Assembly of Patterned Graphene Film Aided by Wetting/Nonwetting Surface on Liquid Interface

This paper demonstrates a methodology for preparing patterned graphene films through the destabilization of dispersed graphene in N-methyl-pyrrolidone (NMP) by addition of water, which causes the graphene to be trapped at the interface of NMP/hexane. The trapped graphene film is transferred onto the patterned wetting/nonwetting surface through dip-coating process. The quality of graphene film is studied by scanning electron microscopy and atomic force microscopy. The sheet resistance of graphene film is 1.49 × 10² kΩ/□ with surface coverage of 70% measured by the four-probe method. Field effect transistor based on such patterned graphene film is then fabricated. The current on/off ratio of devices is 1.24 with field-effect hole mobility of 159 cm²/Vs.