Molecular Rectification in Metal−SAM−Metal Oxide−Metal Junctions
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- 23 November 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 131 (49), 17814-17827
- https://doi.org/10.1021/ja9048898
Abstract
This Article compares the ability of self-assembled monolayers (SAMs) of alkanethiolates with ferrocene (Fc) head groups (SC11Fc), and SAMs of alkanethiolates lacking the Fc moiety (SC10CH3 and SC14CH3), to conduct charge. Ultraflat surfaces of template-stripped silver (AgTS) supported these SAMs, and a eutectic alloy of gallium and indium (EGaIn), covered with a skin of gallium oxide (presumably Ga2O3), formed electrical top-contacts with them. EGaIn is a liquid at room temperature, but its spontaneously formed surface oxide skin gives it apparent non-Newtonian properties and allows it to be molded into conically shaped tips; these tips formed soft electrical contacts with SAMs and formed stable SAM-based tunneling junctions in high (70−90%) yields. Measurements of current density, J, versus applied voltage, V, showed that tunneling junctions composed of SAMs of SC11Fc rectify current with a rectification ratio R ≈ 1.0 × 102 (R = |J(−V)|/|J(V)| at ±1 V and with a log-standard deviation of 3.0). In contrast, junctions lacking the Fc moiety, that is, junctions composed of SAMs of SCn−1CH3 (with n = 11 or 15 and presenting terminal CH3 groups), showed only slight rectification (R = 1.5 (1.4) and 2.1 (2.5), respectively). A statistical analysis of large numbers (N = 300−1000) of data gave detailed information about the spread in values and the statistical significance of the rectification ratios and demonstrated the ability of the experimental techniques described here to generate SAM-based junctions in high yield useful in physical-organic studies.Keywords
This publication has 69 references indexed in Scilit:
- Conductance of Single Alkanedithiols: Conduction Mechanism and Effect of Molecule−Electrode ContactsJournal of the American Chemical Society, 2006
- Molecular Rectification of a Helical Peptide with a Redox Group in the Metal−Molecule−Metal JunctionThe Journal of Physical Chemistry B, 2005
- Self-Assembled Monolayers of Thiolates on Metals as a Form of NanotechnologyChemical Reviews, 2005
- Current Rectification in a Langmuir−Schaefer Monolayer of Fullerene-bis-[4-diphenylamino-4‘ ‘-(N-ethyl-N-2‘ ‘‘-ethyl)amino-1,4-diphenyl-1,3-butadiene] Malonate between Au ElectrodesThe Journal of Physical Chemistry B, 2004
- Unimolecular Electrical RectifiersChemical Reviews, 2003
- Molecular Rectification and Conductance Switching in Carbon-Based Molecular Junctions by Structural Rearrangement Accompanying Electron InjectionJournal of the American Chemical Society, 2003
- Molecular Rectifying Diodes from Self-Assembly on SiliconNano Letters, 2003
- Molecular Rectification in a Metal−Insulator−Metal Junction Based on Self-Assembled MonolayersJournal of the American Chemical Society, 2002
- Negative Differential Resistance in Patterned Electroactive Self-Assembled MonolayersLangmuir, 2001
- Conductance of a Molecular JunctionScience, 1997