Correlated Energy-Level Alignment Effects Determine Substituent-Tuned Single-Molecule Conductance
| Autor: | Manuel Smeu, Dominic V. McGrath, Aldilene Saraiva-Souza, Oliver L.A. Monti, Roland Himmelhuber, Jeffrey A. Ivie, Stuart Shepard, Keshaba Nanda Parida, Dylan Dyer, Nathan D. Bamberger |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Condensed Matter - Mesoscale and Nanoscale Physics Rational design Substituent Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Molecular electronics Conductance chemistry.chemical_compound chemistry Chemical physics visual_art Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Electronic component visual_art.visual_art_medium Molecule General Materials Science Density functional theory Energy (signal processing) |
| Zdroj: | ACS applied materialsinterfaces. 13(3) |
| ISSN: | 1944-8252 |
| Popis: | The rational design of single-molecule electrical components requires a deep and predictive understanding of structure-function relationships. Here, we explore the relationship between chemical substituents and the conductance of metal-single-molecule-metal junctions, using functionalized oligophenylenevinylenes as a model system. Using a combination of mechanically controlled break-junction experiments and various levels of theory including non-equilibrium Green's functions, we demonstrate that the connection between gas-phase molecular electronic structure and in-junction molecular conductance is complicated by the involvement of multiple mutually correlated and opposing effects that contribute to energy-level alignment in the junction. We propose that these opposing correlations represent powerful new "design principles" because their physical origins make them broadly applicable, and they are capable of predicting the direction and relative magnitude of observed conductance trends. In particular, we show that they are consistent with the observed conductance variability not just within our own experimental results but also within disparate molecular series reported in the literature and, crucially, with the trend in variability across these molecular series, which previous simple models fail to explain. The design principles introduced here can therefore aid in both screening and suggesting novel design strategies for maximizing conductance tunability in single-molecule systems. |
| Databáze: | OpenAIRE |
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