Efeito da variação da temperatura em multicamadas de grafeno usando espectroscopia raman

Abstract

It is known that graphene has been studied and analyzed by several technological centers because of its unique properties, properties that can revolutionize several areas of engineering. One of the properties is the thermal capacity that monolayer or multilayer graphene has, due to its excellent thermal conductivity, large institutions are paying attention to this two-dimensional material. This work aims to study the effects caused by different temperatures in the bands G (~1580 cm−1 ), 2D (~2700 cm−1 ) e 2D’ (~3244 cm−1 ) of graphene multilayer (MLG) Raman spectra using Raman spectroscopy and a low-cost device. For the purpose of the work to be completed, graphene samples were deposited on a substrate of 𝑆𝑖𝑜2(silicon dioxide) using the micromechanical exfoliation method. The device for the samples to be subjected to different temperatures was built using easily accessible and low-cost materials, materials such as voltage and current regulator, nickelchromium resistor, among others. To study the effect of temperature on graphene bands, the temperature device was attached to the base of the Raman microscope. Raman measurements were performed at different temperature ranges (~25°C to 534°C), with an accuracy of 1°C to 2°C. In this work we show the effect that temperature causes on multilayer graphene (ML). Where it was observed that as the temperature increases, the positions of the bands G (Pos G), 2D (Pos 2D) and 2D' (Pos 2D') are shifted to smaller wave numbers, and this shift is non-linear. It was possible to analyze the behavior of the width at average height (FWMH) of the G, 2D and 2D' bands, observing that as the temperature increases the FWMH also increases. With the present work it was proved that using low cost equipment it is possible to have results similar to those of the literature. This fact is of great importance for small research centers that aim to study the thermal and physical properties of graphene multilayers in order to apply them in devices that operate at room temperature. Keywords: Graphene, Raman spectroscopy, temperature effect.