Isolation material, cell back field back electrode and production method thereof, solar cell and production method thereof

Abstract

The invention discloses an isolation material, a cell back field back electrode and a production method thereof, a solar cell and a production method thereof, and belongs to the technical field of crystalline silicon solar cell production. The back field back electrode comprises a silicon back substrate, an aluminum electrode and a silver electrode, the aluminum electrode is arranged on the silicon back substrate, the silver electrode is arranged on the aluminum electrode, an isolation layer is arranged between the silver electrode and the aluminum electrode, and the isolation layer is composed of a glass powder, an auxiliary powder, an organic carrier and auxiliaries. The weight percentage of the glass powder is 35-80%, the weight percentage of the auxiliary powder is 0.5-25%, and the weight percentage of the organic carrier and the auxiliaries is 15-45%. The isolation layer is inserted between the silver electrode and the aluminum electrode to block direct contact between the silver electrode and the aluminum electrode so that mutual permeation of a silver paste and an aluminum paste in a sintering process is effectively isolated, and the improvement or solution of the all-aluminum back field battery on performances such as battery quality, assembly welding, reliability and the like is realized.

Description

technical field [0001] The invention relates to the technical field of preparation of crystalline silicon solar cells, and more specifically relates to an isolation material, a battery back field back electrode and a preparation method, a solar cell and a preparation method. Background technique [0002] At present, electrodes of solar cells are mainly prepared by screen printing. combine Figure 1-Figure 3 , the back electrode is composed of an aluminum electrode main grid 12, an aluminum electrode sub-grid 13 and a silver electrode 14, and the silver and aluminum electrodes are partially overlapped to form an overlapping area 16 to realize mutual connection. The aluminum electrode mainly collects the carriers on the back of the cell, and then conducts the current through the silver electrode. For single-sided batteries, the aluminum electrode area is designed with full aluminum coverage to reduce the resistance of the aluminum electrodes and improve collection efficiency;...

AI Technical Summary

Problems solved by technology

③ In the overlapping area of ​​silver and aluminum electrodes, it is also easy to form a dense structure, thereby reducing the resistivity of the electrode area

[0004] But there are also the following deficiencies: ①The contact resistance is large and the recombination is serious

The direct contact between the silver electrode and the silicon substrate makes the recombination of carriers in the silver electrode area due to the gold-semi-contact of silver and silicon. Even with the current passivation structure on the back of the PERC cell, the back silver paste still burns through the back dielectric The case where the layer is in contact with the wafer substrate

②Blank area for current collection: For PERC batteries, when the silver electrode area is laser-grooved, it will cause thermal stress during component welding and lead to high fragmentation rate. Therefore, no laser is often used in the back silver electrode area and its surrounding Slots solve this problem, but this creates a blank area for current collection

[0007] However, the all-aluminum back field solution of the authorized patent CN201110208995.7 has the problem of low silver electrode tension or direct welding failure, which cannot meet the welding requirements of components.

The all-aluminum back field solution of the patent CN201810739434.1 solves the problem of component welding, but there is a problem of failure of component cold and hot cycle tests

In addition, the current electrode preparation method of printing silver electrodes first and then printing aluminum backfields has problems such as blank areas for current collection, and there is room for improvement in the conversion efficiency of cells; and the current all-aluminum backfield solutions all have battery quality or The lack of reliability requires further improvement and optimization before it can be promoted and used

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