Preparation method of spherical silver powder for photovoltaic positive silver electrode

Abstract

The invention relates to a preparation method of spherical silver powder for a photovoltaic positive silver electrode. The spherical silver powder prepared through the method is high in dispersity, high in sphericity and high in tap density; the particle size ranges from 1-3 microns, and the spherical silver powder is subjected to narrow particle size distribution. The method comprises the steps of adding a thickening agent and a dispersing agent to a prepared silver-ammonia solution; controlling system temperature and adding a weak reductant to an ultrasonic water bath kettle; and reducing toobtain the high-dispersity and high-density spherical silver powder. The silver powder is used for preparing photovoltaic positive silver electrode sizing, and uniform silver-silicon contact is realized after sintering; and meanwhile, the silver powder is high in photoelectric conversion efficiency and stable electricity performance.

Description

technical field [0001] The invention belongs to the technical field of photovoltaics, and in particular relates to a method for preparing spherical silver powder for photovoltaic positive silver electrodes. Background technique [0002] Solar conductive silver paste is the main raw material for manufacturing solar cells, and its preparation technology is the key to high-efficiency and low-cost solar cells. In recent years, with the development of my country's photovoltaic industry, the pace of development of conductive silver paste has been accelerating. Through the improvement of paste technology, the purity of silicon materials, the optimization of the grid line and the configuration of the bottom plate, the efficiency of solar cell paste has gradually increased from the initial 12% to 13%, and there will be an increase of 0.5% to 1% every year after 2002. , At present, the efficiency of monocrystalline silicon cells has reached more than 18%. Generally speaking, the tec...

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Problems solved by technology

If the particle size of the silver powder is too small, it will start to melt at the initial stage of sintering, which is not conducive to the corrosion of the SiN layer by the liquefied binder phase through the capillary flow between particles, making it difficult to form an ideal silver-silicon contact; if the particle size of the silver powder is too large, the silver particles will sinter The activity decreases and the wire resistance of the electrode increases

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