5th International Conference on Advances in Solidification Processes (ICASP-5) 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR-5)

Silicon is widely used in the industry of solar panels. During the manufacturing process, the molten silicon is solidified into ingots. These ingots are cut into very thin layers which are assembled into solar cells. It turns out that the solar cells efficiency depends on the solidification process and the final microstructure of the ingots. Several experimental studies of solidification showed that the growth shapes exhibit facets along the {111} directions because the growth rate of facets being much lower than that of rough surfaces, it thus controls the process. There seems to be an overall agreement on the fact that the facets appear because of the anisotropy of surface energy, kinetic attachment, or both. However, the experimental results do not allow a definite conclusion about which phenomenon is the most relevant and this question is still a challenge for the numerical methods. In this work, we developed a 3D phase-field code incorporating the two phenomena and that takes into account the experimental conditions described in [1,2]. The results of the simulations are compared to the experimental ones and conclusions are drawn out [3]. [1] X. Yang, K. Fujiwara, K. Maeda, J. Nozawa, H. Koizumi and S. Uda, Crystal growth and equilibrium crystal shapes of silicon in the melt, Prog. Photovolt: Res. Appl. 2014,22:574-580. [2]A. Tandjaoui, N. Mangelinck-noel, G. Reinhart, B.Billia, T. Lafford, J. Baruchel, Investigation of grain boundary grooves at the solid-liquid interface during directional solidification of multi-crystalline silicon: in situ characterization by X-ray imaging, J.Cryst.Growth, 2013,377:203-211 [3] A. K. Boukellal and J-M. Debierre, the effect of the anisotropy of surface energy and kinetic attachment on silicon solidification (in progress).