紫外光照射在摩擦ITO配向膜所形成的扭轉向列型液晶盒中產生的離子分析

Abstract

本論文使用電壓保持率（Voltage Holding Ratio，VHR）的方法來量測摩擦ITO為配向層的液晶盒樣品分別在不照射紫外光和照射波長365 nm的紫外光下之離子特性，以分析紫外光對液晶盒中產生離子的影響。 藉由VHR的量測和解析解的模型可以得到液晶盒中高、低解離率離子的初始濃度和離子遷移率，並在不同溫度下量測以得到離子解離及遷移時所需的活化能。 比較其結果，可發現在未照射紫外光時僅含有低解離率離子的液晶盒樣品，在經過紫外光照射後，會額外產生高解離率離子，而原本的低解離率離子之物理特性也會做相當程度的改變。

To analyze the effect of UV-induced generation of ions in a rubbed ITO-aligned TN cell, we have measured and analyzed the VHR (voltage holding ratio) data obtained from the TN cell with and without UV-illumination. Using the theoretical model for the ion generations from HIR (high-ionization-rate) and LIR (low-ionization-rate) impurities within the LC mixture to fit the measured VHR data, we can derive initial ion concentration and ion mobility for HIR and LIR ions within the TN cell. By analyzing the VHR data measured at three different temperatures, we have obtained the corresponding ion concentrations and activation energies of ion-dissociation and ionic mobility of the LC mixture within the TN cell with and without UV illumination. The results of our investigation have showed that most of ions existed in the rubbed ITO-aligned TN cell without UV illumination were from LIR impurities. However, after UV illumination, plentiful HIR ions have been generated in the TN cell, and the physical properties of the LIR ions existed before UV-illumination have been altered slightly by the UV-illumination.