Direct Silicon Wafer Molding
Year: 2012
Type: article
Abstract: Photovoltaic silicon wafers are currently obtained through ingot casting in silica crucibles covered by a porous silicon nitride coating which prevents sticking of solidified silicon to the crucible. The purpose of this work is to develop a new injection molding process of multicrystalline silicon wafers in order to avoid kerf losses due to the wire sawing steps. Mold parts are demonstrated to be reusable via a surface modification of the porous graphite substrate with a SiC impervious layer, which is validated through a comprehensive study of the interactions (i.e. wetting, infiltration and adhesion) of molten Si on graphite-based Si3N4-coated substrates performed by the sessile drop technique. Labscale mono-wafer and injection multi-wafer molding experiments are designed in order to explore the consequences of said detrimental surface to volume ratio inherent in the molding process, on the concentration of impurities contained in the silicon and its microstructure. Conclusions are drawn regarding the solid / liquid interface destabilization and velocity during this directional crystallization process.
Source: EU PVSEC
Authors: Huguet, C., Mercier, F., Flahaut, E., Drevet, B., Camel, D., Eustathopoulos, N., Nowakowski, P.
Institution: Université Grenoble Alpes
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2338878110