Observation of current reversal in the scanning tunneling spectra of fullerene-like WS2 nanoparticles.
Current-voltage characteristics measured using STM on fullerene-like WS2 nanoparticles show zero-bias current and contain segments in which the tunneling current flows opposite to the applied bias voltage. In addition, negative differential conductance peaks emerge in these reversed current segments, and the characteristics are hysteretic with respect to the change in the voltage sweep direction. Such unusual features resemble those appearing in cyclic voltammograms, but are uniquely observed here in tunneling spectra measured in vacuum, as well as in ambient and dry atmosphere conditions. This behavior is attributed to tunneling-driven electrochemical processes.
Azulay
Doron
D
Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Kopnov
Frieda
F
Tenne
Reshef
R
Balberg
Isaac
I
Millo
Oded
O
D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D037741:Fullerenes / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing; D016252:Microscopy, Scanning Tunneling / Q000379:methods; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012666:Semiconductors; D013057:Spectrum Analysis; D013457:Sulfur Compounds / Q000737:chemistry*; D017973:Tungsten Compounds / Q000737:chemistry*
D037741:Fullerenes; D013457:Sulfur Compounds; D017973:Tungsten Compounds