A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative effort, a team of physicists at the Technical University of Munich has succeeded to use single molecules as switching elements for light signals.
"Switching with just a single molecule brings future electronics one step closer to the ultimate limit of miniaturization," says nanoscientist Joachim Reichert from the Physics Department of the Technical University of Munich.
Different structure – different optical properties
The team initially developed a method that allowed them to create precise electrical contacts with molecules in strong optical fields and to address them using an applied voltage. At a potential difference of around one volt, the molecule changes its structure: It becomes flat, conductive and scatters light.
This optical behavior, which strongly depends on the structure of the molecule, is quite exciting for the researchers because the scattering activity – Raman scattering, in this case – can be both observed and, at the same time, switched on and off via an applied voltage.
The researchers used molecules synthesized by a team based in Basel and Karlsruhe. The molecules change their structure in a specific way when they get charged. They are arranged on a metal surface and contacted using the corner of a glass fragment with a very thin metal coating as a tip.
This serves as an electrical contact, light source and light collector, all in one. The researchers used the fragment to direct laser light to the molecule and measure tiny spectroscopic signals that vary with the applied voltage.
Establishing reliable electric contacts between individual molecules is extremely challenging from a technical point of view. The scientists have now successfully combined this procedure with single-molecule spectroscopy, allowing them to observe even the smallest structural changes in molecules with great precision.
Competition for Silicon
One goal of molecular electronics is to develop novel devices that can replace traditional silicon-based components using integrated and directly addressable molecules.
Thanks to its tiny dimensions, this nanosystem is suitable for applications in optoelectronics, in which light needs to be switched by an electrical potential.
Hai Bi, Carlos-Andres Palma, Yuxiang Gong, Peter Hasch, Mark Elbing, Marcel Mayor, Joachim Reichert und Johannes V. Barth,
Voltage-Driven Conformational Switching with Distinct Raman Signature in a Single-Molecule Junction: J. Am. Chem. Soc. 140, 14, 4835-4840
The research project was funded by the German Research Foundation (DFG) via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) and the SPP 1243, as well as the European Union (ERC Advanced Grant MolArt and FET Measure 2D-ink) and the China Scholarship Council (CSC).
Dr. Joachim Reichert / Prof. Dr. Johannes Barth
Technical University of Munich
Surface and Interface Physics (E20)
Tel.: +49 89 289 12608 – E-Mail: email@example.com
https://www.tum.de/nc/en/about-tum/news/press-releases/detail/article/34665/ Link to the press release
Dr. Ulrich Marsch | Technische Universität München
Studying how unconventional metals behave, with an eye on high-temperature superconductors
13.12.2018 | Princeton University
An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes
13.12.2018 | Rutgers University
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
13.12.2018 | Life Sciences
13.12.2018 | Physics and Astronomy
13.12.2018 | Earth Sciences