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Journal of Shanghai University >

2020 , Vol. 26 >Issue 2: 197 - 206

DOI: https://doi.org/10.12066/j.issn.1007-2861.2028

Research Articles

Qualitative analysis of the asymmetric I-V curve in STM molecular junctions

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  • College of Sciences, Shanghai University, Shanghai 200444, China

Received date: 2018-03-08

  Online published: 2020-04-29

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Abstract

Quantum transport properties of molecular devices are mostly measured by scanning tunneling microscopy (STM). The results show abnormal features such as asymmetric I-V (AIV) curve or negative differential conductance (NDC), which are not to be observed in the case of common macroscopic devices. Based on finite element method and parameter models, the Hamiltonian of a sample system with a local state is presented. The non-equilibrium Green's function method is used to calculate the electron density and the tunneling current of the device after self-consistent convergence. After investigating the effects of different parameters, including the electrode coupling strength, molecular energy level, local energy level, the influences of the local states and geometrical asymmetry on the transport properties of molecular devices have been analyzed. It is concluded that the intrinsic region of AIV and NDC in STM related molecular devices experiments is the offset of the local states in the tip.

Key words： non-equilibrium Green's function; molecular device; quantum transport; density functional theory

Cite this article

QIAN Lijiang, LI Weiju, ZHANG Yibing, CHEN Jingzhe . Qualitative analysis of the asymmetric I-V curve in STM molecular junctions[J]. Journal of Shanghai University, 2020 , 26(2) : 197 -206 . DOI: 10.12066/j.issn.1007-2861.2028

References

[1] Park J, Pasupathy A N, Goldsmith J I , et al. Coulomb blockade and the Kondo effect in single-atom transistors[J]. Nature, 2002,417(6890):722-725.
[2] Reed M A, Zhou C, Muller C J , et al. Conductance of a molecular junction[J]. Science, 1997,278(5336):252-254.
[3] Ferry D K, Goodnick S M. Transport in nanostructures [M]. Cambridge: Cambridge University Press, 1997.
[4] Xu B, Tao N J . Measurement of single-molecule resistance by repeated formation of molecular junctions[J]. Science, 2003,301(5637):1221-1223.
[5] Wada Y . Prospects for single molecule information processing devices[J]. Proceedings of the IEEE, 2001,89(8):1147-1173.
[6] Nitzan A, Ratner M A . Electron transport in molecular wire junctions[J]. Science, 2003,300(5624):1384-1389.
[7] Datta S. Electronic transport in mesoscopic systems [M]. Cambridge: Cambridge University Press, 1997.
[8] Hall L E, Reimers J R, Hush N S , et al. Formalism, analytical model, and a priori Green's-function-based calculations of the current-voltage characteristics of molecular wires[J]. Journal of Chemical Physics, 2000,112(3):1510-1521.
[9] Supriyo D . Nanoscale device modeling: the Green's function method[J]. Superlattices and Microstructures, 2000,28(4):253-278.
[10] Jeremy T, Hong G, Wang J . Ab initio modeling of quantum transport properties of molecular electronic devices[J]. Physical Review B, 2000,63:245407.
[11] Chen J Z, Thygesen K S, Jacobsen K W . Ab initio nonequilibrium quantum transport and forces with the real-space projector augmented wave method[J]. Physical Review B, 2012,85:155140.
[12] Anna R B, Laura A, Michel S , et al. AFM, STM and ellipsometry characterization of a monolayer of azurin molecules self assembled on a gold surface in air [J]. Nanotechnology, 2005, 1: 1-11.
[13] Huang C, Yang J S . Nano-molecular junctions on STM tips[J]. Nano-Micro Letters, 2011,3(1):1-5.
[14] Siya S, Gabino R B, Elena P C , et al. Current rectification in a single molecule diode: the role of electrode coupling[J]. Nanotechnology, 2015,26(29):291001.
[15] Ghosh A W, Zahid F, Damle P S , et al. Insights into molecular conduction from $I$-$V$ asymmetry [J]. American Physical Society, 2002. arXiv: cond-mat/0202519v/.
[16] Komoto Y, Fujii S, Kiguchi M . Statistical $I$-$V$ measurements of single-molecule junctions with an asymmetric anchoring group 1,4-aminobenzenethiol[J]. Advances in Natural Sciences Nanoscience & Nanotechnology, 2017,8(2):025007.
[17] Gaudioso J, Lauhon L J, Ho W . Vibrationally mediated negative differential resistance in a single molecule[J]. Angewandte Chemie International Edition, 2000,85(9):1918.
[18] Xu B, Dubi Y . Negative differential conductance in molecular junctions: an overview of experiment and theory[J]. Journal of Physics: Condensed Matter, 2015. DOI: 10.1088/0953-8984/27/26/263
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