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Taehoon Yoon - One of the best experts on this subject based on the ideXlab platform.

  • 27 3 2 d confinement of lcs with virtual walls for a fast response lcd
    SID Symposium Digest of Technical Papers, 2017
    Co-Authors: Taehoon Choi, Yeongyu Choi, Seungwon Oh, Jaehyeon Woo, Taehoon Yoon
    Abstract:

    We report a simple method for reducing the response time of homogeneously aligned liquid crystal (LC) cells by using two-dimensional confinement of the LCs. We have shown that the switching speed can be increased by serval fold in in-plane switching and fringe-field switching cells by introducing interdigitated Electrodes parallel to the LC alignment direction. We also report an interdigitated pixel Electrode Structure with alternating tilts for a much wider viewing angle by aligning the LCs without a pretilt. In addition to a short response time and wide viewing angle, this device allows a much larger deviation of the LC alignment direction which is essential for mass production. Moreover, LCs with negative dielectric anisotropy can be used to minimize the transmittance decrease.

  • interdigitated pixel Electrodes with alternating tilts for fast fringe field switching of liquid crystals
    Optics Express, 2016
    Co-Authors: Taehoon Choi, Yeongyu Choi, Jaehyeon Woo, Taehoon Yoon
    Abstract:

    We propose an interdigitated pixel Electrode Structure with alternating tilts for fast fringe-field switching of liquid crystals (LCs). In contrast to an LC cell, where the pixel Electrodes are parallel to the LC alignment direction, this device does not require a non-zero pretilt angle, owing to an obliquely applied electric field; thus, it can retain a much wider viewing angle by aligning the LCs without a pretilt. In addition to a short response time and wide viewing angle, the proposed device allows a much larger deviation of the LC alignment direction, which is essential for mass production. Moreover, LCs with negative dielectric anisotropy can be used to minimize the transmittance decrease.

  • electro optical characteristics of an in plane switching liquid crystal cell with zero rubbing angle dependence on the Electrode Structure
    Optics Express, 2016
    Co-Authors: Taehoon Choi, Yeongyu Choi, Seungwon Oh, Taehoon Yoon
    Abstract:

    When an electric field is applied to in-plane switching (IPS) and fringe-field switching (FFS) cells with zero rubbing angle, virtual walls are built such that the switching speed can be increased several-fold. In this study, we investigate the dependence on the interdigitated Electrode Structure of the electro-optical characteristics of IPS and FFS cells with zero rubbing angle. We found that when the rubbing angle is zero, the single-layered IPS Electrode Structure provides a higher transmittance than the double-layered FFS Electrode Structure because of the reduced width of dead zones at domain boundaries between interdigitated Electrodes. Single-layered IPS Electrodes not only minimize the transmittance decrease but also provide a shorter response time than double-layered FFS Electrodes, although the operating voltage is higher and fabrication requires a more precise rubbing process. The transmittance decrease due to the zero rubbing angle in an IPS cell can be minimized using optimization of the Electrode Structure while retaining a short response time.

  • in plane switching of vertically aligned negative liquid crystals for high transmittance and wide viewing angle
    Applied Optics, 2013
    Co-Authors: Jungwook Kim, Kihan Kim, Dong Han Song, Sungtae Shin, Taehoon Yoon
    Abstract:

    We propose a method for in-plane switching of vertically aligned negative liquid crystals (LCs) for high transmittance and wide viewing angle. By applying an in-plane electric field using a double-layered Electrode Structure, LC molecules can be rotated by the vertical as well as the in-plane components of the applied field over the entire region so that high transmittance can be achieved. The threshold voltage difference can be obtained simply by varying the Electrode Structure, which can reduce the off-axis gamma shift in a multidomain vertical alignment LC cell.

  • pixel Electrode Structure for high transmittance in a multi domain vertical alignment liquid crystal display device
    Journal of Physics D, 2012
    Co-Authors: Kihan Kim, Eunyoung Jeon, Byung Wok Park, Dong Han Song, Jihoon Lee, Gak Seok Lee, Kichul Shin, Hee Seop Kim, Taehoon Yoon
    Abstract:

    We propose a pixel Electrode Structure for the multi-domain vertical alignment liquid crystal mode with high optical efficiency. We form a micro-slit Electrode Structure on the top substrate to reduce the width of disclination lines at domain boundaries. We insert additional Electrodes on the bottom substrate to improve the transmittance at the edges of each pixel. We confirm that using both Structures, the transmittance can be increased from 22.9% to 27.3% with no change in the operating voltage.

Yong Li - One of the best experts on this subject based on the ideXlab platform.

  • Structure models and nano energy system design for proton exchange membrane fuel cells in electric energy vehicles
    Renewable & Sustainable Energy Reviews, 2017
    Co-Authors: Jie Yang, Yong Li, Jian Song
    Abstract:

    Electric vehicles require fuel cells with a highly specific energy for the purpose of environmental protection and energy saving. However, proton exchange membrane vehicle fuel cells (PEMFC) face problems in terms of energy conversion efficiency, power density, costs and lifespan. This paper reviews key technical issues regarding the application of vehicle PEMFC especially the integration of nano-electro-catalytic energy system with high-performance electrolyte membranes. It also discusses the relation between vehicle PEMFC membrane Structures and Electrode performance revealing the nanoStructured system model and the membrane Electrode interface characterization. Manipulation of vehicle PEMFC Electrode Structure and quantitative characterization of the nanoscale catalyst interface are summarized aiming at improving Pt utilization efficiency, ionic conductivity and nano membrane Electrode performance.

Huamin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • novel Electrode Structure for dmfc operated with liquid methanol
    Electrochemistry Communications, 2006
    Co-Authors: Zhigang Shao, Wenfeng Lin, Fuyun Zhu, P A Christensen, Huamin Zhang
    Abstract:

    Abstract Novel Electrode Structures for the direct methanol fuel cell (DMFC) based on Ti mesh are reported. A new anode with a hydrophilic Structure prepared by coating Pt–Ru catalyst on Ti mesh using thermal decomposition showed a performance comparable to that of the conventional porous carbon-based Structure one in DMFC, whilst a cathode with the same Structure showed a poor performance. When a porous Structure based on Ti mesh pre-coated with carbon was used as the cathode Structure, the performance increased significantly to reach that of conventional carbon paper-based cathode.

  • composite Electrode for unitized regenerative proton exchange membrane fuel cell with improved cycle life
    Electrochemical and Solid State Letters, 2004
    Co-Authors: Hao Liu, Ming Hou, Zhongjun Hou, Huamin Zhang
    Abstract:

    to improve the cycle life of unitized regenerative fuel cells (urfcs), an Electrode with a composite Structure has been developed. the cycle life and polarization curves for both fuel cell and electrolysis modes of urfc operation were investigated. the cycle life of urfcs was improved considerably and the performance was fairly constant during 25 cycles, which illustrates that the composite Electrode is effective in sustaining the cyclic performance of urfcs. it shows the urfcs with such an Electrode Structure are promising for practical applications. (c) 2004 the electrochemical society.

Jian Song - One of the best experts on this subject based on the ideXlab platform.

  • Structure models and nano energy system design for proton exchange membrane fuel cells in electric energy vehicles
    Renewable & Sustainable Energy Reviews, 2017
    Co-Authors: Jie Yang, Yong Li, Jian Song
    Abstract:

    Electric vehicles require fuel cells with a highly specific energy for the purpose of environmental protection and energy saving. However, proton exchange membrane vehicle fuel cells (PEMFC) face problems in terms of energy conversion efficiency, power density, costs and lifespan. This paper reviews key technical issues regarding the application of vehicle PEMFC especially the integration of nano-electro-catalytic energy system with high-performance electrolyte membranes. It also discusses the relation between vehicle PEMFC membrane Structures and Electrode performance revealing the nanoStructured system model and the membrane Electrode interface characterization. Manipulation of vehicle PEMFC Electrode Structure and quantitative characterization of the nanoscale catalyst interface are summarized aiming at improving Pt utilization efficiency, ionic conductivity and nano membrane Electrode performance.

Taehoon Choi - One of the best experts on this subject based on the ideXlab platform.

  • 27 3 2 d confinement of lcs with virtual walls for a fast response lcd
    SID Symposium Digest of Technical Papers, 2017
    Co-Authors: Taehoon Choi, Yeongyu Choi, Seungwon Oh, Jaehyeon Woo, Taehoon Yoon
    Abstract:

    We report a simple method for reducing the response time of homogeneously aligned liquid crystal (LC) cells by using two-dimensional confinement of the LCs. We have shown that the switching speed can be increased by serval fold in in-plane switching and fringe-field switching cells by introducing interdigitated Electrodes parallel to the LC alignment direction. We also report an interdigitated pixel Electrode Structure with alternating tilts for a much wider viewing angle by aligning the LCs without a pretilt. In addition to a short response time and wide viewing angle, this device allows a much larger deviation of the LC alignment direction which is essential for mass production. Moreover, LCs with negative dielectric anisotropy can be used to minimize the transmittance decrease.

  • interdigitated pixel Electrodes with alternating tilts for fast fringe field switching of liquid crystals
    Optics Express, 2016
    Co-Authors: Taehoon Choi, Yeongyu Choi, Jaehyeon Woo, Taehoon Yoon
    Abstract:

    We propose an interdigitated pixel Electrode Structure with alternating tilts for fast fringe-field switching of liquid crystals (LCs). In contrast to an LC cell, where the pixel Electrodes are parallel to the LC alignment direction, this device does not require a non-zero pretilt angle, owing to an obliquely applied electric field; thus, it can retain a much wider viewing angle by aligning the LCs without a pretilt. In addition to a short response time and wide viewing angle, the proposed device allows a much larger deviation of the LC alignment direction, which is essential for mass production. Moreover, LCs with negative dielectric anisotropy can be used to minimize the transmittance decrease.

  • electro optical characteristics of an in plane switching liquid crystal cell with zero rubbing angle dependence on the Electrode Structure
    Optics Express, 2016
    Co-Authors: Taehoon Choi, Yeongyu Choi, Seungwon Oh, Taehoon Yoon
    Abstract:

    When an electric field is applied to in-plane switching (IPS) and fringe-field switching (FFS) cells with zero rubbing angle, virtual walls are built such that the switching speed can be increased several-fold. In this study, we investigate the dependence on the interdigitated Electrode Structure of the electro-optical characteristics of IPS and FFS cells with zero rubbing angle. We found that when the rubbing angle is zero, the single-layered IPS Electrode Structure provides a higher transmittance than the double-layered FFS Electrode Structure because of the reduced width of dead zones at domain boundaries between interdigitated Electrodes. Single-layered IPS Electrodes not only minimize the transmittance decrease but also provide a shorter response time than double-layered FFS Electrodes, although the operating voltage is higher and fabrication requires a more precise rubbing process. The transmittance decrease due to the zero rubbing angle in an IPS cell can be minimized using optimization of the Electrode Structure while retaining a short response time.