The formation mechanism of hexagonal Mo2C defects in CVD graphene grown on liquid copper

Abstract

Thin Mo₂C hexagonal defects precipitate in CVD graphene when Mo crucibles are engaged to hold the liquid copper substrate, while these defects disappear when W crucibles are present. These defects have been identified as the thin precipitates of Mo₂C. The growth mechanism of the Mo₂C defects is demonstrated through thermodynamic calculations. This can be beneficial in graphene defect engineering through the vapour phase transport of the volatile MoO₃ phase.