High-adhesion low-warpage crystalline silicon cell back side aluminum slurry

Abstract

The invention discloses a high-adhesion low-warpage crystalline silicon cell back side aluminum slurry. The aluminum slurry comprises, in percentage by weight, 60-80% of aluminum powder, 0.1-6% of glass powder, 15-35% of an organic carrier and 0.1 to 5% of an additive, wherein the additive is an organic matter containing a metal source. The additive, during a slurry processing or sintering process, is subjected to volatilization, decomposition and a reaction to generate metal oxides, nitrides and carbide particles which are in nanometer forms, have expansion coefficients smaller than 10*10-6 K, and have heat expansion coefficients close to the heat expansion coefficient of silicon, and nanometer particles are inlaid among aluminum powder particles in the aluminum slurry so that while back field adhesion and back field passivation are guaranteed, the low warpage of a solar cell back side aluminum slurry is realized.

Description

technical field [0001] The invention belongs to the field of aluminum paste on the back of a crystalline silicon battery, in particular to an aluminum paste on the back of a crystalline silicon battery with high adhesion and low warpage. Background technique [0002] A solar cell is a semiconductor device that can convert solar energy into electrical energy. Under the condition of light, a photogenerated current will be generated inside the solar cell, and the electrical energy can be output through the electrodes. A solar cell structure with P-type silicon typically has its negative electrode on the front side of the cell and its positive electrode on the back. When illuminated with light, radiation of the appropriate wavelength results in the creation of hole-electron pairs in the semiconductor. The potential difference that exists across the P-N junction causes holes and electrons to migrate across the junction in opposite directions, creating a flow of current that tran...

AI Technical Summary

Problems solved by technology

With the thinning trend of solar cell technology, the warping of silicon wafers will cause a significant decrease in yield

There are usually three ways to reduce battery warpage: 1. Reduce the wet weight of aluminum paste printing, that is, reduce the weight of aluminum paste printed on the back of the battery by increasing the printing pressure, etc. This method has limited space for reducing, and at the same time because of the weight of aluminum paste Reduce the passivation performance of weakening the aluminum back field; 2. Reduce the thermal expansion coefficient of Al-Si, by adding additives with low or negative expansion coefficients to the aluminum paste, the effect of this method is not obvious and the additives are more expensive

3. Reduce the interaction of aluminum paste particles. This method can greatly reduce the warpage of silicon wafers. It is achieved by changing the composition and quantity of glass frit, but it will lead to weak adhesion of aluminum paste and weaken the passivation ability of the back field. Seriously affect the mechanical and electrical performance of the battery

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