Low resistance monocrystalline silicon doping method

Abstract

The invention discloses a low-resistance monocrystalline silicon doping method, which comprises the following steps of: firstly, preparing a low-resistance gallium-boron-silicon alloy material by using a low-resistance gallium material and a low-resistance boron material, then adding the low-resistance gallium-boron-silicon alloy material into a silicon material, and then carrying out vacuum pumping, seeding, necking and shouldering for better meeting the production of low resistance monocrystalline silicon. The specific resistance of the monocrystalline silicon is 0.5-1.5 omega centimeter, and the photoelectric conversion efficiency of the monocrystalline silicon solar cell is improved to 21.71%; without affecting anti-attenuation ability of the monocrystalline, the method solves the problem of uneven distribution of the specific resistance of monocrystalline due to low gallium separation coefficient, both the utilization rate of the raw materials and qualified rate of the low-resistance monocrystalline silicon products are improved, and the waste is reduced.

Description

technical field [0001] The present application relates to the technical field of single crystal preparation, in particular to a low-resistance single-crystal silicon doping method by doping various low-resistance dopants. Background technique [0002] Solar crystalline silicon material is the most important photovoltaic material. It is used in solar cells and can convert solar energy into electrical energy. In today's shortage of conventional energy sources, solar energy has huge application value. In recent years, the global solar photovoltaic industry has grown rapidly. Solar cells The rapid increase in output has directly driven the sharp expansion of polysilicon demand. Solar crystalline silicon materials include monocrystalline silicon and polycrystalline silicon materials. The high manufacturing cost and complex preparation process of solar-grade crystalline silicon materials are the bottlenecks restricting the development of the photovoltaic industry, which seriously...

AI Technical Summary

Problems solved by technology

However, adding low-resistance gallium materials or low-resistance boron materials has its own advantages and disadvantages, and neither can better meet the needs of the solar cell industry.

[0005] Due to the very low segregation coefficient of gallium, the doping concentration of gallium in single crystal silicon varies greatly, so the axial resistivity distribution of gallium-doped single crystal silicon is not uniform, and the axial resistivity changes greatly

Although Suntech has made a series of technological improvements to make the distribution of gallium in the monocrystalline silicon more uniform, the axial resistivity distribution of monocrystalline silicon is still very wide, which will inevitably lead to some products that cannot meet the needs of solar cells. will waste material

[0006] The axial resistivity distribution of low-resistance monocrystalline silicon doped with low-resistance boron material is relatively uniform, but the anti-attenuation ability is weak, mainly due to the high addition of boron material, resulting in weakened anti-attenuation ability

[0007] In the prior art, gallium and boron are also used as co-dopants, but the addition method is to add gallium and boron one after another. This addition method cannot well relieve the single crystal crystal caused by the low segregation coefficient of gallium. The problem of uneven distribution of resistivity in the axial direction of silicon cannot solve the problem of weak anti-attenuation ability of single crystal silicon caused by boron

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