High-boiling point monocrystalline silicon wafer surface texturing additive and using method thereof

Abstract

The invention relates to a high-boiling point monocrystalline silicon wafer surface texturing additive and a using method thereof and belongs to the technical field of production of solar cells. The additive is prepared from the following raw materials in percentage by weight: 0.01 to 3 percent of sodium alginate, 0.01 to 3 percent of trisodium phosphate, 0.001 to 1 percent of lauryl sodium sulfate, 0.1 to 2 percent of vitamin, 0.1 to 5 percent of propylene carbonate and the balance of deionized water; when the additive is used, a sodium oxide solution is needed to be added into the additive so as to obtain a texturing solution; the volume percentage ratio of the additive to the sodium oxide solution is (0.1-5):100; the temperature of the texturing solution is 70 to 90 DEG C; and the texturing time of the monocrystalline silicon is 600 to 1,500s. The reaction speed is controlled by using high viscosity of the sodium alginate, and the concentration of sodium hydroxide is increased simultaneously, so that a pyramid texture which is uniform in size is obtained; and the sodium alginate has the chelation function on metal and the function of cleaning the silicon wafer, and is low in cost.

Description

technical field [0001] The invention relates to a high-boiling-point monocrystalline silicon chip surface texture additive and a method for using the same, belonging to the technical field of solar cell production. Background technique [0002] In the preparation process of crystalline silicon solar cells, in order to improve the performance and efficiency of solar cells, it is necessary to make suede on the surface of the silicon wafer to form a pyramid structure, so that the optical path of the incident light is increased, the light absorption is increased, and the reflectivity is reduced. , thereby improving the conversion efficiency of solar cells. At present, wet etching is mainly used in the production of industrialized monocrystalline silicon cells. Sodium hydroxide and isopropanol are added to the etching solution. The following problems exist in the process: ①The reaction process is not well controlled, and it is easy to cause excessive corrosion, thereby It leads ...

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Problems solved by technology

At present, wet etching is mainly used in the production of industrialized monocrystalline silicon cells. Sodium hydroxide and isopropanol are added to the etching solution. The following problems exist in the process: ①The reaction process is not well controlled, and it is easy to cause excessive corrosion, thereby It leads to an increase in the fragmentation rate of silicon wafers; ②With the increase of sodium silicate in the reaction process, the texturing effect is unstable and the yield is difficult to control; ③The temperature of the texturing process is close to the boiling point of isopropanol, and as the reaction proceeds, it will cause A large amount of volatilization of isopropanol, on the one hand, because isopropanol is flammable and toxic, the high content of isopropanol in the air will cause safety hazards, and at the same time, it will also bring hidden dangers to the health of operators; on the other hand, with the The reduction of isopropanol in the liquid requires additional addition in batches, which greatly increases the production cost. At the same time, it is difficult to control the amount of additional addition, which affects the texturing effect; ④The amount of isopropanol added in the texturing liquid Too much will make the COD of wastewater significantly higher, which will increase the pollution of the environment and increase the cost of wastewater treatment

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