Passivation contact structure preparation method and crystalline silicon with passivation contact structure

Abstract

A passivation contact structure preparation method is characterized in that a SiOx / AlOx / p-poly three-layer passivation contact structure is formed on crystalline silicon, and comprises the following steps: S1, pretreating a crystalline silicon wafer; S2, preparing an AlOx film on the surface of the pretreated crystal silicon wafer; S3, preparing an amorphous silicon film on the surface of the crystalline silicon wafer on which the AlOx film is prepared, wherein the amorphous silicon film is an intrinsic amorphous silicon film or a boron-doped amorphous silicon film; S4, carrying out boron doping treatment on the intrinsic amorphous silicon thin film to make the intrinsic amorphous silicon thin film form a p-poly layer, and introducing excessive oxygen by means of the annealing process in the boron doping treatment to form a compact SiOx layer on the crystalline silicon below the AlOx thin film; or carrying out annealing treatment on the boron-doped amorphous silicon thin film, forming a p-poly layer on the boron-doped amorphous silicon thin film, and introducing excessive oxygen by virtue of the annealing process to form the compact SiOx layer on the crystalline silicon below the AlOx thin film; and S5, cleaning the BSG. According to the preparation method of the passivation contact structure, the procedure of independently preparing the SiOx layer can be omitted, and the carrier selectivity of p-poly silicon can be enhanced due to the existence of the AlOx thin film with negative charges, so that the passivation effect is enhanced.

Description

technical field [0001] The invention relates to the field of silicon substrate passivation, in particular to a method for preparing a passivation contact structure and crystalline silicon with a passivation contact structure. Background technique [0002] With the continuous development of solar cell technology, people have higher and higher requirements for the photoelectric conversion efficiency of cells. However, the improvement of industrial cell efficiency still faces many challenges. Among them, the contact recombination of the metal and silicon contact area and the silicon substrate The Auger recombination and SRH recombination caused by diffusion are the main factors restricting the improvement of battery efficiency. In order to reduce the recombination rate, prolong the minority carrier lifetime, and improve the photoelectric conversion efficiency of the battery, the silicon substrate is generally passivated, and a passivated contact structure is formed on the surfa...

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Problems solved by technology

Although the technical solution described in the invention patent has also undergone annealing treatment, it cannot omit the preparation of SiO 2 The process of tunneling through the oxide layer, the cost of the process remains high

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