Pierre-Yves Pichon successfully defended his PhD thesis at the Ruhr-Universität Bochum on 25-06-2015. He is a member of the group "Undercooling of Materials". His work focused on the investigations of the competition of wetting and solidification kinetics for liquid silicon during its solidification on a textured substrate. In order to achieve well-defined experimental conditions liquid silicon droplets were melted using an electromagnetic levitation tool, the droplets were let fall on substrates placed underneath. Both the crystal growth and spreading kinetics were recorded in situ with a high-speed camera. These investigations are relevant to the RGS casting process (RGS: Ribbon Growth on Substrate). Similarly as in a tape casting process, in the RGS process layers of silicon and silicon-based alloy are solidified onto reusable substrates. Such layers can then be directly used as base material for different devices such as photovoltaic solar cells, thermoelectric generator, or battery anodes. A key aspect of the process is to control the formation of the substrate-solidifying layer interface since it strongly influences the heat transfer, crystal growth and layer detachment behavior. The fundamental understanding gained in this work resulted in the development of a new RGS solar cell material with improved conversion efficiency. The PhD work was supported by RGS Development B.V. , Broek op Langedijk, The Netherlands.