Abstract
The electrical, optical and dielectric performance of high-dielectric-constant TiO2 nanoparticles (NPs) dispersed in nematic liquid crystals (NLCs) with high dielectric anisotropy is demonstrated. TiO2 doping decreases the pretilt angle of the NLC cell because of the increase in Van der Waals interaction between the NLC molecule and alignment layer. Moreover, TiO2 doping strengthens the electric field in the NLC bulk and suppresses the ionic screen effect on the substrate surface, thus decreasing the threshold and driving voltages of the NLC cell. The measured field-off response time and estimated conductivity initially increase and then decrease with increased TiO2 concentrations. This phenomenon is due to the antagonism between the entrained ion impurities during fabrication and the ion harvest effect of TiO2 NPs. Dielectric spectral measurements reveal that TiO2 doping changes the relative permittivity and dielectric anisotropy of NLCs because of the changed space–charge polarisation and order parameters in the NLC bulk. The physical mechanisms are discussed in detail accordingly.
| Original language | English |
|---|---|
| Article number | 110902 |
| Journal | Journal of Molecular Liquids |
| Volume | 286 |
| DOIs | |
| Publication status | Published - 2019 Jul 15 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Spectroscopy
- Physical and Theoretical Chemistry
- Materials Chemistry
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Electro-optical and dielectric properties of TiO2 nanoparticles in nematic liquid crystals with high dielectric anisotropy. / Huang, Chi-Yen; Selvaraj, Pravinraj; Senguttuvan, Govindan; Hsu, Che Ju.
In: Journal of Molecular Liquids, Vol. 286, 110902, 15.07.2019.Research output: Contribution to journal › Article
TY - JOUR
T1 - Electro-optical and dielectric properties of TiO2 nanoparticles in nematic liquid crystals with high dielectric anisotropy
AU - Huang, Chi-Yen
AU - Selvaraj, Pravinraj
AU - Senguttuvan, Govindan
AU - Hsu, Che Ju
PY - 2019/7/15
Y1 - 2019/7/15
N2 - The electrical, optical and dielectric performance of high-dielectric-constant TiO2 nanoparticles (NPs) dispersed in nematic liquid crystals (NLCs) with high dielectric anisotropy is demonstrated. TiO2 doping decreases the pretilt angle of the NLC cell because of the increase in Van der Waals interaction between the NLC molecule and alignment layer. Moreover, TiO2 doping strengthens the electric field in the NLC bulk and suppresses the ionic screen effect on the substrate surface, thus decreasing the threshold and driving voltages of the NLC cell. The measured field-off response time and estimated conductivity initially increase and then decrease with increased TiO2 concentrations. This phenomenon is due to the antagonism between the entrained ion impurities during fabrication and the ion harvest effect of TiO2 NPs. Dielectric spectral measurements reveal that TiO2 doping changes the relative permittivity and dielectric anisotropy of NLCs because of the changed space–charge polarisation and order parameters in the NLC bulk. The physical mechanisms are discussed in detail accordingly.
AB - The electrical, optical and dielectric performance of high-dielectric-constant TiO2 nanoparticles (NPs) dispersed in nematic liquid crystals (NLCs) with high dielectric anisotropy is demonstrated. TiO2 doping decreases the pretilt angle of the NLC cell because of the increase in Van der Waals interaction between the NLC molecule and alignment layer. Moreover, TiO2 doping strengthens the electric field in the NLC bulk and suppresses the ionic screen effect on the substrate surface, thus decreasing the threshold and driving voltages of the NLC cell. The measured field-off response time and estimated conductivity initially increase and then decrease with increased TiO2 concentrations. This phenomenon is due to the antagonism between the entrained ion impurities during fabrication and the ion harvest effect of TiO2 NPs. Dielectric spectral measurements reveal that TiO2 doping changes the relative permittivity and dielectric anisotropy of NLCs because of the changed space–charge polarisation and order parameters in the NLC bulk. The physical mechanisms are discussed in detail accordingly.
UR - http://www.scopus.com/inward/record.url?scp=85065446160&partnerID=8YFLogxK
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U2 - 10.1016/j.molliq.2019.110902
DO - 10.1016/j.molliq.2019.110902
M3 - Article
AN - SCOPUS:85065446160
VL - 286
JO - Journal of Molecular Liquids
JF - Journal of Molecular Liquids
SN - 0167-7322
M1 - 110902
ER -