Temperature dependence of the Raman spectra of graphene and graphene multilayers

We investigated the temperature dependence of the frequency of G peak in the Raman spectra of graphene on Si/SiO2 substrates. The microRaman spectroscopy was carried out under the 488 nm laser excitation over the temperature range from -190 to +100 degrees C. The extracted value of the temperature coefficient of G mode of graphene is X = -0.016 cm(-1)/degrees C for the single layer and X = -0.015 cm(-1)/degrees C for the bilayer. The obtained results shed light on the anharmonic properties of graphene.