Polycrystal ingot casting furnace and method for producing single crystal-like silicon ingot by utilizing same

Abstract

The invention provides a method for producing a single crystal-like silicon ingot by utilizing a polycrystal ingot casting furnace. The method comprises the following steps: spraying a coating on the inner surface of a crucible; sintering the coating and cooling to room temperature; placing a single crystal silicon material and a polycrystal silicon material into the crucible in turn, and placing the crucible into a graphite supporting box; placing the graphite supporting box into the polycrystal ingot casting furnace without bottom edge carbon bars; vacuumizing the polycrystal ingot casting furnace; heating and monitoring temperature; introducing argon when the polycrystal ingot casting furnace is heated to a preset temperature; when the polycrystal silicon material begins to smelt, moving a heat-isolating cage in the polycrystal ingot casting furnace to the top of the polycrystal ingot casting furnace; and when the polycrystal silicon material is completely smelted, reducing the heating temperature, controlling the silicon material to solidify at constant speed to grow the crystal, thereby forming the single crystal-like silicon ingot. According to the method provided by the invention, the present polycrystal ingot casting furnace is utilized to realize the production of the single crystal-like silicon ingot; the casting cost of the single crystal-like silicon ingot is reduced; the large-scale production of the single crystal-like silicon ingot is boosted; and the invention also provides the polycrystal ingot casting furnace for producing the single crystal-like silicon ingot.

Description

technical field [0001] The invention relates to the technical field of producing quasi-monocrystalline silicon ingots, more specifically, to a polycrystalline ingot casting furnace and a method for producing quasi-monocrystalline silicon ingots. Background technique [0002] With the rapid development of the solar cell industry, the production process of polycrystalline silicon ingots has gradually been widely used. The quality of polycrystalline silicon ingots produced by polycrystalline ingot furnaces is stable, so polycrystalline ingot furnace systems are widely used in polycrystalline silicon ingot casting in solar energy enterprises. [0003] Judging from the current solar cell market environment, improving the conversion efficiency of solar cells is the mainstream direction of the solar cell industry. Although the conversion efficiency of monocrystalline silicon is much higher than that of polycrystalline silicon, the cost of monocrystalline silicon is relatively high...

AI Technical Summary

Problems solved by technology

[0004] However, in the production method of quasi-monocrystalline silicon ingots, the precise melting temperature and solidification temperature of the silicon material are required to obtain polycrystalline silicon ingots with similar appearance and electrical properties to single crystals. The production method of such monocrystalline silicon ingots requires complex The hot field equipment (heating device and heat preservation device, such as heater and heat insulation layer) of the ingot furnace can be realized, and the hot field equipment required for the production method of the quasi-monocrystalline silicon ingot and the polycrystalline casting widely used at present The ingot equipment is not compatible. Therefore, the existing production method of quasi-monocrystalline silicon ingots needs a special ingot casting furnace to realize, which makes the casting cost of quasi-monocrystalline silicon ingots relatively high, and greatly reduces the cost of quasi-monocrystalline silicon ingots. The economic benefits of the monocrystalline silicon ingot eventually hindered the large-scale production

[0005] In addition, the seed crystal required by the existing production method of quasi-single crystal silicon ingot (seed crystal is an indispensable seed for pulling single crystal, on the one hand, the seed crystal is used as a replica sample, which can make the same crystal as the seed crystal be drawn. On the other hand, the seed crystal is used as a crystal nucleus, and the existence of a larger crystal nucleus can reduce the potential barrier that must be overcome when the melt transforms into a crystal) It is a single crystal block, and the seed crystal is of a higher grade. It is necessary to select a single crystal block with a certain thickness after the single crystal silicon ingot rod is broken into squares. The economic benefits brought by the single crystal technology itself hinder the large-scale production of quasi-monocrystalline silicon ingots

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