Method for preparing solar cell by using local area back field

A technology of solar cells and local back field, applied in the field of solar cells, can solve the problems of slurry environmental pollution and leakage, achieve the effect of small contact area, avoid leakage problems and improve production speed

Active Publication Date: 2010-10-06
JA SOLAR TECH YANGZHOU
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The existing process includes texturing, diffusion + plasma etching + PSG / BSG cleaning, deposition of SiNx anti-reflection film, deposition of one or more passivation layers on the back side, sputtering aluminum back field, printing front silver electrode and sintering, plasma The etching lamination process will cause leakage problems, and the method of printing the back field will cause the paste to pollute the environment

Method used

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  • Method for preparing solar cell by using local area back field
  • Method for preparing solar cell by using local area back field
  • Method for preparing solar cell by using local area back field

Examples

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Embodiment 1

[0043] The method for preparing a solar cell using a local back field provided in this example is as follows: first select an N-type or P-type silicon wafer for texturing, then perform boron or phosphorus diffusion on the N-type silicon wafer, and perform phosphorus diffusion on the P-type silicon wafer After cleaning the borosilicate glass or phosphosilicate glass layer remaining on the surface of the silicon wafer after diffusion, the silicon nitride film is deposited on the front side of the silicon wafer by PECVD, and then the back side is polished by hot lye, and a passivation film is deposited on the polished back side. Thin film, laser opening and sputtering aluminum layer, and finally silver electrode screen printing on the front of the silicon wafer, sintering and test sorting.

[0044] The lye used for back polishing is inorganic lye, the inorganic lye is sodium hydroxide or potassium hydroxide aqueous solution, its weight percentage is 5-50%, and the temperature is 5...

Embodiment 2

[0047] The method for preparing a solar cell using a localized back field provided in this embodiment includes the following steps:

[0048] (1) Wafer selection, texturing and cleaning

[0049] Select N-type monocrystalline silicon wafers, use 0.5-3% by weight sodium hydroxide aqueous solution to make texture to obtain pyramid-shaped texture, and then wash off the lye;

[0050] (2) Diffusion doping of phosphorus or boron

[0051] For N-type silicon wafers, the boron tribromide liquid source is used to diffuse, and the boron source diffuses into the silicon wafer after diffusion;

[0052] (3) Removal of borosilicate glass

[0053] Immersing the diffused silicon wafer in hydrofluoric acid with a volume percentage of 5-15% to clean away the borosilicate glass remaining on the surface of the silicon wafer;

[0054] (4) SiNx film deposition

[0055] The silicon wafer cleaned with borosilicate glass is deposited on the front side of the silicon nitride film by PECVD;

[0056] (...

Embodiment 3

[0066] The method for preparing a solar cell using a localized back field provided in this embodiment includes the following steps:

[0067] (1) Wafer selection, texturing and cleaning

[0068] Select P-type monocrystalline silicon wafers, use 0.5-3% by weight sodium hydroxide aqueous solution to make texture to obtain pyramid-shaped texture, and then wash off the lye;

[0069] (2) Diffusion doping of phosphorus or boron

[0070] For P-type silicon wafers, phosphorus oxychloride liquid source is used to diffuse, and the phosphorus source diffuses into the silicon wafer after diffusion;

[0071] (3) Removal of phosphosilicate glass

[0072] Immersing the diffused silicon wafer in hydrofluoric acid with a volume percentage of 5-15% to wash off the phosphosilicate glass remaining on the surface of the silicon wafer;

[0073] (4) SiNx film deposition

[0074] Deposit silicon nitride film on the front side of the silicon wafer cleaned with phospho-silicate glass by PECVD;

[0...

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Abstract

The invention discloses a method for preparing a solar cell by using a local area back field, which comprises the following steps of: selecting a silicon chip and making the silicon chip into a soft silicon chip, then performing boron or phosphorus dispersion, cleaning a boron-silicon glass layer or a phosphorus-silicon glass layer left on the surface of the silicon chip after the dispersion, depositing a silicon nitride film on the front of the silicon chip by using PECVD, polishing the back of the silicon chip by using hot alkali liquid, and depositing a passive film, performing laser perforation and sputtering an aluminum layer on the polished back; and finally, screen-printing a silver electrode on the front of the silicon chip, and sintering, testing and separating the silicon chip. The method avoids the problem of current leakage caused by lamination during etching; the PECVD process adopted by the passive film on the back is more suitable for large-scale production; the adoption of the back laser perforation improves the manufacturing speed, reduces the process step and avoids pollution brought by corrosive slurry; and the Al layer can be well sintered and contacted with the silicon through pores so that the contact area of the metal and the back surface silicon is smaller and the current carrier compounding rate of the back surface is reduced.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and in particular relates to a method for preparing a solar cell by using a localized back field. Background technique [0002] Human beings have never stopped their efforts to improve the conversion efficiency of solar cells and reduce the cost of solar cells. In the process of improving the efficiency of silicon crystal cells, various new structure solar cells have appeared one after another. PERL (passivated emitter and back local Diffusion) batteries, LSBF (local back field) batteries, HIT batteries, and grooved buried grid batteries can all improve battery efficiency to a relatively high level. Among them, increasing the passivation of the silicon wafer surface and reducing the surface recombination rate are one of the keys to improving the conversion efficiency of solar cells. The preparation of solar cells using local back field is an effective method to improve the conversion efficie...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/18
CPCY02P70/50
Inventor 何胜尹海鹏朱生宾金井升单伟
Owner JA SOLAR TECH YANGZHOU
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