Press Releases / Pressemitteilungen
Karl Leo nominated for the European Inventor Award 2021 in the "Lifetime Achievement" category
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Professor Karl Leo, director of the Institute of Applied Physics (IAP) and founder of the Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) at TU Dresden, is one of three finalists nominated in the "Lifetime Achievement" category for the European Inventor Award 2021. This is an outstanding tribute to the 60-year-old exceptional scientist who, with a great deal of innovative spirit, perseverance and, not least, business acumen, has repeatedly managed to successfully commercialize his fundamental ideas in the field of organic semiconductor optics.
Karl Leo himself always emphasizes that his path was a team effort and that he was always supported by talented and motivated partners. First and foremost are his doctoral students Martin Pfeiffer and Jan Blochwitz, who in 1998, under Leo's guidance, produced the first organic semiconductor LED (OLED), which was much more efficient, sustainable and had a longer lifetime than its inorganic counterparts.
In 2001, Leo founded Novaled with Pfeiffer and Blochwitz to commercialize the OLED technologies and materials conceived at TU Dresden. In 2013, Novaled was acquired by Samsung and is hence considered one of the most successful German start-ups. Over the course of his career, Leo has co-founded numerous other spin-offs, including Heliatek GmbH, Senorics GmbH and other companies in the Silicon Saxony technology region.
The full impact of Leo's innovations has arrived in numerous products on the international market: OLEDs provide improved image brightness, color resolution and energy efficiency in the latest models of smartphones, television screens and other electronic devices. Organic solar cells have also been brought to market maturity.
Karl Leo has already been honored with numerous prizes for his outstanding achievements, including the Leibniz Prize (2002), the Berlin-Brandenburg Academy Prize (2002), the Manfred von Ardenne Prize (2006), the Future Prize of the German President (2011), the Technology Transfer Prize of the DPG (2016) and, just recently, the Jan Rajchmann Prize of the US Society for Information Display (SID).
On the question of whether he has thought about retiring after so many successes and a nomination for his Lifetime Achievement, he states: "No, I have never thought about retiring. I always need something to tinker around with, whether physics, engineering or whatsoever."
Further innovations and projects are already planned for the coming years: "On the one hand, we also want to bring our organic transistors into products, and on the other hand, we are working on providing our organic electronics with an interface to biological systems so that they can also be used sensibly directly on or even in humans. We just got approval for a first project in which we want to use biodegradable sensor technology for postoperative monitoring."
The European Inventor Award
The European Inventor Award was launched by the EPO in 2006 and is one of the most prestigious innovation awards in Europe. It highlights how creative thinking contributes to societal development, drives economic growth and improves our everyday lives. An independent jury consisting of international personalities from business, politics, science and research selects the finalists and winners. In total, the prize is awarded in five categories. For the first time in the history of the European Inventor Award, the 2021 ceremony will take place in an augmented reality format. No pre-registration is required for the digital event on 17 June 2021, starting at 7 p.m., so audiences from around the world can follow the journey of the fifteen finalists.
Watch the livestream on 17 June at: https://www.epo.org/news-events/events/european-inventor/stream_de.html
Vote for the Popular Prize!
Starting today, 4 May 2021, the voting for the Popular Prize of the European Inventor Award is open. The public has the opportunity to vote online for their favorites from the 15 finalists. The winner will be announced in the live show on June 17. Join in and vote for Karl Leo!
Dedicated Popular Prize link: https://popular-prize.epo.org/i/i/karl-leo-de#inventor-karl-leo-de
Media inquiries:
echolot public relations
Philipp Nisster
Tel.: 0159 01929655
nisster@echolot-pr.de
A General Approach to High-efficiency Perovskite Solar Cells
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Perovskites, a class of materials first reported in the early 19th century, were “re-discovered” in 2009 as a possible candidate for power generation via their use in solar cells. Since then, they have taken the photovoltaic (PV) research community by storm, reaching new record efficiencies at an unprecedented pace. This improvement has been so rapid that by 2021, barely more than a decade of research later, they are already achieving performance similar to conventional silicon devices. What makes perovskites especially promising is the manner in which they can be created. Where silicon-based devices are heavy and require high temperatures for fabrication, perovskite devices can be lightweight and formed with minimal energy investiture. It is this combination – high performance and facile fabrication – which has excited the research community.
As the performance of perovskite photovoltaics rocketed upward, left behind were some of the supporting developments needed to make a commercially viable technology. One issue that continues to plague perovskite development is device reproducibility. While some PV devices can be made with the desired level of performance, others made in the exact same manner often have significantly lower efficiencies, puzzling and frustrating the research community.
Recently, researchers from the Emerging Electronic Technologies Group of Prof. Yana Vaynzof have identified that fundamental processes that occur during the perovskite film formation strongly influence the reproducibility of the photovoltaic devices. When depositing the perovskite layer from solution, an antisolvent is dripped onto the perovskite solution to trigger its crystallization. “We found that the duration for which the perovskite was exposed to the antisolvent had a dramatic impact on the final device performance, a variable which had, until now, gone unnoticed in the field.” says Dr. Alexander Taylor, a postdoctoral research associate in the Vaynzof group and the first author on the study. “This is related to the fact that certain antisolvents may at least partly dissolve the precursors of the perovskite layer, thus altering its final composition. Additionally, the miscibility of antisolvents with the perovskite solution solvents influences their efficacy in triggering crystallization.”
These results reveal that, as researchers fabricate their PV devices, differences in this antisolvent step could cause the observed irreproducibility in performance. Going further, the authors tested a wide range of potential antisolvents, and showed that by controlling for these phenomena, they could obtain cutting-edge performance from nearly every candidate tested. “By identifying the key antisolvent characteristics that influence the quality of the perovskite active layers, we are also able to predict the optimal processing for new antisolvents, thus eliminating the need for the tedious trial-and-error optimization so common in the field.” adds Dr. Fabian Paulus, leader of the Transport in Hybrid Materials Group at cfaed and a contributor to the study.
“Another important aspect of our study is the fact that we demonstrate how an optimal application of an antisolvent can significantly widen the processibility window of perovskite photovoltaic devices” notes Prof. Vaynzof, who led the work. “Our results offer the perovskite research community valuable insights necessary for the advancement of this promising technology into a commercial product.”
The results were published in the prestigious journal "Nature Communications".
Title: A general approach to high-efficiency perovskite solar cells by any antisolvent
Authors: Alexander D. Taylor, Qing Sun, Katelyn P. Goetz, Qingzhi An, Tim Schramm, Yvonne Hofstetter, Maximillian Litterst, Fabian Paulus & Yana Vaynzof
Nature Communications 2021, 12, 1878
DOI: 10.1038/s41467-021-22049-8
www.nature.com/articles/s41467-021-22049-8
Contact details:
Prof. Dr. Yana Vaynzof
Chair for Emerging Electronic Technologies at the Institute for Applied Physics and Center for Advancing Electronics Dresden - cfaed at TU Dresden
Tel. +49 351 463-42132
E-Mail: yana.vaynzof@tu-dresden.de
Matthias Hahndorf
Center for Advancing Electronics Dresden – cfaed an der TU Dresden
Science communications
Tel.: +49 (0)351 463 42847
E-mail: matthias.hahndorf@tu-dresden.de
Ein umfassender Ansatz für hocheffiziente Perowskit-Solarzellen
Forscher:innen des Instituts für Angewandte Physik (IAP) und des Center for Advancing Electronics Dresden (cfaed) an der TU Dresden haben eine allgemeine Methode für die reproduzierbare Herstellung von hocheffizienten Perowskit-Solarzellen entwickelt. Die Studie wurde nun im angesehenen Journal Nature Communications veröffentlicht.
Perowskite sind eine Materialklasse, die erstmals im frühen 19. Jahrhundert beschrieben wurde. Im Jahr 2009 wurden sie als mögliches Material für die Energiegewinnung aus Solarzellen „wiederentdeckt”. Seitdem haben sie die Forschung im Bereich neuartiger Photovoltaik-Technologien auf den Kopf gestellt. Ihre Wirkungsgrade konnten mit noch nie da gewesener Geschwindigkeit verbessert werden. Diese Effizienzsteigerung war so rapide, dass im Jahr 2021, nach einem guten Jahrzehnt Forschung, Perowskite bereits Leistungen und Wirkungsgrade erreichen, die sich kaum noch von konventionellen Silizium-Solarzellen unterscheiden. Was Perowskite besonders vielversprechend macht, ist die Art und Weise, mit der sie hergestellt werden können. Im Gegensatz zu Silizium-basierten Elementen, die schwer sind und hohe Temperaturen in der Herstellung benötigen, sind Perowskit-Bauteile leicht und lassen sich durch einen viel geringeren Energieeinsatz fertigen. Diese Kombination aus hoher Effizienz und einfacher Herstellung hat die Forschung auf diesem Gebiet beflügelt.
Während die Leistungsfähigkeit von Perowskit-Solarzellen in die Höhe stiegen, wurden andere wichtige Entwicklungen, die es braucht, um eine solche Technologie kommerziell erfolgreich zu machen, vernachlässigt. Ein Problem, dass die Entwicklung von Perowskiten erschwert, ist die geringe Reproduzierbarkeit der elektrischen Bauteile. Während manche Solarzellen die angestrebte Leistungsfähigkeit erreichen können, zeigen andere, die in der exakt gleichen Art und Weise hergestellt wurden, oft signifikant geringere Effizienzen, was die Wissenschaftsgemeinde zusehends frustrierte und ratlos machte.
Jetzt haben Forscher:innen der Forschungsgruppe „Neuartige Elektronik-Technologien“ unter Leitung von Prof. Yana Vaynzof die fundamentalen Prozesse identifiziert, die während der Schichtbildung der Perowskite ablaufen, und die die Reproduzierbarkeit der Photovoltaik-Bauelemente maßgeblich beeinflussen. Bei der Herstellung von Perowskitschichten aus einer Lösung wird im entscheidenden Prozessschritt ein Anti Lösungsmittel aufgetragen, welches die Kristallisation des Materials initiiert. „Wir haben herausgefunden, dass die Dauer, für die die Perowskitschichten dem Anti-Lösungsmittel ausgesetzt sind, einen dramatischen Einfluss auf die finale Bauteilleistung hat. Das ist eine wichtige Variable, die bisher im Herstellungsprozess keine Beachtung gefunden hat“, sagt Dr. Alexander Taylor, Postdoktorand in der Vaynzof-Gruppe und Erstautor der Studie. „Dies beruht auf der Tatsache, dass gewisse Anti Lösungsmittel die Bestandteile der Perowskitschichten teilweise herauslösen und so letztlich deren Zusammensetzung verändern können. Zusätzlich beeinflusst die Mischbarkeit zwischen dem Anti-Lösungsmittel und dem Lösungsmittel, in dem die Perowskite zuvor gelöst waren, den Zeitpunkt des Einsetzens der Kristallisation.“
Die Ergebnisse zeigen, dass bei der Herstellung von PV-Bauelementen im Labor Unterschiede im Prozessschritt des Anti-Lösungsmittels die sehr geringe Reproduzierbarkeit und schwankende Leistungsfähigkeit der Perowskit-Bauteile erklären können. Im weiteren Verlauf der Studie testeten die Forscher eine breite Palette von Anti-Lösungsmitteln und konnten zeigen, dass bei kontrollierter Berücksichtigung der beschriebenen Phänomene quasi jedes Anti-Lösungsmittel hoch-effiziente Bauteile erzeugen kann.
„Durch die Identifizierung der Schlüsseleigenschaften, die ein gutes Anti-Lösungsmittel aufweisen muss, um qualitativ hochwertige Perowskitschichten zu erzeugen, können wir vorhersagen, wie ein neues Anti-Lösungsmittel angewendet werden muss. Somit entfällt die mühsame und oft durch Ausprobieren erreichte Optimierung dieses Prozessschrittes“, fügt Dr. Fabian Paulus, Leiter der Forschungsgruppe „Transport in Hybridmaterialien“ am cfaed und Mitwirkender der Studie, hinzu.
„Ein weiterer wichtiger Aspekt unserer Studie ist, dass wir zeigen konnten, wie eine optimale Anwendung eines Anti-Lösungsmittel das Prozessierungsfenster von Peroswkit-Photovoltaik-Bauteilen beträchtlich vergrößern kann“, erläutert Studienleiterin Prof. Vaynzof. „Unsere Ergebnisse auf diesem Gebiet bieten damit wertvolle Einblicke, um eine Weiterentwicklung dieser vielversprechenden Technologie in ein kommerziell erfolgreiches Produkt zu ermöglichen.”
Die Ergebnisse wurden im prestigeträchtigen Journal „Nature Communications“ veröffentlicht.
Titel: A general approach to high-efficiency perovskite solar cells by any antisolvent
Autor:innen: Alexander D. Taylor, Qing Sun, Katelyn P. Goetz, Qingzhi An, Tim Schramm, Yvonne Hofstetter, Maximillian Litterst, Fabian Paulus & Yana Vaynzof
Nature Communications 2021, 12, 1878
DOI: 10.1038/s41467-021-22049-8
www.nature.com/articles/s41467-021-22049-8
Kontakt:
Prof. Dr. Yana Vaynzof
Professur für Neuartige Elektronik-Technologien sowie Center for Advancing Electronics Dresden – cfaed an der TU Dresden
Tel. +49 351 463-42132
E-Mail: yana.vaynzof@tu-dresden.de
Matthias Hahndorf
Center for Advancing Electronics Dresden – cfaed an der TU Dresden
Wissenschaftskommunikation
Tel.: +49 (0)351 463 42847
E-mail: matthias.hahndorf@tu-dresden.de
Ionic Defect Landscape in Perovskite Solar Cells Revealed
Published on in PRESS RELEASES
The advantageous properties of metal halide perovskites include their high light-harvesting capacity and their remarkable ability to efficiently convert solar energy into electrical energy. Another special feature of these materials is that both charge carriers and ions are mobile within them. While charge carrier transport is a fundamental process required for the photovoltaic operation of the solar cell, ionic defects and ion transport often have undesirable consequences on the performance of these devices. Despite significant progress in this field of research, many questions regarding the physics of ions in perovskite materials remain open.
On the way to a better understanding of these structures, the Technical Universities of Chemnitz and Dresden have now taken a big step forward. In a joint investigation by the research groups around Prof. Dr. Yana Vaynzof (Chair of Emerging Electronic Technologies at the Institute of Applied Physics and Center for Advancing Electronics Dresden – cfaed, TU Dresden) and Prof. Dr. Carsten Deibel (Optics and Photonics of Condensed Matter, Chemnitz University of Technology) under the leadership of Chemnitz University of Technology, the two teams uncovered the ionic defect landscape in metal halide perovskites. They were able to identify essential properties of the ions that make up these materials. The migration of the ions leads to the presence of defects in the material, which have a negative effect on the efficiency and stability of perovskite solar cells. The working groups found that the motion of all observed ions, despite their different properties (such as positive or negative charge), follows a common transport mechanism and also allows the assignment of defects and ions. This is known as the Meyer-Neldel rule. The results were published in the renowned journal "Nature Communications" (11, 6098 (2020)) (https://www.nature.com/articles/s41467-020-19769-8).
Finding Order in Chaos: Scientists Determine the Structure of Glass-shaping Protein in Sponges
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Overpriced? TUD Researchers Explain Artificial Price Increases in the Taxi App Uber
Press Release 2020 Sep 24
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