Ultralong, High Aspect Ratio Graphene Nanoribbon Arrays Fabricated by Laser Interference Lithography: Implications for Integrated Nanocircuits

Ultralong graphene nanoribbons (GNRs) have drawn much attention in the field of high performance nanoelectronics. In this work, a mask-free ultrafast laser lithography method is demonstrated for the mass production of ultralong GNR arrays with an intact carbon network. The longest GNR reaches ∼42 μm with a width of ∼400 nm. The orientation of the as-received GNR arrays is always parallel to the incident laser polarization direction. Original carbon network structures of remaining GNRs are preserved, which are ascribed to the precise energy injection and selective nanoablation in graphene flakes. The formation of large-scale GNR arrays is mainly determined by the interference between the incident laser and the stimulated transverse electric mode surface plasmon (TE-SPs) wave. The excitation of the TE-SPs wave prefers to be triggered at the geometrical fluctuations on ablated graphene surfaces as well as the interface with a large discrepancy of dielectric permittivity (e.g., graphene and SiO2). With the initial generation of the nanoablated groove on the surface, the interference between TE-SPs waves and incident laser beams further extends to the far end with periodic intervals, which results in the continuous formation of GNRs. This ultrafast laser-induced periodic lithography may provide an alternative for ultralong and high aspect ratio GNR array fabrication, which is promising in high performance nanodevice development.