Polysilicon ingot furnace

Abstract

The invention discloses a polysilicon ingot furnace capable of uniformly distributing the resistivity of ingots. The gas outlet of a gas inlet pipe of the polysilicon ingot furnace is extended to a position close to the inner wall of a crucible, the included angle between the central axis of gas flow ejected from the gas outlet and the central axis of the crucible is 20-30 degrees, when being ejected from the gas outlet of the gas inlet pipe, argon is ejected to the surface of silicon liquid obliquely downwards, the original direct blowing manner is changed into an oblique blowing manner, and the central axis of gas flow ejected from the gas outlet and the central axis of the crucible are skew lines, so that the gas flow ejected obliquely downwards can drive the silicon liquid in the crucible to rotate to fully disperse impurities contained in the silicon liquid in a silicon solution to uniformly distribute the liquid phase components so as to avoid the existence of impurity enrichment regions in the ingots and ensure the uniform distribution of the resistivity of the ingots, and the silicon liquid in the crucible is stirred to promote the volatilizable impurities contained in the silicon liquid to be volatilized as soon as possible. The polysilicon ingot furnace is suitable for popularization and application in the field of polysilicon production equipment.

Description

technical field [0001] The invention relates to the field of polysilicon production equipment, in particular to a polysilicon ingot casting furnace. Background technique [0002] Solar cells can convert light energy into electrical energy, which is a key point in the development of a modern energy-saving society. According to different substrate materials, existing solar cells are divided into polycrystalline silicon solar cells, monocrystalline silicon solar cells and quasi-monocrystalline silicon solar cells. Among them, the conversion efficiency of monocrystalline silicon solar cells is high, but the production cost is also high. The conversion efficiency of polycrystalline silicon solar cells is 1%-2% lower than that of monocrystalline silicon solar cells, but its production cost is also low. The battery is a battery between a monocrystalline silicon battery and a polycrystalline silicon solar battery. Comprehensive consideration, the current solar cells on the market ...

AI Technical Summary

Problems solved by technology

However, too long time after the silicon material is melted will lead to the destruction of the silicon nitride coating inside the crucible. Therefore, after the silicon material is melted, it will start to cool down to the crystal growth temperature. The free volatilization time is short, and most of the volatile impurities Before volatilization, it enters the crystal growth stage, and the impurities are solidified in the silicon ingot. At this time, the viscosity of the silicon liquid is relatively high, and the non-volatile impurities and volatile impurities are not fully diffused in the silicon solution. Uneven distribution leads to impurity-enriched areas in the solidified ingot, resulting in uneven distribution of the resistivity of the ingot, which seriously affects the quality and performance of the ingot itself

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