UHV-CVD growth of graphene for spintronic applications

スピントロニクス応用のための超高真空化学気相蒸着法によるグラフェン成長

圓谷 志郎; 松本 吉弘; 大伴 真名歩; 桜庭 裕弥*; Avramov, P.; 楢本 洋*; 高梨 弘毅; 境 誠司

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

In this study, the process of the ultrahigh vacuum chemical vapor deposition (UHV-CVD) growth of graphene on Ni(111) films was investigated using in-situ spectroscopes. It is successfully shown that single-layer and bilayer graphenes can be synthesized by the control of benzene exposure in the range of 10-100000 langumuirs reflecting a change in the growth rate by three orders of magnitude in between the first and second graphene layer on the Ni(111) surface. Ex-situ micro-Raman analysis on the large area graphene sheet transformed on a SiO substrate makes it clear that, in contrast to exfoliated graphene, an atomically and electrically uniform graphene sheet can be obtained by precisely adjusting the exposure amount as 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 including the realization of a long spin diffusion length in the graphene-based spintronic devices beyond the limits of exfoliated graphene.