二維材料於空氣-水界面之膜強度調控研究

Abstract

力學削切方法從3維材料得到2維材料已有不少文獻回報，因其簡易及可大量生產等優點而獲得重視。然而如何從削切所得之2維材料再進一步做成勻質薄膜乃至應用在電子元件上仍未完整了解。此篇論文將會研究純石墨烯在水-大氣介面上的成膜機置、構型及其電子元件特性。借由Langmuir-Blodgett (L-B)方法，我們發現一種全新且不可逆的緊密排列石墨烯薄膜。此外，我們也觀測到於高擠壓下，此固相膜會產生週期性的側潰現象。這些特殊之物理表現使我們發現一些新的製成手法。轉印於矽基板和玻璃後之光學、電子及原子力顯微鏡量測，證明此法有辦法達到大面積、勻質、輕薄等優異之特性，使其有未來應用於電子元件之可適性。

Exfoliation of 3-dimensional bulk to 2-dimensional material has been reported for years, and it is easily achieved to mass production. However, creating uniform thin films from exfoliated 2-dimensional material is one of the biggest challenges to utilizing it in many applications, such as transparent conducting film (TCF). In this thesis we study the behavior of pristine graphene films on the water-air interface through Langmuir-Blodgett method. We identify a novel morphological solid phase where graphene flakes form continuous and irreversibly connected films that are surprisingly stable. Under higher mechanical compression, those closely packed graphene films buckle with a periodic shape, but they are elastic enough to restore back to the irreversible films. Some fabrication techniques are discovered with these special behaviors. Upon transfer, we characterize its quality by optical microscope, SEM and AFM measurements. The data show that Langmuir-Blodgett graphene film is thin and uniform, and suitable for large scale electronics applications.