Inverted pyramid structure of polysilicon surface and fabrication method of inverted pyramid structure

Abstract

The invention discloses an inverted pyramid structure of a polysilicon surface and a fabrication method of the inverted pyramid structure. The method comprises the following steps: preparing black silicon by different methods; rinsing a sample in a mixed liquid of hydrogen peroxide and ethanol amine; and carrying out retreatment on the washed black silicon in a mixed liquid of hydrogen peroxide, hydrofluoric acid, metaphosphoric acid and ammonium fluoride, so as to form the inverted pyramid structure of the polysilicon surface. A wet-chemical method which is different from acid and alkaline corrosion is adopted. According to the method, the effects of anisotropy can be reduced to the maximal extent; and the black silicon with different nano-structures can be corroded into a nano textured structure with a regular inverted pyramid structure through oxidation. Compared with the traditional polycrystalline silicon texture, the polysilicon inverted pyramid light-trapping structure disclosed by the invention is relatively high in light utilization rate and relatively low in reflectivity, so that the polysilicon inverted pyramid light-trapping structure has the characteristics of the inverted pyramid structure; compared with the traditional high surface recombination of a small and dense structure of the black silicon, the surface recombination is obviously reduced; and the efficiency of a solar cell is higher.

Description

technical field

[0001] The invention belongs to the technical field of solar cells, in particular to an inverted pyramid structure on the surface of polycrystalline silicon and a preparation method thereof. Background technique

[0002] Conventional polysilicon textured surfaces are all micron-scale worm-like structures. Polycrystalline silicon textured surfaces are made by utilizing the anisotropic properties of silicon, and using acid corrosion to form a honeycomb structure on the surface, which has a certain light trapping effect and can reduce the surface of the silicon wafer. Reflectivity.

[0003] There is also a new nano-light-trapping structure, which is generally called "black silicon", which has a good The light trapping effect can significantly reduce the reflectivity of the silicon wafer surface, and is considered to be a structure that can effectively improve the conversion efficiency of solar cells. At present, there are many laboratories that can prepare bla...

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