Electronic and Magnetic Properties of Patterned Hydrogenated Graphene: A First-principles Study

Graphene is recognized as a promising 2D material with abundant physical properties, and flexibility in designing, but the zero band gap limited its applications. Graphane, a fully hydrogenated graphene, opens a remarkable energy gap. Furthermore, the hydrogenation also provide magnetic configuration of partial hydrogenated graphene due to the unpaired or localized electrons of unhydrogenated carbon atoms. In hydrogenated graphene, the carbon atoms of missing hydrogen atom prefer aggregate and form a cluster or zigzag chains. The former establishes a graphene quantum dot (GQD) embedded in graphane; the later is as a bare carbon chain or chains in graphane. We found the bare carbon chains and embedded GQDs can interact with each other. Such an inter-chain interaction and inter-dot affect the band structure of patterned hydrogenated graphene, and the inter-dot interaction will further change the magnetic properties of the embedded GQDs. It is interesting that the interaction changes the spin orientation of the atoms in the adjacent triangular GQDs and alters the energy dispersions.