Transport behavior and negative magnetoresistance in chemically reduced graphene oxide nanofilms
Journal
Nanotechnology
Journal Volume
22
Journal Issue
33
Date Issued
2011
Author(s)
Wang, S.-W.
Lin, H.E.
Lin, H.-D.
Chen, K.Y.
Tu, K.-H.
Chen, C.W.
Chen, J.-Y.
Liu, C.-H.
Abstract
The electron transport behavior in chemically reduced graphene oxide (rGO) sheets with different thicknesses of 2, 3, and 5 nm was investigated. The four-probe method for the sheet resistance (R(S)) measurement on the intensively reduced graphene oxide samples indicates an Arrhenius characteristic of the electron transport at zero magnetic field B = 0, consistent with previous experimental results on well-reduced GO samples. The anticipated variable range hopping (VRH) transport of electrons in a two-dimensional electron system at low temperatures was not observed. The measured R(S) of the rGO samples are below 52 kΩ/square at room temperature. With the application of a magnetic field up to 4 T, negative magnetoresistance in the Mott VRH regime was observed. The magnetotransport features support a model based on the spin-coupling effect from the vacancy-induced midgap states that facilitate the Mott VRH conduction in the presence of an external magnetic field.
Type
journal article