All silicon (Si) ingot fabrication processes share challenges to control grain structure, defect and impurity contamination during the solidification step to improve the material properties. The final grain structure and inherent structural defects issued from the solidification step are responsible for the photovoltaic (PV) properties for a large part, all the more as they are often associated with impurity distribution. Impurities play a major role as they not only can modify the development of the grain structure formation but interact as well with structural defects creating regions of deleterious minority carrier lifetime recombination. Samples containing different levels of impurities and solidified with different processes were selected and analyzed as-grown or observed by X-ray imaging during re-solidification from as-grown seeds. The growth features and relative crystallographic orientation of neighbor grains were characterized. Moreover, minority carrier lifetime measurements were performed and correlated to the growth features. The complementarity of the different techniques allows improving the understanding of phenomena at stake during the formation of grains and twins, the effect of impurities and their impact on photovoltaic properties. The results show the significant influence of light and metallic impurities such as copper on the grain structure and on the electrical properties. 2