Conductance of Junctions with Acetyl-Functionalized Thiols: A First-Principles-Based Analysis
| Autor: | Barry D. Dunietz, Austin Hoskins, Atsushi Yamada, Qingguo Feng, Kim M. Lewis, Qi Zhou |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Fabrication Conductance 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Porphyrin 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention chemistry.chemical_compound General Energy chemistry law Molecular conductance Thiol Surface modification Organic chemistry Physical and Theoretical Chemistry Scanning tunneling microscope 0210 nano-technology Quantum tunnelling |
| Zdroj: | The Journal of Physical Chemistry C. 121:10298-10304 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.7b02009 |
| Popis: | Thiol-based contacts are widely used in fabrication of molecular junctions but are associated with several drawbacks due to their chemical reactivity. In particular, their tendency to dimerize by forming sulfur–sulfur bonds is viewed as a barrier for large scale bridge fabrication. Instead, the use of functionalized sulfur end groups in the fabrication of the junctions is promoted. We analyze the effects of thiol functionalization by acetyl on the transport properties of porphyrin based bridges. In scanning tunneling microscopy (STM) experiments, where the conductance is measured as the tip is retracted, we observe molecular conductance steps due to junctions with acetyl protected thiols that are significantly lower than observed for junctions with deprotected thiols (by a factor of ≈5). Using a first-principles based computational approach, we explain the lower conductance of junctions with acetyl functionalized thiol and associate it to chemical changes of the sulfur, where essentially a tunneling barri... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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