Graphene with excellent properties has potential applications in composite materials, sensors, high performance electronic devices, flexible devices and other fields. Controllable preparation of high-quality graphene materials is one of the bottleneck problems in its application and is also the focus of current research. The main methods to prepare graphene include mechanical exfoliation, liquid phase exfoliation, bottom-up preparation method and chemical vapor deposition (CVD). Among them, chemical vapor deposition (CVD) is an effective and controlled method to prepare graphene and large area and high-quality CVD graphene can be obtained. When prepared CVD graphene, the planar substrate is placed in a high-temperature decomposable precursor atmosphere, and carbon atoms will deposit on the surface of the substrate by high-temperature annealing to form CVD graphene. Finally, CVD graphene are obtained after the metal substrate is removed by chemical etching method. The growth of graphene can be controlled by selecting the type of substrate, growth temperature, and flow rate of precursor. Single-layer or multi-layer CVD graphene with large area can be successfully prepared by this method.
Figure 1. Illustration of growth process of CVD graphene on Cu substrate.
Figure 2. An example of CVD graphene applied in solar cell.
According to the thickness and number of layers deposited, CVD graphene can be divided into mono-layer CVD graphene, double-layer CVD graphene and multi-layer CVD graphene.