AC-Impedance Spectroscopic Analysis on the Charge Transport in CVD-Grown Graphene Devices with Chemically Modified Substrates
journal contributionposted on 2016-08-30, 00:00 authored by Bok Ki Min, Seong K. Kim, Seong Ho Kim, Min-A Kang, Suttinart Noothongkaew, Edmund M. Mills, Wooseok Song, Sung Myung, Jongsun Lim, Sangtae Kim, Ki-Seok An
A comprehensive study for the effect of interfacial buffer layers on the electrical transport behavior in CVD-grown graphene based devices has been performed by ac-impedance spectroscopy (IS) analysis. We examine the effects of the trap charges at graphene/SiO2 interface on the total capacitance by introducing self-assembled monolayers (SAMs). Furthermore, the charge transports in the polycrystalline graphene are characterized through the temperature-dependent IS measurement, which can be explained by the potential barrier model. The frequency-dependent conduction reveals that the conductivity of graphene is related with the mobility, which is limited by the scattering caused by charged adsorbates on SiO2 surface.