title: Transport behavior and negative magnetoresistance in chemically reduced graphene oxide nanofilms.
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.
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Shu-Wei
authors.initials: SW
authors.lastname: Wang
authors.forename: H E
authors.initials: HE
authors.lastname: Lin
authors.forename: Huang-De
authors.initials: HD
authors.lastname: Lin
authors.forename: K Y
authors.initials: KY
authors.lastname: Chen
authors.forename: Kun-Hua
authors.initials: KH
authors.lastname: Tu
authors.forename: C W
authors.initials: CW
authors.lastname: Chen
authors.forename: Ju-Ying
authors.initials: JY
authors.lastname: Chen
authors.forename: Cheng-Hua
authors.initials: CH
authors.lastname: Liu
authors.forename: C-T
authors.initials: CT
authors.lastname: Liang
authors.forename: Y F
authors.initials: YF
authors.lastname: Chen