Laying method for casting monocrystalline silicon seed crystal, crystalline silicon ingot and crystalline silicon ingot cutting and squaring method

Abstract

The invention provides a laying method for casting monocrystalline silicon seed crystals. The <110> crystal orientation of adjacent silicon seed crystals points to or is far away from splicing seams obliquely upwards at a smaller acute angle, and the two types of splicing seams are regularly distributed at intervals. <110> crystal orientation obliquely upward pointing splicing seams of the siliconseed crystals on the two sides can significantly inhibit generation and expansion of dislocation in the crystal growth process, and the overall crystal quality of the silicon ingot is improved. The invention also provides a crystalline silicon ingot prepared by using the laying method of the monocrystalline silicon seed crystal and a cutting and squaring method of the crystalline silicon ingot, which can be used for removing the dislocation generated by a seed crystal splicing seam, improving the proportion of a slicing part of the silicon ingot, reducing the cost of a silicon wafer and facilitating the preparation of a large-size silicon wafer. The problem of rapid dislocation propagation at the seed crystal splicing seam during production of monocrystalline silicon by a casting method is solved, and the prepared crystalline silicon solar cell is high in efficiency, centralized in distribution and consistent in appearance color, and has a remarkable market application value.

Description

technical field [0001] The invention belongs to the technical field of crystalline silicon growth, and in particular relates to a method for laying cast monocrystalline silicon seed crystals, a crystalline silicon ingot and a method for cutting and square-cutting the crystalline silicon ingot. Background technique [0002] In the solar photovoltaic industry, crystalline silicon is the most widely used solar cell material. According to the different crystal structures of crystalline materials, crystalline silicon can be divided into two types: monocrystalline silicon and polycrystalline silicon. It is generally believed that the monocrystalline silicon prepared by the Czochralski method has good structural integrity and high photoelectric conversion efficiency, but the preparation cost is high; the polycrystalline silicon prepared by the casting method is low in cost, but has many crystal structure defects and low photoelectric conversion efficiency. In recent years, the gro...

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Problems solved by technology

[0005] In addition, these dislocations are easy to become the recombination center of carriers after the battery is made, resulting in low photoelectric conversion efficiency and wide distribution of the battery, which affects the mass production and application of cast single crystal silicon wafers

[0006] Because of these problems, when preparing cast single crystal silicon wafers, it is necessary to remove the high dislocation area at the seam of each seed crystal, resulting in a decrease in the proportion of silicon ingots that can be sliced, increasing the cost of silicon wafers, and increasing the cost of high dislocations. Misjudgment of the wrong area, the possibility of missed detection flowing into the subsequent process

[0007] In addition, this also leads to the need to use larger-sized single crystal silicon rods to make seed crystals when producing large-sized silicon wafers from cast single crystals, which increases production costs and difficulties, and weakens the quality of cast single crystal silicon wafers and Czochralski single crystals. Competitiveness of silicon wafers in terms of large size and high power

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