Grid line-free full-back contact solar cell module

Abstract

The invention discloses a grid line-free full-back contact solar cell module. The grid line-free full-back contact solar cell module comprises a plurality of back-contact solar small battery pieces which are connected in series, wherein the small battery pieces are obtained through cutting a back-contact solar battery piece; the back-contact solar battery piece comprises an n-type silicon substrate; a p+ doping area and an n+ doping area are arranged on the back of the n-type silicon substrate; a back passivation layer is arranged on the p+ doping area and the n+ doping area; a positive electrode contact part and a negative electrode contact part are arranged on the back passivation layer; soldering tin or conducting adhesive covers on the positive electrode contact parts and the negative electrode contact parts; when two adjacent small battery pieces are connected in series, a copper wire is arranged on the soldering tin or the conducting adhesive of the positive electrode contact part and a copper wire is arranged on the soldering tin or the conducting adhesive of the negative electrode contact part; and every two adjacent battery pieces are directly connected in series through the copper wires, or every two adjacent small battery pieces are connected in series through the copper wires or solder strips. The cell module not only ca enhance the reliability of the full-back contact battery module, but also can reduce the process difficulty and manufacturing cost of the full-back contact battery module.

Description

technical field [0001] The invention belongs to the field of solar cells, and in particular relates to a grid-line-free full-back contact solar cell assembly. Background technique [0002] A solar cell is a semiconductor device that converts light energy into electrical energy. Lower production costs and higher energy conversion efficiency have always been the goals pursued by the solar cell industry. For conventional solar cells at present, the positive electrode contact electrode and the negative electrode contact electrode are respectively located on the front and back sides of the battery sheet. The front of the battery is the light-receiving surface, and the coverage of the metal positive electrode on the front will inevitably cause a part of the incident sunlight to be reflected by the metal electrode, resulting in a part of optical loss. The coverage area of ​​the front metal electrode of an ordinary crystalline silicon solar cell is about 7%, and reducing the front ...

AI Technical Summary

Problems solved by technology

In the previous production process of full back contact solar cells, the metallization process is mostly realized by electroplating with a relatively complicated process. This method does have excellent performance in reducing the series resistance of back contact cells and increasing the open circuit voltage of cells. The process is complicated, the waste discharged seriously pollutes the environment, and is incompatible with the mainstream metallization method for industrial production of solar cells, so it is difficult to promote low-cost industrialization

[0005] The metallization of the back contact battery using the current mainstream screen printing technology, if the conventional busbar design is used, there are two main problems: (1) between the busbar and the opposite electrode fine grid and the busbar The insulation between the doped regions corresponding to the opposite electrodes; (2) Because the current of the full back contact battery is significantly higher than that of the conventional battery, in order to reduce the power loss caused by the line resistance on the main grid line and the fine grid line, it is necessary to use a wider Grid lines, more slurry consumption brings a sharp rise in cost

However, the disadvantage of this method is that due to the lateral transmission distance, the electrons corresponding to the position of the main grid of the positive electrode are difficult to be collected by the negative electrode, and the holes corresponding to the position of the main grid of the negative electrode are difficult to be collected by the positive electrode.

In this way, the fill factor and photoelectric conversion efficiency of the battery are greatly affected

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