AmirAli Abbaspourmani, Ritika S. Petersen, Abhay Shivayogimath,Stephan S. Keller, Timothy J. Booth a Department of Physics, Technical University of Denmark, DTU Fysik, Building 345B, DK-2800 Kgs. Lyngby, Denmark b National Centre for Nano Fabrication and Characterization, Technical University of Denmark, DTU Nanolab, Building 345B, DK-2800 Kgs. Lyngby, Denmark  Graphene patterning is regarded as one of the areas of interest due to its necessity for applications. Owing to the recent developments in large area production of CVD grown graphene, it has now become more accessible to study the emergent nanoscale properties of graphene in larger scales. However, transferring such nanoscale properties to large scales by using conventional graphene patterning methods has remained a challenge. The current graphene micro-patterning techniques, including electron beam lithography (EBL), optical lithography, and nanoimprint lithography are time consuming and scale with sample size. In such methods, graphene is patterned in a plasma environment through dry etching reactions with gases like O2. These reactions lead to rough edges and no preferred crystal alignment in patterned graphene, which prevent a systematic approach in understanding some of graphene’s mechanical behaviors like tearing [1][2]. Consequently, there is a need to provide a reliable method for largescale graphene micro-patterning, which will further constitute a way for studying some of graphene’s properties such as tearing and cracking [3]. Here, we present hot punching as a novel method for largescale micro-patterning of CVD graphene. We have used a micro-patterned nickel stamp to replicate 300 µm micro-patterns in graphene by applying pressure and temperature. We have investigated micro- and nanostructures of patterned graphene by using optical microscopy, Raman spectroscopy, AFM, and TEM. AFM results show that graphene ribbons with an average width of 0.69 ± 0.21 μm, normal to the edges of the punched areas, are formed, while wrinkles have changed their orientation normal to the ribbons edge. [1] D. Sen et al., ‘’Tearing graphene from adhesive substrates produces tapered nanoribbons’’, Small, Vol. 6, pp. 1108-1116, 2010. [2] K. S. Kim et al., ‘’Large-scale pattern growth of graphene films for stretchable transparent electrodes’’, Nature, Vol. 457, pp. 706-710, 2009. [3] K. Kim et al., ‘’Ripping graphene: Preferred Directions’’, Nano Lett., Vol. 12, pp. 293-297, 2012.  |
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