Aluminum conductive paste for silicon solar cell back surface field and preparation method thereof

Abstract

The invention relates to aluminum conductive paste for a silicon solar cell back surface field and a preparation method thereof. The paste is prepared by dissolving ethyl cellulose into terpineol, adding organic solvent and additive into the mixture, then stirring the solution, adding aluminum powder, stannum powder, gallium powder, stibium powder and magnalium alloy powder, stirring the solutionand rolling by a three-roller muller. A silicon solar cell prepared by the paste has high photoelectric conversion efficiency, good conductivity of an aluminum film, smooth surface, no aluminum pills, no foaming and firm attachment of an aluminum sheet. In the invention, the stannum powder is used as inorganic binder and has extremely little pollution to silicon sheet heavy metal ions accordingly, and a manufactured solar cell has slower declination during using. The invention solves the problems of poor conductivity, bend silicon sheet, heavy metal pollution and the like existing in an aluminum film made of aluminum paste in the prior silicon solar cell. The aluminum conductive paste is especially suitable for fast sintering process in the prior silicon solar cell production line.

Description

technical field [0001] The invention relates to a conductive paste and a preparation method thereof, more specifically, the present invention relates to an aluminum conductive paste for the back field of a silicon solar cell and a preparation method thereof. Background technique [0002] Silicon solar cell is a kind of clean and environment-friendly renewable energy. With the consumption of non-renewable energy, the utilization of renewable energy has been paid more and more attention by various countries. It is a hotspot of international research. What everyone pursues is to improve the photoelectric conversion efficiency. The aluminum conductive paste is used to make the back field of silicon solar cells, which affects the photoelectric conversion efficiency of silicon solar cells. The sintered aluminum film must be firmly attached, the silicon wafer should not be bent, dust free, aluminum beads should not be free, and the surface should be smooth. It is also necessary to...

AI Technical Summary

Problems solved by technology

[0003] At present, glass powder is added or has glass powder components after sintering in the existing technologies, such as patents with application numbers 200580018265. Powder and silicon wafer, and glass powder will affect the conductivity of aluminum paste, and glass powder contains a variety of metal ions, and the diffusion of some metal components in silicon is much higher than that of aluminum, destroying the PN junction of silicon wafers and accelerating the development of silicon solar cells At the same time, the glass powder is brittle, and it is easier to bend and strain the silicon wafer