q&more
My watch list
my.chemie.de  
Login  

News

Molecular Lego blocks

Chemical data mining boosts search for new organic semiconductors

C. Kunkel / TUM

Both the carbon-based molecular frameworks and the functional groups decisively influence the conductivity of organic semiconductors.

18-Feb-2019: Organic semiconductors are lightweight, flexible and easy to manufacture. But they often fail to meet expectations regarding efficiency and stability. Researchers at the Technical University of Munich (TUM) are now deploying data mining approaches to identify promising organic compounds for the electronics of the future.

Producing traditional solar cells made of silicon is very energy intensive. On top of that, they are rigid and brittle. Organic semiconductor materials, on the other hand, are flexible and lightweight. They would be a promising alternative, if only their efficiency and stability were on par with traditional cells.

Together with his team, Karsten Reuter, Professor of Theoretical Chemistry at the Technical University of Munich, is looking for novel substances for photovoltaics applications, as well as for displays and light-emitting diodes – OLEDs. The researchers have set their sights on organic compounds that build on frameworks of carbon atoms.

Contenders for the electronics of tomorrow

Depending on their structure and composition, these molecules, and the materials formed from them, display a wide variety of physical properties, providing a host of promising candidates for the electronics of the future.

"To date, a major problem has been tracking them down: It takes weeks to months to synthesize, test and optimize new materials in the laboratory," says Reuter. "Using computational screening, we can accelerate this process immensely."

Computers instead of test tubes

The researcher needs neither test tubes nor Bunsen burners to search for promising organic semiconductors. Using a powerful computer, he and his team analyze existing databases. This virtual search for relationships and patterns is known as data mining.

"Knowing what you are looking for is crucial in data mining,” says PD Dr. Harald Oberhofer, who heads the project. "In our case, it is electrical conductivity. High conductivity ensures, for example, that a lot of current flows in photovoltaic cells when sunlight excites the molecules."

Algorithms identify key parameters

Using his algorithms, he can search for very specific physical parameters: An important one is, for example, the "coupling parameter.” The larger it is, the faster electrons move from one molecule to the next.

A further parameter is the "reorganization energy": It defines how costly it is for a molecule to adapt its structure to the new charge following a charge transfer – the less energy required, the better the conductivity.

The research team analyzed the structural data of 64,000 organic compounds using the algorithms and grouped them into clusters. The result: Both the carbon-based molecular frameworks and the "functional groups", i.e. the compounds attached laterally to the central framework, decisively influence the conductivity.

Identifying molecules using artificial intelligence

The clusters highlight structural frameworks and functional groups that facilitate favorable charge transport, making them particularly suitable for the development of electronic components.

"We can now use this to not only predict the properties of a molecule, but using artificial intelligence we can also design new compounds in which both the structural framework and the functional groups promise very good conductivity," explains Reuter.

Original publication:
"Finding the Right Bricks for Molecular Lego: A Data Mining Approach to Organic Semiconductor Design"; Christian Kunkel, Christoph Schober, Johannes T. Margraf, Karsten Reuter, Harald Oberhofer; Chem. Mater.; 2019, 31, 3, 969-978

Facts, background information, dossiers

More about TU München

  • News

    Salt could be a key factor in allergic immune reactions

    Salt apparently affects allergic immune reactions. A team working with Prof. Christina Zielinski at the Technical University of Munich (TUM) has demonstrated in cell cultures that salt leads to the formation of Th2 cells. These immune cells are active in allergic conditions such as atopic d ... more

    Photochemical deracemization of chiral compounds achieved

    Enantiomeric molecules resemble each other like right and left hands. Both variants normally arise in chemical reactions. But frequently only one of the two forms is effectual in biology and medicine. Hitherto, completely converting this mixture into the desired enantiomer was deemed imposs ... more

    Test predicts outcome of hay fever therapies

    Allergen-specific immunotherapy can make everyday life much more pleasant for allergy sufferers. It is unclear, however, what exactly happens during this treatment. A team at the Technical University of Munich (TUM) investigated the processes taking place in the body over the course of a th ... more

  • q&more articles

    Translation

    The structure of the big chemical and pharmaceutical companies has changed. Traditional centralised research departments conducting fundamental research have fallen victim to economic considerations. In exchange, young, dynamic start-up enterprises are increasingly brightening up the scene. ... more

  • Authors

    Prof. Dr. Arne Skerra

    Arne Skerra, born in 1961, studied chemistry at the Technical University of Darmstadt and obtained his doctoral degree as Dr. rer. nat. at the Gene Center of the Ludwig-Maximilians Univer­sity Munich in 1989. After staying at the MRC Laboratory of Molecular Biology in Cambridge, UK, and the ... more

    Dr. Thomas Letzel

    Thomas Letzel, born 1970, studied chemistry (1992–1998) at the TU Muenchen and the LMU Muenchen. He acquired his doctorate in 2001 with an environmental-analytical subject at the TU Muenchen, followed by a two years' postdoc stay at the Vrijen Universiteit Amsterdam. He qualified as a profe ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:



Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE