Suede structure of crystalline silicon solar cells and manufacture method thereof

Abstract

The invention discloses a manufacture method of a suede structure of crystalline silicon solar cells. The manufacture method comprises the following steps of (1) corroding a silicon wafer to be processed through acid liquor or alkali liquor and forming a micron-scale suede structure on the surface of the silicon wafer; and (2) conducting gaseous corrosion on the silicon wafer obtained in the step (1), further forming a nano-scale suede structure on the micron-scale suede structure. Gass for gaseous corrosion comprises nitric oxide gas, steam and hydrogen fluoride, and the nitric oxide gas is one or a plurality of nitric oxide, nitrogen dioxide and nitrogen tetroxide. The nano-scale suede structure is further formed on the micron-scale suede structure through the gaseous corrosion on the basis of the existing micron-scale suede structure, and surface reflectivity is further reduced.

Description

technical field [0001] The invention relates to a textured surface structure of a crystalline silicon solar cell and a preparation method thereof, belonging to the technical field of solar energy. Background technique [0002] With the wide application of solar cell components, photovoltaic power generation occupies an increasingly important proportion in new energy and has achieved rapid development. At present, in the production process of solar cells, the textured structure on the surface of silicon wafers can effectively reduce the surface reflectance of solar cells, which is one of the important factors affecting the photoelectric conversion efficiency of solar cells. [0003] In order to obtain a good textured structure on the surface of crystalline silicon solar cells to achieve a better anti-reflection effect, many methods have been tried, including mechanical grooving, laser etching, and reactive ion etching (RIE). , Isotropic chemical etching method, etc. Among t...

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Problems solved by technology

Among them, the mechanical grooving method can obtain lower surface reflectivity, but this method causes serious mechanical damage to the surface of the silicon wafer, and its yield is relatively low, so it is rarely used in industrial production.

For the laser etching method, lasers are used to make different groove patterns. Striped and inverted pyramid-shaped surfaces have been fabricated. The reflectivity can be as low as 8.3%, but the efficiency of the cells made by them is relatively high. low and cannot be effectively used in production

The RIE method can use different templates for etching. The etching is generally dry etching, which can form a so-called "black silicon" structure on the surface of the silicon wafer, and its reflectivity can be as low as 7.9%, or even 4%. However, due to expensive equipment and high production costs, it is less used in industrial production

The isotropic chemical etching method has the characteristics of simple process, low cost and high quality, and good compatibility with existing processes, and has become the most used method in the existing industry. However, the reflectivity of this method after texturing is still as high as 22%.

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