Solar cell and preparation method thereof

Abstract

The invention discloses a solar cell and a preparation method of the solar cell. The preparation method of the solar cell comprises the following steps: sequentially forming a tunneling silicon oxide layer, an N-type doped polycrystalline silicon layer and a back passivation anti-reflection film on the back surface of an N-type silicon substrate; grooving the back passivation anti-reflection film, and forming a nickel metal layer in a grooving area; printing a back fine gate electrode on the nickel metal layer, printing a back main gate electrode on the back passivation anti-reflection film, and electrically connecting the back fine gate electrode with the back main gate electrode. According to the preparation method, the binding force between the metal gate line and silicon can be ensured, meanwhile, the damage of the slurry to the thin polycrystalline silicon layer in the using process is avoided, the passivation effect of the passivation contact structure is ensured, the manufacturing cost of the solar cell is reduced, parasitic light absorption is reduced, and the light utilization efficiency is improved. And the efficiency of the solar cell is improved.

Description

technical field [0001] The invention relates to a solar cell and a preparation method of the solar cell. Background technique [0002] PERC (Passivated Emitter and Rear Cell, Passivated Emitter and Rear Cell) solar cells use a silicon oxide layer passivation on the back surface of the silicon substrate, and local openings to achieve point contact to reduce the area of ​​​​the non-passivation area, through local metal contact , greatly reducing the recombination speed of the back surface, while improving the light reflection of the back surface and improving the conversion efficiency of the solar cell. Passivated contact solar cells (such as TOPCon (Tunnel Oxide Passivated Contact, tunneling oxidation passivated contact) solar cells) adopt a passivated contact structure composed of a tunneling silicon oxide layer and a doped polysilicon layer, which can effectively reduce surface recombination and Metal contact compounding improves the conversion efficiency of the battery. ...

AI Technical Summary

Problems solved by technology

However, due to the low content of silver in the earth's crust and the relatively high price, the production cost of solar cells is relatively high; at the same time, since it is often necessary to corrode part of the silicon through the glass frit in the silver paste to form an ohmic contact, the junction depth requirements for diffusion Deeper, if used to passivate contact cells, a thicker polysilicon layer is required

If aluminum paste is used instead of silver paste to reduce costs, it is difficult to ensure that the thin polysilicon layer will not be damaged when the glass frit in aluminum paste reacts with silicon under high temperature conditions

The thicker polysilicon layer not only increases the manufacturing cost of solar cells, but also increases the parasitic light absorption, reduces the light utilization efficiency, and limits the efficiency of solar cells.

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