Alkali polishing additive for rapid polishing of monocrystalline silicon and use method of alkali polishing additive

Abstract

The invention discloses an alkali polishing additive for rapid polishing of monocrystalline silicon and a use method of the alkali polishing additive, and relates to the technical field of monocrystalline silicon etching, and the alkali polishing additive comprises the following components: a reaction accelerator, a corrosion and scale inhibitor, a PH regulator, a defoaming agent, 1, 3-bis (2-hydroxyethyl)-2-imidazolinone, 2, 5-furandimethanol, quinoline yellow, sodium glycyrrhizinate, melamine, hydroxypropyl chitosan and deionized water. The additive is good in alkali polishing effect under low weight loss, high in efficiency, good in stability, good in polished surface appearance and obvious in gain effect on the light conversion efficiency of the solar cell.

Description

Technical Field

[0001] The invention relates to the technical field of single crystal silicon etching, and in particular to an alkali polishing additive for rapid polishing of single crystal silicon and a use method thereof. Background Art

[0002] In the production of monocrystalline silicon solar cells, the back of the silicon wafer is usually alkali polished. On the one hand, the alkali polishing treatment can greatly improve the reflectivity of the back surface and increase the absorption of long-wavelength light; on the other hand, the flatness of the back surface after alkali polishing also determines the uniformity of the back passivation film, which has a direct impact on the efficiency of the solar cell. In order to improve the alkali polishing effect and efficiency, the use of alkali polishing additives is indispensable in the alkali polishing process. Its performance directly affects the alkali polishing effect and efficiency, and then affects the photoelectric conversion efficiency and fill factor of the solar cell. It can be seen that it is particularly important to develop alkali polishing additives with excellent comprehensive performance and performance stability.

[0003] The existing common alkali polishing additives often use inorganic oxidants to enhance the corrosion rate of alkali on silicon, but the degree of enhancement of the corrosion rate by such substances is limited. On the one hand, such additives require a long reaction time, which affects production capacity; on the other hand, as the client reduces costs, the alkali concentration gradually decreases, and small black nuclei are prone to appear on the surface of the alkali polishing back, affecting performance; conventional alkali polishing additives often use polyol reducing agents as degassing agents to accelerate the desorption of bubbles. There is a conflict between the oxidant and reducing agent in the additives, which will gradually cause chemical reactions and lead to failure. The product has a shelf life of as short as 1 month, and will fail in fifteen days when the temperature is high in summer. When such products are used after failure, it will cause raindrop marks and the tower base is too small. In addition, the alkali polishing additives on the market have more or less poor stability, poor flatness, and the polishing effect under low weight loss needs to be further improved. The polishing efficiency needs to be further improved when used for alkali polishing, and the amount of alkali needs to be further reduced. Other technical defects.

[0004] In order to solve the above problems, the Chinese invention patent with application announcement number CN117946591A discloses a single crystal silicon alkali polishing additive and its preparation method and polishing method, wherein the single crystal silicon alkali polishing additive comprises the following components in percentage by mass: 0.5% to 2% sodium aluminate, 2% to 4% polyvinyl alcohol, 0.5% to 3% surfactant, 1% to 3% defoamer, 0.5% to 1% isomeric alcohol oleic acid soap, and the balance is deionized water. The single crystal silicon alkali polishing additive of the invention limits the raw materials and the amount used, so that the prepared single crystal silicon alkali polishing additive can improve the alkali corrosion performance of alkali solution to single crystal silicon, realize the polishing treatment of single crystal silicon at a relatively low weight loss, and the back of the single crystal silicon after polishing has excellent flatness and reflectivity, thereby improving the conversion efficiency of solar cells; in addition, the single crystal silicon alkali polishing method of the invention limits the concentration and amount of each substance, so as to realize the rapid polishing of single crystal silicon and good polishing effect. However, the stability of the alkaline polishing additive and the appearance of the polished surface need to be further improved, and the gain effect on the light conversion efficiency of solar cells needs to be further enhanced. Summary of the invention

[0005] The main purpose of the present invention is to provide an alkali polishing additive for rapid polishing of single crystal silicon, which has good alkali polishing effect at low weight loss, high efficiency, good stability, good polishing surface appearance, and obvious gain effect on the light conversion efficiency of solar cells, and a method of using the alkali polishing additive.

[0006] To achieve the above purpose, the present invention provides an alkali polishing additive for rapid polishing of single crystal silicon, comprising the following components calculated by mass percentage: 0.5wt%-1wt% of a reaction accelerator, 1wt%-3wt% of a corrosion and scale inhibitor, 2wt%-4wt% of a pH regulator, 0.05wt%-1wt% of a defoaming agent, 0.05wt%-0.15wt% of 1,3-bis(2-hydroxyethyl)-2-imidazolidinone, 0.03wt%-0.12wt% of 2,5-furan dimethanol, 0.01wt%-0.06wt% of quinoline yellow, 0.01wt%-0.05wt% of sodium glycyrrhizinate, 0.06wt%-0.11wt% of melamine, 0.04wt%-0.1wt% of hydroxypropyl chitosan, and the balance being deionized water.

[0007] Preferably, the reaction accelerator is one or more of m-nitrophenol, sodium 3-nitrobenzoate, 4-nitrobenzene potassium sulfate, N-tert-butyloxycarbonyl-L-2-nitrophenylalanine, and 2-nitrobenzyl alcohol.

[0008] Preferably, the corrosion and scale inhibitor is one of methyl benzotriazole, benzotriazole, and citric acid, or a combination of two or more thereof.

[0009] Preferably, the pH regulator is one or a combination of formic acid, acetic acid, sodium citrate, citraconic acid, aminosulfonic acid, and methanesulfonic acid.

[0010] Preferably, the defoaming agent is one or a combination of saccharin, soluble starch, polyvinyl pyrrolidone, decaglycerol, and alkyl glycoside.

[0011] Preferably, the degree of substitution of the hydroxypropyl chitosan is ≥80.0%, and is provided by Nantong Lvshen Bioengineering Co., Ltd.

[0012] Another object of the present invention is to provide a method for using the alkali polishing additive for rapid polishing of single crystal silicon, comprising the following steps: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

[0013] Preferably, the mass content of the alkali polishing additive for rapid polishing of single crystal silicon in the polishing liquid in step S2 is 0.3% to 1%.

[0014] Preferably, the alkali solution in step S2 is a sodium hydroxide solution or a potassium hydroxide solution; the mass percentage concentration of the alkali solution is 3% to 6%.

[0015] Preferably, the polishing process in step S3 is performed at a temperature of 58 to 70° C. and for a time of 140 to 200 seconds.

[0016] Preferably, the single crystal silicon in step S3 is a 182×182 single crystal silicon wafer.

[0017] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The method for using the alkaline polishing additive for rapid polishing of single crystal silicon disclosed in the present invention is simple and easy to implement, has low dependence on equipment, consumes less energy, has low impact on the environment, has high polishing efficiency and good effect, is suitable for continuous large-scale production, and has high promotion and application value.

[0018] (2) The alkali polishing additive for rapid polishing of single crystal silicon disclosed in the present invention comprises the following components calculated by mass percentage: reaction accelerator 0.5wt%-1wt%, corrosion inhibitor 1wt%-3wt%, pH regulator 2wt%-4wt%, defoamer 0.05wt%-1wt%, 1,3-bis(2-hydroxyethyl)-2-imidazolidinone 0.05wt%-0.15wt%, 2,5-furan dimethanol 0.03wt%-0.12wt%, quinoline yellow 0.01wt%-0.06wt%, sodium glycyrrhizinate 0.01wt%-0.05wt%, melamine 0.06wt%-0.11wt%, hydroxypropyl chitosan 0.04wt%-0.1wt%, and the balance is deionized water. Through the mutual coordination and joint action of the components, the manufactured product has good alkali polishing effect, high efficiency, good stability, good polishing surface appearance, and obvious gain effect on the light conversion efficiency of solar cells.

[0019] (3) The alkali polishing additive for rapid polishing of single crystal silicon disclosed in the present invention, wherein the reaction accelerator is one or more of m-nitrophenol, sodium 3-nitrobenzoate, potassium 4-nitrobenzene sulfate, N-tert-butyloxycarbonyl-L-2-nitrophenylalanine, and 2-nitrobenzyl alcohol; all of which contain nitro groups. The nitrogen and oxygen atoms in the nitro groups have very high electronegativity and can attract electrons. They have very strong electron-accepting ability and can accelerate the process of silicon losing electrons to generate sodium silicate, thereby increasing the reaction rate of alkali and silicon. This electron-attracting effect can be explained by the inductive effect and the conjugated effect. The electron-withdrawing property of the nitro group affects the electron distribution and reaction activity of the entire molecule, and its ability to promote the reaction of alkali and silicon is far superior to conventional inorganic oxides; the corrosion and scale inhibitor is one or a combination of two or more of methyl benzotriazole, benzotriazole, and citric acid, which can be adsorbed on the surface of phosphosilicate glass, reducing the corrosion rate of alkali and the front side of the silicon wafer, so that the front PN junction is not destroyed during the alkali polishing process, and the back side of the battery also obtains a better polishing effect; the degassing agent is one or a combination of several of saccharin, soluble starch, polyvinyl pyrrolidone, polyglycerol, and alkyl glycoside, which can effectively reduce the surface tension of the product and accelerate the desorption of bubbles from the surface of the silicon wafer.

[0020] (4) The alkali polishing additive for rapid polishing of single crystal silicon disclosed in the present invention has a relatively fast alkali polishing corrosion rate, low alkali consumption, no problems such as poor edge polishing and residual black core, and sufficient stability through reasonable selection of component types and dosage ratios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a ZETA diagram of a silicon wafer after alkali polishing using the alkali polishing additive of Example 1 of the present invention; Figure 2This is a ZETA diagram of a silicon wafer after alkali polishing using the alkali polishing additive of Example 2 of the present invention; Figure 3 This is the ZETA diagram of a silicon wafer after alkali polishing using the alkali polishing additive of Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0023] Example 1, an alkali polishing additive for rapid polishing of single crystal silicon, comprising the following components calculated by mass percentage: a reaction accelerator 0.5wt%, a corrosion inhibitor and scale inhibitor 1wt%, a pH regulator 2wt%, a defoaming agent 0.05wt%, 1,3-bis(2-hydroxyethyl)-2-imidazolidinone 0.05wt%, 2,5-furan dimethanol 0.03wt%, quinoline yellow 0.01wt%, sodium glycyrrhizate 0.01wt%, melamine 0.06wt%, hydroxypropyl chitosan 0.04wt%, and the balance being deionized water.

[0024] The reaction accelerator is m-nitrophenol; the corrosion and scale inhibitor is methyl benzotriazole; the pH regulator is formic acid; the defoaming agent is saccharin; the degree of substitution of hydroxypropyl chitosan is ≥80.0%, and it is provided by Nantong Lvshen Bioengineering Co., Ltd.

[0025] A method for using the alkali polishing additive for rapid polishing of single crystal silicon comprises the following steps: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

[0026] The mass content of the alkali polishing additive used for rapid polishing of single crystal silicon in the polishing liquid described in step S2 is 0.3%; the alkali solution described in step S2 is sodium hydroxide solution; the mass percentage concentration of the alkali solution is 3%; the temperature of the polishing treatment described in step S3 is 58°C and the time is 140s; the single crystal silicon described in step S3 is a 182×182 single crystal silicon wafer.

[0027] Example 2, an alkali polishing additive for rapid polishing of single crystal silicon, comprising the following components calculated by mass percentage: a reaction accelerator 0.6wt%, a corrosion inhibitor and scale inhibitor 1.5wt%, a pH regulator 2.5wt%, a defoaming agent 0.07wt%, 1,3-bis(2-hydroxyethyl)-2-imidazolidinone 0.08wt%, 2,5-furan dimethanol 0.05wt%, quinoline yellow 0.02wt%, sodium glycyrrhizate 0.02wt%, melamine 0.07wt%, hydroxypropyl chitosan 0.06wt%, and the balance being deionized water.

[0028] The reaction accelerator is sodium 3-nitrobenzoate; the corrosion and scale inhibitor is benzotriazole; the pH regulator is acetic acid; the defoaming agent is soluble starch; the degree of substitution of the hydroxypropyl chitosan is ≥80.0%, and it is provided by Nantong Lvshen Bioengineering Co., Ltd.

[0029] A method for using the alkali polishing additive for rapid polishing of single crystal silicon comprises the following steps: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

[0030] The mass content of the alkali polishing additive used for rapid polishing of single crystal silicon in the polishing liquid described in step S2 is 0.6%; the alkali solution described in step S2 is a potassium hydroxide solution; the mass percentage concentration of the alkali solution is 4%; the temperature of the polishing treatment described in step S3 is 62°C and the time is 170s; the single crystal silicon described in step S3 is a 182×182 single crystal silicon wafer.

[0031] Example 3, an alkali polishing additive for rapid polishing of single crystal silicon, comprising the following components calculated by mass percentage: a reaction accelerator 0.8wt%, a corrosion inhibitor and scale inhibitor 2wt%, a pH regulator 3wt%, a defoaming agent 0.08wt%, 1,3-bis(2-hydroxyethyl)-2-imidazolidinone 0.1wt%, 2,5-furan dimethanol 0.08wt%, quinoline yellow 0.04wt%, sodium glycyrrhizate 0.03wt%, melamine 0.09wt%, hydroxypropyl chitosan 0.08wt%, and the balance being deionized water.

[0032] The reaction accelerator is potassium 4-nitrobenzene sulfate; the corrosion and scale inhibitor is citric acid; the pH regulator is sodium citrate; the defoaming agent is polyvinyl pyrrolidone; the degree of substitution of the hydroxypropyl chitosan is ≥80.0%, and it is provided by Nantong Lvshen Bioengineering Co., Ltd.

[0033] A method for using the alkali polishing additive for rapid polishing of single crystal silicon comprises the following steps: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

[0034] The mass content of the alkali polishing additive used for rapid polishing of single crystal silicon in the polishing liquid in step S2 is 0.8%; the alkali solution in step S2 is a sodium hydroxide solution; the mass percentage concentration of the alkali solution is 4.5%; the temperature of the polishing treatment in step S3 is 64°C and the time is 180s; the single crystal silicon in step S3 is a 182×182 single crystal silicon wafer.

[0035] Example 4, an alkali polishing additive for rapid polishing of single crystal silicon, comprising the following components calculated by mass percentage: a reaction accelerator 0.9wt%, a corrosion inhibitor and scale inhibitor 2.5wt%, a pH regulator 3.5wt%, a defoaming agent 0.09wt%, 1,3-bis(2-hydroxyethyl)-2-imidazolidinone 0.13wt%, 2,5-furan dimethanol 0.1wt%, quinoline yellow 0.05wt%, sodium glycyrrhizate 0.04wt%, melamine 0.1wt%, hydroxypropyl chitosan 0.09wt%, and the balance being deionized water.

[0036] The reaction accelerator is a mixture of m-nitrophenol, sodium 3-nitrobenzoate, potassium 4-nitrobenzene sulfate, N-tert-butyloxycarbonyl-L-2-nitrophenylalanine and 2-nitrobenzyl alcohol in a mass ratio of 1:1:2:2:3; the corrosion and scale inhibitor is a mixture of methylbenzotriazole, benzotriazole and citric acid in a mass ratio of 1:3:5; the pH regulator is a mixture of formic acid, acetic acid, sodium citrate, citraconic acid, aminosulfonic acid and methylsulfonic acid in a mass ratio of 1:1:1:1:3:2; the defoaming agent is a mixture of saccharin, soluble starch, polyvinyl pyrrolidone, polyglycerol and alkyl glycoside in a mass ratio of 1:3:2:2:1; the degree of substitution of the hydroxypropyl chitosan is ≥80.0%, and it is provided by Nantong Lushen Bioengineering Co., Ltd.

[0037] A method for using the alkali polishing additive for rapid polishing of single crystal silicon comprises the following steps: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

[0038] The mass content of the alkali polishing additive used for rapid polishing of single crystal silicon in the polishing liquid described in step S2 is 0.9%; the alkali solution described in step S2 is sodium hydroxide solution; the mass percentage concentration of the alkali solution is 5.5%; the temperature of the polishing treatment described in step S3 is 68°C and the time is 190s; the single crystal silicon described in step S3 is a 182×182 single crystal silicon wafer.

[0039] Example 5, an alkali polishing additive for rapid polishing of single crystal silicon, comprising the following components calculated by mass percentage: 1wt% reaction accelerator, 3wt% corrosion inhibitor and scale inhibitor, 4wt% pH regulator, 1wt% defoaming agent, 0.15wt% 1,3-bis(2-hydroxyethyl)-2-imidazolidinone, 0.12wt% 2,5-furan dimethanol, 0.06wt% quinoline yellow, 0.05wt% sodium glycyrrhizate, 0.11wt% melamine, 0.1wt% hydroxypropyl chitosan, and the balance being deionized water.

[0040] The reaction accelerator is 2-nitrobenzyl alcohol; the corrosion and scale inhibitor is methyl benzotriazole; the pH regulator is citraconic acid; the defoaming agent is alkyl glycoside; the degree of substitution of the hydroxypropyl chitosan is ≥80.0%, and it is provided by Nantong Lvshen Bioengineering Co., Ltd.

[0041] A method for using the alkali polishing additive for rapid polishing of single crystal silicon comprises the following steps: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

[0042] The mass content of the alkali polishing additive used for rapid polishing of single crystal silicon in the polishing liquid in step S2 is 1%; the alkali solution in step S2 is sodium hydroxide solution or potassium hydroxide solution; the mass percentage concentration of the alkali solution is 6%; the temperature of the polishing treatment in step S3 is 70°C and the time is 200s; the single crystal silicon in step S3 is a 182×182 single crystal silicon wafer.

[0043] Comparative Example 1 The present invention provides an alkali polishing additive for rapid polishing of single crystal silicon and a method of using the same, which is similar to Example 1, except that 1,3-bis(2-hydroxyethyl)-2-imidazolidinone and sodium glycyrrhizinate are not added.

[0044] Comparative Example 2 The present invention provides an alkali polishing additive for rapid polishing of single crystal silicon and a method for using the same, which is similar to Example 1, except that 2,5-furan dimethanol and hydroxypropyl chitosan are not added.

[0045] Comparative Example 3 The present invention provides an alkali polishing additive for rapid polishing of single crystal silicon and a method of using the same, which is similar to Example 1, except that quinoline yellow and melamine are not added.

[0046] The alkali polishing additives for rapid polishing of single crystal silicon involved in the above Examples 1-5 and Comparative Examples 1-3 were subjected to relevant performance tests. The test results are shown in Table 1. The test method is as follows: (1) Appearance: Observe the appearance changes of the silicon wafer after polishing. If the tower base has high flatness, a fused tower base, and no black core, the appearance passes. If there are raindrop marks, poor tower base flatness, an independent tower base, or any of the following conditions, the appearance fails.

[0047] (2) Reflectivity and weight loss: Use a reflectivity test system to measure the integrated reflectivity within the wavelength range of 300-1100nm; count and calculate the weight loss; (3) Stability: The additives prepared in each example were placed at room temperature for 6 months, and samples were taken and the reflectivity was tested again according to the method in (2). The reflectivity retention rate was calculated, and the larger the value, the better the stability.

[0048] (4) Electrical performance: The finished solar cells of each example were tested using a dedicated test instrument for solar cells, such as a single flash simulator; the test conditions were standard test conditions (STC): light intensity 1000W / m 2 ; Spectrum AM1.5; Temperature 25℃; Test method is in accordance with IEC904-1, main electrical performance parameters of the cell: Photoelectric conversion efficiency (Eta, unit: %).

[0049] At the same time, taking Example 1, Example 2 and Comparative Example 1 as examples, the ZETA diagrams of silicon wafers after alkali polishing using the alkali polishing additives of each example are respectively as follows: Figure 1 , Figure 2 , Figure 3 shown; from Figure 1-Figure 3 It can be seen that the product of the embodiment of the present invention has a better appearance after alkali polishing.

[0050] Table 1

[0051] As can be seen from Table 1, the alkali polishing additive for rapid polishing of single crystal silicon disclosed in the embodiment of the present invention has a more excellent low weight loss alkali polishing effect, a better photoelectric conversion efficiency gain effect on solar cells, higher stability and reflectivity, and a better appearance of the polished silicon wafer; the addition of 1,3-bis(2-hydroxyethyl)-2-imidazolidinone, sodium glycyrrhizinate, 2,5-furan dimethanol, hydroxypropyl chitosan, quinoline yellow and melamine is beneficial to improving the above properties.

[0052] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. An alkali polishing additive for rapid polishing of single crystal silicon, characterized in that: The invention comprises the following components calculated by mass percentage: a reaction accelerator 0.5wt%-1wt%, a corrosion and scale inhibitor 1wt%-3wt%, a pH regulator 2wt%-4wt%, a defoaming agent 0.05wt%-1wt%, 1,3-bis(2-hydroxyethyl)-2-imidazolidinone 0.05wt%-0.15wt%, 2,5-furan dimethanol 0.03wt%-0.12wt%, quinoline yellow 0.01wt%-0.06wt%, sodium glycyrrhizinate 0.01wt%-0.05wt%, melamine 0.06wt%-0.11wt%, hydroxypropyl chitosan 0.04wt%-0.1wt%, and the balance is deionized water.

2. The alkali polishing additive for rapid polishing of single crystal silicon according to claim 1, characterized in that: The reaction accelerator is one or more of m-nitrophenol, sodium 3-nitrobenzoate, potassium 4-nitrobenzene sulfate, N-tert-butyloxycarbonyl-L-2-nitrophenylalanine, and 2-nitrobenzyl alcohol.

3. The alkali polishing additive for rapid polishing of single crystal silicon according to claim 1, characterized in that: The corrosion and scale inhibitor is one of methyl benzotriazole, benzotriazole and citric acid or a combination of two or more thereof.

4. The alkali polishing additive for rapid polishing of single crystal silicon according to claim 1, characterized in that: The pH regulator is one or a combination of formic acid, acetic acid, sodium citrate, citraconic acid, aminosulfonic acid, and methanesulfonic acid.

5. The alkali polishing additive for rapid polishing of single crystal silicon according to claim 1, characterized in that: The defoaming agent is one or a combination of saccharin, soluble starch, polyvinyl pyrrolidone, polyglycerol, and alkyl glycoside.

6. The alkali polishing additive for rapid polishing of single crystal silicon according to claim 1, characterized in that: The degree of substitution of the hydroxypropyl chitosan is ≥80.0%.

7. A method for using the alkali polishing additive for rapid polishing of single crystal silicon according to any one of claims 1 to 6, characterized in that: The steps include: Step S1, uniformly mixing the components of the alkali polishing additive for rapid polishing of single crystal silicon to obtain the alkali polishing additive for rapid polishing of single crystal silicon; Step S2, adding the alkali polishing additive for rapid polishing of single crystal silicon prepared in step S1 into the alkali solution and stirring evenly to obtain a polishing solution; Step S3, using the polishing liquid prepared in step S2 to polish the single crystal silicon, and then entering the subsequent solar cell preparation process to obtain a finished solar cell.

8. The method for using the alkali polishing additive for rapid polishing of single crystal silicon according to claim 7, characterized in that: The mass content of the alkali polishing additive for rapid polishing of single crystal silicon in the polishing liquid in step S2 is 0.3% to 1%; the alkali solution in step S2 is sodium hydroxide solution or potassium hydroxide solution; the mass percentage concentration of the alkali solution is 3% to 6%.

9. The method for using the alkali polishing additive for rapid polishing of single crystal silicon according to claim 7, characterized in that: The polishing process in step S3 is performed at a temperature of 58 to 70° C. and for a time of 140 to 200 seconds.

10. The method for using the alkali polishing additive for rapid polishing of single crystal silicon according to claim 7, characterized in that: The single crystal silicon in step S3 is a 182×182 single crystal silicon wafer.

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