Quick-melting and slow crystal growth high-efficiency polycrystalline silicon ingot casting process

Abstract

The invention belongs to the field of polycrystalline silicon cast ingots and particularly relates to a quick-melting and slow crystal growth high-efficiency polycrystalline silicon ingot casting process. The quick-melting and slow crystal growth high-efficiency polycrystalline silicon ingot casting process comprises the steps of loading, vacuumizing and preheating, melting and preserving heat, growing the crystal, annealing, cooling and blocking, wherein the melting and heat preserving phase and the crystal growing phase are carried out according to the following steps: introducing argon gas into an ingot casting furnace to be used as shielding gas; then heating and raising temperature to enable the temperature of a quartz crucible to reach 1545-1560 DEG C within 4-5 hours, and preserving heat for 7-8 hours; reducing the temperature to 1440 DEG C after 0.5 hour; reducing the temperature of the quartz crucible from 1440 DEG C to 1420 DEG C through 29 hours and finishing the central crystal growing phase of the polycrystalline silicon cast ingot; reducing the temperature to 1410 DEG C after 3 hours to finish the corner crystal growing phase of the polycrystalline silicon cast ingot. The quick-melting and slow crystal growth high-efficiency polycrystalline silicon ingot casting process disclosed by the invention has the advantages that firstly, the photoelectric conversion efficiency of a solar cell can be improved from 17.1 percent to 17.4 percent; secondly, the time of the whole process is shortened while the quality of the polycrystalline silicon cast ingot is improved.

Description

technical field [0001] The invention belongs to the field of polysilicon ingot casting, and in particular relates to a process of fast-melting slow crystal growth and high-efficiency polysilicon ingot casting. Background technique [0002] At present, my country has become the world's largest energy production and consumption country, but the per capita energy consumption level is still very low. With the continuous development of the economy and society, my country's energy demand will continue to grow. In response to the current energy shortage, countries around the world are thinking deeply, and are working hard to improve energy efficiency, promote the development and application of renewable energy, and reduce the impact on energy consumption. Reliance on imported oil to enhance energy security. [0003] As one of the important development directions of renewable energy, solar photovoltaic power generation has developed rapidly in recent years, and its proportion is inc...

AI Technical Summary

Problems solved by technology

[0005] At present, the photoelectric conversion efficiency of polycrystalline silicon solar cells is not very high. The photoelectric conversion efficiency of polycrystalline silicon solar cells obtained by the existing technology is 17.1%, which makes the cost of solar power generation still high and cannot meet people's requirements for solar power generation.