Growth and Characterization of Graphene on Polycrystalline SiC Substrate Using Heating by CO2 Laser Beam

Abstract

The thermal decomposition of silicon carbide (SiC), with the subsequent formation of graphene, can be achieved by heating treatment. Several heating processes have been applied for this purpose by using SiC, either in form of powder particles or monocrystalline substrate. In this work, instead of using an expensive commercially available SiC wafer, a polycrystalline SiC substrate was obtained, based on powder metallurgy process, in order to explore the synthesis of graphene layers on its surface by using a CO 2 laser beam as heating source. Different levels of energy density (fluence) were applied and Raman spectroscopy analyses demonstrated that graphene layers were formed on the polycrystalline SiC surface. The ratio of the integrated intensity of the D and G bands, and the crystallite size were calculated. The FWHM of the 2D band peaks are in excellent agreement with the range of values found in the literature. The samples irradiated with energy density of 138.4 J/cm 2 presented lower concentration of defects and higher crystallite size, while the lowest FWHM was obtained for energy density of 188 J/cm 2 . The process occurred at room conditions and no gas flow was used. The results reveal a simple and cost-effective alternative for synthesis of graphene-based structures on SiC.

A Novel Method of Synthesizing Graphene for Electronic Device Applications

“…The energy densities of each scanning velocity were calculated and are shown in Table 1. One can note that in this investigation the energy densities were between 127-145 J cm -2 , whereas in the previous works the values were between 132-200 J cm -2 [18]. The choice of a lower energy density range is due to the properties of the synthesized graphene at higher laser energy density did not present significant difference in comparison with samples produced with lower energy density [18].…”

“…In addition, the laser heating may also have influenced the growth and quality of graphene. As obtained by Galvão et al [18], the limited growth of graphene and nondissociation of SiC in some regions of the material may have been influenced by the heat transfer along and across the heterogeneous surface. Inhomogenities on the surface cause a non-uniform temperature distribution.…”

“…The heating of the SiC thin film was carried out by using a CO2 laser (Synrad Evolution -125) with a beam diameter of 200 µm, which emits infrared laser radiation at a wavelength band of 10.6 µm. The samples were positioned at 5 mm below the laser focal point (see schematic diagram of the laser irradiation process in [18]). For all the processes, a beam overlap of 50% was used.…”

“…In other recent study, Galvão et al reported on the growth of graphene layers on a low cost polycrystalline SiC substrate obtained from powder metallurgy using a CO2 laser beam [18].…”

Effective Synthesis of Silicon Carbide Nanotubes by Microwave Heating of Blended Silicon Dioxide and Multi-Walled Carbon Nanotube

“…It is more economical to synthesize materials using microwave heating as compared to conventional methods such as mechanical milling, carbothermal reduction and laser synthesis since microwave heating is well known for low energy consumption, shorter reaction time and very low impurities such as oxygen and metals reside in the end products after synthesis [14][15][16] . The characteristic of microwave heating is attributed to the fact that microwave is a form of electromagnetic energy with a frequency range from 300 MHz to 300 GHz and microwave can couple with certain materials which have excellent dielectric properties such as carbon and it can be absorbed into these materials volumetrically which then transformed to heat from the inside of materials 17,18 .…”