Solar cell and preparation method thereof

Abstract

The application discloses a solar cell, comprising: a silicon substrate; a diffusion layer located on a first surface of the silicon substrate; a first passivation layer located on the surface, away from the silicon substrate, of the diffusion layer; a silicon oxynitride layer located on the surface, away from the diffusion layer, of the first passivation layer; an antireflection layer located onthe surface, away from the first passivation layer, of the silicon oxynitride layer; a first electrode located on the surface, away from the silicon oxynitride layer, of the antireflection layer; a tunneling layer located on a second surface of the silicon substrate; a doped polysilicon layer located on the surface, away from the silicon substrate, of the tunneling layer; a second passivation layer located on the surface, away from the tunneling layer, of the doped polysilicon layer; and a second electrode located on the surface, away from the doped polysilicon layer, of the second passivationlayer. The solar cell in the application is provided with the silicon oxynitride layer, which acts together with the antireflection layer. The silicon oxynitride layer not only has a passivation effect and enhances the passivation of the diffusion layer, but also has the antireflection characteristic, enhances the antireflection effect and improves the conversion efficiency of the cell. The application also provides a preparation method with the advantages.

Description

technical field [0001] The present application relates to the technical field of solar cells, in particular to a solar cell and a preparation method thereof. Background technique [0002] Tunnel Oxide Passivated Contact (TOPCon for short) technology is to prepare a layer of tunnel oxide layer and a layer of doped polysilicon layer on the back of the battery, the two together form a passivated contact structure, please refer to figure 1 . This structure provides a good surface passivation for the back of the silicon wafer. The oxide layer can allow the tunneling of many electrons into the doped polysilicon layer while blocking the recombination of the minority electrons and holes, and then the electrons are transported laterally in the doped polysilicon layer and collected by the metal. , thus greatly reducing the metal contact recombination current and increasing the open circuit voltage and short circuit current of the battery. [0003] At present, the aluminum oxide film...

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Problems solved by technology

[0003] At present, the aluminum oxide film is generally used as the passivation film of the emitter layer on the front of the solar cell produced by TOPCon technology, which can achieve a certain passivation effect, but can only improve the conversion efficiency of the solar cell to a certain extent.

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