing of mesopatterns on soft surfaces", Nanoscale, vol. 11, pp. 16523-16533, 2019. 
  7. J.-A. Kim, S.-H. Choi, and H.-G. Park, "Effect of Spin Coating Speed on Characteristics of Polyimide Alignment Layer for Liquid Crystal Display", Journal of the Korean Institute of Electrical and Electronic Material Engineers, vol. 35, no. 1, pp. 58-65, 2022. 
  8. J. Q. Carou, N.J. Mottram, S.K. Wilson, and B.R. Duffy, "A mathematical model for blade coating of a nematic liquid crystal blade coating", Liquid Crystals, vol. 34, no. 5, pp. 621-631, 2007. 
  9. B. Sivaranjini, R. Mangaiyarkarasi, V. Ganesh, and S. Umadevi, "Vertical Alignment of Liquid Crystals Over a Functionalized Flexible Substrate", Scientific Reports, vol. 8, pp. 8891, 2018. 
  10. D. W. Lee, E. M. Kim, G. S. Heo, D. H. Kim, J. Y. Oh, D.-H. Kim, Y. Liu, and D.-S. Seo, "A solution-derived bismuth aluminum gallium tin oxide film constructed by a brush coating method for spontaneous liquid crystal alignment", Materials Advances, vol. 3, pp. 6019-2037, 2022. 
  11. D. W. Lee, E. M. Kim, G. S. Heo, D. H. Kim, J. Y. Oh, D.-H. Kim, Y. Liu, and D.-S. Seo, "Oriented Yttrium Strontium Tin Oxide Micro/Nanostructures Induced by Brush Coating for Low-Voltage Liquid Crystal Systems", ACS Applied Nano Materials, vol. 5, pp. 6925-6934, 2022. 
  12. G. Baur, V. Wittwer, and D. W. Berreman, "Determination of the tilt angles at surfaces of substrates in liquid crystal cells", Physics Letters A, vol. 56, no. 2, pp. 142-144, 1976. 
  13. K. Shirota, M. Yaginuma, K. Ishikawa, H. Takezoe, and A. Fukuda, "Modified Crystal Rotation Method for Measuring High Pretilt Angle in Liquid Crystal Cells", Japanese Journal of Applied Physics, vol. 34, no. 9R, pp. 4905-4906, 1995. 
  14. R. Basu, "Enhancement of polar anchoring strength in a graphene-nematic suspension and its effect on nematic electro-optic switching", Physical Review E, vol. 96, pp. 012707, 2017. 
  15. J. S. Gwag, J. C. Kim, T.-H. Yoon, and S. J. Cho, "Effect of polyimide layer surfaces on pretilt angles and polar anchoring energy of liquid crystals", Journal of Applied Physics, vol. 100, no. 9, pp. 093502, 2006. 
  16. H. Hernandez-Arriaga, E. Lopez-Luna, E. Martinez-Guerra, M. M. Turrubiartes, A. G. Rodriguez, and M. A. Vidal, "Growth of HfO2/TiO2 nanolaminates by atomic layer deposition and HfO2-TiO2 by atomic partial layer deposition", Journal of Applied Physics. vol. 121, pp. 064302, 2017. 
  17. D. Jiang, X. Sun, X. Wu, L. Shi, and F. Du, "Hydrothermal synthesis of single-crystal Cr-doped SrTiO3 for efficient visible-light responsive photocatalytic hydrogen evolution", Materials Research Express, vol. 7, pp. 015047, 2020. 
  18. T. Sureshkumar, S. Thiripuranthagan, S. M. K. Paskalis, S. Kumaravel, K. Kannan, and A. Devarajan, "Synthesis, characterization and photodegradation activity of graphitic C3N4-SrTiO3 nanocomposites", Journal of Photochemistry and Photobiology A: Chemistry, vol. 356, pp. 425-439, 2018. 
  19. P. Lu, X. Hu, Y. Li, M. Zhang, X. Liu, Y. He, F. Dong, M. Fu, and Z. Zhang, "One-step preparation of a novel SrCO3/g-C3N4 nano-composite and its application in selective adsorption of crystal violet", RSC Advances, vol. 8, pp. 6315-6325, 2018. 
  20. T. Svarc, S. Stopi'c, Z. Jelen, M. Zadravec, B. Friedrich, and R. Rudolf, "Synthesis of Ni/Y2O3 Nanocomposite through USP and Lyophilisation for Possible Use as Coating", Materials, vol. 15, pp. 2586, 2022. 
  21. S. Ji, I. Chang, Y. H. Lee, J. Park, J. Y. Paek, M. H. Lee, and S. W. Cha, "Fabrication of low-temperature solid oxide fuel cells with a nanothin protective layer by atomic layer deposition", Nanoscale Research Letters, vol. 8, pp. 48, 2013. 
  22. Y. Duan, F. Sun, Y. Yang, P. Chen, D. Yang, Y. Duan, and X. Wang, "Thin-Film Barrier Performance of Zirconium Oxide Using the Low-Temperature Atomic Layer Deposition Method", ACS Applied Materials & Interfaces, vol. 6, pp. 3799-3804, 2014. 
  23. H.-G. Park, J.-J. Lee, K.-Y. Dong, B.-Y. Oh, Y.-H. Kim, H.-Y. Jeong, B.-K. Ju, and D.-S. Seo, "Homeotropic alignment of liquid crystals on a nano-patterned polyimide surface using nanoimprint lithography", Soft Matter, vol. 7, no. 12, pp. 5610-5614, 2011.