Visualizing fast growth of large single-crystalline graphene by tunable isotopic carbon source

The fast growth of large single-crystalline graphene by chemical vapor deposition on Cu foil remains a challenge for industrial-scale applications.To achieve the fast growth of large single-crystalline graphene,understanding the detailed dynamics governing the entire growth process—including nucleation,growth,and coalescence—is important;however,these remain unexplored.In this study,by using a pulsed carbon isotope labeling technique in conjunction with micro-Raman spectroscopy identification,we visualized the growth dynamics,such as nucleation,growth,and coalescence,during the fast growth of large singlecrystalline graphene domains.By tuning the supply of the carbon source,a growth rate of 320 μm/min and the growth of centimeter-sized graphene single crystals were achieved on Cu foil.