Preparation method of improved type back surface tunnel oxidization and passivation contact efficient battery

Abstract

The invention relates to a preparation method of an improved type back surface tunnel oxidization and passivation contact efficient battery. The preparation method comprises the steps of performing texturing after a silicon wafer damage layer is removed; next, forming a low surface concentration B doped P<+> emitting junction; after performing edge insulating and back surface polishing, enabling ultra-thin tunnel oxide layer SiO<2> and P-doped polysilicon layer to be grown on the back surface of a silicon wafer; depositing an aluminium oxide layer on the surface of the P<+> emitting junction;enabling a hydrogenated amorphous silicon nitride passivated antireflection layer to be grown on the front surface of the silicon wafer; forming partial heavy doping on the back surface of the siliconwafer by adopting a laser doping or wet etching method; enabling the hydrogenated amorphous silicon nitride passivated antireflection layer to be grown on the back surface of the silicon wafer; and finally, printing Ag / Al paste on the front surface of the silicon wafer, and printing Ag paste on the back surface. By adoption of the layer of the ultra-thin tunnel oxide layer SiO<2>, one layer of phosphorus P-doped silicon layer and the P-doped region partial heavy doping, the metal-semiconductor surface compounding on the back surface can be greatly lowered; and the preparation method has the most obvious advantage of capability of greatly improving electrical performance on the basis of compatibility with the conventional battery manufacturing process.

Description

technical field [0001] The invention relates to a preparation method of a solar cell, in particular to a preparation method of an improved back tunnel oxidation passivation contact high-efficiency cell. Background technique [0002] The difference between the heavily doped tunnel oxidation passivation contact cell technology and the conventional cell technology lies in the preparation of the composite structure of the back tunnel oxidation passivation layer and the doped polysilicon layer, and the back metal contact area uses The key points of this method are the preparation control of the ultra-thin tunnel oxide layer and the treatment of the interface state with the silicon substrate before preparation. [0003] Chinese patent CN102544198A discloses a method for preparing a selective emission crystalline silicon solar cell, including single-step high-concentration doping diffusion, and then printing anti-corrosion paste on the electrode area by printing process, and chemic...

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Problems solved by technology

[0003] Chinese patent CN102544198A discloses a method for preparing a selective emission crystalline silicon solar cell, including single-step high-concentration doping diffusion, and then printing anti-corrosion paste on the electrode area by printing process, and chemically etching the non-electrode area to achieve light doping The emitter junction, and then remove the anti-corrosion barrier layer, and finally use the conventional solar energy preparation method to make the selective emission crystalline silicon solar cell, but this patent application still uses the back point contact of the N-type crystalline silicon cell, so the electrical performance is not great. improvement

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