COLÓQUIO - IFUSP:Resonance Raman Spectroscopy as a tool to probe the electronic structure of graphene and carbon nanotubes

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Publicado em Thu Aug 22 18:27:07 GMT-03:00 2013
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Resonance Raman spectroscopy (RRS) is a useful tool to study the electronic structure of carbon nanotubes and graphene. It provides structural (n,m) assignment of the nanotubes present in the samples due to the enhancement of the Raman signal when the photon is in resonance with its optical transitions We will present the RRS results in chirality-enriched nanotube samples with specific (n,m) nanotubes, where the resonance Raman profile of the high energy phonons is analyzed. RRS is also useful to investigate electrons and phonons near the K point of graphene, since the double resonance (DR) Raman process allow us to probe different points within the interior of the Brillouin zone. We will show that RRS can be useful to characterize Moiré patterns graphene twisted layers, due to the strong enhancement of the G band when the laser excitation energy is in resonance with the van Hove singularities in the joint density of state of the twisted layers.