Preparation method of surface micro and nano composite structure of monocrystalline cell

Abstract

The invention discloses a preparation method of a surface micro and nano composite structure of a monocrystalline cell. The preparation method comprises the following steps: S1, alkali texture surfacemaking: forming a pyramid textured surface with the reflectivity being 15-17%, wherein the size of a pyramid is 5-10 mu m; S2, primary acid pickling: carrying out acid pickling by using a HNO3 solution, wherein the concentration of the HNO3 solution is 0.5-1%, the temperature is a normal temperature, and the acid pickling time lasts for 60-100 s; and S3, silver ion auxiliary texture surface making: forming nano pits of which the diameters are 80-130 nm and the depths are 150-200 nm. Conventional monocrystal alkali texture surface making is combined to conventional black silicon silver ion auxiliary texture surface making, texturing on the surface of monocrystalline silicon is realized to form a micro-nano composite-structured textured surface, while the low reflectivity is ensured, the specific surface area is small, surface compounding is relieved, the cell conversion efficiency is further improved, the practicality is quite high, and thus, the preparation method is quite worthy of being popularized.

Description

technical field [0001] The invention relates to the technical field of single crystal silicon texturing, in particular to a method for preparing a surface micron nanocomposite structure of a single crystal cell. Background technique [0002] The existing single crystal texturing method, while obtaining lower reflectivity (that is, higher light absorption rate), makes the specific surface area of ​​the silicon wafer larger, increases the surface recombination of minority carriers, and limits the Further improvement in efficiency. [0003] Black silicon technology is currently one of the mainstream efficiency-enhancing technologies used in polycrystalline products, and its application in monocrystalline products is also foreseeable. At present, production lines use more alkali-made textures to form pyramid-structured textures for single crystals. On the surface, its high specific surface area under low reflectivity limits the further improvement of the texturing effect. [0...

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Problems solved by technology

[0002] The existing single crystal texturing method, while obtaining lower reflectivity (that is, higher light absorption rate), makes the specific surface area of ​​the silicon wafer larger, increases the surface recombination of minority carriers, and limits the Further improvement in efficiency

[0003] Black silicon technology is currently one of the mainstream efficiency-enhancing technologies used in polycrystalline products, and its application in monocrystalline products is also foreseeable. At present, production lines use more alkali-made textures to form pyramid-structured textures for single crystals. surface, its high specific surface area under low reflectivity limits the further improvement of the texturing effect

[0004] The steps of the conventional polycrystalline black silicon texturing process are as attached to the instruction manual. figure 1 As shown, after the texturing process step, the surface of the black silicon can be formed as shown in the description attached image 3 Texture structure as shown; the steps of the conventional monocrystalline silicon texturing process are as attached to the description figure 2 As shown, after the texturing process steps, the surface of the single crystal silicon can be formed as shown in the description attached Figure 4 The texture structure shown above, the reflectivity of the above two texture structures is still high, so that the light absorption rate cannot be improved, and the photoelectric conversion efficiency of the monocrystalline silicon cell is greatly reduced.

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