Surface Potential Imaging of Chemical Vapor Deposition Graphene by Electrical Force Microscopy

Department of Mechanical Engineering
Advisor: Professor Cengiz Ozkan

Abstract: Recently, graphene-derived nanomaterials are heated studied as future replacement of silicon. In this   study,   electrical   force   miscroscopy   (EFM)   and   surface   potential   imaging   (SPI)   are   utilized   to characterize the electrical properties of chemical vapor deposition graphene and micromechanical exfoliated graphene.  A  comparison  of  graphene  came from  both  of  these  methods  is investigated  in  terms  of  phase shifts  and  distinct  tip  bias.  The  presented  results  show  that  the  phase  shifts of  graphene  by  these  two methods  share  the  same  trend,  and  defects  of  CVD  graphene  as  well  as  the  micromechanical  exfoliate ones, follow certain directions, which will trace back to the formation of defects in graphene. It is shown in this study that the similarity of both of these plots and the cause of the difference is further discussed. These results  will  encourage  future  studies  regarding  graphene-based  electronics  and  applications  of  material defects manipulations.