Preparation of High-performance Multicrystalline Silicon Ingot Based on Innovative Seeding Strategy for Recycled Seeds

Abstract

In the preparation of high-performance multicrystalline silicon (HPM-Si) wafers, it is usually necessary to use costly polycrystalline silicon (Poly-Si) as the seed layer. In order to reduce cost and simplify process control, this paper presents an innovative strategy for the preparation of HPM-Si wafers using recycled multicrystalline silicon (mc-Si) seeds, aiming to reduce cost and simplify the production process. HPM-Si ingots were successfully prepared by using the substandard region at the ingot bottom as the seed layer combined with an intentional seed arrangement and seeding process. The results show that the Si ingots prepared from recycled seeds do not differ significantly from the conventional method in terms of yield, crystal quality and solar cell performance, while remarkably reducing the preparation cost. In particular, the height, grain morphology and defect distribution of the red zone at the bottom of the silicon brick grown by laying the bottom region of the ingot upside down as seeds are comparable to those of common HPM-Si. In addition, the efficiency of the fabricated solar cells is also comparable to that of common HPM-Si wafers, which provides a new idea for the industrialized production of low-cost HPM-Si wafers.