title: Probing confined phonon modes in individual CdSe nanoplatelets using surface-enhanced Raman scattering.
abstract: The phonon modes of individual ultrathin CdSe nanoplatelets are investigated using surface-enhanced Raman scattering in a tightly confined plasmonic geometry. The surface-enhanced Raman scattering spectra, taken on single nanoplatelets sandwiched between a gold nanoparticle and a gold surface, reveal a phonon doublet arising from oscillations perpendicular to and within the platelet plane. The out-of-plane mode cannot be observed with conventional Raman spectroscopy. The resulting strong electric field enhancements and the field vector reorientation within such nanometer-sized plasmonic gaps reveal otherwise hidden information deep into the Brillouin zone illuminating the vibrational properties of ultrathin materials.
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Sigle
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: James T
authors.initials: JT
authors.lastname: Hugall
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR8213 du CNRS, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ithurria
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR8213 du CNRS, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Dubertret
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Baumberg