Interface traps in graphene field effect devices: extraction methods and influence on characteristics

摘要

We study impact of the near-interfacial oxide traps on the C-V and I-Vcharacteristics of graphene gated structures. Methods of extraction ofinterface trap level density in graphene field effect devices from thecapacitance-voltage measurements are described and discussed. It has been foundthat the effects of electron-electron or hole-hole interactions andelectron-hole puddles can be mixed in C-V characteristics putting obstacles inthe way of uniquely determined extraction of the interface trap density ingraphene. Influence of the interface traps on DC and AC capacitance andconductance characteristics of graphene field-effect structures is described.It has been shown that variety of widths of resistivity peaks in varioussamples could be explained by different interface trap capacitance values.