Back-contact solar cell and preparation method thereof

Abstract

The invention relates to a back-contact solar cell. The cell comprises a P-type crystal silicon matrix, the back surface orderly comprises a tunneling oxide layer, back n+doped polycrystalline siliconregion and a laser slotting region in alternative arrangement, a passivation film, and a metal electrode from inside to outside; the metal electrode comprises a silver electrode in ohmic contact withback surface n+doped polycrystalline silicon region and an aluminum electrode in ohmic contact with back surface laser slotting region; the front surface is a p+doped region and a front surface passivation anti-reflection film from inside to outside in order. The solar cell disclosed by the invention has the advantages that the transmitter region on the back surface of the P-type crystalline silicon matrix adopts the n+doped polycrystalline silicon passivation layer, the back surface forms a p+region by adopting an aluminum paste and is passivated by using the aluminum oxide film, thereby realizing the passivation contact and field passivation effect of the back surface, the composite rate of the cell back surface is reduced, and the open-circuit voltage and the short-circuit current areimproved; the back p+region is formed by using the aluminum paste, in comparison with the traditional process, the one-step diffusion doping step is reduced, the process flow is simplified, and the cell cost is saved.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a back-contact solar cell and a preparation method thereof. Background technique [0002] A solar cell is a semiconductor device that converts light energy into electrical energy. Lower production costs and higher energy conversion efficiency have always been the goals pursued by the solar cell industry. For conventional solar cells, the p+ doped region contact electrodes and the n+ doped region contact electrodes are respectively located on the front and back sides of the battery sheet. The front of the battery is the light-receiving surface, and the coverage of the metal contact electrodes on the front will inevitably cause a part of the incident sunlight to be blocked and reflected by the metal electrodes, resulting in a part of optical loss. The coverage area of ​​the front metal electrode of an ordinary crystalline silicon solar cell is about 7%, and reducing the front ...

AI Technical Summary

Problems solved by technology

In addition, the multi-step diffusion and silver paste printing in the preparation process of the back contact battery is an important factor that leads to the relatively high cost of this high-efficiency battery.

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