A kind of negative leveling agent used for electroplating copper on the front electrode of solar cell

Abstract

The invention discloses a negative leveling agent for electroplating copper on front electrodes of solar cells. The concentration of polysulfide organic sulfonate is 0.02-0.1g / L, and the concentration of composite surfactant is 0.70-1.3g / L. The concentration of chloride ions is 8-25mg / L, and the concentration of azo-based dyes is 0.1-1g / L; the negative leveling agent of the present invention refines the crystal grains through polysulfur organic sulfonate, and improves the level of the plating solution through composite surfactants. Excellent deep plating ability, negative leveling ability achieved by chloride ions and azo-based dyes, by changing the composition of the electroplating solution and adding an appropriate negative leveling agent, the current higher than the two edges of the seed layer can be obtained at the micropeak of the seed layer Density, so that the thickness of the coating at this place is higher than that of the coating on both sides of the seed layer, so as to realize the selective growth of the coating in different directions, so that the growth rate of the seed layer of the front electrode of the solar cell in the vertical direction is higher than that in the horizontal direction. The electrode with good electrical performance minimizes the increase of the light-receiving area, reduces the shading loss, and improves the overall efficiency of the battery.

Description

technical field [0001] The invention relates to the field of solar cell manufacturing technology, in particular to a front electrode electroplating copper process. Background technique [0002] At present, the electrodes of crystalline silicon solar cells are mainly made of silver. If copper can be used as the main conductive layer of solar cell electrodes with a conductivity comparable to that of silver, but the price is low, it will greatly reduce the manufacturing cost of solar cells. Due to its simple equipment and mature process, screen printing has become the mainstream electrode preparation technology for crystalline silicon solar cells. However, with the continuous increase in the efficiency of solar cells, the requirements for battery electrodes, especially the front electrodes, are becoming more and more stringent. The traditional screen printing method is limited by its technical principles, and it is difficult to achieve narrow line width and low resistance of hi...

AI Technical Summary

Problems solved by technology

However, the traditional electroplating process will cover the surface of the seed layer with a uniform thickness of the plating layer, and the width of the electrode increases as the thickness increases. Since the front electrode is generally located on the light-receiving surface of the solar cell, the increase in the electrode width will reduce the light-receiving area of ​​the cell. thereby reducing short-circuit current and efficiency