Silver paste used for positive electrodes of solar batteries and grid lines, preparation method thereof and solar battery containing same

Abstract

The invention discloses a silver paste used for positive electrodes of solar batteries and grid lines, which comprises silver powder, glass powder, additive and an organic carrier. The silver paste is prepared by the following steps of: preparing a highly dispersed superfine silver grout used as the silver powder through a chemical liquid phase reduction method, then obtaining wet silver powder through solid-liquid separation, and preparing the agglomerate-free silver paste through direct mixing of the wet silver powder and the glass powder, the additive and the organic carrier according to the specified proportion without drying. The method for preparing the positive silver paste directly by using the wet silver powder comprises the steps of: preparation of the superfine silver powder through the chemical liquid phase reduction method, solid-liquid separation, washing, and direct preparation of the silver paste without a drying procedure in which the silver powder is easily agglomerated. The silver paste is characterized by high dispersity, no agglomeration and smaller fineness; and positive electrodes of solar batteries and grid lines, prepared through the screen printing and fast sintering process, have high definition, high evenness, high electrical conductivity and excellent photoelectric conversion efficiency.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and relates to a conductive silver paste for front electrodes and grid lines of solar cells prepared from wet silver powder, a preparation method thereof, and a solar cell prepared with the silver paste. Background technique [0002] Solar energy is a kind of green energy. People pay more and more attention to it because of its advantages of no pollution, inexhaustibility, and no limitation of geographical resources. Therefore, solar cells have emerged as the times require. A solar cell is a semiconductor device that can convert solar energy into electrical energy. Under the condition of light, the solar cell will generate current, collect and transmit electricity through grid lines and electrodes. The front electrodes and grid lines of solar cells are made of conductive silver paste through high-speed and high-precision screen printing, low-temperature drying, and high-temperature sintering....

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is that the silver powder existing in the prior art is easy to form agglomerates during the drying process, especially hard agglomerates, so that it is difficult for the prepared silver paste to pass through the screen during the screen printing process, resulting in blockage. The wire mesh makes the electrodes and the grid lines form breakpoints and broken lines, which makes it difficult to effectively transmit the current generated by the battery sheet, and finally makes the photoelectric conversion efficiency low. These defects provide a silver paste for the preparation of solar cell front electrodes and grid lines. Its preparation method and the solar cell prepared by containing the silver paste, the silver powder in the silver paste adopts wet silver powder, the wet silver powder does not have agglomeration phenomenon, and the prepared silver paste has no hard aggregates and no Or soft agglomerates are not easy to appear, and during the screen printing process, there will be no clogging of the screen, so that there are no breaks and disconnections in the electrodes and grid lines, and excellent solar cells can be obtained

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