DOI QR코드

DOI QR Code

Aligning Capabilities for Vatical-Alignment (VA) Liquid Crystal Display using AZO Film

  • Oh, Yong-Cheul (Department of Electrical Engineering, Kwangwwon University)
  • Published : 2006.12.01

Abstract

We have investigated liquid crystal (LC) aligning capabilities and electro-optical (EO) characteristics of transparent electrodes as Al-doped ZnO (AZO) substituting indium tin oxide (ITO). The experiment results show that a uniform vertical LC alignment on AZO electrodes based on a rubbed polyimide (PI) surface were achieved. A high pretilt angle of about $88^{\circ}$ was obtained. EO performances of the VA cell on rubbed PI surfaces with AZO electrodes are almost the same as that of the VA cell with ITO electrodes. These results appeared that AZO electrodes as transparent electrodes of LCDs could substitute ITO electrodes.

References

  1. C. C. Wu, C. I. Wu, J. C. Sturm, and A. Kahn, 'Surface modification of indium tin oxide by plasma treatment: An effective method to improve the efficiency, brightness, and reliability of organic light emitting devices', Appl. Phys. Lett., Vol. 70, p. 1348, 1997
  2. H. Kobayashi, T. Ishida, Y. Nakato, and H. Tsubomura, 'Mechanism of carrier transport in highly efficient solar cells having indium tin oxide/Si junctions', J. Appl. Phys., Vol. 69, p. 1736, 1991
  3. J. Hu and R. G. Gordon, 'Textured aluminum -doped zinc oxide thin films from atmospheric pressure chemical-vapor deposition', J. Appl, Phys., Vol. 71, p, 880, 1992 https://doi.org/10.1063/1.351309
  4. J.-Y. Hwang, D.-S. Sea, E.-J. Hahn, and J.-H. Kim, 'Liquid crystal alignment effects for the photo-aligned VA-LCD on the photo-polymer', Trans. EEM, Vol. 1, p. 3, 2000
  5. Y.-M. Jo, J.-Y. Hwang, D.-S. Seo, and S.-K. Lee, 'Alignment effects for nematic liquid crystal on a new diamond-like carbon layer', Trans. EEM, Vol. 3, p. 1, 2002
  6. J.-Y. Hwang, D.-S. Sea, and E.-J. Hahn, 'Electro-optical characteristics of photoaligned vertical-alignment cells on photo-crosslinkable copolymer surfaces containing cholesteryl moiety', Liq. Cryst., Vol. 29, p. 4, 2002
  7. C.-J. Park, J.-Y. Hwang, H.-K. Kang, H.-J Ahn, J.-B. Kim, K.-C. Kim, H.-K. Baik, and D.-S. Seo, 'Liquid crystal alignment effects and electro optical performances of twisted nematic-liquid crystal display using ion-beam alignment method on nitrogen doped diamond-like carbon thin film layer', Jpn. J. Appl. Phys., Vol. 44, p. 1352, 2005 https://doi.org/10.1143/JJAP.44.1352
  8. H.-K. Kang, J.-Y. Hwang, C.-J. Park, K-C. Kim, H.-J. Ahn, J.-B. Kim, H.-K. Baik, and D.-So Seo, 'Liquid crystal alignment effects using a SiO thin film', Mol. Cryst. Liq. Cryst., Vol. 434, p. 135, 2005 https://doi.org/10.1080/15421400590954876
  9. J.-Y. Hwang, K.-J. Lee, T.-H. Kim, and D.-S. Seo, 'Electrooptical characteristics of multidomain vertical-alignment liquid crystal display using a grating surface with a homeotropic photopolymer', Jpn. J. Appl, Phys., Vol. 42, p. L672, 2003 https://doi.org/10.1143/JJAP.42.672
  10. H.-Y. Kim, J.-H. Kim, E.-J. Hahn, and D.-S. Seo, 'Residual d.c. characteristics in the in-plane switching liquid crystal display by the capacitance-voltage hysteresis method on a polymer surface', Liq. Cryst., Vol. 29, p. 1051, 200 https://doi.org/10.1080/02678290210148758
  11. S.-K. Lee, J.-M. Han, J.-Y. Hwang, and D.-S. Seo, 'Washing effects on generation of pretilt angle in NLC, 5CB, on a polyimide surface with trifluoromethyl moieties', Trans. EEM, Vol. 4, p. 21, 2003