Heterojunction cell low-temperature silver paste and preparation method thereof

Abstract

The invention discloses heterojunction cell low-temperature silver paste, which comprises the following raw materials by weight: 1%-3% of nano spherical silver powder, 2%-4% of nano spherical silver wires, 5%-12% of flake silver powder, 75%-80% of spherical silver powder, 1%-5% of epoxy resin, 1%-2% of hydroxymethyl cellulose, 0.5%-1% of a coupling agent, 0.5%-1% of a leveling agent, 0.2%-0.8% ofa surfactant, 0.5%-1% of a dispersant and 25%-35% of an organic solvent. The heterojunction cell low-temperature silver paste provided by the invention creatively chooses four kinds of silver powder with different shapes and different specifications for matching, each kinds of silver powder takes its advantages to reduce the contact resistance, the flake silver powder ensures a certain welding tension, the resistance after sintering is greatly reduced through the contact between surfaces, and a good contact effect with ITO on the upper layer of an amorphous silicon film of the HIT is achieved.

Description

technical field [0001] The invention relates to the technical field of conductive silver paste for heterojunction solar cells (HIT), in particular to a low-temperature silver paste for heterojunction solar cells and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of solar photovoltaic applications, in the field of renewable energy in my country, wind power and hydropower go hand in hand, and occupy the main market; at the same time, due to the strong support of the country, solar photovoltaic will continue its strong momentum. Sensitized solar cells are the main , of which silicon-based solar cells occupy more than 90% of the market. [0003] At present, the mainstream of the international market is still focusing on monocrystalline PERC and polycrystalline PERC. The mass production efficiency of monocrystalline PERC cells from first-class manufacturers can reach 22%. However, due to the limitations of raw materials and ...

AI Technical Summary

Problems solved by technology

The surface or line contact between the flake silver powder can improve the conductivity of the silver paste and obtain high conductivity with low silver content. It is mostly used in electronic components such as membrane switches and filters, but the printing adaptability will decrease

Spherical silver powder relies on point-to-point contact, has fluidity and rheology, and has good printing adaptability. The disadvantage is that the conductivity is slightly low. If the sintering temperature is too high, the silver powder particles will shrink greatly, and the tap density will be low. It leads to high series resistance, and if the formulation does not match, the high solid content will cause agglomeration during the paste process and storage and affect the printing effect

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