Gettering method for prolonging effective service life of crystalline silicon substrate

A technology of effective life and crystalline silicon, which is applied in the field of solar cells, can solve problems such as the inability to use solar cells to produce, and achieve the effects of improving photoelectric conversion performance, increasing life, and facilitating large-scale production

Active Publication Date: 2012-12-12
JA SOLAR TECH YANGZHOU
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It cannot be connected with the solar cell production process before and after, and cannot be used for large-scale solar cell production at all

Method used

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  • Gettering method for prolonging effective service life of crystalline silicon substrate
  • Gettering method for prolonging effective service life of crystalline silicon substrate
  • Gettering method for prolonging effective service life of crystalline silicon substrate

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0020] figure 1 Is the preparation flowchart of the solar cell in embodiment 1-3;

[0021] figure 2 It is the test data comparison of the high-temperature gettering in embodiment 1 applied to the minority carrier lifetime of p-type polysilicon wafer;

Embodiment 1

[0024] (1) Select a p-type polycrystalline silicon wafer with a resistivity of 0.5~5Ω·cm, and use a chemical solution to pre-clean the silicon wafer to remove the damaged layer on the surface of the silicon wafer before gettering. The chemical solution is hydrofluoric acid, hydrofluoric acid The mass percentage content of the silicon wafer is 10%, the cleaning time is 0.5-60 minutes, the temperature is 5-90°C, and the weight loss range of the silicon wafer after removal is: 0.1g-0.5g.

[0025] (2) Diffusion gettering of heavy phosphorus

[0026] Phosphorus oxychloride liquid source is used to carry out heavy phosphorus diffusion and gettering in an industrial tubular diffusion furnace, which is divided into two processes, one is the constant temperature process of phosphorus diffusion, and the other is the variable temperature process of phosphorus gettering; The temperature in the constant temperature zone is 850°C, the diffusion time is 50 minutes, and the diffusion square r...

Embodiment 2

[0042] (1) Select a p-type single crystal silicon wafer with a resistivity of 0.5~5Ω·cm, and use a chemical solution to pre-clean the silicon wafer before gettering to remove the damaged layer on the surface of the silicon wafer. The chemical solution is hydrofluoric acid, hydrogen The mass percentage of hydrofluoric acid is 40%, the cleaning time is 0.5-60 minutes, the temperature is 5-90°C, and the weight loss range of the silicon wafer after removal is: 0.1g-0.5g.

[0043] (2) Diffusion gettering of heavy phosphorus

[0044] Phosphorus oxychloride liquid source is used to carry out heavy phosphorus diffusion and gettering in an industrial tubular diffusion furnace, which is divided into two processes, one is the constant temperature process of phosphorus diffusion, and the other is the variable temperature process of phosphorus gettering. In the constant temperature process of phosphorus diffusion, the temperature in the constant temperature zone is 900°C, the diffusion tim...

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Abstract

The invention provides a gettering method for prolonging the effective service life of a crystalline silicon substrate. The method comprises the following steps: carrying out a heavy phosphorous diffusion gettering on the crystalline silicon substrate without a surface damage layer by using a phosphorus source, and removing a phosphorous diffusion layer from the crystalline silicon substrate after phosphorous gettering and then carrying out the following processes. The heavy phosphorous diffusion gettering step comprises a phosphorous diffusion constant temperature process and a two-section cooling process for phosphorous gettering; the temperature of a constant temperature region in the phosphorous diffusion constant-temperature process is 800-950 DEG C, and the time of the phosphorous diffusion constant-temperature process is 30-50min; in the two-section cooling process for the phosphorous gettering, the temperature range of the first section is 980-800 DEG C and the treatment time of the temperature range of the first section is 5-30min, the temperature range of the second section is 800-700 DEG C and the treatment time of the temperature range of the second section is 30-90min, and a cooling rate is 2-10 DEG C / min. With the adoption of the method provided by the invention, the effective service life of a photo-production carrier can be prolonged; the photo-electric conversion efficiency of a solar battery is increased; the gettering method can be completely compatible with the conventional solar battery production process; and the gettering method can be directly applied to the mass production of the solar battery.

Description

technical field [0001] The invention belongs to the technical field of solar cells, in particular to a gettering method for improving the effective life of a crystalline silicon substrate. Background technique [0002] Photovoltaic technology is a technology that uses large-area p-n junction diodes to convert solar energy into electrical energy. This p-n junction diode is called a solar cell. The semiconductor materials used to make solar cells have a certain band gap. When the solar cell is irradiated by the sun, photons with energy exceeding the band gap generate electron-hole pairs in the solar cell, and the asymmetry of the p-n junction separates the electron-hole pairs. , and determines the flow direction of different types of photogenerated carriers. When the solar cell is connected with an external circuit, it can output power to the outside. [0003] Generally speaking, the photoelectric conversion efficiency of solar cells is directly related to the lifetime of m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/18
CPCY02P70/50
Inventor 于海斌王俊延刚单伟张红玲
Owner JA SOLAR TECH YANGZHOU
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