Practical implementation of graphene relies on affordable, reliable and scalable production of graphene with consistent quality. Wafer-scale production of graphene can be achieved via chemical vapor deposition (CVD), annealing SiC, reduced graphene oxides (R-GOs), and liquid exfoliation of graphite. Each demonstrates strengths and weaknesses. Liquid exfoliation and R-GOs suffer from high sheet resistance. Annealing SiC provides the highest quality graphene. However, the prohibitively high cost of SiC makes it unrealistic for practical applications. CVD of graphene on catalytic metal surfaces is by far the most promising technique. However, multiple deposition and transfer steps are required to deposit graphene on target surfaces, which are not desired for scalable device fabrications. Therefore, a synthetic technique with economic and technical viability is still absent. It is highly desired to develop an innovative synthetic technique providing high throughput and scalable production of graphene directly on dielectric surfaces with satisfactory conductivity and transmittance.
In this study, we report the development of a solid-state rapid thermal processing (RTP) technique depositing wafer-scale graphene directly on dielectric surfaces, such as SiO2, fused silica, quartz, and sapphire. The Ni catalyst evaporates spontaneously, therefore, eliminating the post-growth Ni etching and graphene transfer procedures. By tuning Ni/C ratio, graphene of controlled number of graphitic layers can be obtained, including single-layer graphene (SLG), bilayer graphene (BLG), and multilayer graphene (MLG). SLG of high transmittance (~ 93 % at 550 nm) and low sheet resistance (~ 50 ?/sq) was obtained. According to temperature resolved Auger electron spectroscopy (AES) depth profiling studies, the graphene formation and Ni evaporation are ascribed to the formation and decomposition of nickel carbide (Ni3C).