An alcohol-free monocrystalline silicon stabilizing texturing additive, its preparation method and use

Abstract

The present invention provides an alcohol-free single crystal silicon stable texturing additive, a texturing liquid containing the same, a preparation method and use thereof, wherein the alcohol-free single crystal silicon stable texturing additive comprises the following components in the following weight proportions: 1-15 parts of a main corrosion inhibitor; 0.5-3 parts of a secondary corrosion inhibitor; 0.5-6 parts of a surfactant; 1-25 parts of a small molecule sugar; 30-60 parts of an inorganic base; and 30-60 parts of deionized water. The alcohol-free single crystal silicon stable texturing additive of the present invention has excellent velvet surface uniformity, and at the same time successfully solves the problem of easy oxidation of catechol derivative corrosion inhibitors, effectively improving the stability of the texturing system. The present invention also discloses a texturing liquid, comprising the above-mentioned alcohol-free single crystal silicon stable texturing additive, an alkaline solution and deionized water. The texturing liquid containing the alcohol-free single crystal silicon stable texturing additive is used for single crystal silicon texturing, which has the advantages of high efficiency, stability and rapidity.

Description

Technical Field

[0001] The present invention relates to a single crystal silicon surface treatment technology, in particular to an alcohol-free single crystal silicon stable texturing additive, a texturing liquid containing the same, and a preparation method and use thereof. Background Art

[0002] Solar energy, due to its renewable nature, high energy content, and safe and readily available resources, has become a highly promising renewable energy source. Photovoltaic technology, the primary method for converting solar energy into electricity, has seen decades of progress in developing its key component, solar cells, towards high efficiency and low cost. Currently, silicon-based solar cells dominate the commercial solar cell market, accounting for approximately 92% of total photovoltaic cell production, while the commercial efficiency of monocrystalline silicon solar cells has exceeded 18%. The main limitation to further improving the photoelectric conversion efficiency of monocrystalline silicon solar cells is light loss. Therefore, surface texturing, as the most effective method for reducing light loss in monocrystalline silicon solar cells, has become a key and challenging topic in the modern photovoltaic field. Surface texturing increases the effective optical path length, thereby enhancing light absorption on the silicon wafer surface. This not only improves the efficiency of crystalline silicon solar cells but also reduces their production costs. Currently, both wet chemical etching and dry etching are used for surface texturing. However, wet chemical texturing is the most widely used in industrial applications due to its faster and lower-cost nature. The current industrialized single-crystal silicon texturing process is mainly based on an alkali (KOH or NaOH) alcohol (isopropyl alcohol, abbreviated as IPA) system. The basic principle of single-crystal silicon texturing can be simply attributed to the anisotropic etching caused by the difference in the dangling bond and back bond structure on the silicon wafer surface. The chemical reaction formula can be summarized as follows:

[0003] Si+NaOH+H2O→Na2SiO3+H2↑

[0004] Each silicon atom on the (111) crystal plane of single crystal silicon has one dangling bond and three covalent bonds, while each silicon atom on the (100) crystal plane has two dangling bonds and two covalent bonds. Therefore, etching one silicon atom from the silicon crystal on the (100) crystal plane requires breaking two covalent bonds, while the (111) crystal plane requires breaking three covalent bonds. Obviously, the etching rate of the (100) crystal plane is higher than that of the (111) crystal plane, and the difference in etching rate between the two crystal planes can even be as high as one hundred times. Therefore, the "pyramid" microstructure is finally formed on the surface of the crystalline silicon by utilizing this etching rate difference. Alkali is used as a corrosive agent, and <100> Anisotropic selective chemical etching is performed on the Si surface to form a random, upright "pyramid" texture. IPA acts as a surfactant to improve the wettability of the silicon wafer surface and reduce the surface tension of the texturing solution. This allows the generated H2 to quickly leave the silicon wafer surface, regulating the nucleation process and ultimately achieving a more uniform "pyramid" microstructure across the entire wafer.

[0005] Although the most mature process for commercial monocrystalline silicon texturing is still the alkali-alcohol process, the texturing process involving IPA still has obvious defects. First, the low boiling point (82.6°C) and strong volatility of IPA cause IPA to evaporate continuously during the entire texturing process (the texturing temperature is generally controlled at 80-85°C). This requires continuous replenishment of IPA throughout the texturing process to ensure that its concentration is basically constant. Secondly, IPA is toxic and expensive, which is not friendly to environmental and price control. Furthermore, IPA has a small molecular weight and weak adsorption capacity for silicon, and cannot play a sufficient masking role, thereby affecting the texturing rate, resulting in a larger texturing surface size and a higher reflectivity of the texturing silicon wafer. Therefore, the development of a new alternative alkali solution system has become a key research and development direction for monocrystalline silicon texturing. Based on the alkali-alcohol process, Na2CO3, NaHCO3, Na3PO4, ethylenediamine and tetramethylammonium hydroxide (TMAH) have been successively proposed to replace NaOH or KOH as etchants for texturing of single-crystal silicon surfaces, with good anti-reflection effects; however, the surface uniformity and reaction reproducibility of the texturing are poor, and the reaction time is long (about 1h). In order to further optimize the texturing process, many researchers have also proposed a strategy of using organic acid compounded surfactants to assist nucleation. Although this strategy greatly improves the surface uniformity and reduces the reflectivity, a small amount of alcohol compounds are still required to assist nucleation during the texturing process, and the reaction time is still long. Therefore, the development of a new alcohol-free stable texturing additive system has a more urgent industrial application demand.

[0006] CN112144122A discloses a texturing additive suitable for large-sized single-crystal silicon wafers. The additive comprises: 0.5-10% primary nucleating agent, 0.2-5% supplemental nucleating agent, 0.01-0.1% branching dispersant, 0.05-0.5% degassing agent, and the balance water. This additive uses hydrolyzed sodium polyacrylonitrile as the primary nucleating agent and polyamino acid as a supplemental nucleating agent, addressing the problem of uneven texture within large silicon wafers. The resulting texture offers low reflectivity and a short processing time.

[0007] CN112226819A discloses a texturing additive suitable for thin single-crystal silicon wafers. The additive consists of the following components in percentage by weight: 0.5-5.0% texture nucleating agent, 0.02-0.5% texture corrosion inhibitor, 0.001-0.01% texture size adjuster, and the balance deionized water. Using a water-soluble polymer such as sodium carboxymethyl cellulose as a nucleating agent, this additive solves the problem of fragmentation caused by stress warping after texturing thin single-crystal silicon wafers. The resulting solar cells exhibit stable short-circuit current with minimal fluctuation.

[0008] CN111321471B discloses a low-weight-loss single-crystal silicon texturing additive, comprising: 0.01-1% polysaccharide sulfonate, 0.1-3% degassing dispersant, 0.01-1% corrosion inhibitor, 0.05-0.5% water-soluble polymer protective agent, 0.05-2% alkali, and the balance being water. This additive overcomes the shortcomings of existing technologies, such as low production capacity, high weight loss for texturing silicon wafers, high alkali consumption, and short service life.

[0009] The texturing agents disclosed in the aforementioned technologies still suffer from various technical issues, such as the high volatility of alcohols, long texturing times, and poor surface uniformity of the textured silicon wafer surface. Therefore, it is imperative to develop green and environmentally friendly texturing additives with high boiling points and low volatility, and efficient, stable, and rapid texturing. Summary of the Invention

[0010] The purpose of the present invention is to propose a preparation method and use method of a new type of alcohol-free single crystal stable texturing additive to address the problems that the low-boiling point alcohols used in existing texturing additives are extremely volatile and need to be constantly replenished, the texturing time is long, and the texturing surface uniformity of the silicon wafer is poor. The texturing additive has excellent texturing surface uniformity and successfully solves the problem that catechol derivative corrosion inhibitors are easily oxidized, thereby effectively improving the stability of the texturing system.

[0011] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "consisting of..." etc. and similar meanings.

[0012] To achieve the above object, the technical solution adopted by the present invention is: an alcohol-free single crystal silicon stabilizing texturing additive, comprising the following components in the following weight proportions:

[0013]

[0014] Furthermore, the alcohol-free single crystal silicon stable texturing additive does not contain low-boiling point alcohols, and the low-boiling point alcohols refer to alcohols with a boiling point lower than the texturing reaction temperature of 85°C, and the low-boiling point alcohols include but are not limited to isopropyl alcohol and / or ethanol.

[0015] Furthermore, the main corrosion inhibitor is a catechol derivative compound.

[0016] Furthermore, the main corrosion inhibitor is selected from one or more of dopamine hydrochloride, tannic acid, and tea polyphenols.

[0017] Furthermore, the main corrosion inhibitor is preferably dopamine hydrochloride.

[0018] Furthermore, the main corrosion inhibitor is 1-15 parts.

[0019] Furthermore, the main corrosion inhibitor is preferably 5-15 parts.

[0020] Furthermore, the main corrosion inhibitor is more preferably 7-10 parts.

[0021] Furthermore, the secondary corrosion inhibitor is selected from one or more of amines, alcoholamines and amino acid compounds.

[0022] Furthermore, the secondary corrosion inhibitor is selected from one or more of tripropylamine, tributylamine, benzylamine, aniline, N-methylaniline, acetamide, ethylenediamine, 1,6-hexanediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, isobutanolamine, N,N-diethylethanolamine, glycine, serine, tyrosine, alanine, phenylalanine, tryptophan, aspartic acid, glutamic acid, lysine, arginine and histidine.

[0023] Furthermore, the secondary corrosion inhibitor is preferably a triamine or alcoholamine compound.

[0024] Furthermore, the secondary corrosion inhibitor is more preferably an alcoholamine compound.

[0025] Furthermore, the secondary corrosion inhibitor is most preferably triethanolamine.

[0026] Furthermore, the secondary corrosion inhibitor is 0.5-3 parts.

[0027] Furthermore, the secondary corrosion inhibitor is preferably 1-2 parts.

[0028] Furthermore, the mass ratio of the primary corrosion inhibitor to the secondary corrosion inhibitor is 10-1:1.

[0029] Furthermore, the mass ratio of the primary corrosion inhibitor to the secondary corrosion inhibitor is preferably 5-1:1.

[0030] Furthermore, the mass ratio of the primary corrosion inhibitor to the secondary corrosion inhibitor is more preferably 4:1.

[0031] Furthermore, the surfactant is selected from one or more of isooctyl alcohol polyoxyethylene ether monophosphate, methyl laurate ethoxylate, methyl stearate ethoxylate, methyl oleate ethoxylate, methyl cocoate ethoxylate, lauryl alcohol polyoxyethylene ether and cetyl alcohol polyoxyethylene ether.

[0032] Furthermore, the surfactant is preferably one or more of methyl laurate ethoxylate, methyl stearate ethoxylate, methyl oleate ethoxylate and methyl cocoate ethoxylate.

[0033] Furthermore, the surfactant is more preferably methyl stearate ethoxylate.

[0034] Furthermore, the surfactant is 0.5-6 parts.

[0035] Furthermore, the surfactant is preferably 0.5-4 parts.

[0036] Furthermore, the surfactant is more preferably 0.5-2 parts.

[0037] Furthermore, the small molecule sugar is selected from one or more of erythrose, arabinose, glucose, fructose, galactose, sucrose, trehalose, cellobiose, gentiobiose and melibiose.

[0038] Furthermore, the small molecule sugar is preferably glucose.

[0039] Furthermore, the small molecule sugar is 1-25 parts.

[0040] Furthermore, the small molecule sugar is preferably 5-15 parts.

[0041] Furthermore, the small molecule sugar is more preferably 6-10 parts.

[0042] Furthermore, the inorganic alkali solution is selected from NaOH and / or KOH.

[0043] Furthermore, the inorganic alkali solution is 30-60 parts.

[0044] Furthermore, the inorganic alkali solution is preferably 35-45 parts.

[0045] Furthermore, the inorganic alkali solution is more preferably 35-40 parts.

[0046] Furthermore, the inorganic alkali solution is a 1-5 wt% aqueous solution.

[0047] Furthermore, the inorganic alkali solution is preferably a 2-3 wt% aqueous solution.

[0048] Furthermore, the deionized water is 30-60 parts.

[0049] Furthermore, the deionized water is preferably 30-40 parts.

[0050] Another object of the present invention is to disclose a method for preparing the above-mentioned alcohol-free single crystal silicon stabilizing texturing additive, comprising the following steps:

[0051] Step 1: Weigh each component according to the weight ratio;

[0052] Step 2: At room temperature, first add all the components except deionized water to deionized water accounting for 1 / 3-1 / 2 of the total amount, stir magnetically until all the raw materials are completely dissolved, then add the remaining deionized water, and continue stirring for 1-2 hours to obtain an alcohol-free single crystal silicon stable texturing additive.

[0053] Another object of the present invention is to disclose a use of the above-mentioned alcohol-free single crystal silicon stabilizing texturing additive in the field of single crystal silicon etching and texturing.

[0054] Another object of the present invention is to disclose a texturing solution comprising the above-mentioned alcohol-free single crystal silicon stable texturing additive, an alkaline solution and deionized water.

[0055] Furthermore, the mass ratio of the alcohol-free single crystal silicon stabilizing texturing additive to the alkaline solution is 0.5-2:100.

[0056] Furthermore, the mass ratio of the alcohol-free single crystal silicon stabilizing texturing additive to the alkaline solution is preferably 0.5-0.7:100.

[0057] Furthermore, the mass ratio of the alcohol-free single crystal silicon stabilizing texturing additive to the alkaline solution is more preferably 0.6:100.

[0058] Furthermore, the alkaline solution is an aqueous solution of an alkali, and the alkali in the alkaline solution is NaOH and / or KOH.

[0059] Furthermore, the concentration of the alkaline solution is 1-5 wt%.

[0060] Furthermore, the concentration of the alkaline solution is preferably 1-3 wt%.

[0061] Furthermore, the concentration of the alkaline solution is more preferably 2 wt %.

[0062] Furthermore, the deionized water is preferably 40-50 parts.

[0063] Another object of the present invention is to disclose a method for preparing a texturing solution, comprising the following steps: weighing an alcohol-free single crystal silicon stabilizing texturing additive and an inorganic alkali solution, adding them to deionized water at 80-85°C, stirring and mixing them evenly to prepare a single crystal silicon etching texturing solution.

[0064] Another object of the present invention is to disclose a use of the above-mentioned texturing liquid in the field of single crystal silicon etching and texturing.

[0065] Furthermore, the texturing steps are as follows:

[0066] Place the single crystal silicon wafer into the above texturing solution for texturing reaction, the texturing temperature is 80-85℃, the texturing time is 400-500s, take out the single crystal silicon wafer, rinse the front and back of the wafer with deionized water and ethanol respectively, and dry it in N2 atmosphere.

[0067] Furthermore, the texturing temperature is 85°C.

[0068] Furthermore, the texturing time is 450-500s.

[0069] Furthermore, the flushing time is 5-30s, preferably 10-20s, and more preferably 15s.

[0070] The alcohol-free single crystal silicon stable texturing additive and texturing solution of the present invention abandon the traditional alcohol-alkali system and adopt catechol derivative compounds in conjunction with amines and / or alcoholamine compounds, surfactants, small molecule sugars and other high-boiling point substances for texturing. Compared with the existing technology, it has the following advantages:

[0071] 1. The texturing additive of the present invention adopts a catechol derivative corrosion inhibitor, which contains a large number of phenolic hydroxyl groups in its molecules and can be adsorbed on the surface of the silicon wafer through hydrogen bonding or chelation. It can serve as a nucleation starting point to effectively regulate the distribution of the velvet "pyramid" and form a good light-trapping structure on the surface of the silicon wafer. It can also reduce the contact between OH- and the silicon wafer surface, thereby slowing down the etching rate and controlling the weight loss.

[0072] 2. The nitrogen atoms in the amine and amino acid secondary corrosion inhibitors used in this invention can form hydrogen bonds with the phenolic hydroxyl groups in catechol derivatives. The synergistic effect of these inhibitors significantly inhibits the oxidative effects of the catechol derivatives, enhancing molecular stability and effectively improving the stability of the texturing additive and the texturing system. The secondary corrosion inhibitors can also serve as suede modifiers, further enhancing suede density and reducing reflectivity.

[0073] 3. The present invention uses an environmentally friendly high-boiling-point surfactant to replace traditional toxic and volatile low-boiling-point alcohols such as isopropyl alcohol. This is not only environmentally friendly but also eliminates the need for continuous replenishment during the texturing process, saving both time and effort, as well as cost. Furthermore, the surfactant used in the present invention has superior wetting, solubilizing, and dispersing properties, significantly reducing the surface tension of the texturing solution and promoting the rapid detachment of hydrogen bubbles generated by the reaction from the silicon wafer surface, effectively removing impurities that contaminate the silicon wafer surface.

[0074] 4. The small molecule sugar compounds added to the texturing system contain a large number of hydroxyl groups in their molecules, which can also be adsorbed on the surface of the silicon wafer through hydrogen bonding or chelation as a nucleation starting point, playing the role of texturing surface modification and further reducing the reflectivity of the texturing silicon wafer.

[0075] 5. The present invention relates to a texturing additive system comprising a catechol derivative as a main corrosion inhibitor, a synergistic amine and an amino acid secondary corrosion inhibitor, and a compound surfactant and a small molecule sugar. When the mass ratio of the texturing additive to the inorganic alkaline solution is 0.8-1:100, and the texturing is carried out at 85°C for 480 seconds, the weight loss rate of the first batch of silicon wafers is about 3%, and the weighted average reflectivity in the wavelength range of 400-950nm is 9.6%. Without replenishing the liquid, after continuous heating at 85°C for 24 hours, the weight loss rate increased by less than 1.3%, and the reflectivity increased by about 4%. For the texturing additive system without amine or amino acid compounds, the weight loss rate and reflectivity of the first batch of silicon wafers were slightly higher than those of the synergistic system with amine compounds. However, after continuous heating at 85°C for 24 hours, the weight loss rate increased by as much as 2.5%, and the reflectivity increased by nearly 15%.

[0076] The present invention utilizes the phenolic hydroxyl group of the main corrosion inhibitor, catechol derivative dopamine, to react with silicon to form nuclei, which can not only slow down the etching rate to a greater extent and control weight loss, but also form a better light-trapping structure on the surface of the silicon wafer, and can significantly reduce the use of low-boiling point alcohol compounds. The two ortho-phenolic hydroxyl groups in the dopamine hydrochloride molecule are easily oxidized into a quinone structure, causing the stability of the system to deteriorate. The amine or amino acid secondary corrosion inhibitor introduced by the present invention can not only play a role in corrosion inhibition, but also synergistically act with the main corrosion inhibitor to prevent the hydroxyl group of the main corrosion inhibitor from being oxidized, thereby significantly improving the stability of the system. Therefore, the texturing additive of the present invention has very good application prospects and large-scale industrial promotion potential in the field of single crystal silicon texturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a dark field optical microscope image magnified 1000 times of the textured surface of the silicon wafer obtained by the texturing method in Example 1;

[0078] Figure 2 This is a bright field optical microscope image magnified 500 times of the textured surface of the silicon wafer obtained by the texturing method in Example 1;

[0079] Figure 3 This is a dark field optical microscope image magnified 1000 times of the textured surface of the silicon wafer obtained by the texturing method in Comparative Example 1;

[0080] Figure 4 This is a bright field optical microscope image magnified 500 times of the textured surface of the silicon wafer obtained by the texturing method in Comparative Example 1;

[0081] Figure 5 This is a 10,000x magnified SEM image of the textured surface of the silicon wafer obtained by texturing in Example 1;

[0082] Figure 6 This is a 50,000x magnified SEM image of the cross-section of the textured silicon wafer obtained by texturing in Example 1;

[0083] Figure 7 This is a dark field optical microscope image magnified 1000 times of the textured surface of the silicon wafer obtained after heating for 24 hours in Example 1;

[0084] Figure 8 This is a bright field optical microscope image magnified 500 times of the textured surface of the silicon wafer obtained after heating for 24 hours in Example 1;

[0085] Figure 9 This is a dark field optical microscope image magnified 1000 times of the textured surface of the silicon wafer obtained after heating for 24 hours using Comparative Example 1;

[0086] Figure 10 This is a bright field optical microscope image magnified 500 times of the textured surface of the silicon wafer obtained after heating for 24 hours using Comparative Example 1;

[0087] Figure 11 The weight loss rate of Example 1 and Comparative Example 1 varies with heating time.

[0088] Figure 12 The graph shows the change curve of the weighted average reflectivity of Example 1 and Comparative Example 1 with the heating time. DETAILED DESCRIPTION

[0089] The present invention is further described below with reference to the embodiments:

[0090] Examples 1-15

[0091] Examples 1-15 disclose a variety of alcohol-free single crystal silicon stabilization texturing additives, the components and mass ratios of which are shown in Table 1.

[0092] The preparation method of Example 1-15 alcohol-free single crystal silicon stable texturing additive is as follows: add salt main corrosion inhibitor, secondary corrosion inhibitor, surfactant, small molecule sugar and inorganic alkali solution to 1 / 2 deionized water, stir magnetically until all raw materials are completely dissolved, then add the remaining 1 / 2 deionized water, continue stirring for 2 hours, and the desired alcohol-free single crystal silicon stable texturing additive is obtained.

[0093] Table 1 Components and mass ratios of alcohol-free monocrystalline silicon stabilized texturing additives in Examples 1-15

[0094]

[0095]

[0096] Comparative Examples 1-4

[0097] Comparative Examples 1-4 disclose a variety of texturing additives, the components and mass ratios of which are shown in Table 2. The preparation methods thereof are the same as those of Example 1.

[0098] Table 2 Components and mass ratios of texturing additives in comparative examples 1-4

[0099]

[0100]

[0101] Performance Testing

[0102] Texturing was performed using the texturing solutions containing the alcohol-free single crystal silicon stabilizing texturing additives of Examples 1-15 and the texturing additives of Comparative Examples 1-4.

[0103] The preparation method of the texturing solution is as follows:

[0104] The texturing additive and 2 wt % NaOH solution were weighed in a mass ratio of 0.6:100, added into 85° C. deionized water, and stirred to mix evenly.

[0105] Single crystal silicon etching and texturing method: Place a single crystal silicon wafer in the texturing solution, texturing at 85°C for 480 seconds, then rinse the front and back of the silicon wafer with deionized water and ethanol for 15 seconds each, and dry it in a N2 atmosphere.

[0106] The performance test data of the texturing additives of Examples 1-15 and Comparative Examples 1-4 are shown in Table 3:

[0107] Table 3 Performance test data of Examples 1-15 and Comparative Examples 1-4

[0108]

[0109]

[0110] The above results show that the texture of the first batch of silicon wafers obtained by texturing in Example 1 (see Figure 1 and Figure 2 ) than the silicon wafer texture obtained by using comparative example 1 (see Figure 3 and Figure 4 ) The velvet yield is higher and the uniformity is better. The velvet additive of Example 1 can completely cover the silicon substrate without any white areas. The corresponding velvet pyramid diameter is about 1-3 μm (see Figure 5 ), the pyramid height is about 1-2 μm (see Figure 6 ). Under the condition of no supplement, both systems were heated at 85°C for 24h. Example 1 ( Figure 7 ) The degree of pyramid growth is significantly smaller than that of comparative example 1 (see Figure 9 ), and Example 1 (see Figure 8 ) No white leakage, but the comparative example 1 is almost completely white leakage ( Figure 10 ). By weight loss rate (see Figure 11 ) and reflectivity (see Figure 12) It can be seen more clearly from the curve of change with heating time that the initial weight loss rate and reflectivity of the two systems are basically the same, but with the increase of heating time, the weight loss rate and reflectivity of the silicon wafer textured by the texture additive system of Example 1 are significantly lower than those of Comparative Example 1. After heating at 85°C for 24 hours, the weight loss rate and weighted average reflectivity of Example 1 are 4.16% and 13.76%, respectively. Under the same conditions, the weight loss rate and weighted average reflectivity of Comparative Example 1 are as high as 5.63% and 24.07%. In short, in terms of the texture effect of the first batch of textured samples, the embodiment samples are better than the comparative examples in terms of the performance of the white leakage problem. The embodiment samples basically have no white leakage, while the comparative examples have a certain degree of white leakage; in terms of heating stability, the embodiment is significantly better than the comparative example.

[0111] Performance testing:

[0112] Weight loss rate determination method: Use a balance with a graduation value of 0.0001g to weigh the silicon wafer before and after texturing, respectively, and record it as W 前 and W 后 , then the weight loss rate η is calculated as: η=(W 前 -W 后 ) / W 前 *100%.

[0113] Reflectivity measurement: Use the film thickness meter's fast matching mode to measure the absolute reflectivity, then integrate the obtained data to obtain the weighted average reflectivity - that is, the reflectivity filled in the table.

[0114] The level of white leakage indicates the velveting effect: no white leakage - excellent velveting, occasional white leakage - good velveting, slight white leakage - slightly poor velveting, moderate white leakage - poor velveting, severe white leakage - extremely poor velveting, almost complete white leakage - basically no velveting.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An alcohol-free single crystal silicon stabilizing texturing additive, characterized in that: The composition comprises the following components in the following weight ratios: 1-15 parts of main corrosion inhibitor; Secondary corrosion inhibitor 0.5-3 parts; 0.5-6 parts of surfactant; 1-25 parts of small molecule sugar; 30-60 parts of inorganic alkali solution; 30-60 parts of deionized water; The main corrosion inhibitor is selected from one or more of dopamine hydrochloride, tannic acid, and tea polyphenols; The secondary corrosion inhibitor is selected from one or more of tripropylamine, tributylamine, benzylamine, aniline, N-methylaniline, acetamide, ethylenediamine, 1,6-hexanediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, isobutanolamine, N,N-diethylethanolamine, glycine, serine, tyrosine, alanine, phenylalanine, tryptophan, aspartic acid, glutamic acid, lysine, arginine and histidine; The surfactant is selected from one or a mixture of polyoxyethylene isooctyl ether monophosphate, methyl laurate ethoxylate, methyl stearate ethoxylate, methyl oleate ethoxylate, methyl cocoate ethoxylate, polyoxyethylene lauryl ether and polyoxyethylene cetyl alcohol ether; The small molecule sugar is selected from one or more of erythrose, arabinose, glucose, fructose, galactose, sucrose, trehalose, cellobiose, gentiobiose and melibiose.

2. A method for preparing the alcohol-free single crystal silicon stabilizing texturing additive according to claim 1, comprising the following steps: Step 1: Weigh each component according to the weight ratio; Step 2: At room temperature, first add all the components except deionized water to deionized water accounting for 1 / 3-1 / 2 of the total amount, stir magnetically until all the raw materials are completely dissolved, then add the remaining deionized water, and continue stirring for 1-2 hours to obtain an alcohol-free single crystal silicon stable texturing additive.

3. Use of the alcohol-free single crystal silicon stabilizing texturing additive according to claim 1 in the field of single crystal silicon etching and texturing.

4. A texturing liquid, characterized in that: The invention comprises the alcohol-free single crystal silicon stable texturing additive as claimed in claim 1, an inorganic alkali solution and deionized water.

5. A method for preparing the texturing liquid according to claim 4, characterized in that: The steps include: The alcohol-free single crystal silicon stabilizing texturing additive and the inorganic alkali solution were weighed, added into deionized water at 80-85° C., stirred and mixed uniformly to prepare a single crystal silicon etching texturing solution.

6. Use of the texturing liquid according to claim 4 in the field of single crystal silicon etching and texturing.

Images