A kind of preparation method of local passivation contact structure

Abstract

The invention relates to a method for preparing a local passivation contact structure, comprising growing a tunnel oxide layer and an amorphous silicon layer, partially printing a doping paste on the amorphous silicon layer, high-temperature annealing and oxidation, and removing an oxide layer in a non-doped region 1. Removing the polysilicon layer in the non-doped region by alkali etching to form a local passivation contact structure. The local passivation contact structure of the present invention greatly expands the application range of the passivation contact, making it no longer limited to the light-receiving surface. At the same time, the preparation method of the local passivation contact structure of the present invention can form a local structure without additional mask steps, the method has a large process window, is easy to implement, and is very suitable for industrial promotion.

Description

Technical field [0001] The present invention relates to the field of solar cell technology, and more particularly to a method of preparing a local passivation contact structure. Background technique [0002] The surface passivation of the crystalline silicon solar cell has always been the key to design and optimization. From the early stage, only the backdrop field is passivated, to the front silicon nitride passivation, and then introduce a perc / perl design such as a passivation partial opening in which silicon oxide, aluminum oxide, silicon nitride, etc.. Although this structure temporarily eases the problem of back passivation, it is not eradicated, and the high composite rate at the opening is still present, and the process is further complicated. Although the battery of the Perc and Perl structure has a relatively perfect surface passivation structure, but the contact range of the back is limited to the opening area, in addition to adding the complexity of the process, the...

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Problems solved by technology

[0004] However, the doped polysilicon layer in the passivation contact structure has a high extinction coefficient and has a high absorption of visible light. When the doped polysilicon layer is located on the light-receiving surface of the battery, it will significantly reduce the short-circuit current of the battery. Based on this For one reason, the current passivation contact structure is located on the non-light-receiving surface of the battery, which will greatly limit the application range of the advanced structure of passivation contact

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