Please note: unless otherwise specified, the internships are only available for students with a nationality of an EU-member state and/or students from a Dutch university.
DIFFER (Dutch Institute for Fundamental Energy Research) is one of the NWO institutes and focuses on a multidisciplinary approach of the energy research combining physics, chemistry and materials engineering. The institute is an important part of the energy research strategy of NWO and FOM. The DIFFER mission is to carry out leading fundamental research in the field of fusion-energy and solar fuels, in close collaboration with academic institutions, research institutes and industry.
Encapsulation foils are highly demanded in the production of flexible devices such as thin film transistors (TFT), organic LEDs, solar cells and so on. To bring this technology to commercial manufacturing phase, the thin film performance should be further improved and the throughput should be increased. Atmospheric-pressure PECVD is regarded as a promising tool to achieve these industrial targets because of its capability of the roll-to-roll processing and precise control over the thin film properties. It is known that the thin film growth is closely related to the plasma behaviour which, however, is still unclear. In order to obtain a better control over the thin film properties, a detailed understanding of the fundamental principles of atmospheric-pressure DBD is required.
The configuration of our experimental setup is more complicated than the typical parallel-plates DBD structure. The plasma is generated in an industrially relevant electrode geometry consisting of two cylindrical electrodes which are covered by polymeric substrates as the dielectrics. The polymers are driven by the roll-to-roll system, and the plasma-polymer interactions may increase the surface roughness of the polymer. Moreover, the air-like gas mixture is injected into the discharge area through a gas injector.
In the previous work, the discharge development was studied according to the ICCD imaging. It was found that the high-current diffuse discharge experiences a transition from “Townsend-like” mode to “glow-like” mode in N2/O2/Ar gas mixture at time scales below 1 μs. And the discharge area is affected by the surface roughness which may influence the secondary electron emission coefficient and the surface charge distribution.
However, the underlying physics of the discharge development is still not clear. Therefore, the purpose of the present work is to model the discharge behaviour under current experimental conditions.
The work will involve mostly modelling work together with the experiments of the PhD student. The main objectives are:
- To build a 2-D fluid model based on the experimental setup with cylindrical electrodes
- To study the plasma parameters e.g. electric field distribution, electron density, space-surface charge under current conditions
- To study the influence of electrode geometry, surface roughness, secondary electron emission coefficient and gas flow on the discharge development
Enthusiastic master/bachelor student with experience of modelling work related to plasma and motivated to work in the research field.
Yaoge Liu
Mobile: +31 6 38411592
Mail: Y [368] Liu [28] differ [368] nl
