Interaction between hydrogen flux and carbon monolayer on SiC(0001): graphene formation kinetics.

摘要: Manipulation of graphene-based systems is a formidable challenge, since it requires the control atomic interactions over long timescales. Although effectiveness certain number processes has been experimentally demonstrated, underlying mechanisms are often not understood. An import class techniques relies on interaction between hydrogen and graphene, which focus this research. In particular, growth epitaxial graphene SiC(0001) subject to single-atom-thick interface carbon layer strongly bound substrate, can be detached through intercalation. Here we report that nucleation phenomenon induces transformation buffer into graphene. We study graphenization dynamics by an ab initio based method permits simulation large with resolution, spanning time scales from nanoseconds hours. The early evolution stage (∼ms scale) characterised formation metastable H deposited C surface. penetration in monolayer surface rare event due barrier, ∼2 eV. However, at high densities, energetically favoured Si-H bonding appears substrate's local increase density statistical transitions leads overlying atoms. Thermally activated fluctuations promote these graphene-like islands layer: evidenced our simulations later (>10(2) s 700 °C for ∼3.6 × 10(15) at. cm(-2) s(-1) flux). Such nuclei grow quasi-freestanding forms if exposition flux continues sufficiently (∼30 min same conditions). have systematically explored varying substrate temperature flux, demonstrating morphology during post-graphenization anneals significantly depends variables. computational findings consistent experimental analyses reported so far could serve as guidelines future works manipulation.