DFTB investigation of strain affecting the combination of C60 and graphene having single-vacancy on electronic-scale

Abstract

Density functional tight-binding calculations have been employed to study the effect of applying strain on the combination of C 60 and defective graphene with different coverage. Charge density difference indicate that in the more stable configurations, the active 6:6 bond atoms in C 60 combine with carbon atoms with dangling bonds in graphene by forming two typical C C covalent bonds for chemisorption, where more charge are transferred from the s or p orbitals of bonded C atoms in graphene to C atoms in C 60 whereas the charge transfer occurs only on the atoms near the defect in graphene for the physisorption case. For the comparison of different coverages of C 60 on graphene, strain engineering under smaller coverage was more likely to achieve a stable chemisorption configuration via the newly formed two C C bonds. The magnitudes and directions of the applied strain, and whether it is uniaxial or biaxial, significantly affect the combination of C 60 /graphene nanohybrid systems. • The active 6:6 bond atoms in C 60 combine with carbon atoms with dangling bonds in graphene by forming two typical C C covalent bonds for chemisorption. • Strain engineering under smaller coverage was more likely to achieve a stable chemisorption configuration via the newly formed C C bonds. • The magnitudes and directions of the applied strain, and whether it is uniaxial or biaxial, significantly affect the combination of C 60 /graphene nanohybrid system.