Reversible Graphene decoupling by NaCl photo-dissociation

Abstract

We describe the reversible intercalation of Na under graphene on Ir(111) by photo-dissociation of a previously adsorbed NaCl overlayer. After room temperature evaporation, NaCl adsorbs on top of graphene forming a bilayer. With a combination of electron diffraction and photoemission techniques we demonstrate that the NaCl overlayer dissociates upon a short exposure to an X-ray beam. As a result, chlorine desorbs while sodium intercalates under the graphene, inducing an electronic decoupling from the underlying metal. Low energy electron diffraction shows the disappearance of the moiré pattern when Na intercalates between graphene and iridium. Analysis of the Na 2p core-level by X-ray photoelectron spectroscopy shows a chemical change from NaCl to metallic buried Na at the graphene/Ir interface. The intercalation-decoupling process leads to a n-doped graphene due to the charge transfer from the Na, as revealed by constant energy angle resolved X-ray photoemission maps. Moreover, the process is reversible by a mild annealing of the samples without damaging the graphene.

References in corpus (8)

• Quasi-free Standing Epitaxial Graphene on SiC by Hydrogen Intercalation
• Dirac Cones and Minigaps for Graphene on Ir(111)
• Electronic decoupling of an epitaxial graphene monolayer by gold intercalation
• The mechanism of caesium intercalation of graphene
• Large Bandgap Opening Between Graphene Dirac Cones Induced by Na Adsorption onto an Ir Superlattice
• Li-intercalated Graphene on SiC(0001): an STM study
• Opening and reversible control of a wide energy gap in uniform monolayer graphene
• Penetration of alkali atoms throughout graphene membrane: theoretical modeling

Cited by in corpus (1)

• Electronic Decoupling of Polyacenes from the Underlying Metal Substrate by sp3 Carbon Atoms