以石墨烯為電極的反向平行液晶晶胞 與液晶光閥之製備與特性研究

Abstract

在液晶顯示器的結構中，透明電極的導電性與穿透率扮演著重要的角色，隨著石墨烯的發現以及各項文獻指出，石墨烯的高穿透率以及高導電性使其成為極具潛力的透明電極材料，但是文獻中也顯示，石墨烯薄膜與玻璃基板的弱黏著性，使得施加應力很容易破壞薄膜的完整性，造成元件製程應用的困難，特別是像在液晶晶包這類的應用，製程時需要機械摩擦產生液晶分子對準層，所以目前文獻鮮少有相關的報導。 在本論文，我們提出以紫外光曝光對準技術來取代機械摩擦的方法，成功製作大面積的以石墨烯薄膜為透明導電層之液晶晶包，並測試其光電調制特性，不遜於傳統以ITO為導電層的類似樣品。文中，首先，介紹我們使用濕式轉印法將單層石墨烯薄膜轉印至玻璃與BSO薄板上，並利用拉曼光譜儀證實利用低壓氣象沉積法製作的石墨烯層品質與轉印過程產生的缺陷。測量石墨烯層玻璃基板的電阻與穿透率和ITO玻璃比較後證實石墨烯足以取代氧化銦錫。因此，利用曝光對準技術在石墨烯電極玻璃基板及石墨烯電極BSO薄板上製作曝光對準層，進而製作成石墨烯電極反向平行液晶晶胞與液晶光閥，並且分別量測其相位調制與反應時間特性。最後我們測量所得的液晶光閥之特性，設計實驗參數條件，將其應用於光定址的光空間調制器。

The conductivity and transmittance of a transparent electrode in optoelectronic device play an important role for its application. In recent years, more and more researches indicate that graphene is one of the best candidates because of its extremely high conductivity and transmittance. Due to stress problem, it is hard to make an alignment layer on graphene film as transparent electrode in LC display. In this thesis, we transfer graphene on BSO and glass substrates by wet transfer process. And proving the Graphene quality by Raman microscopy, it shows over 90% is single graphene layer and only few defect was made during transfer. The resistance and transmittance of graphene-based glass substrate is measured and is compared to ITO glass. It shows graphene can replace ITO as transparent electrode. Therefore, we made photo-alignment layer on substrates, building it as anti-parallel cell and liquid crystal light valve(LCLV). The phase retardation and response time are measured. At last we input image in LCLV and real-time displays images.