Cleaning method of solar cell texturing cleaning tank and texturing method

Abstract

The invention relates to a cleaning method of a solar cell texturing cleaning tank and a texturing method, and belongs to the technical field of solar cell manufacturing. The cleaning solution of the solar cell texturing cleaning tank is composed of the following raw materials in percentage by weight: 0.3%-0.5% of NaOH, 0.5%-1% of hydrogen peroxide, 0.3%-0.6% of a cleaning additive and the balance of a pure water solvent. The cleaning solution of the solar cell texturing cleaning tank comprises the cleaning additive, and the cleaning additive can assist in reducing consumption of sodium hydroxide and hydrogen peroxide and can also effectively remove inorganic particles and organic stains on the surface of a silicon wafer, so that the cost of chemicals and the danger in the using process are greatly reduced, and the service life of the solar cell texturing cleaning tank is prolonged. And meanwhile, an ideal cleaning effect can be achieved after cleaning of the cleaning tank.

Description

Technical Field

[0001] The invention relates to the technical field of solar cell manufacturing, and in particular to a cleaning method of a solar cell texturing cleaning tank and a texturing method. Background Art

[0002] With the rapid development of photovoltaic and electronic industries, silicon wafers are important raw materials in these industries, and their surface cleanliness has a vital impact on the quality and performance of products. In the manufacturing process of solar cells, the texturing process is a crucial link. It forms a pyramid structure by corroding the silicon wafer to increase the number of light refractions and reduce the reflectivity, thereby enhancing the ability to absorb light.

[0003] In the traditional texturing process, high-concentration sodium hydroxide and hydrogen peroxide are usually used as cleaning solutions in the pre-cleaning and post-cleaning operations of the texturing process. Hydrogen peroxide, as a strong oxidant, mainly cleans the organic matter on the surface of the silicon wafer. Its oxidation can decompose the organic matter adsorbed on the surface of the silicon wafer and effectively remove these pollutants. Sodium hydroxide mainly plays a dissolving and cleaning role in the cleaning process. It can remove impurities such as colorants and colloids in the tank and improve the quality of the velvet surface. In addition, sodium hydroxide can also enhance the oxidizing property of hydrogen peroxide, further improving the cleaning effect.

[0004] However, the consumption of hydrogen peroxide in the traditional texturing process is huge, which not only increases the production cost, but also the treatment of hydrogen peroxide is a huge expense. Therefore, researching and developing an efficient and low-cost cleaning process for the texturing process is of great significance to improving the technical level and market competitiveness of the photovoltaic industry. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a cleaning method of a solar cell texturing cleaning tank and a texturing method. The technical solution of the present invention is as follows:

[0006] In a first aspect, a method for cleaning a solar cell texturing cleaning tank is provided, comprising:

[0007] S20, preparing a cleaning solution for a texturing cleaning tank, wherein the cleaning solution for the texturing cleaning tank is composed of the following raw materials in percentage by weight: 0.3%-0.5% NaOH, 0.5%-1% hydrogen peroxide, 0.3%-0.6% cleaning additive, and the remainder being pure water solvent;

[0008] S30, during the pre-cleaning and / or post-cleaning of the texturing process, the single crystal silicon wafer is placed in a cleaning solution in a cleaning tank for reaction at a reaction temperature of 65-75°C for a reaction time of 100-140s to clean impurities, oxides and damaged layers on the surface of the single crystal silicon wafer.

[0009] Optionally, the cleaning additive is composed of the following raw materials: sodium benzoate, surfactant, deionized water, chelating agent, wetting agent, surfactant and preservative, wherein the content of sodium benzoate is 0.2%, the content of surfactant is 3.0%, the content of deionized water is 94.4%, and the content of other chemical components is 2.4%.

[0010] Optionally, the surfactant is sodium dodecyl sulfonate; the chelating agent is ethylenediaminetetraacetic acid, sodium polyphosphate or 2-(benzimidazol-1-yl)-ethylamine; the wetting agent is ethanol; the surfactant is fatty acid glyceride or sodium styrene sulfonate; and the preservative is isothiazolinone.

[0011] In a second aspect, a texturing method for a solar cell is provided, which adopts the cleaning method of the solar cell texturing cleaning tank described in the first aspect, comprising:

[0012] S1, preparing a cleaning solution for the texturing cleaning tank: preparing a cleaning solution for the texturing cleaning tank according to the components and mass percentages of the cleaning solution for the texturing cleaning tank;

[0013] S2, pre-cleaning: placing the single crystal silicon wafer in the cleaning solution of the texturing cleaning tank for reaction at a temperature of 65-75°C for a reaction time of 100-140s to clean the surface impurities, oxides and damaged layers of the single crystal silicon wafer;

[0014] S3, water washing;

[0015] S4, velveting;

[0016] S5, water washing;

[0017] S6, post-cleaning: placing the single crystal silicon wafer in the cleaning solution of the texturing cleaning tank for reaction at a temperature of 65-75°C for a reaction time of 100-140s to clean the surface impurities, oxides and damaged layers of the single crystal silicon wafer;

[0018] S7, pickling;

[0019] S8, water washing;

[0020] S9, pre-dehydration;

[0021] S10, drying.

[0022] Optionally, the texturing in S4 comprises: immersing the single crystal silicon wafer in a mixed aqueous solution of 0.8-1.4% by mass of NaOH and 0.5-1.0% by mass of a texturing additive at 80-84° C. for 400-440 seconds.

[0023] Optionally, the water washing in S3, S5 and S8 includes: immersing the single crystal silicon wafer in flowing deionized water for 100-140 seconds.

[0024] Optionally, the pickling in S7 includes: immersing the single crystal silicon wafer in a mixed aqueous solution of 0.2-0.6% by mass HF and 0.8-1.2% by mass HCl at 15-30° C. for 100-160 seconds.

[0025] Optionally, the pre-dehydration in S9 includes: immersing the single crystal silicon wafer in flowing deionized water at 60-80° C. for 20-60 seconds.

[0026] Optionally, the drying in S10 includes: drying the single crystal silicon wafer in an oven at a temperature of 85-95° C. for 600-800 seconds.

[0027] All the above optional technical solutions can be combined arbitrarily, and the present invention does not provide detailed descriptions of the structures after the combinations.

[0028] By means of the above scheme, the beneficial effects of the present invention are as follows:

[0029] The cleaning method of setting a solar cell texturing cleaning tank includes preparing a cleaning solution of the texturing cleaning tank, and the cleaning solution of the texturing cleaning tank is composed of the following raw materials in weight percentage: NaOH 0.3%-0.5%, hydrogen peroxide 0.5%-1%, cleaning additives 0.3%-0.6%, and the rest is pure water solvent. Compared with the components and contents of the cleaning solution in the cleaning tank of the traditional texturing process, the dosage of sodium hydroxide and hydrogen peroxide is optimized. The use of cleaning additives can not only help reduce the consumption of sodium hydroxide and hydrogen peroxide, but also effectively remove the adsorption of inorganic particles and organic stains on the surface of silicon wafers, greatly reducing the cost of chemicals and the danger of the use process, and at the same time can ensure that the ideal cleaning effect is achieved after the cleaning tank is cleaned.

[0030] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flow chart of a texturing method for a solar cell provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0033] The embodiment of the present invention provides a method for cleaning a solar cell texturing cleaning tank, which comprises:

[0034] S20, preparing a cleaning solution for a texturing cleaning tank, wherein the cleaning solution for the texturing cleaning tank is composed of the following raw materials in percentage by weight: 0.3%-0.5% NaOH, 0.5%-1% hydrogen peroxide, 0.3%-0.6% cleaning additive, and the remainder being pure water solvent;

[0035] S30, during the pre-cleaning and / or post-cleaning of the texturing process, the single crystal silicon wafer is placed in a cleaning solution in a cleaning tank for reaction at a reaction temperature of 65-75°C for a reaction time of 100-140s to clean impurities, oxides and damaged layers on the surface of the single crystal silicon wafer.

[0036] It should be noted that the present invention does not specifically limit the components of the cleaning additive. For example, a cleaning additive available on the market may be selected.

[0037] In a specific embodiment, the cleaning additive is composed of the following raw materials: sodium benzoate, surfactant, deionized water, chelating agent, wetting agent, surfactant and preservative, wherein the content of sodium benzoate is 0.2%, the content of surfactant is 3.0%, the content of deionized water is 94.4%, and the content of other chemical components is 2.4%.

[0038] In a specific embodiment, the surfactant is sodium dodecyl sulfate, in a specific embodiment, the chelating agent is ethylenediaminetetraacetic acid, sodium polyphosphate or 2-(benzimidazol-1-yl)-ethylamine, the wetting agent is ethanol; the surfactant is fatty acid glyceride or sodium styrene sulfonate; the preservative is isothiazolinone.

[0039] The content of the chelating agent, wetting agent, surfactant and preservative is not specifically limited in the embodiment of the present invention, and can be flexibly adjusted according to the texturing requirements during the specific implementation. For example, the content of the chelating agent, wetting agent, surfactant and preservative is 1%, 0.3%, 0.5% and 0.6% respectively.

[0040] Chelating agents can chelate metal ions, leaving no metal residue on the surface of single crystal silicon wafers. Wetting agents can enhance wettability, making it easier for organic matter to separate from single crystal silicon wafers. Surfactants can enhance the decontamination ability and reduce the interfacial energy of single crystal silicon wafers. Preservatives can prevent additives from spoiling.

[0041] The embodiment of the present invention also provides a solar cell texturing method, which adopts the above-mentioned solar cell texturing cleaning tank cleaning method, such as Figure 1 As shown, including:

[0042] S1, preparing a cleaning solution for a texturing cleaning tank: preparing a cleaning solution for a texturing cleaning tank according to the components and mass percentages of the cleaning solution for the texturing cleaning tank described above;

[0043] S2, pre-cleaning: placing the single crystal silicon wafer in the cleaning solution of the texturing cleaning tank configured in S1 for reaction at a reaction temperature of 65-75°C for a reaction time of 100-140s to clean the impurities, oxides and damaged layers on the surface of the single crystal silicon wafer;

[0044] S3, water washing;

[0045] S4, velveting;

[0046] S5, water washing;

[0047] S6, post-cleaning: placing the single crystal silicon wafer in the cleaning solution of the texturing cleaning tank configured in S1 for reaction at a reaction temperature of 65-75°C for a reaction time of 100-140s to clean the surface impurities, oxides and damaged layers of the single crystal silicon wafer;

[0048] S7, pickling;

[0049] S8, water washing;

[0050] S9, pre-dehydration;

[0051] S10, drying.

[0052] In a specific embodiment, the texturing in S4 includes: soaking the single crystal silicon wafer in a mixed aqueous solution of 0.8-1.4% by mass of NaOH and 0.5-1.0% by mass of a texturing additive at 80-84° C. for 400-440 seconds. As for the specific components of the texturing additive, the above-mentioned texturing additives can be used, and the embodiment of the present invention does not specifically limit this.

[0053] In a specific embodiment, the water washing in S3, S5 and S8 includes: immersing the single crystal silicon wafer in flowing deionized water for 100-140 seconds.

[0054] In a specific embodiment, the pickling in S7 includes: immersing the single crystal silicon wafer in a mixed aqueous solution of 0.2-0.6% by mass HF and 0.8-1.2% by mass HCl at 15-30° C. for 100-160 seconds.

[0055] In a specific embodiment, the pre-dehydration in S9 includes: immersing the single crystal silicon wafer in flowing deionized water at 60-80° C. for 20-60 seconds.

[0056] In a specific embodiment, the drying in S10 includes: drying the single crystal silicon wafer in an oven at a temperature of 85-95° C. for 600-800 seconds.

[0057] In order to verify the beneficial effects of the texturing method for solar cells provided by the embodiments of the present invention, the following embodiments and comparative examples are provided below.

[0058] Example

[0059] The texturing method of the solar cell provided in this embodiment comprises the following steps:

[0060] S1, preparing a cleaning solution for a texturing cleaning tank: preparing a cleaning solution for a texturing cleaning tank according to the components and mass percentages of the cleaning solution for the texturing cleaning tank described above;

[0061] Among them, the cleaning solution of the solar cell texturing cleaning tank is composed of the following raw materials in weight percentage: NaOH 0.42%, hydrogen peroxide 0.72%, cleaning additive 0.43%, and the rest is pure water solvent; the cleaning additive is composed of the following raw materials: sodium benzoate, surfactant (sodium dodecyl sulfate), deionized water, chelating agent, wetting agent, surfactant and preservative; among them, the content of sodium benzoate is 0.2%, the content of surfactant is 3.0%, the content of deionized water is 94.4%, and the contents of chelating agent, wetting agent, surfactant and preservative are 1%, 0.3%, 0.5% and 0.6% respectively.

[0062] S2, water washing: immerse the single crystal silicon wafer in flowing deionized water for 120s;

[0063] S3, pre-cleaning: immerse the single crystal silicon wafer in a mixed aqueous solution of 0.41% by mass NaOH, 1.0% by mass H2O2 and 0.43% by mass cleaning additive at 70°C for 120s;

[0064] S4, texturing, immersing the single crystal silicon wafer in a mixed aqueous solution of 1.2% by mass NaOH and 0.61% by mass texturing additive at 82° C. for 420 s;

[0065] S5, water washing, immersing the single crystal silicon wafer in flowing deionized water for 120 seconds;

[0066] S6, post-cleaning: immerse the single crystal silicon wafer in a mixed aqueous solution of 0.41% by mass of NaOH, 1.0% by mass of H2O2 and 0.43% by mass of a cleaning additive at 70° C. for 120 s;

[0067] S7, pickling: immersing the single crystal silicon wafer in a mixed aqueous solution of 0.5% by mass HF and 1% by mass HCl for 120 seconds at 20°C;

[0068] S8, water washing, immersing the single crystal silicon wafer in flowing deionized water for 120 seconds;

[0069] S9, pre-dehydration: immerse the single crystal silicon wafer in flowing deionized water at 70°C for 20s;

[0070] S10, drying: drying the single crystal silicon wafer in an oven at a temperature of 95° C. for 700 seconds.

[0071] Comparative Example

[0072] The texturing method of the solar cell provided in this comparative example comprises the following steps:

[0073] S1, preparing a cleaning solution for the texturing cleaning tank: preparing a cleaning solution for the texturing cleaning tank according to the components and mass percentages of the cleaning solution for the texturing cleaning tank;

[0074] The cleaning solution of the solar cell texturing cleaning tank is composed of the following raw materials in weight percentage: NaOH 1.10%, H2O2 1.52%, and the rest is pure water solvent;

[0075] S2, water washing: immerse the single crystal silicon wafer in flowing deionized water for 120s;

[0076] S3, pre-cleaning: immerse the single crystal silicon wafer in a mixed aqueous solution of 1.10% by mass NaOH and 1.52% by mass H2O2 at 70°C for 120s;

[0077] S4, texturing, immersing the single crystal silicon wafer in a mixed aqueous solution of 1.2% by mass NaOH and 0.61% by mass texturing additive at 82° C. for 420 s;

[0078] S5, water washing: immersing the single crystal silicon wafer in flowing deionized water for 120 seconds;

[0079] S6, post-cleaning: immerse the single crystal silicon wafer in a mixed aqueous solution of 1.10% by mass NaOH and 1.52% by mass H2O2 at 70°C for 120s;

[0080] S7, pickling: immersing the single crystal silicon wafer in a mixed aqueous solution of 0.5% by mass HF and 1% by mass HCl for 120 seconds at 20°C;

[0081] S8, water washing: immersing the single crystal silicon wafer in flowing deionized water for 120 seconds;

[0082] S9, pre-dehydration: immerse the single crystal silicon wafer in flowing deionized water at 70°C for 20s;

[0083] S10, drying: drying the single crystal silicon wafer in an oven at a temperature of 95° C. for 700 seconds.

[0084] The comparison results of the electrical properties of the solar cells obtained by the texturing of the embodiment and the comparative example are shown in Table 1.

[0085] Table 1

[0086]

[0087] As shown in Table 1, the efficiency gain of the embodiment is 0.003% compared with the comparative example, and the efficiency is basically the same. The electrical properties of the monocrystalline silicon wafers after pre-cleaning and post-cleaning in the embodiment have no negative impact, and the appearance of the finished solar cell is normal.

[0088] In addition, the cleaning solution, cleaning solution cleaning process and texturing process of the solar cell texturing cleaning tank provided by the embodiments of the present invention can achieve the ideal effect after the cleaning tank is cleaned while reducing the amount of sodium hydroxide and hydrogen peroxide used and reducing costs, as shown in the chemical consumption comparison table of the embodiment and the comparative example in Table 2 below.

[0089] Table 2

[0090]

[0091]

[0092] As shown in Table 2, the embodiment saves 28.56L of H2O2 solution per 10,000 pieces, and the consumption rate is 45.63%, and the NaOH solution saves 1.62L per 10,000 pieces, and the consumption rate is 27.36%. That is to say, the present invention is particularly suitable for cleaning single crystal solar cells with low chemical consumption and low cost.

[0093] In summary, the cleaning solution of the solar cell texturing cleaning tank provided by the present invention can not only reduce the consumption of sodium hydroxide and hydrogen peroxide, effectively reducing the production cost of the solar cell manufacturing end, but also improve the cleaning effect, thereby improving the photoelectric conversion efficiency of the solar cell.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for cleaning a solar cell texturing cleaning tank, characterized in that: include: S20, preparing a cleaning solution for a texturing cleaning tank, wherein the cleaning solution for the texturing cleaning tank is composed of the following raw materials in percentage by weight: 0.3%-0.5% NaOH, 0.5%-1% hydrogen peroxide, 0.3%-0.6% cleaning additive, and the remainder being pure water solvent; S30, during the pre-cleaning and / or post-cleaning of the texturing process, the single crystal silicon wafer is placed in a cleaning solution in a cleaning tank for reaction at a reaction temperature of 65-75°C for a reaction time of 100-140s to clean impurities, oxides and damaged layers on the surface of the single crystal silicon wafer.

2. The cleaning method of the solar cell texturing cleaning tank according to claim 1, characterized in that: The cleaning additive is composed of the following raw materials: sodium benzoate, surfactant, deionized water, chelating agent, wetting agent, surfactant and preservative, wherein the content of sodium benzoate is 0.2%, the content of surfactant is 3.0%, the content of deionized water is 94.4%, and the content of other chemical components is 2.4%.

3. The cleaning method of the solar cell texturing cleaning tank according to claim 1, characterized in that: The surfactant is sodium dodecyl sulfonate; the chelating agent is ethylenediaminetetraacetic acid, sodium polyphosphate or 2-(benzimidazole-1-yl)-ethylamine; the wetting agent is ethanol; the surfactant is fatty acid glyceride or sodium styrene sulfonate; and the preservative is isothiazolinone.

4. A method for making a texture of a solar cell, characterized in that: The cleaning method of the solar cell texturing cleaning tank according to any one of claims 1 to 3 comprises: S1, preparing a cleaning solution for the texturing cleaning tank: preparing a cleaning solution for the texturing cleaning tank according to the components and mass percentages of the cleaning solution for the texturing cleaning tank; S2, pre-cleaning: placing the single crystal silicon wafer in the cleaning solution of the texturing cleaning tank for reaction at a temperature of 65-75°C for a reaction time of 100-140s to clean the surface impurities, oxides and damaged layers of the single crystal silicon wafer; S3, water washing; S4, velveting; S5, water washing; S6, post-cleaning: placing the single crystal silicon wafer in the cleaning solution of the texturing cleaning tank for reaction at a temperature of 65-75°C for a reaction time of 100-140s to clean the surface impurities, oxides and damaged layers of the single crystal silicon wafer; S7, pickling; S8, water washing; S9, pre-dehydration; S10, drying.

5. The method for making a texturing process for a solar cell according to claim 4, characterized in that: The texturing in S4 comprises: soaking the single crystal silicon wafer in a mixed aqueous solution of 0.8-1.4% by mass of NaOH and 0.5-1.0% by mass of a texturing additive at 80-84° C. for 400-440 seconds.

6. The method for making a texturing process for a solar cell according to claim 4, characterized in that: The water washing in S3, S5 and S8 includes: immersing the single crystal silicon wafer in flowing deionized water for 100-140 seconds.

7. The method for texturing a solar cell according to claim 4, characterized in that: The pickling in S7 includes: immersing the single crystal silicon wafer in a mixed aqueous solution of 0.2-0.6% by mass HF and 0.8-1.2% by mass HCl at 15-30° C. for 100-160 seconds.

8. The method for texturing a solar cell according to claim 4, characterized in that: The pre-dehydration in S9 includes: soaking the single crystal silicon wafer in flowing deionized water at 60-80° C. for 20-60 seconds.

9. The method for texturing a solar cell according to claim 4, characterized in that: The drying in S10 includes: drying the single crystal silicon wafer in an oven at a temperature of 85-95° C. for 600-800 seconds.

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