A back-junction back-contact solar cell structure and preparation method thereof

Abstract

The present patent provides a back-junction back-contact solar cell structure and a preparation method thereof. The cell structure includes, from top to bottom, an antireflection layer (1), a passivation film (2), an N+ doped layer ( 3), an N-type silicon substrate (4), a P+ doped layer (5) on the back side, a Topcon structure and a battery electrode; the back P+ doped layer (5) and the Topcon structure are cross-distributed in the same layer; the The Topcon structure is an ultra-thin oxide layer (6) and an N+ polysilicon / amorphous silicon layer (7); the battery electrode includes a positive electrode (8) and a negative electrode (9); the positive electrode (8) is doped with P+ The layer (5) is in contact; the negative electrode (9) is in contact with the N+ polysilicon / amorphous silicon layer (7). By changing the N+ back doping area of ​​the back doping layer in the prior art to a Topcon structure, the battery open voltage can be improved without increasing the complexity of the process flow, and the LCOE of the battery can be fundamentally reduced.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to back-junction and back-contact solar cells. Background technique [0002] With the continuous improvement of solar cells in texturing, diffusion, number of grid lines and paste, the efficiency of solar cells has been greatly improved. Compared with other cell types, back-junction back-contact solar cells have improved short-circuit current due to the gain in light absorption due to placing the electrode grid lines on the back side. However, in terms of optimizing the open circuit voltage, in addition to the commonly used method of increasing the diffusion resistance and the number of busbars, the present invention proposes a Topcon back-junction back-contact solar cell structure and its preparation method, which avoids the N+ doping area. The carrier recombination when in contact with the metal improves the conversion efficiency of the battery. At the same time, the battery productio...

AI Technical Summary

Problems solved by technology

[0003] At present, the technical process of back-junction and back-contact solar cells is relatively complicated and the production cost remains high. In view of this situation, the present invention improves the efficiency of the battery by changing the structure of the battery and the process preparation method, and at the same time reduces the production cost of the battery due to the simplification of the technical process.

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