Spontaneous formation of graphene on diamond (111) driven by B-doping induced surface reconstruction

Spontaneous construction of graphene on boron-doped diamond (111) surface has been found in first-principles calculations. Boron-doping-induced surface reconstruction is the mechanism responsible for the diamond-to-graphene phase transition. Furthermore, the effect on the surface is unexpectedly observed at any doping depth down to the 7th layer, and a low concentration of substituent boron – only ¼ – is effective for graphene formation. Amazingly, when boron atoms are incorporated into the fifth layer, the direct optimization of the 1 × 1 surface automatically gives rise to a graphene structure from the first bilayer with no energy barrier, indicating that the formation of graphene is spontaneous. These findings provide an alternative strategy for graphene synthesis on wide-gap insulators with high thermal conductivity.

Graphical abstractSpontaneous construction of graphene on boron-doped diamond (111) surface has been found in first-principles calculations. Boron-doping-induced surface reconstruction is the mechanism responsible for the diamond-to-graphene phase transition. Furthermore, the effect on the surface is unexpectedly observed at any doping depth down to the 7th layer, and a low concentration of substituent boron – only ¼ – is effective for graphene formation. Amazingly, when boron atoms are incorporated into the fifth layer, the direct optimization of the 1 × 1 surface automatically gives rise to a graphene structure from the first bilayer with no energy barrier, indicating that the formation of graphene is spontaneous. These findings provide an alternative strategy for graphene synthesis on wide-gap insulators with high thermal conductivity. (a) and (b) Optimized diamond (111) with 1/4 of the carbon atoms in the first and third layer replaced by boron atoms, respectively. (c) and (d) Initial and optimized structures, respectively, both with 1/4 of the carbon atoms in the fifth layer replaced by boron atoms. (e) and (f) Initial and optimized structures, respectively, both with 1/16 boron doping concentration in the fifth layer. Pink balls represent incorporated boron atoms, and grey balls indicate carbon atoms. In (e) and (f), the blue balls represent carbon atoms before and after forming hexagonal graphite structure in the first bilayer, while the purple balls represent carbon atoms before and after forming sp2 bonds with Ctop atom.Figure optionsDownload full-size imageDownload high-quality image (290 K)Download as PowerPoint slide