University of Bayreuth: Leading EU OLED Network

University of Bayreuth: Leading EU OLED Network

The international research network “TADFsolutions” coordinated by the University of Bayreuth was recently launched. It will be funded by the EU with around 3.1 million euros over the next four years. The aim of the association is the development of semiconductor materials for a new generation of organic light-emitting diodes (OLEDs). These should be characterized by an unprecedented luminosity and color purity, consume little energy and have a significantly longer service life than the currently commercially available light emitting diodes.

Organic light-emitting diodes play a key role in the screen quality of computers, tablets, televisions, smartphones and other high-tech devices. A still young research approach, which is referred to as “thermally activated delayed fluorescence” (TADF), will make it possible to significantly increase the luminosity, color purity, energy efficiency and stability of OLEDs. Energy states that do not emit light are transformed into emitting energy states. The partners from science and industry involved in the new research network want to develop materials for OLEDs that are superior to the materials used to date in terms of their optoelectronic and physicochemical properties. At the same time, the new materials should be able to be dissolved in liquid solvents and then further processed. Solution-based manufacturing processes for OLEDs consume less energy and are more cost-effective overall. In addition, they are compatible with the processes established in the plastics industry, so that the OLEDs can be applied to flexible plastic carrier foils, for example, using inkjet printers or roll-to-roll processes.

“High-performance, energy-efficient and stable organic light-emitting diodes have enormous technological and economic potential. Global competition in research and development in this field is becoming increasingly intense, with the countries of the Far East now playing a dominant role. European universities, research institutes and companies therefore have a great interest not only in keeping up with global competition, but also in being able to gain a head start wherever possible. This requires highly motivated and innovative young talents in chemistry, physics and materials science, which we want to support extensively in TADFsolutions. It’s about imparting in-depth basic and application skills and research experience in an international network, but we also want to contribute to the general personality development of our doctoral students,” says the spokeswoman for TADFsolutions, the Bayreuth experimental physicist Prof. Dr. Anna Köhler, who significantly initiated the European network. She refers to the close cooperation with universities in Israel and Japan, which are involved in the training of doctoral students with their high-tech laboratories.

A New Marie Skłodowska-Curie Innovative Training Network (ITN) at the University of Bayreuth

The new research network is funded by the European Union as the “Marie Skłodowska-Curie Innovative Training Network (ITN)”. Nine European partners form the core of the network: the University of Bayreuth and the University of Cologne (Germany), the TU Eindhoven and the company Simbeyond B.V. (Netherlands), the University of St. Andrews and Durham University (UK), the Université de Bordeaux and the Center National de la Recherche Scientifique in Rennes (France) and the Universitat de València (Spain). There are also nine universities, research institutes and companies in Europe and Japan that are associated with the network. These associated partners include, for example, Merck KGaA in Darmstadt and Bayerische Forschungsallianz GmbH (BayFOR) in Munich.

The pronounced interdisciplinarity and internationality of TADFsolutions will ensure that all doctoral students always keep an eye on the entire network with its different research areas and do not focus exclusively on their own research topics. In principle, they will work on changing topics and locations in the course of their funding, so that they can get to know the advantages of innovative “multistreaming” concepts in scientific cooperation and use them independently in later professional activities. Even while they are working on their doctoral projects, the doctoral students are given the opportunity to publish in renowned scientific journals. Close contacts to European industrial partners familiarize you with processes and instruments of knowledge and technology transfer and give you well-founded insights into the markets for high-tech products based on organic light-emitting diodes.

The training concept of TADFsolutions is based on the experience that many of the participating partner institutions have gained through their participation in previous EU-funded joint projects. This also includes TADFlife, a “Marie Skłodowska-Curie Innovative Training Network (ITN)” run by Prof. Dr. Anna Köhler at the University of Bayreuth and also dealt with the photophysical processes in OLEDs. “Many doctoral students that we trained as part of this previous project are now in responsible positions in science and industry. With their skills, they will be able to give our TADFsolutions network valuable suggestions and impetus,” says the experimental physicist from Bayreuth.

From TADFlife to TADFsolutions

The previous project TADFlife aimed to understand the processes that limit the lifetime and efficiency of conventional OLEDs made of non-soluble materials. With the knowledge gained, it was then possible to improve these light-emitting diodes in terms of their stability and efficiency. The new TADFsolutions project goes beyond that: Now it should be a question of investigating these processes in organic semiconductor layers, which are produced from liquid solution and therefore have a particularly disordered morphology. This makes the physical processes to be examined more complex, but the production of these light-emitting diodes is cheaper.

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