Silver-aluminum paste for P + electrode of solar cell and solar cell

Abstract

The invention provides silver-aluminum paste for a P + electrode of a solar cell and the solar cell. The silver-aluminum paste for the P + electrode of the solar cell comprises conductive silver powder, aluminum powder or aluminum-containing alloy, inorganic powder, an organic carrier and alloy-containing or non-containing powder, wherein the inorganic powder contains boron oxide and selenium oxide, and the inorganic powder does not contain tellurium element and tellurium-containing compound. According to the silver-aluminum paste for the P + electrode of the solar cell, a B-Se-O glass system is adopted, and compared with an existing Pb-B-O glass system, the B-Se-O glass system has the advantages of being high in glass fluidity and milder in etching reaction; in the sintering process, the glass of the B-Se-O system can be rapidly liquefied and flow, and more and thinner contact area is formed between the glass of the B-Se-O system and the surface of a cell piece, so that while the passivation layer is eliminated, the damage to the p-n junction can be obviously reduced, and the recombination can be reduced; and meanwhile, the effects of improving the open-circuit voltage, reducing the contact resistance, improving the filling factor and finally improving the conversion efficiency can be achieved.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a silver-aluminum paste for a solar cell P+ electrode and a solar cell. Background technique [0002] In the field of solar cells, there are two types of crystalline silicon cells, P-type and N-type. Although P-type crystalline silicon cells currently occupy a major market share, N-type crystalline silicon cells are increasingly favored by the market due to their high carrier life and reduced light-induced attenuation. At present, N-PERT (emitter junction passivation and back field full diffusion), nTOPCon (tunneling oxidation passivation contact), HJT (heterojunction) and IBC (full back electrode contact) are the main battery design schemes of N-type batteries. . [0003] In order to further improve the conversion efficiency of the battery, passivation layers with different thicknesses and structures have been improved and applied to N-type batteries. This poses a challenge to the ...

AI Technical Summary

Problems solved by technology

However, as the difficulty of etching the passivation insulating layer increases, simply changing the concentration of lead or boron glass, or increasing the percentage of aluminum powder, is prone to excessive etching recombination and poor glass wetting, which will lead to an increase in contact resistance. High, open circuit voltage loss, lower photoelectric conversion efficiency and other issues

[0004] Different from the contact of the n-electrode in the P-type battery, Pb-Te-O glass, which is commonly used with the most balanced fluidity and etching properties, cannot be used on the p+ electrode of the N-type battery due to its strong oxidizing ability to elements such as aluminum powder.

Although thallium-containing glass is also widely used in N-type batteries, it is not considered in the present invention due to the risk of easy toxicity in its preparation and use.

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