Crack-and-Fold Style Defects in CVD Graphene on Raw Cu Foils

Abstract

The rarely reported defects with crack-and-fold (CAF) style graphene grown on raw Cu foils substrates by chemical vapor deposition (CVD) were examined in this study. Factors for the formation of CAF defects were explored by performing different substrate treatments and varied hydrogen inflow. A clear relationship was found between CAF defects and Cu (110) facets by electron back-scattered diffraction measurement. CAF defects were affected by the interaction between graphene and the substrate. A model with a two-step process, including cracking and folding, is established to elucidate the formation of CAF defects. CAF defects can be reduced by performing substrate treatment, varying hydrogen flow and controlling the orientation of the Cu substrate. This study was performed to improve the quality of graphene grown by CVD for industrial production.