層化高分子/液晶複合薄膜之光電特性

近年來平面顯示器產業技術已趨成熟，許多公司及研究單位紛紛投入下一世代顯示器―可撓式軟性顯示器―的開發。軟性顯示器具有輕、薄、耐衝擊之特性，適用於各式可攜式產品，而其可採用捲軸連續式印刷的製程優點及可撓曲之特性，因此開啟顯示器新的應用範圍。相分離層化高分子/液晶元件為近年來所發展出可應用於軟性液晶顯示元件的一種型態，其基本原理為樣品製作過程中未完美層化所形成的垂直支撐結構。我們根據本實驗室多年來在液晶中添加碳奈米材料之經驗，來探討在層化高分子/液晶中添加少量奈米碳管後之光電特性。另外，高分子穩定型液晶以聚合物網絡來穩定液晶塊材之結構，進而維繫受彎曲應力作用下元件的光電品質，本論文將結合這兩種結構，製成層化高分子穩定型液晶並探究其光電特性。研究結果顯示：一、如文獻所揭，層化高分子/液晶元件能大幅降低元件之反應時間；二、層化高分子/液晶元件在高頻操作下之驅動電壓大於低頻之驅動電壓；三、在層化高分子/液晶元件中添加碳奈米物質可以有效的降低液晶之鬆弛時間並提升元件之對比；四、層化高分子穩定型液晶元件亦能減少液晶之鬆弛時間。

關鍵字

液晶；相分離；高分子穩定型液晶；聚合物

並列摘要

In recent years industrial technologies are approaching to maturity, leading to the development in the next-generation displayoflexible displayoby numerous companies and research institutes. The flexible display is characterized by lightweight, thinness and shock-resistance, and suitable for various mobile products. It can be manufactured by a continuous roll-to-roll process and is flexible, thereby opening up a wide spectrum of new applications in displays. Phase-separated polymer/liquid-crystal composite devices are one of the types developed recently that can be applied to flexible liquid-crystal displays. Its basic principle lies in the formation of vertical supports due to imperfect stratification during the manufacturing process. Based on our years’ experience in the laboratory, carbon nanomaterials are added in the liquid crystal to form phase-separated composite films for characterization by electro-optical measurements. Polymer-stabilized liquid crystals also rely on their internal polymer networks to stabilize the bulk structures and, in turn, to sustain the electro-optical performance under a bending stress. In this thesis we combine these two structures for a new study of electro-optical properties. The present thesis reveals the following results: first, as the literature indicates, the polymer/ liquid-crystal composite films exhibit a reduced response time; second, the operation voltage of the composite film at a high frequency is greater than that at a low frequency; third, carbon nanotubes added in the composite film shorten the liquid-crystal relaxation time and raise the contrast ratio; fourth, stratified polymer-stabilized liquid-crystal structure can also decrease the relaxation time.

並列關鍵字

Phase separation ； Liquid crystal ； Polymer ； Polymer-stabilized liquid crystal

參考文獻

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