TY - JOUR
T1 - Electrical conductivities of nanosheets studied by conductive atomic force microscopy
AU - Yilmaz, Neval
AU - Ida, Shintaro
AU - Matsumoto, Yasumichi
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research (A) (No. 19205025) from Japan Society for the Promotion of Science. We thank Dr. Ugur Unal, Chikako Ogata, and Takato Nakashima for providing the exfoliation suspensions used in this work.
PY - 2009/7/15
Y1 - 2009/7/15
N2 - The electrical conductivities of single nanosheets of titanium oxide (TiO2), manganese oxide (MnO2), double-layered titanium perovskite oxide (GdEuTiO), niobium oxide (NbO), and graphite oxide (GO) adsorbed on HOPG were studied by conductive atomic force microscopy (C-AFM) with a Pt-Ir tip. The conduction mechanism for different types of nanosheets could be clarified by using electrodes (HOPG and Pt-Ir tip) having different work functions. While the TiO2, GdEuTiO, and NbO nanosheets showed asymmetric (rectifying) current/voltage (I/V)-profiles, those for the MnO2 and GO nanosheets were symmetric (nonrectifying). The differences in the I/V-profile indicated that the dominant electron transfer mechanism in case of TiO2, GdEuTiO, and NbO nanosheets was tunneling under reverse bias like an n-type semiconductor and that for MnO2 and GO nanosheets, having a defected structure, was hopping. Among all these nanosheets, MnO2 exhibited the highest conductivity.
AB - The electrical conductivities of single nanosheets of titanium oxide (TiO2), manganese oxide (MnO2), double-layered titanium perovskite oxide (GdEuTiO), niobium oxide (NbO), and graphite oxide (GO) adsorbed on HOPG were studied by conductive atomic force microscopy (C-AFM) with a Pt-Ir tip. The conduction mechanism for different types of nanosheets could be clarified by using electrodes (HOPG and Pt-Ir tip) having different work functions. While the TiO2, GdEuTiO, and NbO nanosheets showed asymmetric (rectifying) current/voltage (I/V)-profiles, those for the MnO2 and GO nanosheets were symmetric (nonrectifying). The differences in the I/V-profile indicated that the dominant electron transfer mechanism in case of TiO2, GdEuTiO, and NbO nanosheets was tunneling under reverse bias like an n-type semiconductor and that for MnO2 and GO nanosheets, having a defected structure, was hopping. Among all these nanosheets, MnO2 exhibited the highest conductivity.
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U2 - 10.1016/j.matchemphys.2009.02.043
DO - 10.1016/j.matchemphys.2009.02.043
M3 - Article
AN - SCOPUS:67349229087
SN - 0254-0584
VL - 116
SP - 62
EP - 66
JO - Materials Chemistry and Physics
JF - Materials Chemistry and Physics
IS - 1
ER -