NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States
Graphene is a novel two-dimensional material with great potential for electronic applications due to its exceptional electrical properties such as extremely high electron mobility of 200,000 cm2V-1s-1and carrier concentration of 10exp12 cm-2. Thus, the potential of graphene for applications in many technologies such as flexible electronic devices, chemical and biological sensors, energy storage devices, etc. has been successfully demonstrated in laboratory settings. However, before technological applications of graphene can be realized, cost-effective, high quality, large-scale production is necessary. Low-pressure chemical vapor deposition LPCVD growth of graphene on copper foils offers a technologically promising approach for this endeavor. However, while highly encouraging, there is still a critical need to tune and optimize the method to produce large grains and reduce graphene film defects. In this work, we provide a comprehensive study on the effects of different parameters such as substrate type, time, temperature, pressure, and gas flow rates for each synthesis step on the final graphene film quality. Extensive surface characterization was performed using optical microscope imaging and Raman spectroscopy. The impact of this work is to provide a correlation between the growth parameters and the chemical, structural, and morphological properties of graphene films grown on copper foils.