Scalable Synthesis of Monolayer Graphene and Graphene Oxide Films by CVD
- Author(s): Ruiz, Isaac
- Advisor(s): Ozkan, Mihri
- et al.
Over the last decade, graphene has generated immense excitement in the scientific and engineering community due to its extraordinary properties stemming from its 2 dimensional structure. As research in graphene has begun to taper off and demand for its applications begins to increase, the challenge of synthesizing large uniform sheets of graphene for mass production has begun to be undertaken. To date, one of the most promising methods of fabricating large, uniform, single layer, high quality graphene is on Cu foils by chemical vapor deposition. In this work, some of the inherit synthesis problems of graphene on Cu foils by CVD are studied and solved. The first problem examined is the formation of contamination on the surface of graphene grown inside quartz tubes. This contamination, commonly referred to as “the white dots”, has been the subject of much confusion and speculation, with its source being unknown and its composition never thoroughly studied, until it is presented here along with a simple solution to avoid the contamination. The second problem address in this dissertation is that of rapid synthesis of uniform, single layer graphene sheets by CVD. While much work has been focused on recipe optimization in order to produce high quality graphene sheets, here another approach is taken. Using a generic recipe which will saturate the Cu substrate with graphene quickly, emphasis on Cu foil preparation is taken in order to produce high quality, uniform single layer graphene sheets in as little as a 60 second growth time. The surface morphology of the foils, which allow the self-limiting growth of graphene on the Cu foils is examined and shown to be implementable on inexpensive Cu foils. This allows for the potential to synthesize large sheets of uniform single layer graphene rapidly and inexpensively, with a relatively low initial capital investment. Finally, a new method for synthesizing graphene oxide by chemical vapor deposition s introduced. This method is the first to be able to produce uniform single layer sheets of graphene oxide, which is scalable for semiconducting applications. This opens up the possibility for tunable functionalization of the graphene oxide and potential for band gap introduction in graphene.