Manipulation of the graphene surface potential by ion irradiation

Abstract

We show that the work function of exfoliated single layer graphene can be modified by irradiation with swift (E_{kin}=92 MeV) heavy ions under glancing angles of incidence. Upon ion impact individual surface tracks are created in graphene on SiC. Due to the very localized energy deposition characteristic for ions in this energy range, the surface area which is structurally altered is limited to ~ 0.01 mum^2 per track. Kelvin probe force microscopy reveals that those surface tracks consist of electronically modified material and that a few tracks suffice to shift the surface potential of the whole single layer flake by ~ 400 meV. Thus, the irradiation turns the initially n-doped graphene into p-doped graphene with a hole density of 8.5 x 10^{12} holes/cm^2. This doping effect persists even after heating the irradiated samples to 500°C. Therefore, this charge transfer is not due to adsorbates but must instead be attributed to implanted atoms. The method presented here opens up a new way to efficiently manipulate the charge carrier concentration of graphene.

6 pages, 4 figures

References in corpus (4)

• The Raman Fingerprint of Graphene
• Doping graphene with metal contacts
• Anisotropic behaviors of massless Dirac fermions in graphene under periodic potential
• Water-Gated Charge Doping of Graphene Induced by Mica Substrates

Cited by in corpus (4)

• Radiation Hardness of Graphene and MoS2 Field Effect Devices Against Swift Heavy Ion Irradiation
• Charge Exchange and Energy Loss of Slow Highly Charged Ions in 1nm Thick Carbon Nanomembranes
• Apparent Differences between Single Layer Molybdenum Disulfide Fabricated via Chemical Vapor Deposition and Exfoliation
• Double-resonant LA phonon scattering in defective graphene and carbon nanotubes