The German Research Foundation funds three research projects in the field of plasma physics at Kiel University.
The question of what happens when you introduce tiny particles into a plasma, an ionized gas or a gas discharge, is currently being studied very intensively. On one hand, many fundamental questions in this field of research, and they generally extend to the field of the plasma interaction with any solid surfaces, remain unanswered. On the other hand, many important technological applications are based on nano- and microparticles, such as improved catalysts for chemical reactions, electrodes for very high-capacity rechargeable batteries, or a new generation of solar cells or LEDs. The German Research Foundation (DFG) is funding with almost 1.1 million Euro three research projects in the field of plasma physics at the Kiel University that study the interaction of plasmas with particles of different sizes.
Often the small particles are in particular those that have great technological potential. “We want to track down their secrets using state-of-the-art measuring methods”, Prof. Jan Benedikt, Institute of Experimental and Applied Physics, sums up. He, Prof. Dietmar Block, and Dr. Franko Greiner want now to penetrate, with these recently granted three research projects, into the little-studied world of the interaction of plasmas and microscopic surfaces. The particle size ranges from a few nanometers to a few micrometers. "Although the particle sizes we study are different, we hope that we can identify fundamental processes that play a role at all scales and that can be used to develop novel materials", says Benedikt.
The three scientists applied for the funding together with their colleagues Prof. Franz Faupel, Institute of Materials Science, and Prof. Sebastian Wolf, Institute of Theoretical Physics and Astrophysics and the research efforts are part of the priority research area Kiel Nano Surface and Interface Science (KiNSIS) at Kiel University. They build on important contributions to the investigation of particles in plasmas the scientists achieved within the Collaborative Research Center TR24 “Fundamentals ofComplex Plasmas”.
Modifying particle in a targeted way
In the project “Change of Size and Morphology of Microparticles in Plasmas” a research team aroundProf. Dietmar Block will investigate microscopic particles and their surface changes in order to influence them in a targeted way in the future. "Thanks to a newly developed diagnostics in collaboration with Dr. Franko Greiner, we are now able to observe the surface changes live with an accuracy of one millionth of a millimeter” Block outlines the project. The underlying measurement method was already honored as a research highlight by the journal Physics of Plasmas.
Nano dust as dense as fog
Instead of single particles in plasmas, Dr. Franko Greiner and Prof. Sebastian Wolf study dusty plasmas with billions of particles and high electron depletion in their project “Investigation of Fundamental Mechanisms and Properties by Means of Particle and Plasma Diagnostics”. It describes the changes in plasmas in which the nano dust becomes as dense as fog and almost all free electrons have disappeared. “The completely new properties of such "ion-dust" plasmas have so far been poorly understood. To investigate them and thus evaluate their technological potential, new diagnostic methods have to be created”, describe the scientists. These will be based on numerical simulation techniques that have already been developed and successfully applied for the investigation of interstellar matter in the group of Prof. Wolf.
Application potential for sensors, solar cells, batteries or as catalysts
The nanoparticles that are being investigated in the project “In-situ Analysis of Plasma-Induced Material Modifications on Nanoparticles for Functional Applications” by Benedikt and Faupel are particularly exciting in terms of technology. With a diameter of only a few nanometers, their electronic and optical properties change. They are, therefore, also referred to as quantum dots. In addition, these properties also strongly depend on the state of their surface. The plasma-induced changes of semiconductor and metal particles are determined and analyzed in real-time during the plasma treatment (in-situ) by means of optical absorption methods. “The results obtained could pave the way to applications in sensors, solar cells, batteries or as catalysts”, Faupel says.
In connection with these projects, the activities for the modification of nanoparticles and microparticles in the group of Prof. Holger Kersten at the Institute of Experimental Physics should be mentioned. He and Prof. Lorenz Kienle from the Faculty of Engineering investigates now the elementary processes involved in the DFG-funded (around 400.000 €) project "New instruments for in-operando TEM: plasma modification live".
Prof. Dr. rer. nat. Jan Benedikt
Institute of Experimental and Applied Physics
Tel.: +49 (0)431 880-3879
Details, which are only a millionth of a millimetre in size: this is what the priority research area "Kiel Nano, Surface and Interface Science – KiNSIS" at Kiel University has been working on. In the nano-cosmos, different laws prevail than in the macroscopic world - those of quantum physics. Through intensive, interdisciplinary cooperation between physics, chemistry, engineering and life sciences, the priority research area aims to understand the systems in this dimension and to implement the findings in an application-oriented manner. Molecular machines, innovative sensors, bionic materials, quantum computers, advanced therapies and much more could be the result. More information at www.kinsis.uni-kiel.de