Texturing agent composition and texturing liquid

Abstract

The invention relates to a texturing agent composition and a texturing solution. The texturing agent composition is prepared from the following components based on the total weight: 0.001 to 20 weight percent of nucleating agent, 0.00001 to 10 weight percent of dispersing agent, 0.001 to 20 weight percent of corrosion inhibitor, 0.001 to 20 weight percent of surfactant, 0.001 to 10 weight percent of alkaline substance and water. According to the texturing agent composition disclosed by the invention, a plurality of auxiliaries are compounded to play a synergistic role, so that the prepared texturing liquid can realize efficient texturing of a silicon wafer, and the textured silicon wafer is low in weight loss rate and high in stability, and can meet the process requirements in the production and manufacturing process of solar cells including but not limited to heterojunction solar cells.

Description

Technical Field

[0001] The present disclosure relates to a texturing agent composition and a texturing liquid, which are mainly used in the production and manufacturing process of solar cells, including but not limited to heterojunction cells, and belongs to the field of solar cell manufacturing. Background Art

[0002] Crystalline silicon solar cells are solar cells based on silicon. With their mature technology and high conversion efficiency, they have taken a leading position in commercial applications. Heterojunction (HJT) solar cells are a new type of high-efficiency solar cells based on N-type silicon wafers. They have attracted much attention due to their excellent photoelectric conversion efficiency and future cost-effectiveness.

[0003] Monocrystalline silicon is a common substrate material for preparing solar cells. After the surface is textured, it can not only reduce the reflectivity of the surface, but also make the light enter the cell at an angle to increase the optical path, effectively improving the photoelectric conversion efficiency of the cell. As a force that cannot be ignored, the thinning of silicon wafers is gradually becoming one of the core trends that promote the development of crystalline silicon solar cells. Of course, this process is also accompanied by a series of new technical challenges, such as increased processing difficulty and increased risk of fragmentation. The thinning of silicon wafers also puts forward higher requirements for the texture process, that is, while ensuring the quality of the velvet structure, the weight loss of silicon wafers during the texture process is controlled to reduce the risk of silicon wafer breakage in subsequent processes.

[0004] In view of the texturing requirements for matching thin silicon wafers, there is an urgent need in the art to develop a texturing agent composition and a texturing liquid that can achieve efficient texturing of silicon wafers, with low weight loss rate and high stability of the silicon wafers after texturing. Summary of the invention

[0005] The present disclosure provides a texturing agent composition, comprising the following components based on the total weight of the texturing agent composition:

[0006] Nucleating agent 0.001-20wt%,

[0007] Dispersant 0.00001-10wt%,

[0008] Corrosion inhibitor 0.001-20wt%,

[0009] Surfactant 0.001-20wt%,

[0010] Alkaline substance 0.001-10wt%,

[0011] water;

[0012] Wherein, the sum of the weight percentages of the components of the texturing agent composition is 100wt%;

[0013] The nucleating agent is an amino polysaccharide polymer;

[0014] The dispersant is one or more of aromatic ring formaldehyde condensates, pyrrolidone ring substances and polyethylene imine substances;

[0015] The corrosion inhibitor is one or more of polymeric polyols and polyethers;

[0016] The surfactant is an ethoxylate surfactant.

[0017] In one embodiment, the aminopolysaccharide polymer is selected from one or more of chondroitin sulfate, keratan sulfate, hyaluronic acid, chitosan and derivatives thereof; the chitosan derivative can be selected from one or more of carboxymethyl chitosan, N,N-dicarboxymethyl chitosan, hydroxypropyl chitosan and carboxyethyl chitosan.

[0018] In one embodiment, the aminopolysaccharide polymer is selected from one or more of chondroitin sulfate, keratan sulfate and hyaluronic acid.

[0019] In one embodiment, the aromatic ring formaldehyde condensate is an aromatic sulfonic acid compound formaldehyde condensate or an aromatic sulfonate compound formaldehyde condensate, preferably one or more selected from naphthalenesulfonic acid formaldehyde condensate, benzylnaphthalenesulfonic acid formaldehyde condensate, and sodium methylnaphthalenesulfonate formaldehyde condensate;

[0020] The pyrrolidone ring substance is selected from one or more of N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone and polyvinylpyrrolidone;

[0021] The polyethyleneimine substance is selected from one or more of branched polyethyleneimine and linear polyethyleneimine.

[0022] In one embodiment, the dispersant is a pyrrolidone ring substance, preferably one or more selected from N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and polyvinyl pyrrolidone.

[0023] In one embodiment, the corrosion inhibitor is a polyether, preferably one or more selected from the group consisting of fatty alcohol polyoxyethylene ether, aromatic alcohol polyoxyethylene ether, amide polyoxyalkyl ether, fatty amine polyoxyethylene ether, and polyethanolamine polyoxyethylene ether.

[0024] In one embodiment, the surfactant is selected from one or more of fatty acid methyl ester ethoxylates, fatty alcohol ethoxylates, ethoxylated castor oil, and polyethyleneimine ethoxylates.

[0025] In one embodiment, the alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, sodium carbonate, sodium hypochlorite, sodium sulfite and sodium pyrosulfite.

[0026] In one embodiment, based on the total weight of the texturing agent composition, the nucleating agent accounts for 0.001-15wt%, preferably 0.002-10wt%, more preferably 0.002-8wt%; and / or

[0027] Based on the total weight of the texturing agent composition, the dispersant accounts for 0.00001-8wt%, preferably 0.00001-5wt%, more preferably 0.00002-4wt%; and / or

[0028] Based on the total weight of the texturing agent composition, the corrosion inhibitor accounts for 0.001-15wt%, preferably 0.001-10wt%, more preferably 0.002-5wt%; and / or

[0029] Based on the total weight of the texturing agent composition, the surfactant accounts for 0.001-15wt%, preferably 0.005-15wt%, more preferably 0.01-10wt%, and / or

[0030] Based on the total weight of the texturing agent composition, the alkaline substance accounts for 0.001-8 wt %, preferably 0.002-8 wt %, and more preferably 0.01-5 wt %.

[0031] The present disclosure also provides a texturing liquid, which comprises the texturing agent composition of the present disclosure. In one embodiment, based on the total weight of the texturing liquid, the amount of the texturing agent composition is 0.05-1.5 wt%.

[0032] The texturing agent composition disclosed in the present invention is compounded with a variety of auxiliary agents to exert a synergistic effect, so that the prepared texturing liquid can, on the one hand, achieve efficient texturing of silicon wafers, complete pyramid nucleation within about 390 seconds and quickly form a velvet surface on the silicon surface, obtaining a highly pyramidal velvet structure with excellent uniformity, greatly enhancing the performance of the HJT battery; on the other hand, the weight loss rate of the silicon wafer after texturing is low and the weight loss stability is high, thereby reducing the risk of silicon wafer breakage in subsequent processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 When the texturing liquid formed by the texturing agent composition of Example 2 is used for texturing, the SEM picture of the textured surface of the silicon wafer obtained after texturing;

[0034] Figure 2 This is a SEM picture of the textured surface of a silicon wafer obtained after texturing when the texturing liquid formed by the texturing agent composition in Comparative Example 1 is used for texturing;

[0035] Figure 3This is a SEM picture of the textured surface of a silicon wafer obtained after texturing when the texturing liquid formed by the texturing agent composition in Comparative Example 2 is used for texturing;

[0036] Figure 4 This is a SEM picture of the textured surface of a silicon wafer obtained after texturing when the texturing liquid formed by the texturing agent composition of Comparative Example 3 is used for texturing;

[0037] Figure 5 This is a SEM picture of the textured surface of a silicon wafer obtained after texturing when the texturing liquid formed by the texturing agent composition in Comparative Example 4 is used for texturing. DETAILED DESCRIPTION

[0038] The present disclosure is further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present disclosure will become more clear and distinct.

[0039] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0040] In addition, the technical features involved in different embodiments of the present disclosure described below can be combined with each other as long as they do not conflict with each other.

[0041] The present disclosure provides a texturing agent composition, comprising the following components based on the total weight of the texturing agent composition:

[0042] Nucleating agent 0.001-20wt%,

[0043] Dispersant 0.00001-10wt%,

[0044] Corrosion inhibitor 0.001-20wt%,

[0045] Surfactant 0.001-20wt%,

[0046] Alkaline substance 0.001-10wt%,

[0047] water;

[0048] Wherein, the sum of the weight percentages of the components of the texturing agent composition is 100wt%;

[0049] The nucleating agent is an amino polysaccharide polymer;

[0050] The dispersant is one or more of aromatic ring formaldehyde condensates, pyrrolidone ring substances and polyethylene imine substances;

[0051] The corrosion inhibitor is one or more of polymeric polyols and polyethers;

[0052] The surfactant is an ethoxylate surfactant.

[0053] The present disclosure also relates to a texturing liquid, which comprises the texturing agent composition of the present disclosure. The texturing agent composition can be used as a basis, and each component can be formulated into a texturing agent composition according to a proportional relationship; and an alkaline substance is dissolved in water, and then a certain amount of the texturing agent composition is added to the alkaline solution according to a proportional relationship to obtain the texturing liquid. In one embodiment, based on the total weight of the texturing liquid, the amount of the texturing agent composition is 0.05-1.5wt%.

[0054] The texturing agent composition and various components of the texturing liquid of the present disclosure are further described below. It should be noted that the relevant descriptions about the texturing agent composition are also applicable to the texturing liquid, and vice versa.

[0055] The texturing agent composition disclosed herein comprises a nucleating agent. In the present disclosure, the nucleating agent is an amino polysaccharide polymer. The amino polysaccharide polymer refers to a type of polysaccharide molecule in which monosaccharide units are bonded via amino groups (-NH).

[0056] In one embodiment, the aminopolysaccharide polymer used in the present invention is selected from one or more of chondroitin sulfate, keratan sulfate, hyaluronic acid, chitosan and its derivatives. The chitosan derivative used in the present invention can be selected from one or more of carboxymethyl chitosan, N,N-dicarboxymethyl chitosan, hydroxypropyl chitosan and carboxyethyl chitosan.

[0057] Preferably, the nucleating agent used in the present disclosure is selected from one or more of chondroitin sulfate, keratan sulfate and hyaluronic acid.

[0058] The texturing agent composition disclosed in the present invention comprises a dispersant, which may be one or more of an aromatic ring formaldehyde condensate, a pyrrolidone ring substance and a polyethyleneimine substance.

[0059] In one embodiment, the dispersant is an aromatic ring formaldehyde condensate. Aromatic ring formaldehyde condensates refer to substances generated by condensation reactions of aromatic aldehydes (such as benzaldehyde) and other compounds such as alcohol compounds such as methanol. They can also be formed by condensation reactions of aromatic compounds with active hydrogen on the aromatic ring (such as naphthalenesulfonic acid and its salts, and substituted naphthalenesulfonic acid and its salts) with formaldehyde. The aromatic ring formaldehyde condensate may contain multiple aromatic rings or heteroaromatic rings. In one embodiment, the dispersant may be an aromatic sulfonic acid compound formaldehyde condensate or an aromatic sulfonate compound formaldehyde condensate. Aromatic sulfonic acid compounds and their salts may be naphthalenesulfonic acid, benzylnaphthalenesulfonic acid, methylnaphthalenesulfonic acid and their salts, such as sodium salts, potassium salts, etc. These aromatic sulfonic acid compounds and their salts have active hydrogen on the aromatic ring and can undergo condensation reactions with formaldehyde in the presence of acid or alkali to obtain corresponding condensates. In one embodiment, the aromatic ring formaldehyde condensate is selected from one or more of naphthalenesulfonic acid formaldehyde condensates, benzylnaphthalenesulfonic acid formaldehyde condensates, and methylnaphthalenesulfonic acid sodium formaldehyde condensates. These substances are commercially available. For example, naphthalenesulfonic acid formaldehyde condensate can be purchased from Shanghai Xiaoyan Technology Co., Ltd., benzylnaphthalenesulfonic acid formaldehyde condensate can be purchased from Shenzhen Shengyan Technology Co., Ltd., and methylnaphthalenesulfonic acid sodium formaldehyde condensate can be purchased from Shandong Wenhe New Materials Co., Ltd. (trade name Dispersant MF) 。

[0060] In one embodiment, the dispersant is a pyrrolidone ring substance. The pyrrolidone ring substance refers to a substance with a pyrrolidone ring, for example, it can be selected from one or more of N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and polyvinyl pyrrolidone.

[0061] In one embodiment, the dispersant is a polyethyleneimine substance. In one embodiment, the polyethyleneimine substance can be selected from one or more of branched polyethyleneimine and linear polyethyleneimine.

[0062] In one embodiment, the dispersant is a pyrrolidone ring substance, preferably one or more selected from N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and polyvinyl pyrrolidone.

[0063] The texturing agent composition disclosed herein comprises a corrosion inhibitor, which may be one or more of polymeric polyols and polyethers. The polymeric polyol may be polyethylene glycol, polypropylene glycol, and the like.

[0064] In one embodiment, the corrosion inhibitor is a polyether, preferably one or more selected from fatty alcohol polyoxyethylene ether, aromatic alcohol polyoxyethylene ether, amide polyoxyalkylene ether, fatty amine polyoxyethylene ether, and polyethanolamine polyoxyethylene ether. Fatty alcohol polyoxyethylene ether is a type of ether that can be formed by condensation of polyethylene glycol (PEG) and fatty alcohol, and can be represented by the following general formula: RO(CH2CH2O)n H, wherein n is the degree of polymerization, which can be an integer of 3-20; R can be a saturated or unsaturated C2~C 18 Hydrocarbon groups (e.g. C6~C 18 The hydrocarbon group may be a straight chain hydrocarbon group or a branched hydrocarbon group. For example, fatty alcohol polyoxyethylene ether can be purchased from Changzhou Junxin Plastics Co., Ltd. under the trade name C12-15 fatty alcohol polyoxyethylene ether. Fatty amine polyoxyethylene ether can be represented by the following general formula: RN(CH2CH2O) n H, wherein n is the degree of polymerization, which can be an integer of 2-20; R can be a saturated or unsaturated C2~C 18 Hydrocarbon groups (e.g. C6~C 18 The polyoxyethylene ether of the present invention can be a straight chain polyoxyethylene ether or a branched chain polyoxyethylene ether. For example, the polyoxyethylene ether of the fatty amine can be purchased from Haian Petrochemical Plant, Jiangsu Province under the trade name of dodecylamine polyoxyethylene ether or octadecylamine polyoxyethylene ether. Other polyethers are also known in the art and can be obtained through commercial channels, which will not be described in detail here.

[0065] The texturing agent composition disclosed herein comprises a surfactant, which is an ethoxylate surfactant, and can be selected from one or more of fatty acid methyl ester ethoxylate, fatty alcohol ethoxylate, ethoxylated castor oil, and polyethyleneimine ethoxylate. These ethoxylate surfactants are known in the art and can be obtained through commercial channels, and will not be described in detail here.

[0066] The texturing agent composition disclosed herein comprises an alkaline substance, and the alkaline substance may be selected from, for example, one or more of sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, sodium carbonate, sodium hypochlorite, sodium sulfite and sodium pyrosulfite.

[0067] In one embodiment, based on the total weight of the texturing agent composition, the nucleating agent accounts for 0.001%-20wt%, preferably 0.001-15wt%, preferably 0.002-10wt%, more preferably 0.002-8wt%; and / or

[0068] Based on the total weight of the texturing agent composition, the dispersant accounts for 0.00001-10wt%, preferably 0.00001-8wt%, preferably 0.00001-5wt%, more preferably 0.00002-4wt%; and / or

[0069] Based on the total weight of the texturing agent composition, the corrosion inhibitor accounts for 0.001-20wt%, preferably 0.001-15wt%, preferably 0.001-10wt%, more preferably 0.002-5wt%; and / or

[0070] Based on the total weight of the texturing agent composition, the surfactant accounts for 0.001-20wt%, preferably 0.001-15wt%, preferably 0.005-15wt%, more preferably 0.01-10wt%; and / or

[0071] Based on the total weight of the texturing agent composition, the alkaline substance accounts for 0.001-10 wt %, preferably 0.001-8 wt %, preferably 0.002-8 wt %, more preferably 0.01-5 wt %.

[0072] In one embodiment, the texturing agent composition of the present disclosure may include the following components:

[0073] Hyaluronic acid,

[0074] Pyrrolidone ring substances,

[0075] Polyether,

[0076] Ethoxylated surfactants,

[0077] Alkaline substances, and

[0078] water,

[0079] Among them, based on the total weight of the texturing liquid, hyaluronic acid accounts for 0.001%-20wt%, pyrrolidone ring substances account for 0.00001-10wt%, polyether accounts for 0.001%-20wt%, ethoxylate surfactants account for 0.001-20wt%, and alkaline substances account for 0.001-10wt%; and the sum of the weight percentages of the components of the texturing liquid is 100wt%.

[0080] In one embodiment, based on the total weight of the composition, hyaluronic acid accounts for 0.001%-20wt%, preferably 0.001-15wt%, more preferably 0.002-10wt%; and / or

[0081] Based on the total weight of the texturing agent composition, the pyrrolidone ring substance accounts for 0.00001-10wt%, preferably 0.00001-8wt%, more preferably 0.00002-4wt%; and / or

[0082] Based on the total weight of the texturing agent composition, the polyether accounts for 0.001-20wt%, preferably 0.001-10wt%, more preferably 0.002-5wt%; and / or

[0083] Based on the total weight of the texturing agent composition, the ethoxylate surfactant accounts for 0.001-20wt%, preferably 0.005-15wt%, more preferably 0.01-10wt%; and / or

[0084] Based on the total weight of the texturing agent composition, the alkaline substance accounts for 0.001-8 wt %, preferably 0.002-8 wt %, and more preferably 0.01-5 wt %.

[0085] Texturing is an important step in the manufacturing process of photovoltaic cells. By forming a fine velvet structure on the surface of silicon wafers, it increases the scattering and absorption of light, thereby improving the photoelectric conversion efficiency of photovoltaic cells. For thin silicon wafers, the texturing process has higher requirements, and it is necessary to achieve low weight loss, high weight loss stability and high quality of the velvet surface to reduce the risk of silicon wafer breakage in subsequent processes. Low weight loss in the texturing process means that while ensuring the quality of the velvet structure during the texturing process, the weight loss of the silicon wafer during the texturing process is low.

[0086] As demonstrated in the embodiments of the present disclosure, the texturing agent composition of the present disclosure is compounded with a variety of auxiliary agents to exert a synergistic effect, so that the prepared texturing liquid can, on the one hand, achieve efficient texturing of silicon wafers, complete pyramid nucleation within about 390 seconds and quickly form a velvet surface on the silicon surface, obtaining a highly pyramidal velvet structure with excellent uniformity, greatly enhancing the performance of the HJT battery; on the other hand, the weight loss rate of the silicon wafer after texturing is low and the weight loss stability is high, thereby reducing the risk of silicon wafer breakage in subsequent processes.

[0087] Aminopolysaccharide polymer is used as a nucleating agent and adsorbed on the surface of the silicon wafer, which changes the texturing rate and provides conditions for pyramid nucleation, so that the pyramid velvet structure is quickly formed on the surface of the silicon wafer and is carried out evenly in the subsequent texturing process.

[0088] A dispersant system composed of aromatic ring formaldehyde condensates, pyrrolidone ring substances, and polyethyleneimine substances is used. This system has a multi-electron center and a strong passivation nucleation effect, which promotes the uniform and continuous formation of the pyramid structure. At the same time, the hydrophobicity of the aromatic ring is used together with the amino polysaccharide polymer to maintain the smooth surface of the large pyramid, which is beneficial to the stability of the diffusion resistance.

[0089] By compounding polymer polyols and / or polyether corrosion inhibitors, together with amino polysaccharide polymers, aromatic ring formaldehyde condensates and pyrrolidone ring compounds, through the adsorption of molecular chains, the velvet surface grows rapidly and evenly during the velvet making process, and excessive reaction is prevented, thereby forming a uniform velvet surface structure, reducing weight loss and improving the battery yield.

[0090] The use of surfactants, especially ethoxylated surfactants, can significantly reduce the interfacial tension between the silicon wafer surface and the solvent, promote the formation of a smooth surface on the silicon wafer surface, and cooperate with nucleating agents such as amino polysaccharide polymers to reduce the weight loss of the silicon wafer, thereby improving the yield.

[0091] As pyramid nucleating agents, amino polysaccharide polymers provide necessary active sites in the etching reaction and promote the etching reaction. The addition of dispersants significantly enhances the dispersibility of etching solution on the surface of silicon wafers and optimizes the etching effect. Corrosion inhibitors prevent excessive edge corrosion rate during thinning, which causes the edge of the silicon wafer to be too thin and collapse. Ethoxylated surfactants have surface wettability and can increase the hydrophilicity of silicon wafers. Alkaline substances remove the mechanical damage layer during the wet etching process by reacting with the silicon dioxide on the surface to generate soluble compounds.

[0092] The present disclosure provides a texturing liquid comprising the texturing additive composition of the present disclosure. The texturing liquid further comprises an alkaline substance and water. In one embodiment, the alkaline substance includes an alkali, a metal oxide that becomes an alkali after being dissolved in water, and a salt that is alkaline upon hydrolysis. The alkali may be, for example, an inorganic alkali and / or an organic alkali; preferably, the inorganic alkali is KOH, NaOH, ammonia water and / or calcium hydroxide, and the organic alkali is tetramethylguanidine and / or tetraethylammonium hydroxide. The metal oxide that becomes an alkali after being dissolved in water may be, for example, sodium oxide, potassium oxide and / or calcium oxide. The salt that is alkaline upon hydrolysis may be, for example, a weak acid salt of sodium or potassium, such as sodium carbonate, sodium hypochlorite, sodium sulfite and sodium pyrosulfite, as well as potassium carbonate, potassium hypochlorite, potassium sulfite and potassium pyrosulfite. The alkaline substance may be the same as or different from the alkaline substance contained in the texturing agent composition, but the alkaline substance generally used to prepare the texturing liquid is the same as the alkaline substance contained in the texturing agent composition.

[0093] In one embodiment, the amount of the texturing additive composition is 0.05-1.50 wt %, based on the total weight of the texturing liquid; the amount of the alkaline substance is 0.5-5.5 wt %, based on the total weight of the texturing liquid.

[0094] The texturing liquid can be prepared as follows: in a texturing tank, a certain mass of alkaline substance is dissolved in ultrapure water to prepare an alkaline solution with a mass concentration of 0.5-5.5wt%; then the texturing additive composition disclosed in the present invention is added to the prepared alkaline solution, the content of the texturing additive composition is 0.05-1.5wt% (based on the total weight of the texturing liquid), and the texturing liquid is obtained by stirring evenly.

[0095] When the texturing liquid is used for texturing, the cleaned silicon wafer can be immersed in the texturing liquid. The required texturing time at 75-82°C is within 500s, and the shortest can be 360s, to obtain a thinned silicon wafer that has been texturized. The texturing time of the existing HJT solar cell texturing liquid is about 500s on average. The texturing liquid using the texturing additive composition can reduce the texturing time, improve production efficiency, reduce weight loss, and reduce the production cost of HJT solar cells.

[0096] The inventors of the present disclosure have discovered that the texturing agent composition of the present disclosure contains specific types of nucleating agents, dispersants, corrosion inhibitors and surfactants. When the texturing agent composition is formulated into a texturing liquid for texturing silicon wafers, these components can play a synergistic role in the texturing process, resulting in excellent texturing effects. The weight loss rate of the silicon wafer after texturing is low, which can effectively reduce the risk of silicon wafer breakage in subsequent processes; more importantly, the obtained texturing liquid has good weight loss stability. Even if the texturing time is extended, the weight loss of the silicon wafer still maintains high stability, indicating that extending the etching time will not seriously damage the silicon wafer, and the harshness of the texturing operation can be significantly reduced. The texturing agent composition of the present disclosure optimizes the auxiliary agent combination and is formulated into a texturing liquid for texturing silicon wafers. It can promote the nucleation, growth and uniform dispersion of the pyramids on the silicon wafer, achieving the advantages of low weight loss, high efficiency, and uniform velvet surface, which is beneficial to the subsequent diffusion process.

[0097] The present disclosure also relates to a texturing method and a texturing silicon wafer obtained thereby. Specifically, the texturing method comprises immersing the cleaned silicon wafer to be texturized (e.g., N-type monocrystalline silicon or P-type monocrystalline silicon) in the texturing liquid of the present disclosure, and performing the texturing operation at 75-82° C. The texturing time can be within 500 seconds, and the shortest can be 360 ​​seconds.

[0098] In addition, the present disclosure also relates to a solar cell (especially a single crystal silicon HJT cell), which includes the texturized silicon wafer described above in the present disclosure.

[0099] Examples and Comparative Examples

[0100] The texturing solution for single crystal silicon wafers is prepared as follows:

[0101] (1) Preparation of texturing agent composition: Weigh the corresponding substances according to Table 1-1 to Table 1-3, stir the components evenly, and filter through a 500-mesh nylon filter cloth to remove particles to obtain a silicon wafer texturing agent composition.

[0102] (2) Preparation of texturing liquid: In a texturing tank, a certain mass of potassium hydroxide is dissolved in ultrapure water to prepare an alkaline solution with a mass concentration of 4 wt%, and then the texturing additive composition prepared in (1) is added to the prepared alkaline solution. The content of the texturing additive composition is 0.45 wt% (based on the total weight of the texturing liquid). After bubbling and stirring evenly, the texturing liquid is obtained.

[0103] Velveting process:

[0104] The cleaned silicon wafer is immersed in the texturing solution at 80°C for 390 seconds. The texturing silicon wafer is cleaned with deionized water, and the deionized water on the surface of the silicon wafer is blown dry with high-purity nitrogen.

[0105] Afterwards, the weight loss rate, average reflectivity, five-point reflectivity deviation and average velvet size of the silicon wafer were measured:

[0106] Weight loss rate = (original silicon wafer weight - silicon wafer weight after texturing) / original silicon wafer weight

[0107] The reflectivity and five-point reflectivity deviation range are obtained by the D8 reflectivity tester, the average velvet size is obtained by the field emission scanning electron microscope (Zeiss Gemini SEM 500), and the weight loss rate is calculated by weighing the silicon wafer before and after the velvet process using an electronic balance. The large deviation of the five-point reflectivity indicates that the appearance uniformity of the velvet silicon wafer is poor. Combined with the SEM photos, the uniformity of the pyramid distribution can be confirmed.

[0108] Confirmation of silicon wafer texturing stability: The cleaned silicon wafer is immersed in the texturing solution at 80°C for 600 seconds. The silicon wafer after texturing is cleaned with deionized water, and the deionized water on the surface of the silicon wafer is blown dry with high-purity nitrogen. The weight loss rate of 600-second etching is measured and compared with the weight loss rate of 390-second etching.

[0109] The results are shown in Tables 2-1 to 2-3 respectively.

[0110] The raw materials used in the examples and comparative examples can be obtained through commercial channels, as shown below.

[0111] Nucleating Agent

[0112] A1: Chondroitin sulfate, purchased from Shanghai Yuanye Biotechnology Co., Ltd., analytical grade standard;

[0113] A2: hyaluronic acid, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., molecular weight 100,000-200,000;

[0114] A3: Keratan sulfate, purchased from Jinan Glacon Biotechnology Co., Ltd., purity >90%;

[0115] A4: carboxymethyl chitosan, purchased from Shanghai Yuanye Biotechnology Co., Ltd., with a carboxylation degree ≥ 80%;

[0116] NA: sodium carboxymethyl cellulose, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., with a viscosity of 600-3000 mPa.s;

[0117] Dispersants

[0118] B1: N-methyl-2-pyrrolidone, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.;

[0119] B2: naphthalenesulfonic acid formaldehyde condensate, purchased from Shanghai Xiaoyan Technology Co., Ltd.;

[0120] B3: Polyethyleneimine, purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., molecular weight 600-100000;

[0121] B4: polyvinyl pyrrolidone, purchased from Guangdong Yuemei Chemical Co., Ltd., PVPK10-120;

[0122] NB: fatty acid ethylene oxide, purchased from Shandong Wanhua Tianhe New Materials Co., Ltd., with a molecular weight of 3000-5000;

[0123] Corrosion Inhibitor:

[0124] C1: fatty amine polyoxyethylene ether, purchased from Hubei Xinmingtai Chemical Co., Ltd.;

[0125] C2: fatty alcohol polyoxyethylene ether, purchased from Nantong Deyi Chemical Co., Ltd.;

[0126] C3: polyethylene glycol, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., PEG-200-800;

[0127] NC: pentanediol, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.;

[0128] Surfactants

[0129] D1: fatty acid methyl ester ethoxylate, purchased from Shanghai MacLean Biochemical Technology Co., Ltd., purity ≥70%;

[0130] D2: fatty alcohol ethoxylate, purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.;

[0131] D3: ethoxylated castor oil, purchased from Hubei Xinhongli Chemical Co., Ltd.;

[0132] ND: Alkyl glucamide, purchased from Shaanxi Cuikang Pharmaceutical Technology Co., Ltd.

[0133] Table 1-1

[0134] Group Nucleating Agent Dispersants Corrosion Inhibitor Surfactants Alkaline substances water Example 1 A1,10g B1,0.2g C1,5g D1,1g KOH, 15g 2kg Example 2 A2,10g B1,0.2g C1,5g D1,1g KOH, 15g 2kg Example 3 A3,10g B1,0.2g C1,5g D1,1g KOH, 15g 2kg Example 4 A4,10g B1,0.2g C1,5g D1,1g KOH, 15g 2kg Comparative Example 1 NA,10g B1,0.2g C1,5g D1,1g KOH, 15g 2kg

[0135] Table 1-2

[0136] Group Nucleating Agent Dispersants Corrosion Inhibitor Surfactants Alkaline substances water Example 5 A2,10g B2,0.05g C1,5g D1,1g KOH, 15g 2kg Example 6 A2,10g B3,0.1g C1,5g D1,1g KOH, 15g 2kg Comparative Example 2 A2,10g NB,0.1g C1,5g D1,1g KOH, 15g 2kg Example 7 A2,10g B1,0.2g C2,10g D1,1g KOH, 15g 2kg Example 8 A2,10g B1,0.2g C3,100g D1,1g KOH, 15g 2kg Comparative Example 3 A2,10g B1,0.2g NC,50g D1,1g KOH, 15g 2kg Example 9 A2,10g B1,0.2g C1,5g D2,1g KOH, 15g 2kg Example 10 A2,10g B1,0.2g C1,5g D3,0.2g KOH, 15g 2kg Comparative Example 4 A2,10g B1,0.2g C1,5g ND,0.05g KOH, 15g 2kg

[0137] Table 1-3

[0138]

[0139] Table 2-1

[0140]

[0141] Table 2-2

[0142]

[0143] Table 2-3

[0144] Group Weight loss rate at 390s (%) Weight loss rate at 600s (%) Embodiment 13 7.45 8.60 Embodiment 14 7.76 8.90 Embodiment 15 8.27 9.45 Example 16 7.86 8.99 Embodiment 17 7.49 8.71 Embodiment 18 7.97 9.21 Embodiment 19 8.11 9.32 Embodiment 20 8.24 9.51

[0145] Figure 1 The SEM picture of the textured surface of the silicon wafer obtained after the texturing is shown when the texturing liquid formed by the texturing agent composition of Example 2 is used for texturing. It can be seen that the pyramids on the surface of the silicon wafer are evenly distributed in size and completely cover the silicon wafer, and the texturing effect is excellent; Figure 2-5 The SEM pictures of the texturing surface of the silicon wafer obtained by texturing the texturing liquid formed by the texturing agent composition of comparative examples 1-4 are shown. It can be seen that the surface of the silicon wafer is not completely covered with pyramids, and the texturing effect is not good.

[0146] From the test results of Table 2-1 to Table 2-3, it can be seen that the weight loss rate of the single crystal silicon wafer using the texturing agent composition disclosed in the present invention is low (less than 9%) when etching for 390s, which can effectively reduce the risk of silicon wafer breakage in subsequent processes; the weight loss rate is still maintained at a low level (less than 10%) after being delayed to 600s, indicating that the weight loss stability is high, indicating that even if the etching time is extended, the silicon wafer will not be seriously damaged, and the harshness of the texturing operation can be significantly reduced; at the same time, combined with the SEM image, it is found that they all have good pyramid distribution uniformity and texturing appearance uniformity, which is conducive to the application of thin-film single crystal silicon texturing.

[0147] The present disclosure has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, various replacements and improvements may be made to the present disclosure, all of which fall within the scope of protection of the present disclosure.

Claims

1. A texturing agent composition, comprising the following components based on the total weight of the texturing agent composition: Nucleating agent 0.001-20wt%, Dispersant 0.00001-10wt%, Corrosion inhibitor 0.001-20wt%, Surfactant 0.001-20wt%, Alkaline substance 0.001-10wt%, water; in, The sum of the weight percentages of the components of the texturing agent composition is 100wt%; The nucleating agent is an amino polysaccharide polymer; The dispersant is one or more of aromatic ring formaldehyde condensates, pyrrolidone ring substances and polyethylene imine substances; The corrosion inhibitor is one or more of polymeric polyols and polyethers; The surfactant is an ethoxylate surfactant.

2. The texturing agent composition according to claim 1, wherein The aminopolysaccharide polymer is selected from one or more of chondroitin sulfate, keratan sulfate, hyaluronic acid, chitosan and derivatives thereof; the chitosan derivative can be selected from one or more of carboxymethyl chitosan, N,N-dicarboxymethyl chitosan, hydroxypropyl chitosan and carboxyethyl chitosan.

3. The texturing agent composition according to claim 1, wherein The aminopolysaccharide polymer is selected from one or more of chondroitin sulfate, keratan sulfate and hyaluronic acid.

4. The texturing agent composition according to claim 1, wherein The aromatic ring formaldehyde condensate is an aromatic sulfonic acid compound formaldehyde condensate or an aromatic sulfonate compound formaldehyde condensate, preferably one or more selected from naphthalenesulfonic acid formaldehyde condensate, benzylnaphthalenesulfonic acid formaldehyde condensate, and sodium methylnaphthalenesulfonate formaldehyde condensate; The pyrrolidone ring substance is selected from one or more of N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone and polyvinylpyrrolidone; The polyethyleneimine substance is selected from one or more of branched polyethyleneimine and linear polyethyleneimine.

5. The texturing agent composition according to claim 1, wherein The dispersant is a pyrrolidone ring substance, preferably one or more selected from N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, and polyvinyl pyrrolidone.

6. The texturing agent composition according to claim 1, wherein The corrosion inhibitor is a polyether, preferably one or more selected from the group consisting of fatty alcohol polyoxyethylene ether, aromatic alcohol polyoxyethylene ether, amide polyoxyalkyl ether, fatty amine polyoxyethylene ether, and polyethanolamine polyoxyethylene ether.

7. The texturing agent composition according to claim 1, wherein The surfactant is selected from one or more of fatty acid methyl ester ethoxylate, fatty alcohol ethoxylate, ethoxylated castor oil, and polyethyleneimine ethoxylate.

8. The texturing agent composition according to claim 1, wherein The alkaline substance is selected from one or more of sodium hydroxide, potassium hydroxide, ammonia water, calcium hydroxide, sodium carbonate, sodium hypochlorite, sodium sulfite and sodium pyrosulfite.

9. The texturing agent composition according to claim 1, wherein Based on the total weight of the texturing agent composition, the nucleating agent accounts for 0.001-15wt%, preferably 0.002-10wt%, more preferably 0.002-8wt%; and / or Based on the total weight of the texturing agent composition, the dispersant accounts for 0.00001-8wt%, preferably 0.00001-5wt%, more preferably 0.00002-4wt%; and / or Based on the total weight of the texturing agent composition, the corrosion inhibitor accounts for 0.001-15wt%, preferably 0.001-10wt%, more preferably 0.002-5wt%; and / or Based on the total weight of the texturing agent composition, the surfactant accounts for 0.001-15wt%, preferably 0.005-15wt%, more preferably 0.01-10wt%, and / or Based on the total weight of the texturing agent composition, the alkaline substance accounts for 0.001-8 wt %, preferably 0.002-8 wt %, and more preferably 0.01-5 wt %.

10. A texturing liquid comprising the texturing agent composition according to any one of claims 1 to 9.

11. The texturing liquid according to claim 10, wherein: Based on the total weight of the texturing liquid, the amount of the texturing agent composition is 0.05-1.5 wt %.

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