Effects of acetylene flow rate and processing temperature on graphene films grown by thermal chemical vapor deposition

We used thermal chemical vapor deposition (CVD) to synthesize few-layer graphene (FLG) films at a low temperature (600 °C). The FLG films were synthesized on Ni foils using a gaseous mixture of various ratios of H2 to acetylene (C2H2). We investigated that the effects of C2H2 flow on the structural properties of graphene. The quality of low-temperature CVD FLG films was investigated by Raman spectroscopy, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. The results of Raman spectroscopy revealed that C2H2 flux clearly influences the features of FLG films. To enhance the quality of FLG films grown by low-temperature CVD, the films were grown under various gas flow ratios. The results demonstrated that the common thermal CVD method that uses C2H2 as a supplemental carbon source constitutes a low-cost and easy way to synthesize graphene films at low temperature for graphene-based applications.