Cast single crystal silicon ingot and its preparation method, cast single crystal silicon wafer and its preparation method

Abstract

The invention relates to a cast single crystal silicon ingot and a preparation method thereof, a cast single crystal silicon wafer and a preparation method thereof. The method for preparing a cast monocrystalline silicon ingot comprises the following steps: laying a recovered single crystal seed crystal on the bottom of the container to form a single crystal seed crystal layer; the direction from the recovered single crystal seed crystal away from the bottom of the container to the direction close to the bottom of the container is the first direction, The first direction is the same as the original crystal growth direction of the recovered single crystal seed crystal; put silicon material on the single crystal seed crystal layer, heat to completely melt the silicon material, partially melt the single crystal seed crystal layer, and obtain a cast single crystal silicon ingot after crystal growth . The above method for preparing cast single crystal silicon ingots changes the growth direction of defects in the recovered single crystal seed crystal during the crystal growth process, and utilizes the existing defects in the recovered single crystal seed crystal to guide subsequent defects to expand in the opposite direction to the previous one, realizing In order to improve the yield of cast monocrystalline silicon ingots, the defects of cast monocrystalline silicon ingots grown by using recycled single crystal seed crystals no longer continue to expand and proliferate in the original direction, but gradually narrow or even disappear.

Description

technical field [0001] The invention relates to the technical field of solar photovoltaic materials, in particular to a cast single crystal silicon ingot and a preparation method thereof, a cast single crystal silicon wafer and a preparation method thereof. Background technique [0002] Solar photovoltaic power generation is one of the fastest-growing forms of sustainable energy utilization, and it has developed rapidly in various countries in recent years. At present, the method of producing monocrystalline silicon for solar energy by casting method has received more and more attention. Cast single crystal silicon has the advantages of low defects of Czochralski single crystal silicon, and can form a pyramid-shaped texture by alkali texturing method, which can improve the absorption of light, thereby improving the conversion efficiency; at the same time, cast single crystal silicon also has the advantages of casting Polysilicon has the advantages of low production cost and...

AI Technical Summary

Problems solved by technology

[0004] Based on this, it is necessary to address the problem of how to improve the yield of cast single crystal silicon ingots, to provide a cast single crystal silicon ingot and a preparation method thereof, a cast single crystal silicon wafer and a preparation method thereof

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