Surface-Dependent Adhesion Properties of Graphene on Diamonds for the Fabrication of Nanodevices: A Molecular Dynamics Investigation

Abstract

The physical performance of a heterostructure is strongly influenced by the adhesion properties. The study of adhesion properties between graphene and diamond lattice is an inescapable issue in the development of diamond-based graphene multifunctional nanodevices. Herein, a series of adhesion intensities have been theoretically examined, and the optimum facet of diamond and theoretically recommended orientation angle were obtained, respectively. Moreover, the atomistic peeling behavior and the effect of three typical graphene topological defects on adhesion intensity were explored. The study demonstrated that the presence of double-vacancy defects impairs the adhesion strength due to the reduction of the contact area. In contrast, the presence of Stone-Wales defects is conducive to enhancing the adhesion strength. Interestingly, the effect of single-vacancy defects mainly depends on the delicate competition between single-atom removal and single-atom attraction enhancement. Meanwhile, the effects of diamond surface morphology on graphene adhesion were systematically elaborated by the modeling of one-dimensional and two-dimensional surfaces, and randomly rough surfaces. The adhesion details of graphene on regularly tunable diamonds were explored, and the relations of adhesion intensity and graphene morphology with the random roughness of a diamond surface were further revealed in depth. Since the mechanical and electrical performance of a graphene–diamond heterostructure is sensitively influenced by the adhesion intensity, our findings provide insight into the substrate design of graphene–diamond hybrid devices.