- Synthesize AB-stacked bilayer graphene using solar-thermal chemical vapor deposition (CVD).
- Utilize various characterization techniques, including Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), transmissivity measurements, and sheet resistance testing, to evaluate the quality of graphene.
Mass production of graphene by plasma or thermal chemical vapor deposition consumes much energy, with potentially adverse effects on the environment. This work reports the use of a high-flux solar simulator that approximates the sun’s spectrum and a cold-wall chemical vapor deposition reactor to demonstrate a renewable energy process for graphene growth. Synthesis of high-quality (ID/IG = 0.13) AB-stacked bilayer graphene with greater than 90% coverage is achieved on commercial polycrystalline copper in a one-step process and a short time of 5 min. The graphene exhibits large grain sizes of up to 20 μm with spatial uniformity over a large area up to 20 mm in radius. The transmissivity and sheet resistance of the graphene films fall in the ranges of 92.8–95.3% and 2–4 kΩ/sq, respectively. Thus, direct solar capture provides a compelling option for graphene synthesis that can potentially decrease fabrication costs and environmental pollution1.
