Hydrogenation and etching of single-layer graphene during exposure to atomic hydrogen

Abstract

Opening a band gap in graphene is essential for its integration into electronic devices, but remains a major challenge. Hydrogenation offers a promising route, though the process is complicated by competing mechanisms such as hydrogen desorption and unwanted etching. Here, we investigate one-sided hydrogenation of monolayer graphene on SiO₂/Si substrates at temperatures below ∼100 °C, using a hot-filament-assisted method compatible with semiconductor processing. Our results reveal a regime where hydrogen chemisorption and hole formation (etching) coexist. Dehydrogenation experiments and first-principles calculations indicate that hydrogen atoms preferentially cluster on neighboring carbon sites, potentially leading to dome-like lattice distortions. While hydrogen incorporation is favored at these sites, our simulations suggest that the resulting stresses alone are insufficient to cause carbon–carbon bond breakage. Instead, etching likely requires the presence of energetic atomic hydrogen. These findings help clarify the interplay between hydrogenation and etching and provide guidance for controlled graphene functionalization in device applications.