A kind of manufacturing method of n-type bifacial battery

Abstract

The invention discloses a fabrication method of an N-type double-sized battery. The fabrication method comprises the following steps of cleaning a silicon wafer and texturing a surface; performing boron diffusion on a front surface and a back surface of the silicon wafer to form a front-surface boron diffusion layer and a back-surface boron diffusion layer, wherein borosilicate glass is arranged on a surface of the front-surface boron diffusion layer; fabricating an SiNx mask on the front surface of the silicon wafer; etching the SiNx mask and the back-surface boron diffusion layer; forming protection on the front surface of the silicon wafer by the borosilicate glass, and performing phosphorus diffusion on the back surface of the silicon wafer to form a back-surface phosphorus diffusion layer, wherein phosphorosilicate glass is arranged on a surface of the back-surface phosphorus diffusion layer; etching the borosilicate glass and the phosphorosilicate glass; and fabricating SiNx passivation films on the front surface and the back surface of the silicon wafer, and separately fabricating a front electrode and a back electrode. By the above method, the HF etching time can be reduced, porous silicon on the back surface is prevented from forming, thus, the combination of the back surface of the battery is effectively reduced, the parallel resistance and the open-circuit voltage of the battery are increased, and the battery efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic equipment manufacturing, and in particular relates to a manufacturing method of an N-type double-sided battery. Background technique [0002] In 1954, Bell Laboratories in the United States prepared the world's first monocrystalline silicon solar cell with a conversion efficiency of 6%. After more than 60 years of continuous exploration by scientists, the solar cell has made a huge breakthrough, and the highest conversion efficiency has reached 46%. % (light concentrating multi-junction GaAs). P-type crystalline silicon solar cells, which have occupied the photovoltaic market for many years, are gradually showing disadvantages such as weak efficiency growth and excessive light decay. Although replacing B atom doping with Ga can avoid the light-induced attenuation effect, the resulting wide resistivity distribution range and Fe element pollution will still restrict the further improvement of ...

AI Technical Summary

Problems solved by technology

But there is a problem with this: SiN x After the film is subjected to P expansion temperature, the etching rate is very low, resulting in too long etching time, which will form porous silicon on the back surface, and porous silicon will increase the specific surface area of ​​the back surface, deteriorate the passivation effect, and increase the battery recombination , reducing battery efficiency

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