title: Probing individual point defects in graphene via near-field Raman scattering.
abstract: The Raman scattering D-peak in graphene is spatially localised in close proximity to defects. Here, we demonstrate the capability of tip-enhanced Raman spectroscopy (TERS) to probe individual point defects, even for a graphene layer with an extremely low defect density. This is of practical interest for future graphene electronic devices. The measured TERS spectra enable a direct determination of the average inter-defect distance within the graphene sheet. Analysis of the TERS enhancement factor of the graphene Raman peaks highlights the preferential enhancement and symmetry-dependent selectivity of the D-peak intensity caused by zero-dimensional Raman scatterers.
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. debdulal.roy@npl.co.uk andrew.pollard@npl.co.uk and Department of Physics, King's College London, Strand, London WC2R 2LS, UK.
authors.forename: Sandro
authors.initials: S
authors.lastname: Mignuzzi
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. debdulal.roy@npl.co.uk andrew.pollard@npl.co.uk.
authors.forename: Naresh
authors.initials: N
authors.lastname: Kumar
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. debdulal.roy@npl.co.uk andrew.pollard@npl.co.uk.
authors.forename: Barry
authors.initials: B
authors.lastname: Brennan
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. debdulal.roy@npl.co.uk andrew.pollard@npl.co.uk.
authors.forename: Ian S
authors.initials: IS
authors.lastname: Gilmore
authors.affiliation: Department of Physics, King's College London, Strand, London WC2R 2LS, UK.
authors.forename: David
authors.initials: D
authors.lastname: Richards
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. debdulal.roy@npl.co.uk andrew.pollard@npl.co.uk.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pollard
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK. debdulal.roy@npl.co.uk andrew.pollard@npl.co.uk.
authors.forename: Debdulal
authors.initials: D
authors.lastname: Roy