Slow pulling additive for producing crystalline silicon cell and method for producing silicon wafer for crystalline silicon cell by applying slow pulling additive
By using a specific composition of slow-pull additive in the production of crystalline silicon batteries, the problem of sticky and water stain residue caused by incomplete dehydration of the silicon wafer surface is solved, the cleanliness and photoelectric properties of the silicon wafer are improved, and the battery's goodness is improved. rate and efficiency.
Patent Information
- Application Number
- CN202411526486.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-11
AI Technical Summary
During the production process of crystalline silicon batteries, the presence of the BSG layer leads to the increase in the hydrophilicity of the silicon wafer surface, which leads to incomplete dehydration of the silicon wafer when pre-dehydrated in the slow lifting tank, resulting in sticky and water stains remaining, affecting the subsequent finished battery EL yield and efficiency.
A slow-pull additive for crystalline silicon battery production is used. The additive consists of surface cleaners, stabilizers, dispersants and surfactants. Through the combination of these components, impurities on the surface of the silicon wafer are removed and surface finish and fluidity are improved. , reduce water residue and bubble generation.
Effectively remove impurities and water residues on the surface of the silicon wafer, improve the cleanliness and photoelectric properties of the silicon wafer, reduce the phenomenon of sticking the wafer, and improve the EL yield and efficiency of subsequent finished batteries.
Smart Images
Figure CN119411213A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of slow pulling additives, and in particular to a slow pulling additive for producing crystalline silicon cells and a method for producing silicon wafers for crystalline silicon cells using the slow pulling additive. Background Art
[0002] The development of the photovoltaic industry has also brought about technological changes. Currently, Topcon cells have gradually replaced PERC cells and become the mainstream process with their higher photoelectric conversion rate and high equipment adaptability. In order to be compatible with subsequent battery processes, the current domestic TOPCon technology route needs to retain the BSG on the front side during the current alkaline polishing process to serve as a protective layer for subsequent processes.
[0003] With respect to the above-mentioned prior art, the applicant has found that the presence of the BSG layer leads to enhanced hydrophilicity of the silicon wafer surface, resulting in incomplete dehydration of the silicon wafer surface during the subsequent slow pull-up tank pre-dehydration, which in turn leads to sticking of the silicon wafer and residual water stains on the surface, affecting the EL yield of the subsequent finished battery, which is manifested as a high watermark ratio.
[0004] In addition, there will be a high-temperature drying tank after the slow pull tank, with a temperature of more than 85 degrees and a time of about 15 minutes. Due to the residual water on the surface of the silicon wafer, the oxidation state of the polished surface of the silicon wafer in the drying tank will change. Due to the fast oxidation rate of wet oxygen and water vapor, an oxide layer with a thickness of several angstroms will be formed on the polished surface. At the same time, in the subsequent process, a tunneling oxide layer of about 2nm needs to continue to grow on the back side. Then, the oxide layer grown in the drying tank will affect the subsequent oxide layer growth and tunneling effect, resulting in efficiency loss. As the thickness of the silicon wafer used as the raw material becomes thinner and thinner, the sticking of the wafer in the slow pull tank will become more obvious, which will affect the subsequent yield and efficiency. Summary of the invention
[0005] Based on the technical problems existing in the above-mentioned prior art, the present invention provides a slow pulling additive for the production of crystalline silicon cells and a method for producing silicon wafers for crystalline silicon cells using the slow pulling additive.
[0006] In the first aspect, the present application provides a slow pulling additive for crystalline silicon cell production, which adopts the following technical solution:
[0007] A slow-pulling additive for crystalline silicon cell production, composed of the following percentages:
[0008] 5-10% surface cleaner;
[0009] 0.5-2% stabilizer;
[0010] 0.05-1% dispersant;
[0011] 0.05-1% surfactant;
[0012] The remaining component is water.
[0013] Through the above technical solution, the surface cleaner contained in the additive of the technical solution of the present application can remove impurities on the surface of the silicon wafer and improve the surface finish. The stabilizer helps to maintain the uniform dispersion of the additive and ensure the stability of the additive performance throughout the manufacturing process. The addition of dispersants and surfactants further improves the fluidity and distribution of the additive in the liquid, reduces the generation of bubbles, reduces the surface contamination caused by residual water, and thus improves the yield of the battery cell.
[0014] Furthermore, the surface cleaning agent includes a combination of one or more of small molecule organic matter, small molecule ethers, and small molecule alcohols.
[0015] Through the above technical solution, the technical solution of this application optimizes the composition of the surface cleaner, and by selecting small molecule organic matter, small molecule ethers and small molecule alcohols, it can exert excellent cleaning ability against different types of dirt. These small molecule substances have good hydrophilicity and lipophilicity, so that they can effectively penetrate and remove organic pollutants and tiny particles on the surface of the silicon wafer during the cleaning process, thereby improving the cleanliness and optoelectronic performance of the silicon wafer. In addition, the flexibility of this combination makes it possible to adjust the proportion of ingredients according to specific needs under different production conditions, thereby adapting to different production environments and improving the consistency and stability of the product.
[0016] Furthermore, the stabilizer includes a combination of one or more of butylated hydroxytoluene, fumaric acid, and sodium benzoate.
[0017] Through the above technical scheme, the technical scheme of the present application optimizes the selection of stabilizers, such as butylated hydroxytoluene, fumaric acid and sodium benzoate, which can effectively improve the stability of the additive. Butylated hydroxytoluene is an antioxidant that can prevent the degradation of the additive during the production process, thereby ensuring its service life and effect. Fumaric acid and sodium benzoate have good pH adjustment capabilities and can maintain the effectiveness of the additive in different liquid phase environments. The combination of these ingredients ensures that the additive can remain stable under high temperature and high shear conditions, thereby improving the production efficiency of silicon wafers and the yield of finished products, ensuring the high quality of the final product.
[0018] Furthermore, the dispersant includes a combination of one or more of HPMA, acrylic acid, and sodium dodecyl sulfate.
[0019] Through the above technical solution, the technical solution of the present application optimizes the use of dispersants, such as HPMA, acrylic acid and sodium dodecyl sulfate, which can improve the dispersibility of additives and ensure their uniform distribution in the liquid. This is crucial for the uniformity of materials during the slow pulling process, because uneven distribution may cause defects or uneven photoelectric properties on the surface of the silicon wafer. Good dispersibility helps to reduce precipitation and aggregation during the production process, ensuring that the additives maintain stable performance throughout the pulling process, thereby improving the photoelectric conversion efficiency and overall performance of the silicon wafer.
[0020] Furthermore, the surfactant includes a combination of one or more of anionic surfactants, cationic surfactants, nonionic surfactants, and fluorocarbon surfactants.
[0021] Through the above technical scheme, the technical scheme of the present application optimizes the selectivity of the surfactant and can be adjusted according to different application requirements. The present application enhances the wettability and infiltration of the liquid by adding the surfactant, so that the additive can effectively cover the surface of the silicon wafer and reduce the surface tension, thereby reducing the generation of bubbles and film defects.
[0022] In the second aspect, the present application provides a method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production, using the following technical solutions:
[0023] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production, comprising the following preparation steps:
[0024] Place the silicon wafer to be processed in a pre-cleaning solution for pre-cleaning, and then perform alkaline polishing on it after the pre-cleaning is completed;
[0025] The silicon wafer after alkali polishing is cleaned and placed in a slow pulling tank, slow pulling additives and ultrapure water are added, the slow pulling speed is adjusted to 3-30mm / s, and the temperature of the slow pulling tank is adjusted to 20-70°C. After the slow pulling is completed, the wafer is dried and removed to prepare the silicon wafer for the crystalline silicon cell shown in the figure.
[0026] Through the above technical solution, the technical solution of the present application can remove most of the surface contaminants in the early stage through the use of pre-cleaning liquid, ensuring the effect of subsequent treatment. The alkali polishing step not only improves the smoothness of the silicon wafer surface, but also helps to remove microscopic defects, which is crucial to improving the optoelectronic performance of the final silicon wafer. Using a specific speed and temperature during the slow pulling process can pre-dehydrate the silicon wafer, prevent excessive water residue on the silicon wafer surface, and improve the phenomenon of silicon wafer sticking caused by water residue.
[0027] Furthermore, the pre-cleaning solution includes the following substances in parts by weight:
[0028] 0.2-0.5 parts of alkali;
[0029] 2-5 parts H2O2;
[0030] 95-105 parts water;
[0031] The base includes any one of potassium hydroxide or sodium hydroxide.
[0032] Through the above technical scheme, the technical scheme of the present application effectively removes pollutants and organic matter on the surface of the silicon wafer by using a reasonable ratio of alkali, H2O2 and water when preparing the pre-cleaning solution. Potassium hydroxide or sodium hydroxide, as an alkaline component, can neutralize the acidic substances on the surface of the silicon wafer and further remove impurities. H2O2 is oxidizing and can effectively decompose organic pollutants and improve the cleaning effect. This step ensures that the subsequent alkaline polishing and slow pulling process can be carried out in a clean environment, thereby improving the quality and photoelectric performance of the silicon wafer surface, and ultimately promoting the manufacture of crystalline silicon cells.
[0033] Further, the cleaning process comprises the following steps:
[0034] After the alkaline polishing treatment, the silicon wafer is placed in the treatment liquid A for cleaning treatment. After the cleaning treatment is completed, it is placed in the pickling tank for pickling treatment. After the pickling treatment is completed, it is continued to be washed with water until the washing liquid is neutral, and the cleaning treatment step can be completed.
[0035] Through the above technical scheme, the technical scheme of this application describes the process from alkali polishing to pickling, ensuring that the silicon wafer reaches the optimal clean state during the treatment process. By confining the silicon wafer in clean water, the residues generated during the alkali polishing process can be removed, and the subsequent pickling treatment can effectively remove the oxide layer and other impurities to ensure the surface quality of the silicon wafer. Finally, washing with water until the washing liquid is neutral can ensure that there will be no negative impact on the subsequent process. Through this series of cleaning steps, the cleanliness of the silicon wafer is effectively improved, laying a good foundation for the subsequent slow pulling process, thereby improving the performance of the final product.
[0036] Furthermore, the alkali polishing treatment is carried out using an alkali polishing treatment liquid, and the alkali polishing treatment liquid includes the following substances in parts by weight:
[0037] 0.2-1.0 parts of alkali;
[0038] 0.5-5 parts H2O2;
[0039] 95-105 parts water;
[0040] The base includes any one of potassium hydroxide or sodium hydroxide.
[0041] Furthermore, the pickling solution in the pickling tank includes the following substances in parts by weight:
[0042] 1-15 parts HCl;
[0043] 0-10 parts HF;
[0044] 95-105 parts water.
[0045] Through the above technical solution, the technical solution of this application selects the combined use of HCl and HF to achieve efficient removal effect, wherein HCl is used to remove most of the impurities on the surface of the silicon wafer, and HF is specifically used to remove the silicon oxide layer, avoiding damage to the silicon wafer by other acids. Through the reasonable control of this formula, fine washing of the silicon wafer is achieved, ensuring the excellent performance of the final product.
[0046] In summary, this application has the following beneficial effects:
[0047] First, the surface cleaner contained in the additive of the technical solution of the present application can remove impurities on the surface of the silicon wafer and improve the surface finish. The stabilizer helps to maintain the uniform dispersion of the additive and ensure the stability of the additive performance throughout the manufacturing process. The addition of dispersants and surfactants further improves the fluidity and distribution of the additive in the liquid, reduces the generation of bubbles, reduces the surface contamination caused by residual water, and thus improves the yield of the battery cell.
[0048] Second, the technical solution of this application optimizes the composition of the surface cleaner. By selecting small molecule organic matter, small molecule ethers and small molecule alcohols, it can exert excellent cleaning ability against different types of dirt. These small molecule substances have good hydrophilicity and lipophilicity, so that they can effectively penetrate and remove organic pollutants and tiny particles on the surface of silicon wafers during the cleaning process, thereby improving the cleanliness and optoelectronic performance of silicon wafers. In addition, the flexibility of this combination makes it possible to adjust the proportion of ingredients according to specific needs under different production conditions, thereby adapting to different production environments and improving the consistency and stability of the product.
[0049] Third, the technical solution of this application can remove most of the surface contaminants in the early stage through the use of pre-cleaning liquid, ensuring the effect of subsequent treatment. The alkali polishing step not only improves the smoothness of the silicon wafer surface, but also helps to remove microscopic defects, which is crucial to improving the photoelectric performance of the final silicon wafer. Using a specific speed and temperature during the slow pulling process can effectively control the growth rate of the crystal, thereby forming high-quality silicon wafers and laying the foundation for the production of crystalline silicon cells. BRIEF DESCRIPTION OF THE DRAWINGS
[0050] Figure 1 This is a water residue diagram on the surface of the silicon wafer after slow pulling produced in Example 1 of the present application;
[0051] Figure 2This is a diagram of water residue on the surface of the silicon wafer after slow pulling produced in Comparative Example 1 of the present application. DETAILED DESCRIPTION
[0052] The present application is further described in detail below with reference to the embodiments.
[0053] In the examples of the present application, the raw materials and instruments used are as follows, but not limited thereto. Raw materials not otherwise specified are of analytical grade.
[0054] Preparation Example 1
[0055] Pre-cleaning solution 1
[0056] Take 0.2 kg of potassium hydroxide, 2 kg of H2O2 and 95 kg of deionized water, stir and mix, and prepare a pre-cleaning solution 1.
[0057] Preparation Example 2
[0058] Pre-cleaning solution 2
[0059] Take 0.3 kg of potassium hydroxide, 3 kg of H2O2 and 100 kg of deionized water, stir and mix, and prepare a pre-cleaning solution 2.
[0060] Preparation Example 3
[0061] Pre-cleaning solution 3
[0062] Take 0.5 kg of potassium hydroxide, 5 kg of H2O2 and 105 kg of deionized water, stir and mix, and prepare a pre-cleaning solution 3.
[0063] Preparation Example 4
[0064] Alkali polishing liquid 1
[0065] Take 0.2 kg of sodium hydroxide, 0.5 kg of H2O2 and 95 kg of deionized water, stir and mix, and prepare an alkaline polishing treatment solution 1.
[0066] Preparation Example 5
[0067] Alkali polishing liquid 2
[0068] Take 0.6 kg of sodium hydroxide, 2.5 kg of H2O2 and 100 kg of deionized water, stir and mix, and prepare an alkaline polishing treatment solution 2.
[0069] Preparation Example 6
[0070] Alkali polishing liquid 3
[0071] Take 1.0 kg of sodium hydroxide, 5 kg of H2O2 and 105 kg of deionized water, stir and mix, and prepare an alkaline polishing treatment solution 3.
[0072] Preparation Example 7
[0073] Pickling liquid 1
[0074] 50 kg of 1% HCl and 45 kg of 10% HF were mixed and stirred to prepare an acid wash solution 1.
[0075] Preparation Example 8
[0076] Pickling liquid 2
[0077] 50 kg of 8% by mass HCl and 48 kg of 5% by mass HF were mixed and stirred to prepare an acid wash solution 2.
[0078] Preparation Example 9
[0079] Pickling liquid 3
[0080] 50 kg of 15% HCl and 50 kg of 1% HF were mixed and stirred to prepare an acid wash solution 3.
[0081] Preparation Example 10
[0082] Treatment fluid A1
[0083] 5 kg of 0.2% by mass sodium hydroxide solution and 5 kg of 0.5% by mass H2O2 were mixed to prepare treatment solution A1.
[0084] Preparation Example 11
[0085] Treatment fluid A2
[0086] 5 kg of 1.0% sodium hydroxide solution and 5 kg of 5% H2O2 were mixed to prepare treatment solution A2.
[0087] Example 1
[0088] A slow-pulling additive for producing crystalline silicon cells comprises 5 kg of surface cleaning agent dipropylene glycol butyl ether, 0.5 kg of stabilizer dibutyl hydroxytoluene, 0.05 kg of dispersant HPMA, 0.05 kg of anionic surfactant alkyl polyoxyethylene ether sodium sulfate and 94.4 kg of water.
[0089] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0090] Place the silicon wafer to be processed in pre-cleaning solution 1 for pre-cleaning treatment at a temperature of 35° C. for 30 seconds. After the pre-cleaning is completed, place the wafer in an alkali polishing tank and add alkali polishing solution 1 for alkali polishing treatment.
[0091] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45°C for a treatment time of 30 seconds;
[0092] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0093] After cleaning is completed, add slow pulling additives and ultrapure water for crystalline silicon cell production into the slow pulling tank, control the addition ratio of slow pulling additives for crystalline silicon cell production to 0.2%, adjust the slow pulling speed to 3 mm / s, and the temperature of the slow pulling tank to 20°C. After the slow pulling is completed, dry at 75°C for 500s and then remove the wafer to obtain the silicon wafer for crystalline silicon cell shown in the figure.
[0094] Example 2
[0095] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer fumaric acid, 0.5 kg of dispersant acrylic acid, 0.5 kg of octadecyltrimethylammonium chloride and 90 kg of water.
[0096] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0097] The silicon wafer to be processed is placed in the pre-cleaning liquid 1 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the silicon wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 1 is added for alkali polishing treatment.
[0098] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0099] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0100] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0101] Example 3
[0102] A slow-pulling additive for producing crystalline silicon cells comprises 10 kg of surface cleaning agent dipropylene glycol butyl ether, 2 kg of stabilizer, 1 kg of dispersant, 1 kg of surfactant and 86 kg of water.
[0103] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0104] Place the silicon wafer to be processed in the pre-cleaning solution 1 for pre-cleaning treatment at a temperature of 50° C. for 100 seconds. After the pre-cleaning is completed, place the wafer in an alkali polishing tank and add the alkali polishing solution 1 for alkali polishing treatment.
[0105] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 100s;
[0106] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0107] After cleaning is completed, add slow pulling additives and ultrapure water for the production of crystalline silicon cells into the slow pulling tank, control the addition ratio of slow pulling additives for the production of crystalline silicon cells to 1.5%, adjust the slow pulling speed to 30 mm / s, and the temperature of the slow pulling tank to 70°C. After the slow pulling is completed, dry at 95°C for 900s and then remove the wafer to prepare the silicon wafer for crystalline silicon cells shown in the figure.
[0108] Example 4
[0109] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0110] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0111] The silicon wafer to be processed is placed in the pre-cleaning liquid 1 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the silicon wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 1 is added for alkali polishing treatment.
[0112] The silicon wafer after alkali polishing is placed in the treatment solution A2 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0113] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0114] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0115] Example 5
[0116] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0117] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0118] The silicon wafer to be processed is placed in pre-cleaning liquid 2 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 1 is added for alkali polishing treatment.
[0119] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0120] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0121] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0122] Example 6
[0123] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0124] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0125] The silicon wafer to be processed is placed in the pre-cleaning liquid 3 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 1 is added for alkali polishing treatment.
[0126] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0127] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0128] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0129] Example 7
[0130] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0131] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0132] The silicon wafer to be processed is placed in pre-cleaning liquid 1 for pre-cleaning treatment at a temperature of 42°C for a treatment time of 65 seconds. After the pre-cleaning is completed, the wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 2 is added for alkali polishing treatment.
[0133] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0134] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0135] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0136] Example 8
[0137] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0138] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0139] The silicon wafer to be processed is placed in pre-cleaning liquid 1 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 3 is added for alkali polishing treatment.
[0140] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0141] After the treatment is completed, it is placed in an acid tank, and pickling liquid 1 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0142] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0143] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0144] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0145] The silicon wafer to be processed is placed in the pre-cleaning liquid 1 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the silicon wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 1 is added for alkali polishing treatment.
[0146] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0147] After the treatment is completed, it is placed in an acid tank, and pickling liquid 2 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0148] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0149] Example 10
[0150] A slow-pulling additive for producing crystalline silicon cells comprises 8 kg of surface cleaning agent dipropylene glycol butyl ether, 1 kg of stabilizer sodium benzoate, 0.5 kg of dispersant sodium dodecyl sulfate, 0.5 kg of alkylphenol polyoxyethylene ether and 90 kg of water.
[0151] A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production comprises the following preparation steps:
[0152] The silicon wafer to be processed is placed in the pre-cleaning liquid 1 for pre-cleaning treatment at a temperature of 42° C. for a treatment time of 65 seconds. After the pre-cleaning is completed, the silicon wafer is placed in an alkali polishing tank and alkali polishing treatment liquid 1 is added for alkali polishing treatment.
[0153] The silicon wafer after alkali polishing is placed in the treatment solution A1 at a treatment temperature of 45-65°C for a treatment time of 65s;
[0154] After the treatment is completed, it is placed in an acid tank, and pickling liquid 3 is added for pickling treatment, and then washed with water until the acid value is within the control range of the production line;
[0155] After cleaning is completed, slow pulling additives and ultrapure water for the production of crystalline silicon cells are added to the slow pulling tank, the addition ratio of the slow pulling additives for the production of crystalline silicon cells is controlled to be 0.8%, the slow pulling speed is adjusted to 18 mm / s, and the temperature of the slow pulling tank is 45°C. After the slow pulling is completed, it is dried at 85°C for 700s and then removed to prepare the silicon wafers for the crystalline silicon cells shown in the figure.
[0156] Comparative Example 1
[0157] A method for producing silicon wafers for crystalline silicon cells. Compared with Example 1, no slow-pulling additive for crystalline silicon cell production is added, and the remaining steps are the same as those in Example 1.
[0158] Performance Testing
[0159] The silicon wafers for producing crystalline silicon cells prepared in Examples 1-10 and Comparative Example 1 were tested, specifically to detect the surface defects:
[0160] The results are shown in Table 1 below:
[0161] Table 1 Performance test table
[0162]
[0163]
[0164] From the above examples 1-10 and comparative example 1, combined with the test results in Table 1, it can be found that:
[0165] The present application optimizes the slow-pulling additive components, and uses a surface cleaner to remove impurities on the surface of the silicon wafer to improve the surface smoothness. The stabilizer helps maintain the uniform dispersion of the additive, ensuring the stability of the additive performance throughout the entire manufacturing process. Finally, the addition of dispersants and surfactants further improves the fluidity and distribution of the additive in the liquid, reduces the generation of bubbles, and reduces surface contamination caused by residual water, thereby improving the yield of the battery cell.
[0166] from Figure 1 As can be seen from Table 1, the slow pulling additive component prepared in the present application is used in the silicon wafer processing process, which can effectively improve the number of watermarks on the silicon wafer surface. It can be seen from Table 1 that the number of watermarks in Comparative Example 1 is higher than the number of watermarks in Examples 1-10 of the present application, indicating that the slow pulling additive prepared in the present application can significantly improve the surface tension of the liquid in the slow pulling trough, thereby effectively improving the surface performance of the prepared silicon wafer material, and improving the efficiency and yield of the subsequently prepared crystalline silicon solar cells.
[0167] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.
[0168] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.
[0169] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.
[0170] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.
Claims
1. A slow pulling additive for crystalline silicon cell production, characterized in that: Composed of the following percentages: 5-10% surface cleaner; 0.5-2% stabilizer; 0.05-1% dispersant; 0.05-1% surfactant; The remaining component is water.
2. The slow pulling additive for crystalline silicon cell production according to claim 1, characterized in that: The surface cleaning agent includes one or more combinations of small molecule organic matter, small molecule ethers, and small molecule alcohols.
3. The slow pulling additive for crystalline silicon cell production according to claim 1, characterized in that: The stabilizer includes one or more combinations of butylated hydroxytoluene, fumaric acid, and sodium benzoate.
4. The slow pulling additive for crystalline silicon cell production according to claim 1, characterized in that: The dispersant includes one or more combinations of HPMA, acrylic acid, and sodium dodecyl sulfate.
5. The slow pulling additive for crystalline silicon cell production according to claim 1, characterized in that: The surfactant includes one or more combinations of anionic surfactants, cationic surfactants, nonionic surfactants, and fluorocarbon surfactants.
6. A method for producing silicon wafers for crystalline silicon cells using the slow pulling additive for crystalline silicon cell production according to any one of claims 1 to 5, characterized in that: The method comprises the following preparation steps: Place the silicon wafer to be processed in a pre-cleaning solution for pre-cleaning, and then perform alkaline polishing on it after the pre-cleaning is completed; The silicon wafer after alkali polishing is cleaned and placed in a slow pulling tank, slow pulling additives and ultrapure water are added, the slow pulling speed is adjusted to 3-30mm / s, and the temperature of the slow pulling tank is adjusted to 20-70°C. After the slow pulling is completed, the wafer is dried and removed to prepare the silicon wafer for the crystalline silicon cell shown in the figure.
7. A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production according to claim 6, characterized in that: The pre-cleaning solution comprises the following substances in parts by weight: 0.2-0.5 parts of alkali; 2-5 parts H2O2; 95-105 parts water; The base includes any one of potassium hydroxide or sodium hydroxide.
8. The method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production according to claim 6, characterized in that: The cleaning process comprises the following steps: After the alkaline polishing treatment, the silicon wafer is placed in the treatment liquid A for cleaning treatment. After the cleaning treatment is completed, it is placed in the pickling tank for pickling treatment. After the pickling treatment is completed, it is continued to be washed with water until the washing liquid is neutral, and the cleaning treatment step can be completed.
9. A method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for crystalline silicon cell production according to claim 8, characterized in that: The alkali polishing treatment is carried out using an alkali polishing treatment liquid, and the alkali polishing treatment liquid includes the following substances in parts by weight: 0.2-1.0 parts of alkali; 0.5-5 parts H2O2; 95-105 parts water; The base includes any one of potassium hydroxide or sodium hydroxide.
10. The method for producing silicon wafers for crystalline silicon cells using a slow-pulling additive for producing crystalline silicon cells according to claim 8, characterized in that: The pickling solution in the pickling tank comprises the following substances in parts by weight: 1-15 parts HCl; 0-10 parts HF; 95-105 parts water.