Solidification of multicrystalline silicon comparison between conventional casting and electromagnetic casting processes

In order to compare the different technologies under physical and economical aspects, the authors present the electrical properties and solar cell characteristics obtained by the Polix material based on moulded ingots, and the EMC material produced by OTC and more recently by EPM-Madylam. It was important to determine the main limiting factors of these growth methods for high efficiency Si solar cells. It appears that the main limiting factor for the Polix casting process is close to the content of oxygen and metallic impurities due to contamination from the crucible and the feedstock. For the EMC processes and particularly for EPM-Madylam, the main limiting factor is the crystallographic defects in the shape of small grains and bundles of dislocations decorated by metallic impurities. However, these structural inhomogeneities do not seem to involve a strong recombination in the entire cell. Thereby, solar cell performances are suitable to the photovoltaic material production methods.