Crucible capable of increasing solar energy silicon ingot yield, and preparation method thereof

Abstract

The invention discloses a crucible capable of increasing solar energy silicon ingot yield, and a preparation method thereof. The crucible capable of increasing solar energy silicon ingot yield comprises a quartz crucible main body, a high purity barium hydroxide octahydrate coating layer, a high purity fused quartz slurry coating layer, a high purity quartz wafer, and a demoulding silicon nitridecoating layer. The preparation method comprises following steps: 1, preparation of the high purity barium hydroxide octahydrate coating layer, 2, preparation of the high purity fused quartz slurry coating layer, 3, bottom quartz wafer pasting, and 4, preparation of the demoulding silicon nitride coating layer. The advantages are that: the high purity barium hydroxide octahydrate coating layer andthe high purity fused quartz slurry coating layer are arranged between the internal side wall of the quartz crucible main body and the demoulding silicon nitride coating layer, so that entering of impurities into liquid state silicon is prevented, and silicon ingot yield is increased; the bottom of the quartz crucible main body is provided with the high purity quartz wafer through bonding, so thatentering of impurities into liquid silicon is prevented, and silicon ingot yield is increased; in the demoulding silicon nitride coating layer, an adopted demoulding silicon nitride solution is highin beta crystal phase silicon nitride content, so that it is beneficial for silicon ingot nucleation.

Description

[0001] Technical field: [0002] The invention relates to the technical field of photovoltaic solar polycrystalline silicon ingot casting, in particular to a crucible capable of increasing the yield of solar silicon ingots and a preparation method thereof. [0003] Background technique: [0004] Solar energy is a new type of renewable energy. With the deepening of research on solar energy in recent years, related fields such as photovoltaic power generation using solar energy as energy have also developed rapidly. The key components of photovoltaic power generation are thin solid photovoltaic cells made of semiconductor materials, among which polycrystalline silicon solar cells have become the mainstream due to their low cost and easy manufacture. [0005] The raw material for polycrystalline silicon solar cells is polycrystalline silicon ingots. With the gradual decline in the cost of polycrystalline silicon ingot casting, increasing the yield of ingot casting has become a key...

AI Technical Summary

Problems solved by technology

In the preparation process of polycrystalline silicon ingots, quartz crucibles are often used as ingot containers, but since polycrystalline silicon is melted into liquid silicon, it will produce a wetting effect on silicon dioxide, and the direct contact between liquid silicon and the inner wall of the quartz crucible will not only make the quartz crucible Impurities entering the liquid silicon will increase the impurity content of the polysilicon ingot, and will cause the polysilicon ingot to react with the quartz crucible to cause adhesion. The stress generated by the adhesion will cause the polysilicon ingot to crack during solidification and expansion, directly affecting the quality of the polysilicon ingot. Quality, lower polysilicon ingot yield

At present, in order to overcome the above problems, a layer of silicon nitride coating is usually sprayed between the quartz crucible and liquid silicon. The impurities contained in the silicon coating will enter the liquid silicon during the melting process and increase the impurity content of the polysilicon ingot. Therefore, only by spraying silicon nitride coating on the inner wall of the quartz crucible cannot guarantee the improvement of the yield of the polysilicon ingot. rate, improving the minority carrier life of the side and bottom of the polysilicon ingot

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