Polycrystalline silicon ingot, manufacturing method thereof, and crucible

Abstract

Disclosed are a polycrystalline silicon ingot, a method for producing the same, and a crucible. The crucible has a rough bottom surface, and has a plurality of three-dimensional geometrical shapes of spatial distribution; the inner surface of the crucible is coated with at least one coating, and there are particulate substances as heterogeneous nucleation sites for silicon in the coating on the bottom surface of the crucible. According to an embodiment of the present invention, the bottom surface of the crucible is coated with at least one coating, and the particulate substances in the coating can be used as silicon nucleation sites during the subsequent crystal growth, inhibit the formation of crystal nuclei in other regions, so that the distribution of crystal grains is more uniform. In addition, crystal grains whose nuclei are formed first start to compete in a pit at the bottom surface of the crucible, and crystal grains with a certain crystal orientation predominate during the competing process and are ultimately retained, so the orientations of the nuclei tend to be consistent, i.e., the polycrystalline silicon ingot grown according to the method has a uniform crystal grain size, and a consistent crystal grain orientation, and has a reduced dislocation density inside the crystal and a prolonged minority carrier lifetime, thereby increasing the conversion efficiency of the polycrystalline silicon solar battery.

Description

technical field [0001] The invention relates to the manufacturing technology of monocrystalline silicon and polycrystalline silicon and the field of optoelectronics, in particular to a polycrystalline silicon ingot, a manufacturing method thereof, and a crucible. Background technique [0002] Solar cells can convert light energy into electrical energy. Photoelectric conversion efficiency and attenuation are important parameters to measure the quality of solar cells, and the production cost has also become an important factor restricting the development of solar cells. At present, according to different materials, solar cells are mainly divided into two types: monocrystalline silicon solar cells and polycrystalline silicon solar cells. Monocrystalline silicon solar cells have high conversion efficiency, but the production cost is high, and polycrystalline silicon solar cells are low in cost, but the conversion efficiency is relatively low. At present, polycrystalline silicon...

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Problems solved by technology

[0004] However, the conversion efficiency of solar cells made of polycrystalline silicon ingots produced in the prior art has been difficult to improve. A large part of this situation is due to the quality of polycrystalline silicon ingots. Therefore, how to make polycrystalline silicon ingots with good performance has become a popular research in the industry direction

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