L. G. C. Sobral; http://lattes.cnpq.br/8168977104408461; SÁ, Louis Gustavo da Costa Sobral e.
Résumé:
In this work we present the results of calculations ab initio of systems graphene
and graphene-copper / (111) through WIEN2k code, which uses the method of Full-
Potential Linearized Augmented Plane Wavess (FP-LAPW), based on Density Functional
Theory formalism (DFT). The results obtained are: states of density, band
structure, electron density and normal modes of vibration. Shows that graphene is
a semiconductor with zero gap at the Fermi energy, and when deposited on copper
becomes metallic due to the interaction with copper. Graphene has six normal modes
of vibration: Three acoustic modes and three optical modes.
We also show the experimental results of of four samples of graphene on copper
and silicon. Characterized the samples by the analysis bands D,G and 2D obtained
using Raman spectroscopy. The study was done in Raman spectra at room temperature
using a 532 nm laser line. The results obtained show that there is a difficulty in
quantifying the number of graphene layers due to the heterogeneity of the samples.