Grain growth of cast-multicrystalline silicon grown from small randomly oriented seed crystal

Multicrystalline silicon was grown from seeds with small grains of random orientation and the growth mechanism was studied with respect to grain size, shape, boundary character and orientation. The average grain size perpendicular to growth direction increased steadily initially, became constant and then increased steadily again. Grain size parallel to growth direction increased rapidly with growth due to grain elongation in the growth direction. Grain shape with respect to growth direction changed from spherical to columnar with growth. Initially non-CSL grain boundary fraction was very high but decreased with growth as the Σ3 grain boundary fraction increased. A simple model was proposed to explain the results. •Cast multicrystalline silicon grown from small randomly oriented seed crystal•Growth mechanism studied with respect to grain size, orientation, and grain boundary•A model is proposed for this growth technique based on the experimental results