Lithium Intercalation of Single-Layer Graphene / Boron Nitride Heterostructures

Graphene intercalate compounds form a new generation of graphene derivative systems where novel physical phenomena such as superconductivity and magnetism may emerge. Experimental realization of intercalated few-layer graphenes have been limited by harsh intercalation processes, often incompatible with mesoscopic device fabrication techniques. Using electrochemical methods, we demonstrate lithium intercalation of single and few-layer graphene encapsulated in hexagonal boron nitride (BN), where the BN simultaneously serves as a scaffold for the lithium atoms as well as protects the graphene from parasitic chemical reactions in the electrolyte. In addition, we developed techniques to monitor intercalation electronically. By performing in-situ Raman spectroscopy, we confirmed that the intercalated single layer graphene/BN heterostructure reached a Fermi energy in excess of $1.16eV$, and corresponding Hall measurements showed a density in excess of $7E13 cm^{-2}$.