Polycrystalline silicon and preparation method thereof

Abstract

The invention discloses polycrystalline silicon and a preparation method thereof. The preparation method is characterized by comprising the following steps: paving a plurality of polycrystalline silicon seed crystals in the center of the bottom of a crucible to form a seed crystal layer; paving a plurality of parallelly arranged polycrystalline silicon slices between the seed crystal layer positioned at the bottom of the crucible and the periphery of the crucible to form a flat paving layer; arranging silicon materials which are in a molten state on the seed crystal layer and the flat paving layer to ensure that the heating temperature of the bottom of the crucible is lower than the melting points of the polycrystal seed crystals and the polycrystalline silicon slices; and controlling the temperature inside the crucible to gradually form a temperature gradient upwards along the direction of a plane, where the bottom of the crucible is located, to enable molten silicon materials to form crystals on the seed crystal layer and the flat paving layer so as to obtain a polycrystalline silicon ingot with the polycrystalline silicon as a component. By adopting the mode, the preparation method disclosed by the invention has the advantages that long crystals are less misplaced, the crystal boundary is proper, the conversion efficiency of a battery made from the crystal is improved by 0.4-0.9, a prepared silicon ingot is complete polycrystalline silicon, the subsequent stripping of different components is omitted and the utilization ratio of the silicon materials is increased.

Description

technical field [0001] The invention relates to a polysilicon and a preparation method thereof, in particular to a polysilicon obtained from a silicon ingot which is completely polysilicon and a preparation method thereof, belonging to the field of semiconductor preparation. Background technique [0002] Crystalline silicon is a semiconductor material commonly used in the manufacture of solar cells, and the preparation of crystalline silicon is mainly monocrystalline silicon produced by the current Czochralski method and polycrystalline silicon produced by ingot casting technology. Due to the high conversion efficiency of monocrystalline silicon, there are Due to the problem of long production cycle, polysilicon with high cost performance has great market potential in recent years. In the production of polysilicon, a large amount of silicon material is put into the crucible furnace to grow crystals. However, in terms of the current production process of polysilicon, it is im...

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Problems solved by technology

In the production of polysilicon, a large amount of silicon material is put into the crucible furnace to grow crystals. However, in terms of the current production process of polysilicon, it is impossible to obtain high-quality complete polysilicon materials in the ingot production process. The ingot is surrounded by irregular polycrystalline, and there is a blending zone between the single crystal and polycrystalline; or the core is similar to single crystal, and the silicon ingot is surrounded by polycrystalline

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