Defect effect of graphene on interface properties of copper/graphene/copper composite: A first-principles study

The introduction of defects in graphene will affect the mechanical and electrical properties of the composite interface. We investigate the effect of Stone-Wales (S-W), single-vacancy (S-V), and double-vacancy (D-V) defects on interface properties of copper/graphene/copper (Cu/Gr/Cu) sandwich models using the first-principles study. The results indicate that most defects forming in the Cu/Gr/Cu interface have lower formation energy than that in the free graphene slab. The introduction of defects is beneficial to enhance interface bonding while decreasing electrical properties due to electron scattering. By analyzing the differential charge density of all the Cu/Gr/Cu models with defects, we show that the defects cause changes in electron distribution and facilitate charge transfer between graphene and adjacent copper layers by altering the atomic layer distance.