Aluminized BSF secondary sintering technology for crystal silicon solar cell

Abstract

The invention discloses an aluminized BSF secondary sintering technology for a crystal silicon solar cell. The technology utilizes a laser beam or a microwave beam in a pulse mode to scan or integrally scan an aluminized BSF region at the back of the cell so that aluminum in a scanning region is instantaneously heated and melted and diffuses to a silica body; and a whole or partial aluminum heavily-doped region is formed at the back of the solar cell so as to form a BSF with excellent performance, thereby accelerating the diffusion of minority carriers, improving the collection ratio of the minority carriers, improving the long-wave response of the cell and further improving the whole efficiency of the cell. The technology can control the thermal influence of secondary sintering on the periphery of an aluminum layer so as not to generate obvious adverse influence on other parts of the cell, has various flexible laser sintering design modes, is simple, convenient and rapid to manufacture and can be rapidly combined with the prior industrial production.

Description

technical field [0001] The invention relates to a method for secondary sintering of an aluminum back field of a crystalline silicon solar cell, in particular to a method for secondary sintering of an aluminum layer on the back of a polycrystalline silicon solar cell by using a pulse heat source such as laser or microwave to form a high-performance aluminum back field method. Background technique [0002] Silicon solar cells use p-n junction photovoltaic effect to realize photoelectric conversion, which has become one of the mainstreams of new energy development. In 2008, crystalline silicon solar cells accounted for about 90% of the world's total output of solar cells, and will continue to occupy the mainstream position in the market for a period of time in the future. Most of the crystalline silicon solar cells are made of p-type silicon wafers, and the back is screen-printed. The aluminum layer diffuses aluminum into the silicon matrix through a rapid sintering furnace to...

AI Technical Summary

Problems solved by technology

However, in actual battery production, too high a sintering temperature will adversely affect the performance of other parts of the battery, such as increasing the propagation and diffusion of silicon defects and impurities, and deteriorating the performance of the surface silicon nitride film. The most serious is sintering. During the process, the front electrode burns through the p-n junction, causing serious leakage and battery scrapping

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