Single crystal alkali polishing additive, polishing solution and polishing method

Abstract

The invention discloses a single crystal alkali polishing additive, a polishing solution and a polishing method, and the additive comprises the following components in percentage by mass: 0.1%-10% of organic silicon, 0.1%-10% of a brightener, 0.05%-1% of a fluorocarbon surfactant and the balance of water. When the single crystal alkali polishing additive provided by the invention is applied to a single crystal polishing process, a single crystal with a bright back surface can be obtained, and meanwhile, the reflectivity is greatly increased; and the single crystal alkali polishing additive affects the polishing flatness and enhances the reaction speed.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a wafer additive, a polishing liquid and a polishing method. Background technique [0002] Single crystal alkali polishing additive refers to the chemical additives added during the texturing process of monocrystalline silicon solar cells that are beneficial to the reaction results and product performance. In the production process of crystalline silicon solar cells, in order to further improve the performance and efficiency of the cells, the back of the silicon wafer is usually polished to make the back surface of the silicon wafer smoother or even achieve a mirror effect. After back polishing, the back of the silicon wafer is flat, On the one hand, it can enhance the reflection of transmitted light and reduce the light transmittance; on the other hand, it can make the aluminum paste contact with the surface of the silicon wafer more fully to improve the passivation effect. The curre...

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Problems solved by technology

[0003] At present, the following three methods are mainly used in the polishing production of industrial crystalline silicon solar cells: 1. Tetramethylammonium hydroxide polishing. The silicon wafers prepared by this method have high reflectivity, but the cost of the chemical solution and the tail liquid The processing cost is high, and the pollution to the environment is relatively serious

2. Polishing with nitric acid and hydrofluoric acid. This method has low liquid cost, poor polishing effect, and serious environmental pollution.

3. Inorganic alkali polishing, using high-concentration potassium hydroxide and sodium hydroxide for polishing, this method has low liquid cost, good polishing effect, and less impact on the environment, but its process is unstable and the reaction process is not easy to control At the same time, the alkali will corrode the silicon oxide on the front side of the silicon wafer, thereby destroying the front pn junction and causing the battery to fail

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