A method for making crystalline silicon solar cells by inkjet printing

Abstract

The invention relates to a method employing ink-jet printing to make a crystalline silica solar cell; the method comprises the steps of cleaning velvet on a surface of a P type monocrystalline wafer; carrying out phosphor element doping on one surface of the velvet P type monocrystalline wafer so as to form a PN junction; continuously depositing a passivation and anti-reflection film on a N type surface; employing the ink-jet printing to realize surface metallization; carrying out sintering processing making to obtain the crystalline silica solar cell. Compared with the prior art, the method employing ink-jet printing to make the crystalline silica solar cell is high in printing resolution and grid line aspect ratio, uses non-contact printing, realizes layered metallization, is flexible in technology, and good in uniformity and repeatability.

Description

technical field [0001] The invention relates to a method for manufacturing a crystalline silicon solar cell, in particular to a method for manufacturing a crystalline silicon solar cell by inkjet printing. Background technique [0002] A solar cell is a device that converts light energy into electrical energy. At present, solar cells made of crystalline silicon materials account for more than 90% of the market share. Crystalline silicon cells are mainly divided into monocrystalline silicon cells and polycrystalline silicon cells. Since the purity and crystal quality of monocrystalline silicon are higher than those of polycrystalline silicon, the photoelectric conversion efficiency of monocrystalline silicon cells is generally higher than that of polycrystalline silicon solar cells. At present, the technical route of conventional commercial crystalline silicon solar cells is as follows: first, sort the incoming materials, then clean the damaged layer on the surface of crystal...

AI Technical Summary

Problems solved by technology

The current mass-production screen printing method can print grid lines with a line width of 80-100 μm and a thickness of 15-20 μm. However, due to the limitations of the following situations in screen printing technology, its continuous optimization has reached a technical bottleneck.

First, the aspect ratio of screen printing grid lines is limited, making it difficult to achieve thinner and taller grid lines

Second, screen printing needs to be in direct contact with the silicon wafer, and the fragmentation rate is high, which will affect the application of low-cost thin wafer technology (<160μm or less)

Third, the life of the screen printing screen is about 10,000 times, and each scraper will cause the screen to relax and sag, which obviously limits the printing accuracy

Fourth, during the screen printing process, it is necessary to press the screen scraper to squeeze the metal paste, so it is impossible to ensure that the paste passing through the screen is uniform, resulting in different amounts of paste in different areas of the silicon wafer , thereby affecting the conversion efficiency of the battery

Fifth, screen printing is difficult to achieve low-cost layered metallization while achieving the requirements of low contact resistance and high conductivity

Although this technology has made great progress, there are still a series of problems, such as loss of layer caused by laser ablation, incomplete chemical etching of SiN film, complex electroless plating process, etc.

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