High carrier mobility in chemically modified graphene on an atomically flat high-resistive substrate

Abstract

Special high-resistive substrates for graphene sheets are suggested with the aim of providing high conductivity and mobility of charge carriers in graphene. The substrates were created from N-methylpyrrolidone-intercalated few-layer graphene (FLG) using anneals given to FLG samples in the temperature range 100–180 °C. Structures containing a highly conductive single-layer graphene on an atomically flat, high-resistive substrate were produced by recovering the top-layer conductivity. The obtained structures have potential in electronic applications due to a high carrier mobility (up to 16 000–42 000 cm2 V−1 s−1) and strong gate-voltage-induced modulation (by 4–5 orders of magnitude) of the current in the top graphene layer. The strong gate-voltage-induced modulation of the current clearly demonstrated that the top layer was chemically modified graphene. The possibility of governing the surface conductivity in the described structures offers a unique tool for two-dimensional nanodesign.