Crystal growth method of polycrystalline silicon ingot

Abstract

The invention provides a crystal growth method of a polycrystalline silicon ingot, which comprises a heating stage, a melting stage, a growth stage, an annealing stage and a cooling stage; in the growth stage, from the beginning of the growth starts to the end of the top through, the temperature of a center region of the top of the polycrystalline silicon ingot is maintained at a constant value. According to the crystal growth method, the temperature gradient of the polycrystalline silicon ingot in the vertical direction in a growth process can be reduced, and thus the growth speed of the polycrystalline silicon ingot is more stable, impurities inside the polycrystalline silicon ingot are more uniformly segregated towards a liquid phase, the defect density inside a crystal of the polycrystalline silicon ingot can be effectively reduced, and the integral quality of the polycrystalline silicon ingot is improved, therefore, the battery efficiency of a single battery cell manufactured by adopting the polycrystalline silicon ingot and the integral proportion of the high-efficiency battery cell are increased.

Description

technical field [0001] The invention relates to the field of photovoltaic cells, in particular to a crystal growth method for polycrystalline silicon ingots. Background technique [0002] As a clean and environmentally friendly new energy source, the application of solar cells is becoming more and more popular. The traditional silicon cell technology has low power generation per unit area and low cell efficiency. Since most solar cells are installed on the ground, this greatly increases the area occupied by solar panels. Therefore, the improvement of the cell efficiency of the solar cell is conducive to greatly reducing the land cost. [0003] Polycrystalline silicon ingots, which are used to make cells for solar cells, are typically produced using polycrystalline ingot furnaces. The production process of polycrystalline ingot furnace includes five stages: heating (H), melting (M), growth (G), annealing (A) and cooling (C). Among them, the purpose of the heating stage is ...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a crystal growth method for polycrystalline silicon ingots to solve the problem that the growth rate of polycrystalline silicon ingots varies greatly during the growth stage, resulting in an increase in defect density in the crystal, an overall decline in the quality of polycrystalline silicon ingots, and affecting the overall solar cell produced by it. technical issues of efficiency

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