Raman measurements on plasmon-phonon coupled systems

Mancabelli, Tobia (2016): Raman measurements on plasmon-phonon coupled systems: dynamical back-action between a localized plasmon-polariton and phonons in carbon materials and plasmon-phonon coupling in beryllium doped gallium arsenide nanowires. Dissertation, LMU München: Faculty of Chemistry and Pharmacy

Abstract

In this thesis, Raman spectroscopy is used to characterize the interaction between a plasmon and the lattice vibration of a solid state material. Two systems have been analyzed: the first is composed of a metallic nanostrucure and a carbon material (carbon nanotubes and graphene), the second consists of beryllium-doped gallium arsenide nanowires. In the first system, additionally to the electromagnetic enhancement, a cooperative process (dynamical back-action) between the localized surface plasmon-polariton and the lattice vibration can occur. This process leads to a non-linear response of the Raman signal in dependence on the laser power. In this work the occurrence of this non-linearity is experimentally observed and compared with the theoretical prediction. In the second system, the charge-carriers provided by the dopant act as a plasma, interacting with the electric field related to the longitudinal phonon mode of the crystal lattice. This interaction causes a change in the position and width of the Raman peak, which can consequently been used to extrapolate the change carriers concentration and mobility. The appearance of surface phonons, typical of nanostructures, is also observed and discussed.

• Item Type: Theses (Dissertation, LMU Munich)
• Keywords: Plasmonics, dynamical back-action, Raman scattering, semiconducting nanowires.
• Subjects: 500 Natural sciences and mathematics; 500 Natural sciences and mathematics > 540 Chemistry and allied sciences
• Faculties: Faculty of Chemistry and Pharmacy
• Language: English
• Date of oral examination: 17. November 2016
• 1. Referee: Hartschuh, Achim
• Signature of the printed copy: 0001/UMC 24407