The Growth Of CVD Graphene And Its Raman Characterization

Chemical vapor deposition (CVD) makes it possible to synthesize graphene of high quality, large size and controlled layer numbers, so it has become the major method to massively grow graphene membrane. It has attracted great attention in the optical-electric field owning to its outstanding properties. It's highly efficient to decrease the nucleation density via growth condition optimization. Bilayer or multilayer domains frequently occur in CVD graphene samples. The stacking order, called the twist angle, between the upper layer and downer layer may be distinguished from grains to grains which greatly affects the electric and optical properties of graphene. This article firstly introduces the effect of hydrogen peroxide (both concentration and treatment time) on the graphene nucleation density. Then, the oxygen concentration and roughness of copper surface were analyzed to explore the mechanism. It was found that proper parameters of hydrogen peroxide can improve surface quality and decrease the nucleation density of graphene. Secondly, bilayer graphene was characterized by Raman which furtherly help to rapidly distinguish the twist angle and its distribution in samples. According to our calculation, we prove that the D-like peak appears in the Raman spectroscopy of bilayer graphene doesn't correspond to the defect peak. At last, graphene and n type deeply doped silicon were utilized to fabricate solar cell. Few layers graphene was fabricated to avoid the leak current in the graphene/silicon solar cell. Meanwhile, the optical-electric performance is optimized.