Mono-like silicon growth using functional grain boundaries to limit area of multicrystalline grains

We propose a new growth method for mono-like silicon (Si): the suppression of multicrystallization using functional grain boundaries artificially formed by multiseed crystals. In our previous study, we demonstrated such suppression in an ingot 30 mm in diameter. In this paper, we grew mono-like Si ingots of 100 and 400 mm on a side. Functional grain boundaries successfully suppressed the increase in the area of multicrystalline grains nucleated on crucible side walls, which indicates a large volume of quasi-monocrystalline Si up to the top of the ingots. This enables a large increase in the yield of quasi-monocrystalline wafers in an ingot and would lead to a reduction in the cost of the solar cells.