A kind of high-efficiency polysilicon ingot casting method

Abstract

The invention provides an efficient polycrystalline silicon ingot casting method, which comprises: form a large square ingot by using primary polycrystalline silicon and seed crystal as raw materialsthrough a directional solidification ingot casting method, and squaring the large square ingot to obtain qualified polycrystalline silicon ingot and simultaneously obtain head material top skin, edgeskin top skin and seed crystal tailings; carrying out first remelting on the head material top skin, the edge skin top skin and the seed crystal tailings to obtain a remelted ingot, and laying seed crystals in the remelted ingot casting process; taking the remelted ingot with a minority carriers life time of greater than a first threshold value, and calculating the average minority carriers life time of the remelted ingot; carrying out scribing treatment on the remelted ingot with the average minority carriers life time of greater than a second threshold value, and slicing upwards from the tail scribing position by a preset distance; and directly using the silicon rod obtained through slicing as efficient polycrystalline silicon, and purifying the remaining part to obtain the purified ingot. According to the method of the invention, the problem of the waste of the raw material in the prior art can be solved, and the feeding cost of efficient polycrystalline silicon ingots is reduced.

Description

Technical field [0001] The present invention relates to the field of solar cell technology, and more particularly to a highly efficient polycrystalline silicon ingot. Background technique [0002] The polysilicon ingot is placed in a crucible, and then placed in a ingot in the ingot, using directional coagulation method to be melted, long crystal, annealed, and cooling steps into a large square ingot, and then pass the opening, quality testing, flat Get the qualified high-efficiency polycrystalline silicon wafer after grinding the corner, the strip stick, sliced, cleaning, and the package is passed. [0003] The raw materials used in polysilicon ingots mainly include a certain proportion of native polysilicon, sheet, single polycrystalline circulation, and purified ingot, wherein the seed crystal tailings, head skin and edge skin of the half melt polycrystalline ingot. The top skin, the current practice is to concentrate the seed crystal tail, the top skin of the head and the edg...

AI Technical Summary

Problems solved by technology

[0005] In view of the above situation, it is necessary to provide a method for high-efficiency polysilicon ingot casting, to solve the problem of waste of raw materials in the prior art, and reduce the feeding cost of high-efficiency polysilicon ingot casting

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