近年來液晶光電技術快速成長，不論是顯示技術，或是智慧型窗戶等產品，液晶發展已貼近現代人生活當中，且隨著環保議題的觀念興起，因此如何利用液晶相關元件產生多穩態結構達到節能的效果便備受相當的重視。 本論文之研究以智慧窗戶和產生動態液晶結構元件為主，主要分為兩部分討論，第一部分為電控摻雜二色性染料之膽固醇液晶光閥之各相態研究及光控其旋性之研究，從初始狀態為穿透態，利用電控方式可調整液晶樣品的吸收態，以達到灰階控制，且不具電壓遲滯性。此外，若超過截止電壓VW則會生成散射態，故該元件具有電控切換機制的特色。另液晶樣品在產生散射過程會顯現類似向列型液晶產生的動態結構，亦即Williams Domains，藉由屏幕上觀察到隨電壓上升繞射角度的變化，且利用光控方式影響偶氮苯手性分子產生同素異構化反應，在動態過程會出現膽固醇相的Williams Domains。第二部分為摻雜二色性染料於膽固醇液晶之電流體動力學及光控其旋性之特性研究，將第一部分研究的材料注入不同配向方式的液晶空盒，施加固定電壓後以調整偏光顯微鏡之起偏器和檢偏器觀察其在穩定動態結構之光學上的差異，最後利用光控方式探討在經不同配向處理的液晶盒中所產生膽固醇相之Williams Domains以及其動態結構。 ;Liquid crystal (LC) optoelectronic technologies, including the panel display technology, the applications of smart windows, and others, have made huge progress over the past decades. The convenience brought by such technologies has become an indispensable part of human daily life. Moreover, with the spread of environmental awareness over the world, the development of multi-stable LC devices having the performance of low power consumption attract great attention among the industrial and academic communities. The contents of the thesis are divided into two main topics, they are smart windows and dynamic structures of LCs. The first topic is the study of optically and electrically controllable electro-optical characteristics of LC devices based on dichroic dyes-doped cholesteric LCs. The LC device, functioning as a light shutter, has electrical switching performance which can adjust its gray scales from the initial transparent state to light scattering state by the application of an electric field over the threshold voltage (VW). In addition, when a high electric field is applied, the LCs generate dynamic structures, called Williams Domains, before the appearance of dynamic scattering phenomenon. The rotating diffraction pattern can be observed on the screen with the increase of the applied electric voltage and can also be observed by utilizing the photo-isomerization of the doped azobenzenes between trans- and cis-isomers. Such dynamic processes will generate the Williams Domains of cholesteric textures. The second topic is the studies of the electro-optical characteristics of electrohydrodynamic instability and the optically controllable chirality of dichroic dyes-doped cholesteric LCs. The same materials adopted in the first topic are injected into different LC cells treated with different alignment layers, and then the differences of dynamic structures and optical properties of the LC cells applied with a fixed external voltage observed under a polarized optical microscope by adjusting the polarizer and the analyzer are elucidated. Finally, we discuss the properties of the cholesteric textures having Williams Domains treated with photo-isomerization of the doped azobenzenes between trans- and cis-isomers.
