Interface traps in graphene field effect devices: extraction methods and   influence on characteristics
  We study impact of the near-interfacial oxide traps on the C-V and I-V characteristics of graphene gated structures. Methods of extraction of interface trap level density in graphene field effect devices from the capacitance-voltage measurements are described and discussed. It has been found that the effects of electron-electron or hole-hole interactions and electron-hole puddles can be mixed in C-V characteristics putting obstacles in the way of uniquely determined extraction of the interface trap density in graphene. Influence of the interface traps on DC and AC capacitance and conductance characteristics of graphene field-effect structures is described. It has been shown that variety of widths of resistivity peaks in various samples could be explained by different interface trap capacitance values. 
G.I. Zebrev, E.V. Melnik, A.A. Tselykovskiy
cond-mat.mes-hall