標題: Voltage-induced pseudo-dielectric heating and its application for color tuning in a thermally sensitive cholesteric liquid crystal
作者: Wu, Po-Chang
Wu, Guan-Wei
Yu, Chia-Hua
Lee, Wei
照明與能源光電研究所
影像與生醫光電研究所
Institute of Lighting and Energy Photonics
Institute of Imaging and Biomedical Photonics
關鍵字: Cholesteric liquid crystal;electrical tuning;dielectric heating;pseudo-dielectric relaxation
公開日期: 1-Jan-1970
摘要: We previously proposed an electrical approach enabling the tuning of the center wavelength lambda(c) of the cholesteric liquid crystal (CLC) bandgap in the full-color visible spectrum based on the electro-thermal effect. The idea involved the design of a negative CLC with a thermally sensitive bandgap feature and the use of a sandwich-type cell with finite electrode conductivity, allowing the control of cell temperature by applied voltage via pseudo-dielectric heating. It has been demonstrated experimentally that the induced pseudo-dielectric heating is predominated by the pseudo-dielectric relaxation originating from the designated cell geometry. On the basis of this technique, key factors determining the tuning efficacy of the temperature and thus lambda(c) are primarily investigated in this study. Our results suggest that lowering the electrode resistivity and the specific heat conductivity of the cell can promote the maximum tunable temperature range. Expectedly, optimizing the electrode area, cell gap and dielectric permittivity of the CLC favors a decreased relaxation frequency and, in turn, reducing the voltage as well as the frequency required for lambda(c) tuning.
URI: http://dx.doi.org/10.1080/02678292.2019.1641753
http://hdl.handle.net/11536/152706
ISSN: 0267-8292
DOI: 10.1080/02678292.2019.1641753
期刊: LIQUID CRYSTALS
起始頁: 0
結束頁: 0
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