Growth of highly uniform graphene for spintronic applications

Entani, Shiro; Matsumoto, Yoshihiro; Otomo, Manabu; Avramov, P.; Naramoto, Hiroshi*; Sakai, Seiji

Graphene has attracted wide attention for nanoelectronics and spintronics. In this study, in-situ analysis were performed on the graphene growth in UHV-CVD by exposing the epitaxial Ni(111) thin film to benzene vapor at 873 K. It is shown that the uniform single- and bi-layer graphenes can be synthesized by the control of benzene exposure. Ex-situ micro-Raman analysis on the large area graphene film transformed on a SiO substrate makes it clear that the structural and electrical uniformities can be improved remarkably under the specific exposure conditions at which the growth of the respective graphene layers are completed. The present results demonstrate that the UHV-CVD method enables the growth of highly uniform graphene which would be necessary for controlling the spin transport process as well as realizing a long spin-relaxation length in the graphene-based spintronic devices by optimizing the dosage of precursors and the growth temperature.