Wrinkle-dependent hydrogen etching of chemical vapor deposition-grown graphene domains

Hexagonal single-crystal graphene domains were grown on copper (Cu) foil via chemical vapor deposition and were etched with hydrogen at 950 °C from 7 to 60 min at atmospheric pressure. Numerous trenches were observed on the initial graphene domains after etching, and the trench patterns were closely associated with the Cu crystal orientation. No trenches were found if the etching process was conducted before cooling down. Thus, the etching trenches were bound up with the wrinkles formed during the cooling down process. Then, the process of etching on the wrinkles was examined. This simple hydrogen etching technology proved that wrinkles and point defects existed even in hexagonal single-crystal graphene domains. This method could be a convenient way to detect the distribution and morphology of wrinkles in graphene.