Impact of seed orientation on dislocation propagation in cast seed-assisted monocrystalline silicon

Abstract

Dislocations induced by the misorientation between neighboring seeds severely damage the quality of the cast seed-assisted monocrystalline silicon (CSAM-Si) and its solar cell performance. Two experiments are designed to analyze the impact of seed orientation and functional grain boundary on the dislocation. It is found that the dislocation propagation is severely depending on the seed orientation, and the <110>-oriented seed could block the dislocation spread laterally. The large angle grain boundaries (LA-GBs) could absorb the initial dislocations and block its propagation. The average CSAM-Si solar cell efficiency can reach up to 21.8%, which is close to CZ-Si. Consequently, the dislocation slipping mechanism and functional grain boundary method could be used in industry for further improving CSAM-Si solar cell performance.