Method for ingoting polycrystalline silicon

Abstract

The invention provides a method for ingoting polycrystalline silicon, which comprises the following steps: forming a coating with first preset thickness on bottom of a crucible, wherein the coating contains solid particles, the solid particles can be at least one of quartz sand, silicon nitride powder and silicon carbide powder, spraying silicon nitride on the bottom and inside wall of the crucible; paving the broken silicon chips with second preset thickness on the bottom of the crucible, wherein the shape and size of the broken silicon chips are not same, and distributed at the bottom of the crucible, then placing the silicon material in the crucible, compressing the broken silicon chips by the silicon material, forming dent on the coating; and integrally heating the crucible until the broken silicon chips and the silicon material are fully fused. The method can ensure the high conversion efficiency of polycrystalline silicon ingot, reduce energy consumption during the production process, reduce the production cost, increase the crystalline yield rate of the silicon ingot, and increase the integral production power of the silicon chip.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a method for casting polycrystalline silicon ingots. Background technique [0002] With the development of science and the advancement of technology, countries all over the world pay more and more attention to energy saving, emission reduction and environmental protection. As an important part of energy saving and emission reduction projects, solar cells have been developing rapidly. [0003] Among many types of solar cells, polysilicon solar cells have been industrialized on a large scale due to their low cost. Polysilicon ingot casting is an important basic link in the polysilicon solar cell industry chain. Purified silicon raw materials can only be grown and cast After being made into silicon ingots, it can be used to produce solar cells. How to grow high-quality polysilicon at the stage of polysilicon ingot casting plays a vital role in improving the conversion efficien...

AI Technical Summary

Problems solved by technology

[0005] However, in the actual production process, it was found that the above-mentioned method of high-efficiency polysilicon ingot casting consumes more energy, which leads to higher production costs, and the lower crystallization rate of silicon ingots reduces the overall production capacity of subsequent silicon wafers.

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