氧化鋅奈米柱陣列調制液晶預傾角之研究

Abstract

本論文旨在研究氧化鋅奈米柱陣列對液晶配向之特性，經由改變氧化鋅奈米柱陣列的濕潤性來控制液晶分子的預傾角。氧化鋅奈米柱陣列是經由兩段式水熱法成長於ITO玻璃基板上，我們發現透過控制氧化鋅奈米柱陣列鍛燒溫度的高低可以改變氧化鋅奈米柱陣列之親疏水性，實驗結果指出，液晶分子的預傾角與氧化鋅奈米柱陣列之水的接觸角有一定的關係，當水的接觸角由108°降低至33°，預傾角可約從90°至0°之間連續地變化。 最後，我們成功的選用了鍛燒溫度為235 °C氧化鋅奈米柱陣列，其對應預傾角為52°的配向膜來製作高預傾角的不需偏壓光學補償彎曲型液晶盒(no-bias optically-compensated bend, No-bias OCB)液晶盒，因此可以克服斜展態與彎曲態之間的能量屏障，使得液晶分子只在彎曲態與垂直態之間的做轉換。

In this work, we find that the surface wettability of the ZnO nanorod arrays can be controlled by changing the annealing temperature of the prepared ZnO nanorod arrays, fabricated by using the two-step hydrothermal method. Liquid crystal (LC) molecules aligned on the ZnO nanorod arrays are observed and the pretilt angles of LCs can be adjusted by using ZnO nanorod arrays with different surface wettability. The pretilt angle θ_p of the LCs is successfully adjusted over a range from 88.5°to 0.5° as the contact angle of water on ZnO nanorod arrays changes from 108° to 33°. Finally, one no-bias optically compensated bend (no-bias OCB) cell with a pretilt angle of ~52° was fabricated by using our proposed ZnO nanorod arrays annealed at 235 °C.