Additive used for monocrystalline silicon wafer alkaline flocking and application method thereof

Abstract

The invention relates to an additive used for monocrystalline silicon wafer alkaline flocking and an application method thereof, belonging to the technical field of solar batteries. The additive is prepared by the following components: ethanolamine, polyphosphate, sodium dodecylbenzene sulfonate, sodium hydroxide and water. A flocking agent is prepared through the following steps: (1) dissolving sodium hydroxide in deionized water so as to obtain alkaline flocking liquid; (2) adding the additive motioned above into the alkaline flocking liquid to obtain the flocking agent. During flocking, monocrystalline silicon wafers used for solar batteries are immersed in the flocking agent with temperature controlled to be 75 to 85 DEG C and flocking time controlled to be 15 to 18 minutes. The additive used for monocrystalline silicon wafer alkaline flocking in the invention enables flocking reaction time to be shortened and productivity to be enhanced; prepared texture surface pyramids have a uniform size and low reflectivity; the additive is applicable to solar battery silicon wafer alkaline flocking of different specifications and meets the purpose of industrial production.

Description

technical field [0001] The invention relates to an additive for alkali texturing of monocrystalline silicon sheets and a method for using the same, belonging to the technical field of solar cell production. Background technique [0002] In the preparation process of monocrystalline silicon solar energy, alkaline solution is often used to etch each crystal plane at different rates, forming a "pyramid"-like suede on the surface of the silicon wafer. [0003] The principle of suede growth: at high temperature, silicon and alkali undergo the following chemical reaction: [0004] Si+2OH - +H 2 O = SiO 3 2- 　 +2H 2 [0005] For crystalline silicon, due to the different atomic density of each crystal plane, the speed of reaction with alkali is very different, which is what we usually call the corrosion of (110) plane (111) plane, thus forming a "pyramid" like velvet on the surface. noodle. An effective textured structure can effectively enhance the absorptio...

AI Technical Summary

Problems solved by technology

[0006] At present, the commonly used texturing liquid in industrial production is composed of sodium hydroxide, sodium silicate, isopropanol, and deionized water. The effect of this texturing liquid is not ideal. During the production process of silicon wafer texturing, the solution will be invalid. As a result, the production process fluctuates, and the cause of failure lies in the continuous consumption of NaOH and NaOH during the reaction process. 2 SiO 3 The continuous production of the reactant -OH leads to a decrease in the concentration of the reactant -OH, and the surface of the silicon wafer cannot obtain a sufficient contact rate with it; and because the reaction is carried out at a high temperature of about 80 degrees, a violent reaction often occurs and a large number of bubbles are generated, and it is necessary to continuously replenish isopropanol. Reduce the raindrops on the surface of the silicon wafer, and the resulting suede is not ideal

The traditional process generally suppresses the reaction by adding sodium silicate and IPA (isopropanol) to control the reaction rate, so that the pyramid structure of the suede produced in this way is not uniform, the stability of the suede is not good, and finger prints or Vitiligo, etc., it is difficult to control the reaction speed