自從在2004年時，石墨烯這種用碳原子以蜂巢狀排列而成二維材料被發現以後，由於其在理論上具備各種優越的物理性質，包含對光良好的穿透度、具有相當高的導電度、只有單原子層的厚度、優異的機械強度以及非常穩定的化學性質。因此，近幾年石墨烯已經試圖被大量應用在各種光電元件上，並且被視為取代目前廣泛使用的透明導電電極氧化銦錫(ITO,Indium tin oxide)最有潛力的物質之一。為了可以有效地將石墨烯應用在光電元件上，各種石墨烯的製備和轉印的方法不斷地被研發以及改良，但是一直到現在為止，石墨烯仍然沒有辦法有效的取代氧化銦錫(ITO)主要是因為石墨烯在轉印的過程中常常會產生一些無法避免的破壞以及有機殘留物的影響使得整體元件的表現並不如我們所預期。因此，我們在這個研究裡致力於開發出一種良好的轉印方法並且實際應用於有機發光二極體上(OLED, Organic Light-Emitting Diode)。
因為現行最常被用來轉印石墨烯的兩種方法：PMMA法和Roll-to-Roll法都必須靠著有機物的輔助才能夠將石墨烯轉印至我們的目標基板上，而我們研發出以單純以靜電力吸引的方式，將石墨烯從銅箔上轉移到我們的目標基板上。整個過程中不需要任何有機物的支撐因此也就不會有任何殘留物的產生，進而得到一個乾淨且高品質的石墨烯。此單層的石墨烯電阻值大約為300"Ω/sq" ，I_D/I_G≅0.05。
最後，我們將轉印至目標基板的石墨烯作為透明導電電極，並製作成有機發光二極體，以Alq3作為發光層的螢光有機發光二極體，我們預期利用這種乾淨轉印的方式所得到的高品質的石墨烯能夠有效地提升光電元件的效益。

Since in 2004,graphene , a two-dimensional (2D) form of carbon atoms with the honeycomb lattice structure is found due to its variety of outstanding physical properties, including high optical transparency, high conductivity, one-atom thick planar sheet, excellent mechanical strength and very stable chemical properties. Recently, a large-area graphene film has been applied to a large number of optoelectronic devices, and deemed to one of the most promising candidates to replace indium tin oxide (ITO) film. In order to fabricate graphene-based optoelectronic devices, a variety of methods of preparation of graphene film and transfer technology constantly have been developed and improved. However, it is still no effective way to replace indium tin oxide (ITO) by the graphene film. Main problem is how to avoid the completeness and clean of graphene film during transfer process. The graphene film often caused some damages during transfer process and influenced by the organic residues, resulting in bad performance of the optoelectronic devices. In this study, we focused on developing a good transfer method and practically applied the graphene film as electrode in organic light-emitting diode (OLED) applications.
The current graphene transfer process is PMMA method and Roll-to-Roll method. These methods must rely on organic material support to make graphene transfer to target substrate. Here, we developed a simple way by utilizing electrostatic adsorption to transfer graphene film from the copper foil to our target substrate. Our process does not require any organic material support and therefore have no residue on the graphene film. Finally, a clean and high-quality graphene film was obtained. The monolayer graphene resistance is approximately 300Ω/sq, ID/IG ~ 0.05.
Finally, we used graphene film as a transparent conductive electrode, and applied into organic light emitting diodes, using Alq3 as a light emitting layer. The efficiency of the OLED devices based on residual-free graphene films can be improved.

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