Intrinsically Honeycomb-patterned Hydrogenated Graphene with Spin Polarized Edge-states

TL;DR

This paper reports the millimeter-scale synthesis of honeycomb-patterned hydrogenated graphene on Ru(0001), revealing spin-polarized edge states in unhydrogenated regions, offering new pathways for patterned graphene-based materials.

Contribution

It introduces a novel epitaxial growth method to produce intrinsically honeycomb-patterned hydrogenated graphene with spin-polarized edge states.

Findings

Successful millimeter-scale synthesis of honeycomb-patterned hydrogenated graphene.

Observation of spin-polarized edge states in unhydrogenated graphene regions.

Identification of a hydrogen honeycomb structure serving as a template for patterning.

Abstract

Since the advent of graphene ushered the era of two-dimensional materials, many forms of hydrogenated graphene have been reported, exhibiting diverse properties ranging from a tunable band gap to ferromagnetic ordering. Patterned hydrogenated graphene with micron-scale patterns has been fabricated by lithographic means. Here we report successful millimeter-scale synthesis of an intrinsically honeycomb patterned form of hydrogenated graphene on Ru(0001) by epitaxial growth followed by hydrogenation. Combining scanning tunneling microscopy observations with density-functional-theory (DFT) calculations, we reveal that an atomic-hydrogen layer intercalates between graphene and Ru(0001). The result is a hydrogen honeycomb structure that serves as a template for the final hydrogenation, which converts the graphene into graphane only over the template, yielding honeycomb-patterned hydrogenated graphene (HPHG). In effect, HPHG is a form of patterned graphane. DFT calculations find that the unhydrogenated graphene regions embedded in the patterned graphane exhibit spin-polarized edge states. This type of growth mechanism provides new pathways for the fabrication of intrinsically patterned graphene-based materials.