Graphene field-effect transistors using large-area monolayer graphene grown by chemical vapor deposition on Co thin films

There has been great interest in methods for the synthesis of high-quality, large-area graphene films, as required for practical applications in the electronics industry. In particular, recent developments in chemical vapor deposition (CVD) methods have shown a promising approach to grow large-area graphene on metal substrates by catalyzed CVD growth. Reports of CVD growth on Cu and Ni are common; however, there have been few efforts to grow graphene on Co, and attempts to grow graphene on Co/SiO₂/Si resulted in very small domains of predominantly multilayer graphene that were not suitable for transistor fabrication. Unlike Ni, Co is attractive due to the low lattice mismatch (<; 2%) between graphene and the Co (0001) surface, and Co exhibits greater compatibility with Si than Cu, which is a deep trap in Si and a fast diffuser. Here we have demonstrated graphene field-effect transistors (GFETs) fabricated using large-area monolayer graphene grown by catalyzed CVD on Co films.