Influence of Ionic Concentration on the Optical Response of VA-Cells in a low Frequency electric Field

• Main Authors: Cywan, 萬志勇
• Other Authors: B. J. Liang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/67186956403657556217

碩士 === 逢甲大學 === 電子工程學系 === 89 === In past literature, less people studied completely about negative (△ε<0) liquid crystal of vertical alignment in the low frequency, so this article will study the optical property of the negative liquid crystal and the influence of alignment layer on the optical response in low operation frequency (100Hz~0.01Hz). The purpose of this thesis is to study the effect of ionic concentration on the optical response in vertical aligned (VA-LC) cells. It is including that 1. LC within ions can induce the phenomenon of EDL in LC and the effective voltage over the LC layer decrease. 2. Alignment layer (AL) within ions can also induce the phenomenon of EDL in AL and the effective voltage over the LC layer increase. In general, Ions exist inside LC and AL at the same time, it can induce the phenomenon of DMR, EMR or DMR+EMR probably. In our experimental results, we found that the thicker alignment layer, the larger effective voltage and the value of increased effective voltage, and three phenomenon of optical response in different ionic concentration. We also found the different ionic concentration in different LC materials and the rubbing process would increase ionic concentration.