A solid-liquid additive for single crystal silicon alkali texturing and preparation method thereof

Abstract

The present invention discloses a solid-liquid additive for alkali texturing of single crystal silicon and a preparation method thereof. The solid-liquid additive comprises a liquid component and a solid component; based on 100% of the total mass of the solid component, the solid component comprises 5-20% of a dispersant, 65-80% of a defoaming agent, and 5-20% of a surfactant; based on 100% of the total mass of the liquid component, the liquid component comprises 5-15% of a texturing regulator, 1-10% of a surfactant, 1-10% of an organic acid, and the remainder is water. The additive prepared by the present invention has a long shelf life and the liquid component also has good low-temperature storage performance, which can reduce production and transportation costs and effectively improve the photoelectric conversion efficiency of single crystal silicon.

Description

Technical Field

[0001] The present invention relates to the technical field of single crystal silicon texturing additives, and more specifically, to a single crystal silicon alkali texturing solid-liquid additive and a preparation method thereof. Background Art

[0002] The monocrystalline silicon alkali texturing process is a key step in the manufacture of solar cells. It aims to form a layer of micro-nano structure, the so-called texture, on the surface of the monocrystalline silicon wafer by chemical etching. This structure can enhance the absorption of light, especially increase the scattering of light and reduce surface reflection, thus improving the photoelectric conversion efficiency of solar cells.

[0003] Existing single crystal silicon alkali texturing additives are all liquids, and the system solvent is water, which has many disadvantages: 1. The production of single crystal silicon alkali texturing additives is generally to stir and dissolve the raw materials at room temperature before filling. The efficiency of stirring and dissolving at room temperature is low, the filling process is quite labor-intensive and material-intensive, and the production is time-consuming and labor-intensive; 2. Since the proportion of solvent water in the composition of single crystal silicon alkali texturing additives is very high (generally higher than 90%), the transportation occupies a large volume and has high transportation costs; 3. Since single crystal silicon alkali texturing additives are transported and stored under aqueous solution conditions, it is inevitable that chemical and biological changes and losses of the raw materials will occur, resulting in a short shelf life of the product (generally about 60 days) and a short storage cycle, which is not conducive to large-scale production. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a single crystal silicon alkali texturing solid-liquid additive and a preparation method thereof. The obtained additive has a long shelf life and the liquid component also has good low-temperature storage performance, which can significantly reduce production and transportation costs and effectively improve the photoelectric conversion efficiency of single crystal silicon.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A solid-liquid additive for alkali texturing of single crystal silicon, the solid-liquid additive comprising a liquid component and a solid component 2-5 times the mass of the liquid component; based on 100% of the total mass of the solid component, the solid component comprises 5-20% of a dispersant, 65-80% of a defoaming agent, and 5-20% of a surfactant; based on 100% of the total mass of the liquid component, the liquid component comprises 5-15% of a texturing regulator, 1-10% of a surfactant, 1-10% of an organic acid, and the remainder is water.

[0007] Furthermore, in the solid component, the dispersant is at least one of tetrasodium xylenol orange, sodium lignin sulfonate, and sodium dodecyl sulfate.

[0008] Furthermore, in the solid component, the defoaming agent is at least one of cationic starch, carrageenan and sesbania gum.

[0009] Furthermore, in the solid component, the surfactant is at least one of fatty alcohol polyoxyethylene ether, polyoxyethylene ether, and water-soluble silicone oil.

[0010] Furthermore, in the liquid component, the suede conditioning agent is at least one of triethylene glycol, propylene glycol, ethylene glycol, and dimethylacetamide;

[0011] Furthermore, in the liquid component, the surfactant is at least one of konjac gum, polyvinyl alcohol, polyacrylamide, and sophorolipid biosurfactant;

[0012] Furthermore, in the liquid component, the organic acid is at least one of potassium sorbate, sodium benzoate and potassium glycyrrhizinate.

[0013] Furthermore, the solid-liquid additive includes a liquid component and a solid component that is 3 times the mass of the liquid component; based on 100% of the total mass of the solid component, the solid component includes 15% of a dispersant, 80% of a defoaming agent and 5% of a surfactant; based on 100% of the total mass of the liquid component, the liquid component includes 10% of a suede regulator, 6% of a surfactant, 3% of an organic acid, and the remainder is water.

[0014] A method for preparing a solid-liquid additive for alkali texturing of single crystal silicon as described above, wherein the solid component preparation method is: at a humidity of less than 50% and a temperature of 20-30°C, the dispersant and the defoaming agent are crushed and mixed evenly, and then a surfactant is added to continue crushing and mixing evenly; the liquid component preparation method is: a texturing regulator, a surfactant and an organic acid are added to water in sequence and mixed evenly.

[0015] The beneficial effects of the present invention are:

[0016] By rationally optimizing the compatibility of each component, a solid-liquid additive for alkali texturing of single crystal silicon composed of a solid component and a liquid component is obtained, which has better liquid low-temperature storage performance, greatly extends the shelf life of the product (usually the shelf life of liquid single crystal silicon alkali texturing additive is about 60 days), and significantly reduces the production and transportation costs; after alkali texturing with the solid-liquid additive, the single crystal silicon has a uniform texture and low reflectivity, which effectively improves the photoelectric conversion efficiency of the single crystal silicon; especially when tetrasodium dimethylol orange is used as a solid component dispersant, dimethylacetamide is used as a liquid component texture regulator, and konjac gum and sophora biosurfactant are used as liquid component surfactants for compounding, the synergistic effect between tetrasodium dimethylol orange and dimethylacetamide, konjac gum, and sophora biosurfactant can be further exerted, thereby further improving the storage performance of the additive and the photoelectric conversion efficiency of the single crystal silicon after texturing. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The single crystal silicon alkali texturing solid-liquid additive of the present invention comprises a liquid component and a solid component with a mass 2-5 times that of the liquid component.

[0019] Based on 100% of the total weight of the solid component, the solid component includes 5-20% of a dispersant, 65-80% of a defoaming agent, and 5-20% of a surfactant; the dispersant is at least one of tetrasodium dimethylol orange, sodium lignin sulfonate, and sodium dodecyl sulfate; the defoaming agent is at least one of cationic starch, carrageenan, and sesbania gum; the surfactant is at least one of fatty alcohol polyoxyethylene ether (preferably AEO-9, AEO-7, or AEO-25), polyoxyethylene ether (chemical formula H(OCH2CH2)n OH, preferably polyethylene glycol 2000), and water-soluble silicone oil (preferably polyether-modified silicone oil, more preferably PEG-12 polydimethylsiloxane or PEG-10 polydimethylsiloxane). At a humidity of less than 50% and a temperature of 20-30°C, the dispersant and the defoaming agent are crushed and mixed evenly, and then the surfactant is added to continue crushing and mixing evenly to obtain the solid component.

[0020] Based on 100% of the total mass of the liquid component, the liquid component includes 5-15% of a suede regulator, 1-10% of a surfactant, 1-10% of an organic acid, and the balance is water; the suede regulator is at least one of triethylene glycol, glycerol, ethylene glycol, and dimethylacetamide; the surfactant is at least one of konjac gum, polyvinyl alcohol, polyacrylamide, and sophorolipid biosurfactant; the organic acid is at least one of potassium sorbate, sodium benzoate, and potassium glycyrrhizinate. The suede regulator, the surfactant, and the organic acid are sequentially added to the water and mixed evenly (each raw material is stirred and mixed until the solution is clarified before adding the next raw material) to obtain the liquid component.

[0021] Example 1

[0022] The solid component formula is: dispersant tetrasodium xylenol orange 10%, sodium lignin sulfonate 5%, defoaming agent cationic starch 80%, surfactant fatty alcohol polyoxyethylene ether (AEO-9) 5%. At a humidity of 40% and a temperature of 25°C, tetrasodium xylenol orange, sodium lignin sulfonate, and cationic starch are added in sequence and crushed and mixed evenly, and AEO-9 is added and continued to be crushed and mixed evenly to obtain the solid component.

[0023] The liquid component formula is: 6% triethylene glycol, 4% glycerol, 5% surfactant konjac gum, 1% polyvinyl alcohol-2000, 3% organic acid potassium sorbate, and 81% water. Triethylene glycol, glycerol, konjac gum, polyvinyl alcohol-2000 and potassium sorbate are added to water in sequence and mixed evenly (each raw material is stirred and mixed until the solution is clear before adding the next raw material) to obtain the liquid component.

[0024] Example 2

[0025] The solid component formula is: dispersant tetrasodium xylenol orange 10%, sodium lignin sulfonate 5%, defoaming agent cationic starch 80%, surfactant fatty alcohol polyoxyethylene ether (AEO-9) 5%. At a humidity of 40% and a temperature of 25°C, tetrasodium xylenol orange, sodium lignin sulfonate, and cationic starch are added in sequence and crushed and mixed evenly, and AEO-9 is added and continued to be crushed and mixed evenly to obtain the solid component.

[0026] The liquid component formula is: suede conditioning agent triethylene glycol 6%, dimethylacetamide 4%, surfactant konjac gum 2%, sophorolipid 3%, polyvinyl alcohol-2000 1%, organic acid potassium sorbate 3%, water 81%. Triethylene glycol, dimethylacetamide, konjac gum, sophorolipid, polyvinyl alcohol-2000 and potassium sorbate are added to water in sequence and mixed evenly (each raw material is stirred and mixed until the solution is clear before adding the next raw material) to obtain a liquid component.

[0027] Example 3

[0028] The solid-liquid additive for single crystal silicon alkali texturing is prepared according to the method of Example 2, except that the dispersant of the solid component is 15% sodium lignin sulfonate.

[0029] Example 4

[0030] The solid-liquid additive for alkali texturing of single crystal silicon was prepared according to the method of Example 2, except that the dispersant of the solid component was 10% sodium dodecyl sulfate and 5% sodium lignin sulfonate.

[0031] Example 5

[0032] The solid-liquid additive for alkali texturing of single crystal silicon is prepared according to the method of Example 2, except that the texturing regulator of the liquid component is 10% triethylene glycol.

[0033] Example 6

[0034] The solid-liquid additive for alkali texturing of single crystal silicon is prepared according to the method of Example 2, except that the texturing regulator of the liquid component is 10% ethylene glycol.

[0035] Example 7

[0036] The solid-liquid additive for alkali texturing of single crystal silicon is prepared according to the method of Example 2, except that the texturing regulator of the liquid component is 6% triethylene glycol, 2% propylene glycol, and 3% ethylene glycol.

[0037] Example 8

[0038] The solid-liquid additive for alkali texturing of single crystal silicon was prepared according to the method of Example 2, except that the surfactant of the liquid component was 3% sophorolipid and 3% polyvinyl alcohol-2000.

[0039] Example 9

[0040] The single crystal silicon alkali texturing solid-liquid additive was prepared according to the method of Example 2, except that the surfactant of the liquid component was 2% konjac gum and 4% polyvinyl alcohol-2000.

[0041] Example 10

[0042] The solid-liquid additive for alkali texturing of single crystal silicon was prepared according to the method of Example 2, except that the surfactant of the liquid component was 6% sophorolipid biosurfactant.

[0043] Embodiment 11

[0044] The solid-liquid additive for alkali texturing of single crystal silicon was prepared according to the method of Example 2, except that the surfactant of the liquid component was 6% konjac gum.

[0045] Example 12

[0046] The single crystal silicon alkali texturing solid-liquid additive was prepared according to the method of Example 2, except that the surfactant of the liquid component was 2% konjac gum, 1% polyvinyl alcohol-2000, and 3% polyacrylamide.

[0047] Embodiment 13

[0048] The solid-liquid additive for alkali texturing of single crystal silicon was prepared according to the method of Example 2, except that the surfactant of the liquid component was 3% sophorolipid, 1% polyvinyl alcohol-2000, and 2% polyacrylamide.

[0049] After the preparation of the solid-liquid additive for alkali texturing of single crystal silicon in Example 1-Example 13 was completed, alkali texturing was carried out at 1% NaOH, 80°C, and 1% solid-liquid additive for alkali texturing of single crystal silicon (mass ratio of solid component to liquid component = 3:1) for 7 minutes; and alkali texturing was carried out with a commercially available single crystal silicon alkali texturing additive (which is an aqueous solution purchased from Hangzhou Feilu New Energy Technology Co., Ltd., model MT-051) under the same conditions as Comparative Example 1. The performance of the additives in Example 1-Example 13 and Comparative Example 1 and the performance of the single crystal silicon after texturing are shown in Table 1.

[0050] Table 1

[0051] index Pyramid size / μm Pyramid height / μm Number of pyramids ratio Reflectivity / % Storage stability of liquid components at -5°C Room temperature shelf life Example 1 1.035 1.078 2859 1.345 10.42 Delamination after 34 days 12 months Example 2 1.039 1.159 2947 1.286 9.23 Delamination after 49 days 14 months Example 3 1.036 1.076 2872 1.331 10.37 Delamination after 47 days 14 months Example 4 1.035 1.071 2866 1.342 10.42 Delamination after 49 days 14 months Example 5 1.034 1.073 2876 1.357 10.44 Delamination after 32 days 12 months Example 6 1.033 1.077 2870 1.348 10.31 Delamination after 33 days 12 months Example 7 1.036 1.081 2885 1.324 10.33 Delamination after 35 days 12 months Example 8 1.037 1.074 2865 1.332 10.47 Delamination after 37 days 12 months Example 9 1.035 1.065 2880 1.343 10.35 Delamination after 36 days 12 months Example 10 1.032 1.043 2834 1.352 10.45 Delamination after 31 days 12 months Embodiment 11 1.034 1.056 2820 1.377 10.53 Delamination after 34 days 12 months Example 12 1.036 1.092 2881 1.345 10.61 Delamination after 37 days 12 months Embodiment 13 1.038 1.083 2873 1.341 10.48 Delamination after 35 days 12 months Comparative Example 1 1.042 1.091 2903 1.352 11.46 Delamination after 18 days February

[0052] As can be seen from Table 1, the single crystal silicon alkali texturing solid-liquid additives prepared in Examples 1 to 13 have a long shelf life and good liquid component stability. After texturing with the single crystal silicon alkali texturing solid-liquid additives prepared in Examples 1 to 13, the single crystal silicon has a uniform texture and low reflectivity. The single crystal silicon alkali texturing solid-liquid additive prepared in Example 2 has a longer shelf life and better liquid component stability, and after texturing with the additive, the single crystal silicon has a lower reflectivity and better photoelectric conversion rate. It can be seen that there is a synergistic effect between tetrasodium dimethyl cresol orange, dimethylacetamide, konjac gum, and sophora biosurfactant, thereby further improving the performance of the single crystal silicon alkali texturing solid-liquid additive.

[0053] Embodiment 14

[0054] The solid component formula is: 5% tetrasodium xylenol orange, 77% carrageenan, and 18% PEG-12 polydimethylsiloxane. Under a humidity of 40% and a temperature of 30°C, tetrasodium xylenol orange and carrageenan are added in sequence and crushed and mixed evenly, and PEG-12 polydimethylsiloxane is added, and the crushing and mixing are continued to obtain the solid component.

[0055] The liquid component formula is: 15% of velvet conditioning agent triethylene glycol, 7% of surfactant konjac gum, 1% of organic acid potassium sorbate, and 77% of water. Triethylene glycol, konjac gum and potassium sorbate are added to water in sequence and mixed evenly (each raw material is stirred and mixed until the solution is clear before adding the next raw material) to obtain the liquid component.

[0056] Embodiment 15

[0057] The solid component formula is: 20% tetrasodium xylenol orange, 69% sesbania gum, and 11% fatty alcohol polyoxyethylene ether (AEO-25). At a humidity of 40% and a temperature of 30°C, tetrasodium xylenol orange and sesbania gum are added in sequence and crushed and mixed evenly, and AEO-25 is added, and the crushing and mixing are continued to obtain the solid component.

[0058] The liquid component formula is: 5% triethylene glycol, 10% sophorolipid biosurfactant, 3% potassium sorbate, and 82% water. Triethylene glycol, sophorolipid biosurfactant, and potassium sorbate are added to water in sequence and mixed evenly (each raw material is stirred and mixed until the solution is clear before adding the next raw material) to obtain the liquid component.

[0059] Example 16

[0060] The solid component formula is: sodium lignin sulfonate 18%, cationic starch 65%, polyethylene glycol 2000 17%. At a humidity of 40% and a temperature of 30°C, sodium lignin sulfonate and cationic starch are added in sequence and crushed and mixed evenly, and polyethylene glycol 2000 is added, and the crushing and mixing are continued to obtain the solid component.

[0061] The liquid component formula is: 10% dimethylacetamide, 1% konjac gum, 5% sodium benzoate, and 84% water. Dimethylacetamide, konjac gum, and sodium benzoate are added to water in sequence and mixed evenly (each raw material is stirred and mixed until the solution is clear before adding the next raw material) to obtain the liquid component.

[0062] Embodiment 17

[0063] The solid component formula is: 8% sodium lignin sulfonate, 72% carrageenan, and 20% polyethylene glycol 2000. At a humidity of 40% and a temperature of 30°C, sodium lignin sulfonate and carrageenan are added in sequence and crushed and mixed evenly, and polyethylene glycol 2000 is added, and the crushing and mixing are continued to obtain the solid component.

[0064] The liquid component formula is: 10% of suede regulator dimethylacetamide, 8% of sophorolipid biosurfactant, 10% of potassium glycyrrhizinate, and 72% of water. Dimethylacetamide, sophorolipid and potassium glycyrrhizinate are added to water in sequence and mixed evenly (each raw material is stirred and mixed until the solution is clear before adding the next raw material) to obtain the liquid component.

[0065] After the preparation of the single crystal silicon alkali texturing solid-liquid additive of Example 14-Example 17 was completed, alkali texturing was carried out at 1% NaOH, 80°C, and 1% single crystal silicon alkali texturing solid-liquid additive (mass ratio of solid component to liquid component = 4:1) for 7 minutes. The properties of the additives prepared in Example 14-Example 17 and the properties of the single crystal silicon after texturing are shown in Table 2.

[0066] Table 2

[0067] index Pyramid size / μm Pyramid height / μm Number of pyramids ratio Reflectivity / % Storage stability of liquid components at -5°C Room temperature shelf life Embodiment 14 1.034 1.071 2855 1.311 10.22 Delamination after 35 days 12 months Embodiment 15 1.035 1.067 2851 1.30 10.34 Delamination after 36 days 12 months Example 16 1.031 1.044 2839 1.342 10.51 Delamination after 33 days 12 months Embodiment 17 1.032 1.052 2843 1.336 10.48 Delamination after 34 days 12 months

[0068] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A solid-liquid additive for single crystal silicon alkali texturing, characterized in that: The solid-liquid additive comprises a liquid component and a solid component of 2-5 times the mass of the liquid component; based on 100% of the total mass of the solid component, the solid component comprises 5-20% of a dispersant, 65-80% of a defoaming agent, and 5-20% of a surfactant; based on 100% of the total mass of the liquid component, the liquid component comprises 5-15% of a suede regulator, 1-10% of a surfactant, 1-10% of an organic acid, and the remainder is water; In the solid component, the dispersant is at least one of tetrasodium xylenol orange, sodium lignin sulfonate, and sodium dodecyl sulfate; In the solid component, the degassing agent is at least one of cationic starch, carrageenan and sesbania gum; In the solid component, the surfactant is at least one of fatty alcohol polyoxyethylene ether, polyoxyethylene ether, and water-soluble silicone oil; In the liquid component, the suede conditioning agent is at least one of triethylene glycol, propylene glycol, ethylene glycol, and dimethylacetamide; In the liquid component, the surfactant is at least one of konjac gum, polyvinyl alcohol, polyacrylamide, and sophorolipid biosurfactant; In the liquid component, the organic acid is at least one of potassium sorbate, sodium benzoate and potassium glycyrrhizinate.

2. The solid-liquid additive for single crystal silicon alkali texturing according to claim 1, characterized in that: The solid-liquid additive includes a liquid component and a solid component that is three times the mass of the liquid component; based on 100% of the total mass of the solid component, the solid component includes 15% of a dispersant, 80% of a defoaming agent and 5% of a surfactant; based on 100% of the total mass of the liquid component, the liquid component includes 10% of a suede regulator, 6% of a surfactant, 3% of an organic acid, and the remainder is water.

3. A method for preparing the solid-liquid additive for single crystal silicon alkali texturing according to any one of claims 1-2, characterized in that: The solid component preparation method is as follows: at a humidity of less than 50% and a temperature of 20-30°C, the dispersant and the defoaming agent are crushed and mixed uniformly, and then a surfactant is added to continue crushing and mixing uniformly; The preparation method of the liquid component is as follows: add a suede conditioner, a surfactant and an organic acid into water in sequence and mix them evenly.