Modeling electromagnetically driven free-surface flows motivated by the Ribbon Growth on Substrate (RGS) process

Abstract

The Ribbon Growth on Substrate (RGS) technology is a crystallization technique that allows direct casting of silicon wafers and sheets of advanced metal-silicide compounds. With the potential of reaching high crystallization rates, it promises a very efficient approach for future photo-voltaic silicon wafer production compared to well-established processes in industry. However, a number of remaining problems, like process stability and controllability, need to be addressed for the RGS technology to eventually become a competitor in the near future. In this regard, it is very desirable to gain detailed insights into the characteristic process dynamics. To comply with this demand, we have developed a new numerical tool based on OpenFOAM (foam-extend), capable of simulating the free-surface dynamics of the melt flow under the influence of an applied alternating magnetic field. Our corresponding model thereby resolves the interaction of hydrodynamic and magnetodynamic effects in three-dimensional space. Although we currently focus on the RGS process, the modeling itself has been formulated in a more general form, which may be used for the investigation of similar problems, too. Here we provide a brief overview of these developments.