凯发

Graphene has been attracting great interests because of its many remarkable properties and promising applications. In the past 11 years, a lot of application prototypes have been promoted and demonstrated. Graphene was firstly achieved by mechanical exfoliation (scotch tape method) in the lab, which providing micro flakes, though tiny size but good enough for most fundamental research. Nevertheless, large area with high quality is demanded for both mass production and many applications. Various methods have been pursued for large area graphene production and chemical vapor deposition (CVD) of hydrocarbons (typically methane) on copper foil substrate has been proven the most effective one, which is widely used in both academy and industry today. Theoretically, the area of graphene can be as large as possible as long as large copper foil and reaction chamber are used. However, in practice, though large copper foil is commercially available, reaction chamber is not. With the increase of reaction chamber size, the cost and difficulty to make the equipment increase dramatically. This talk will introduce a method to overcome the limit of reaction chamber dimensions so as to synthesize large area graphene film with the use of small chamber, evidenced with the successful growth of a large area graphene up to 300 inch with the use of a 5 inch diameter quartz tube chamber. Another issue for the current CVD technique for graphene synthesis is the use of hydrocarbon and hydrogen gases, which are flammable and explosive and thus dangerous and cost for safety concern added. Here a new technique will also be introduced by using a non-flammable gas instead. In this talk, factors affecting graphene quality and some solutions to overcome these issues will also be discussed.