Electro-optical and Dielectric Characteristics of Hollow Silica Nanoparticle-doped Liquid Crystal Cells

• Main Author: 黃茂琨
• Other Authors: 黃啟炎
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/934xbf

碩士 === 國立彰化師範大學 === 光電科技研究所 === 105 === This thesis investigates the electro-optical, dielectric spectrum (DS) and ionic characteristics of the hollow silica nanoparticles (HSNs)-doped liquid crystal (LC) cell. This thesis is divided into three parts. In the first part of this thesis, we investigate the effect of HSNs on electro-optical properties of the electrically controlled birefringence (ECB) LC cell. Obtained result indicates that the transmittance to voltage curve (T-V curve) is almost independant, but response time of the cells reduce with the doped HSN concentrations because of the reduced rotation viscosity coefficient of the LC mixture. In the second part of this thesis, we investigate the effects of HSN on DS and ionic properties of the vertical alignment (VA) LC and ECB LC cells. In the high frequency DS, the obtained result indicates that the dielectric relaxation time of the oriented polarization of the cell decreases with the doped HSN concentrations. In the low frequency DS, we calculate the ion density of the LC mixture from the dielectric relaxation curve of ionic polarization of the cell. Obtained result indicates that the ion density of ECB cell reduces with the increasing doped HSNs concentrations, because HSNs adsorb impurities and ions, but it have no significant effect on the VA cell. In the third part of this thesis, we use Zview software to analysis the DS of LC cell. We find that there is interface polarization in addition to ionic polarization in the low frequency DS. The value of ionic polarization is about impurities and ions drifting so it changes as the result of second part, but the value of interface polarization of VA cell is greater than ECB cell, this why HSNs-doped have no significant effect for ion density of VA cell.