Graphene and its derivatives : fabrication and Raman spectroscopy study

• Main Author: Cong, Chunxiao
• Other Authors: Shen Zexiang
• Format: Theses and Dissertations
• Language: English
• Published: 2012
• Subjects: DRNTU::Science::Physics::Optics and light
• Online Access: https://hdl.handle.net/10356/48083
• Institution: Nanyang Technological University

This thesis presents results on fabrication and Raman spectroscopy studies of graphene and its derivates. The works can be divided into two parts as follows. Part 1: Fabrication of graphene layers and its nanopatterns (1) Fabrication of graphene layers by self-limited oxidation method. We demonstrated a simple but yet efficient approach for formation of graphene layers by self-limited oxidation of graphite flakes under the top-down scheme. The extremely fast growth in the demand of graphene layers for various types of fundamental and practical studies strongly urges researchers to develop more novel methods for the fabrication of graphene layers. It was shown here that graphene layers with good crystal quality could be readily formed by self-limited oxidization of graphite flakes through a one-step annealing process. The kinetics of oxidation on graphite was used to elaborate the growth mechanism of this self-limited oxidation approach. Many advantages might be adopted from this method, such as simple process, low-cost, substrate-friendly or transfer-free, high-yield, good quality and pre-determined locations and patterns of graphene layers. This could be useful for further development of graphene based nanodevices. (2) Fabrication of graphene nanodisk arrays Graphene-based nanostructures are considered as promising candidates for an alternative to silicon based mesostructures in future electronic nanodevices. Graphene nanopatterns, which comprise periodic structures in the graphene, are useful for the fabrication of graphene-based devices. Graphene nanodisk, one kind of graphene nanopatterns, is still in its infancy, especially from an experimental point of view. We presented an efficient and manageable way by combining nanosphere lithography (NSL) and reactive ion etching (RIE) processes to fabricate ordered graphene nanodisk arrays. The graphene nanodisk arrays may offer intrinsic advantages in the various fabrication of electronic and spintronic devices due to the periodicity, nanometer dimension and large edge to body ratio. Furthermore, the existence of closed edge structure may endow graphene nanodisk arrays with higher edge density than that of normal graphene sheets, leading to higher edge reactivity property, which may offer key advantages in realizing various electron applications via edge chemical functionalization.