This title appears in the Scientific Report :
2008
Please use the identifier:
http://dx.doi.org/10.1088/0953-8984/20/37/374122 in citations.
Electrochemical gate-controlled electron transport of redox-active single perylene bisimide molecular junctions
Electrochemical gate-controlled electron transport of redox-active single perylene bisimide molecular junctions
We report a scanning tunneling microscopy (STM) experiment in an electrochemical environment which studies a prototype molecular switch. The target molecules were perylene tetracarboxylic acid bisimides modified with pyridine (P-PBI) and methylthiol (T-PBI) linker groups and with bulky tert-butyl-ph...
| Personal Name(s): | Li, C. |
|---|---|
| Mishchenko, A. / Li, Z. / Pobelov, I. / Wandlowski, Th. / Li, X.Q. / Würthner, F. / Begrets, A. / Evers, F. | |
| Contributing Institute: |
Grenz- und Oberflächen; IBN-3 JARA-FIT; JARA-FIT Center of Nanoelectronic Systems for Information Technology; CNI |
| Published in: | Journal of physics / Condensed matter, 20 (2008) S. 374122 |
| Imprint: |
Bristol
IOP Publ.
2008
|
| Physical Description: |
374122 |
| PubMed ID: |
21694429 |
| DOI: |
10.1088/0953-8984/20/37/374122 |
| Document Type: |
Journal Article |
| Research Program: |
Grundlagen für zukünftige Informationstechnologien |
| Series Title: |
Journal of Physics: Condensed Matter
20 |
| Subject (ZB): | |
| Publikationsportal JuSER |
|
We report a scanning tunneling microscopy (STM) experiment in an electrochemical environment which studies a prototype molecular switch. The target molecules were perylene tetracarboxylic acid bisimides modified with pyridine (P-PBI) and methylthiol (T-PBI) linker groups and with bulky tert-butyl-phenoxy substituents in the bay area. At a fixed bias voltage, we can control the transport current through a symmetric molecular wire Au|P-PBI(T-PBI)|Au by variation of the electrochemical 'gate' potential. The current increases by up to two orders of magnitude. The conductances of the P-PBI junctions are typically a factor 3 larger than those of T-PBI. A theoretical analysis explains this effect as a consequence of shifting the lowest unoccupied perylene level (LUMO) in or out of the bias window when tuning the electrochemical gate potential VG. The difference in on/off ratios reflects the variation of hybridization of the LUMO with the electrode states with the anchor groups. I(T)-E(S(T)) curves of asymmetric molecular junctions formed between a bare Au STM tip and a T-PBI (P-PBI) modified Au(111) electrode in an aqueous electrolyte exhibit a pronounced maximum in the tunneling current at -0.740, which is close to the formal potential of the surface-confined molecules. The experimental data were explained by a sequential two-step electron transfer process. |