Simulation of characteristics of a molecular single-electron tunneling transistor with a discrete energy spectrum of the central electrode

Current-voltage curves of molecular single-electron tunneling transistors are simulated based on a modified theory of single electronics that accounts for the discreteness of the energy spectrum of the molecule. The simulation was performed including effects of energy relaxation of the electrons in the molecule for two limiting cases of fast and slow relaxation, and for both equidistant and randomly spaced energy levels of the molecule. An efficient recursion method allowing a fast calculation of the Gibbs canonical distribution for electrons in the molecule is suggested and realized. A comparison of the simulated I-V curves with the experimental ones shows that the experimental conditions correspond to the slow relaxation case. (C) 2002 American Institute of Physics

Correlated electron tunneling in the single-molecule nanosystems

The original approach to the creation of high-temperature single-electron tunneling systems has been developed based on the use of nanocluster molecules. The morphology and electron tunneling characteristics through single nanocluster molecules organized as highly-ordered monolayer Langmuir-Blodgett films on atomically-flat graphite substrate have been studied experimentally using scanning tunneling microscopy (STM) and spectroscopy techniques with sub-nanometer spatial resolution in a double barrier tunnel junction configuration "STM" tip - monomolecular film - conducting substrate" at ambient conditions. Molecular single-electron transistors on the basis of a single nanocluster molecule operating at room temperature were constructed and studied. Various nanocluster molecules with cores from 3 to 23 metal atoms were used as a central electrode in these transistors. Computer simulation of I-V curves of molecular single-electron tunneling (SET) transistor was carried out using the modified theory of single-electronics with consideration of discreteness of the energy spectrum of a molecule as well as the effects of energy relaxation of electrons in the molecule. A comparison of the simulated I-V curves with the experimental ones allow to conclude that the experimental data correspond to the slow energy relaxation case

Molecular cluster based nanoelectronics

The use of molecular clusters as a basis of molecular single-electronic systems is considered experimentally and theoretically. The Langmuir-Blodgett formation and scanning tunneling microscope study of structures with chemically different cluster molecules is described. I-V curves and control curves of molecular single-electron transistors based on various single molecules were studied at room temperature. Comparison of experimental I-V curves with simulated ones allows us to identify a regime of slow energy relaxation of electrons in experimental transistors. Experimental study of electron transport through the planar molecular nanosystems has shown a correlated character of electron tunneling in such systems. (C) 2003 Elsevier B.V. All rights reserved