Polycrystalline quartz ceramic crucible and preparation method thereof

Abstract

The invention provides a polycrystalline quartz ceramic crucible and a preparation method thereof; a coating is arranged on the inner wall of the polycrystalline quartz ceramic crucible provided by the invention; and the coating comprises quartz sand, the particle diameter of which is 10-150mu m. According to the invention, polycrystalline silicon ingot casting is carried out by adopting the quartz ceramic crucible having the quartz sand coating with the particle diameter of 10-150mu m; diffusion of impurity elements in the quartz ceramic crucible to the interior of a silicon ingot can be effectively reduced; the minority carrier lifetime of the silicon ingot is increased; the red-zone width of the silicon ingot is reduced; the EL (Electro Luminescence) detection black margin proportion after a silicon slice is prepared into a battery piece is reduced; the photoelectric conversion efficiency is increased; therefore, the quartz ceramic crucible can satisfy practical production requirements better; and experimental results show that the red-zone width of the polycrystalline cast ingot prepared by adopting the polycrystalline quartz ceramic crucible provided by the invention can be decreased to be below 10 mm, even 0 mm.

Description

technical field [0001] The invention belongs to the technical field of crucibles, in particular to a polycrystalline quartz ceramic crucible and a preparation method thereof. Background technique [0002] As a renewable clean energy, solar energy has been widely used in grid-connected power generation, civil Power generation, public facilities and integrated energy-saving buildings. In the field of solar power generation, crystalline silicon photovoltaic power generation systems occupy a major position in the new energy photovoltaic power generation market. As the main link of photovoltaic power generation - polysilicon, the market has increasingly strict requirements on the quality of polysilicon. [0003] At present, the process flow of polysilicon ingot needs 4 links: crucible spraying, crucible baking, crucible charging to ingot production, in the process of ingot production, need to go through heating, melting, crystal growth, annealing, cooling process. The process ...

AI Technical Summary

Problems solved by technology

[0004] When the traditional method is used for polysilicon ingot casting, the quartz ceramic crucible produced by the traditional method is directly used. During the process of melting and growing the silicon material, the silicon melt and the quartz ceramic crucible are in contact for a long time, which will cause sticking effect; and Due to the different thermal expansion coefficients of polysilicon and quartz ceramic crucibles, when the silicon ingot is cooled, it is likely to cause cracks in the silicon ingot or crucible, which will affect production and application.

Moreover, the quartz ceramic crucible produced by the traditional method has many deficiencies. First, the traditional quartz ceramic crucible has relatively high C, O, and P impurities; metal impurities, especially aluminum impurities

These impurities enter the silicon ingot and react with the silicon liquid, so that the width of the red zone of the silicon ingot reaches 20mm-28mm. The width of the red zone reflects the quality of the silicon ingot. The wider the red zone, the worse the quality of the corner of the silicon ingot; Increase the black edge ratio of EL detection after the silicon wafer supports the cell, and reduce its photoelectric conversion efficiency

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