Back junction and back contact solar cell structure and preparation method thereof

Abstract

The invention provides a back junction and back contact solar cell structure and a preparation method thereof. The cell structure sequentially comprises an anti-reflection layer (1), a passivation film (2), an N+ doped layer (3), an N type silicon substrate (4), a back P+ doped layer (5), a Topcon structure and cell electrodes from top to bottom, wherein the back P+ doped layer (5) and the Topconstructure are distributed on the same layer in a crossed manner, the Topcon structure comprises an ultrathin oxide layer (6) and an N+ polycrystalline silicon / amorphous silicon layer (7), the cell electrodes comprise a positive electrode (8) and a negative electrode (9), the positive electrode (8) is in contact with the P+ doped layer (5), and the negative electrode (9) is in contact with the N+ polycrystalline silicon / amorphous silicon layer (7). According to the invention, the N+ back doped region of the back doped layer in the prior art is changed into the Topcon structure, so that the complexity of the technological process is not increased while the voltage of the battery is increased, and the kilowatt-hour cost of the battery is 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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