Thermally activated electron transport in single redox molecules.
We have studied electron transport through single redox molecules, perylene tetracarboxylic diimides, covalently bound to two gold electrodes via different linker groups, as a function of electrochemical gate voltage and temperature in different solvents. The conductance of these molecules is sensitive to the linker groups because of different electronic coupling strengths between the molecules and electrodes. The current through each of the molecules can be controlled reversibly over 2-3 orders of magnitude with the gate and reaches a peak near the redox potential of the molecules. The similarity in the gate effect of these molecules indicates that they share the same transport mechanism. The temperature dependence measurement indicates that the electron transport is a thermally activated process. Both the gate effect and temperature dependence can be qualitatively described by a two-step sequential electron-transfer process.
Li
Xiulan
X
Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287, USA.
Hihath
Joshua
J
Chen
Fang
F
Masuda
Takuya
T
Zang
Ling
L
Tao
Nongjian
N