Crucible for casting monocrystalline silicon and method for casting monocrystalline silicon

Abstract

The invention discloses a crucible for casting monocrystalline silicon and a method for casting monocrystalline silicon. The crucible comprises a crucible body and a backing plate laid at the bottom in the crucible body, and the backing plate is provided with a seed crystal notch matched with the shape of a monocrystalline silicon seed crystal. And the seed crystal notch is positioned in the middle of the base plate. The backing plate is laid at the bottom of the common finished crucible, the backing plate is provided with the seed crystal notch matched with a single crystal seed crystal in shape, in the crystal growth stage, due to the fact that the crucible structure provides the heat conduction structure with a cold middle portion and hot edge portions, crystal growth from the middle tothe outside is better facilitated, the proportion of mixed crystals in a silicon ingot is reduced, and the protection success rate of the single crystal seed crystal can be simply and effectively increased. And the diameter and the depth of the seed crystal notch can be realized only by changing the shape and the thickness of a fused quartz plate without changing the mold of the crucible, so thatthe qualification rate of the crucible body is not influenced.

Description

technical field [0001] The invention belongs to the technical field of photovoltaics, and in particular relates to a crucible for casting single crystal silicon and a method for casting single crystal silicon. Background technique [0002] Crystalline silicon is currently the mainstream solar cell material, and cast polysilicon still occupies a major share of the crystalline silicon solar energy market. According to the seeding method, cast polysilicon can be divided into ordinary cast polysilicon without seeding steps, cast single crystal (quasi-single crystal, quasi-single crystal, etc.) with single crystal silicon block as seed crystal, because it cannot grow into a perfect Single crystal, so it still belongs to the category of polycrystalline) and high-efficiency polycrystalline with polycrystalline silicon material (powder, granule, fragment, etc.) as the seed crystal for seeding. [0003] Compared with Czochralski single crystal, cast single crystal has the advantage ...

AI Technical Summary

Problems solved by technology

However, due to the joint effect of the single crystal block, the cast single crystal contains a large number of dislocations inside, which seriously affects the crystal quality. In addition, the cost of cutting a square single crystal that can be spliced ​​from the Czochralski single crystal rod is relatively high.

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