Quartz crucible with composite coating layers for preparing polycrystalline silicon ingot

Abstract

The invention discloses a quartz crucible with composite coating layers for preparing a polycrystalline silicon ingot, which comprises a matrix, an intermediate transitional layer, a second intermediate layer and an inner surface coating layer. The inner wall of the matrix is provided with the intermediate transitional layer; the intermediate transitional layer is provided with the second intermediate layer; and the second intermediate layer is provided with the inner surface coating layer. By using the quartz crucible with the composite coating layers for preparing the polycrystalline silicon ingot, according to the high-temperature heating steps and the calcining time of the quartz crucible in a usage process, the corrosion resistance capability of the quartz crucible is improved by adopting coating layer materials with different thermal performance to hierarchically coat the matrix of the quartz crucible, thereby achieving the purpose of decreasing the response strength of silicon and the quartz crucible.

Description

technical field [0001] The invention relates to the field of solar photovoltaics, in particular to a composite coated quartz crucible for preparing solar ingot polysilicon. Background technique [0002] Quartz crucible is one of the important components in the preparation of solar polysilicon ingots, and its quality has an important impact on the quality of polysilicon produced and the yield of ingot production. During the ingot production process, the reaction between silicon in the molten state and silica, the material of the quartz crucible, will cause erosion of the surface of the quartz crucible on the one hand, and aggravate various impurities (such as iron, boron, etc.) in the silicon and quartz crucible. , aluminum, etc.) react, and the phenomenon of adhesion between polycrystalline silicon ingot and quartz crucible occurs. On the other hand, the reaction between silicon and quartz crucible will produce carbon monoxide and oxygen. Oxygen will pollute silicon, and ca...

AI Technical Summary

Problems solved by technology

[0003] Silicon nitride is used as the coating material, and the thickness of the coating is generally more than 300 μm, which not only wastes time, but also makes the quartz crucible expensive.

In addition, since silicon nitride is easy to peel off, it can only be coated at the last moment before use, which is not conducive to the mass production and storage of coated quartz crucibles

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