Ultrafast direct ablative patterning of HOPG by single laser pulses to produce graphene ribbons

Ultrafast, single step and direct patterning of highly oriented pyrolytic graphite (HOPG) is achieved through pulsed laser interference ablation using a near field transmitting phase mask. Periodic arrays of lines are patterned on the HOPG surface over large areas by spatially modulating the laser intensity through the mask. Thus patterned surface serve as a source for multi and few layer graphene ribbons for transferring onto desired substrates using polydimethylsiloxane as transferring agent. The transferred regions are contained with few layer graphene (5-6 layers) ribbons as well as thick graphitic ribbons (30-40 nm), with widths ∼1 μm and lengths of several micrometers. Raman, TEM and electrical measurements have confirmed that the transferred ribbons are highly crystalline in nature. Using combinations of shadow and transmitting phase masks, other patterns such as checker boards and diamond-shaped pits are produced. Ultrafast, large-area and direct patterning of HOPG (highly oriented pyrolytic graphite) is achieved through single laser pulse ablation in presence of a phase mask. The modulating laser intensity can ablate the carbon material periodically to produce different types of patterns on HOPG. AFM topography of those patterns reveals that no modification of the regions adjacent to the periodic ablated patterns. Thus patterned surfaces of HOPG are used as source for graphitic and graphene ribbons enabled by PDMS stamp based transfer. The transferred multi and few layer graphene ribbons are of high quality. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim