All-aluminum back-field back silver paste, preparation method thereof, and application thereof

Abstract

The invention discloses an all-aluminum back-field back silver paste, a preparation method thereof, and an application thereof. The all-aluminum back-field back silver paste comprises the follow materials of, by weight, 10 to 80 parts of specially required silver powder with the purity larger than 99.99%, 0.5 to 5 parts of self-made lead-free main body glass powder, 0 to 3 parts of low-melting-point auxiliary glass powder, 1 to 50 parts of specially required low-melting-point metal powder, 15 to 50 parts of organic binders, and 0.01 to 1 part of organic auxiliary. The all-aluminum back-field back silver paste can be directly printed on an aluminum back-field paste, the considerable welding tensile force and aging tensile force of the all-aluminum back-field back silver paste are guaranteed, a serious electric leakage problem caused by a metal defect generated by the direct contact between silver and a silicon wafer is avoided, therefore, the photoelectric conversion efficiency of a crystalline silicon battery is improved, the width of a back electrode and a printed pattern can be adjusted at will, and therefore, the cost of a back electrode paste is reduced.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and in particular relates to an all-aluminum back field back silver paste and a preparation method and application thereof. Background technique [0002] The conventional back silver paste is directly printed on the surface of the silicon wafer, and then the back aluminum is printed in parallel, and the electrode, the back aluminum and the silicon wafer form ohmic contact through sintering. This kind of battery has the following defects, mainly that the back electrode is directly printed on the silicon wafer to form an ohmic contact, and the silver electrode is easy to form metal defects in the silicon wafer, making the electrode a serious leakage area and reducing the photoelectric conversion efficiency of the solar cell ( 0.1-0.2%); the edge of the back electrode needs to be covered by the aluminum back field, which increases the width of the back electrode and increases the cost of the bac...

AI Technical Summary

Problems solved by technology

This kind of battery has the following defects, mainly that the back electrode is directly printed on the silicon wafer to form an ohmic contact, and the silver electrode is easy to form metal defects in the silicon wafer, making the electrode a serious leakage area and reducing the photoelectric conversion efficiency of the solar cell ( 0.1~0.2%); the edge of the back electrode needs to be covered by the aluminum back field, which increases the width of the back electrode and increases the cost of the back electrode paste

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