Solar aluminum conductor paste and preparation method thereof

Abstract

The invention discloses solar aluminum conductor paste. The solar aluminum conductor paste comprises the constituents based on percent by mass: 60-80% of aluminum powder, 0.5-10% of lead-free glass powder, 18-36% of organic carrier and 0.01-5% of additive, wherein the additive is selected from at least one of elements B, Ga and In, an inorganic compound containing Ga and In and a solid solution, and the additive is a coating additive of which a surface is coated with the lead-free glass powder by grinding. In the solar aluminum conductor paste, the additive is more uniformly dispersed in the aluminum paste by improving a morphology and contact mode of the additive in the aluminum paste, the glass powder is more stable to coat around the aluminum paste, a surface crystal boundary morphology of a solid solution crystal after smashing is maintained, ohmic contact performance of an aluminum layer and a silicon wafer is favorably improved, and the conductivity and the photoelectric conversion efficiency of a solar cell are further improved. The invention also discloses a preparation method of the solar aluminum conductor paste.

Description

Technical field [0001] The invention relates to the technical field of electronic pastes, in particular to a solar aluminum conductor paste and a preparation method thereof. Background technique [0002] In the manufacture of crystalline silicon solar cells, the aluminum paste is printed on the back of the silicon wafer by using a silk screen. After drying, sintering, cooling and other processes, a silicon-aluminum alloy layer can be formed between the silicon substrate and the aluminum layer to eliminate the silicon wafer. The Schottky barrier between the electrode and the electrode achieves a good ohmic contact, and the silicon epitaxial growth layer doped with aluminum, that is, the back field layer, is formed on the cooled silicon wafer to increase the open circuit voltage of the battery and improve the photoelectric conversion effectiveness. The width of the sintering process window of the back aluminum paste and the production cost are important indicators for considering ...

AI Technical Summary

Problems solved by technology

In actual production, the trivalent organometallic compound has better dispersion, but it is easy to volatilize during the sintering process, which affects the density of the aluminum layer and is not conducive to the improvement of the electrical performance of the cell.

In addition, since the mixed form of boron, gallium, indium, and thallium metal elements in the aluminum paste is directly dispersed, the above-mentioned micropowders are similar to aluminum powders, and both have high surface energy, which is prone to agglomeration of metal powders. The density of thallium is greater than that of aluminum powder, so the doping of dopant in the silicon aluminum alloy layer is not uniform, which is not conducive to the formation of ohmic contact

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