Efecto de la temperatura en multicapas de grafeno usando espectroscopia Raman y equipo de bajo costo

Abstract

Thermal properties of two-dimensional materials such as monolayers or multilayers of graphene have attracted special attention, because they are excellent thermal conductors and their thermal properties have attracted a particular attention [1, 2]. In this sense, in this work the effect of temperature on the G (~ 1580 cm^-1), 2D (~ 2700 cm^-1) and 2D '(~ 3244 cm^-1) bands of multilayer graphene (MLG) is reported using Raman spectroscopy and a low cost temperature device. For this purpose the graphene samples were deposited on SiO2 substrates using the micro-mechanical exfoliation method, while the low-cost temperature device was constructed using a voltage and current regulator source, a microm resistance, which it was placed on an insulating base, coupled to the base of the Raman microscope. The temperature on the samples was increased, at different intervals, from room temperature (~ 25 ^oC) to 535 ^oC, being measured in real time using a thermal chamber. Results of this work show that, as the temperature increases, the position of the G (Pos (G)), 2D (Pos (2D)) and 2D '(Pos (2D')) bands are shifted to smaller wavenumbers, showing a non-linear behavior. Similarly, an increase in the full width half maximum (FWHM) of the G, 2D and 2D’ bands was also observed. These displacements are explained in terms of the electron - phonon and phonon - phonon interactions [3, 4]. At the same time, this work shows that using low-cost equipment it is possible to obtain better or equal results than those obtained at high cost, and would be of great utility to understand the thermal properties and physical mechanisms related to graphene multilayers for applications as thermal devices operating at room temperature.