Direct laser fabrication of large-area graphene: An engineering approach to nano-materials

Graphene is a promising material for many potential applications, owing to its extraordinary properties. Numerous synthesizing approaches have been developed to realize the promising applications of graphene. However, there is lack of a comprehensive way, which combines the following features, i.e. large-area growth, patterned graphene and fast growth at the same time. Here, we provide an engineering approach to both large-area and patterned graphene at a high rate. The high power and continuous-wave lasers were employed to irradiate solid carbon source coated on nickel surface. The rate of graphene production by laser irradiation exceeds 28.8 cm²/min and the solid carbon source is less hazardous compared to typical gaseous carbon sources used in chemical vapor deposition (CVD). The influence of laser process on graphene fabrication was investigated systematically. Raman analyses, optical images and scanning electron microscopy (SEM) results show that the quality of graphene strongly depends on the laser process parameters, including laser power density and scanning rate. Adjusting the parameters to input the appropriate heat, so that the high quality graphene can be obtained in an optimal condition. The influence of carbon source on graphene growth was also investigated. Ultimately, the penetration and precipitation mechanism of carbon into Ni substrate during the fabrication process were also discussed. This approach may reach the scale large enough for practical applications.