Etching liquid activator, method for preparing the same, and use thereof

Abstract

The application discloses an etching liquid activator and a preparation method and application thereof, and is used for manufacturing of crystalline silicon solar cells. The etching liquid activator comprises silicon powder and a mixed solution. The mixed solution comprises a surfactant, a catalyst, a dispersing agent and water. In use, the activator is added into the etching liquid for the crystalline silicon solar cells, so that the etching liquid can be rapidly activated, the activation time is reduced, the activation time is shortened to 15-20 minutes, the equipment productivity is improved, the amount of the silicon powder is far less than that of damaged or poor-quality silicon wafers, the cost of the silicon powder is far lower than that of the damaged or poor-quality silicon wafers, and the activation cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of crystalline silicon solar cells, in particular to an etching liquid activator and a preparation method and application thereof. BACKGROUND

[0002] The production of crystalline silicon solar cells needs to go through the processes of slicing, texturing, diffusion, laser doping, etching, film plating, printing and sintering. In the diffusion process, the edges and back surfaces of the silicon wafer also form diffusion layers, which easily cause the edges and back surfaces of the crystalline silicon solar cells to form short circuit rings with the front surface of the silicon wafer, so that the etching process is needed to remove the diffusion layers on the side surfaces and back surface of the silicon wafer to eliminate the short circuit rings. At present, the wet etching method is usually used in the etching process, that is, the silicon wafer is immersed in the etching liquid to remove the diffusion layers on the side surfaces and back surface of the silicon wafer.

[0003] The etching liquid uses a mixed acid solution, which needs to be activated after initial preparation in the etching tank or after a short time of machine restart. At present, the means for activating the etching liquid is to immerse broken silicon wafers or poor-quality silicon wafers in the etching liquid after initial preparation or after a short time of machine restart for continuous running, and then to start normal production after a certain amount of silicon wafers are etched and immersed.

[0004] This activation method needs to consume 4000-8000 silicon wafers for each activation of the etching liquid, and the time consumption is 1.5-2.5 hours, which leads to high cost due to large consumption of silicon wafers and seriously affects the production capacity of the equipment due to long time consumption. SUMMARY

[0005] The purpose of the present application is to provide an etching liquid activator for the production of crystalline silicon solar cells, which can quickly activate the etching liquid of the crystalline silicon solar cells and reduce the production cost of the activated etching liquid.

[0006] Another purpose of the present application is to provide a preparation method of the etching liquid activator for the production of crystalline silicon solar cells, which can prepare the above-mentioned etching liquid activator.

[0007] Still another purpose of the present application is to provide an application of the etching liquid activator, which can use the above-mentioned etching liquid activator to produce and prepare crystalline silicon solar cells, shorten the production time of the crystalline silicon solar cells and reduce the production cost of the crystalline silicon solar cells.

[0008] To achieve the above-mentioned purposes, the technical solution of the present application is as follows: in the first aspect, an etching liquid activator is provided for the production of crystalline silicon solar cells, which comprises silicon powder and a mixed solution, and the mixed solution comprises a surfactant, a catalyst, a dispersing agent and water.

[0009] In a preferred embodiment,

[0010] The surfactant includes at least one of dimethyl dodecyl amine oxide, N,N-dimethyl dodecyl amine oxide, N,N-dimethyl tetradecyl amine oxide, N,N-dimethyl hexadecyl amine oxide, N,N-dimethyl octadecyl amine oxide, N,N-dihydroxyethyl dodecyl amine oxide, N,N-dihydroxyethyl tetradecyl amine oxide, N,N-dihydroxyethyl hexadecyl amine oxide, N,N-dimethyl dodecyl propyl amine oxide, N,N-dimethylene oxide tetradecyl amine oxide, N,N-dimethyl o-cresol amine oxide, and N,N-dimethyl alkyl benzene sulfonic acid propyl amine oxide;

[0011] The catalyst includes at least one of palladium acetate, silver acetate, and lead acetate;

[0012] The dispersant includes at least one of tri-tert-butyl phosphate, alkyl phosphate, aryl phosphate, fatty alcohol polyoxyethylene ether phosphate, alkyl phenol polyoxyethylene ether phosphate, alkyl alcohol amide phosphate, imidazoline phosphate, polyphosphate, and siloxane phosphate.

[0013] In a preferred embodiment, the dispersant includes tri-tert-butyl phosphate, and the tri-tert-butyl phosphate includes tri-tert-butyl phosphine tetrafluoroborate.

[0014] In a preferred embodiment, the mass ratio of the surfactant, the catalyst, and the dispersant to water is (4-6):(1-2):(3-4):40.

[0015] In a preferred embodiment, the mass ratio of the surfactant, the catalyst, and the dispersant to water is 5:(1-2):(3-4):40.

[0016] In a preferred embodiment, the mass ratio of the silicon powder to the mixed solution is (40-70):2000.

[0017] In a preferred embodiment, the mass ratio of the silicon powder to the mixed solution is 50:2000.

[0018] In a preferred embodiment, the particle size of the silicon powder is less than or equal to 0.3 mm.

[0019] In a preferred embodiment, the surfactant includes dimethyl dodecyl amine oxide, the catalyst includes acetate, and the dispersant includes tri-tert-butyl phosphate.

[0020] In a second aspect, the present application provides a method for preparing the etching liquid activator according to any one of the first aspect, the method comprising:

[0021] Dissolving the surfactant, the catalyst and the dispersant in water to obtain a mixed solution;

[0022] Adding silicon powder into the mixed solution to obtain an etching liquid activator.

[0023] In a third aspect, the present application further provides the use of the etching liquid activator according to any one of the first aspect or the etching liquid activator prepared by the preparation method according to the second aspect in the preparation of a crystalline silicon solar cell, comprising:

[0024] Before etching the edge junction of a silicon wafer by using an etching liquid, the etching liquid activator is added into the etching liquid and stirred uniformly to activate the etching liquid.

[0025] The technical solution provided by the present application has at least the following beneficial effects:

[0026] The etching liquid activator provided by the present application is added into the etching liquid for a crystalline silicon solar cell when used, and the dispersant can improve the wettability of the surface of the silicon powder, which is beneficial to the uniform dispersion of the silicon powder in the etching liquid activator, and further beneficial to the rapid reaction of the silicon powder with nitric acid in the etching liquid. Moreover, the specific surface area of the silicon powder is greater than that of the silicon wafer, which makes the reaction speed of the silicon powder with nitric acid greater than that of the silicon wafer with nitric acid. Through the cooperation between the catalyst and other components, the reaction of the silicon powder with nitric acid is catalytically accelerated. Through the cooperation between the surfactant and other components, the bubbles generated in the reaction are rapidly increased and separated from the surface of the silicon powder, which is further beneficial to the continuous reaction of the remaining silicon powder with nitric acid, and beneficial to the acceleration of the activation efficiency. The etching liquid activator can quickly activate the etching liquid, the activation time is reduced to 15-20 minutes, which is beneficial to the improvement of the equipment productivity. Moreover, the amount of the silicon powder is much less than that of the damaged or poor-quality silicon wafer, which is beneficial to the reduction of the activation cost. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] In the prior art, any slight local short circuit on the periphery of a crystalline silicon solar cell will result in the cell being discarded, so etching the crystalline silicon solar cell to remove the diffusion layer formed on the edge and back of the cell to reduce leakage is an important production process for the crystalline silicon solar cell. Currently, a mixed acid solution of HF and HNO3 is usually used to etch the crystalline silicon solar cell, and the principle is that HNO3, as a strong oxidizing agent, oxidizes Si to SiO2 and then reacts with HF. However, in actual industrial production, the oxidation reaction mainly depends on the concentration of HNO2 in the mixed acid solution, and HNO2 is obtained by the reaction of HNO3 and Si. The higher the content of HNO2, the more oxidation reactions occur in the etching tank. The HF-HNO3 system has an induction period in the initial reaction process with silicon, and the content of HNO2 is low during the induction period, and the reaction speed is slow. If the content of HNO2 is increased at the beginning of the reaction, the induction period can be reduced. Therefore, after the initial preparation of the mixed acid solution or after the machine is restarted for a short time, the solution needs to be activated, that is, the activity of the nitrous acid solution needs to be enhanced to support the corrosion reaction. At present, the activation of the mixed acid solution is achieved by immersing damaged silicon wafers or poor quality silicon wafers in the etching solution for continuous wafer running after the initial preparation or after the machine is restarted for a short time, so that Si reacts with HNO3 to give the required HNO2. HNO2 generates more HNO2 through its own catalytic reaction. With the increase of reaction batches, the content of HNO2 in the solution gradually increases, and the content of HNO3 gradually decreases. When a certain balance is reached, the reaction tends to be stable. However, a large amount of silicon wafers are consumed during the activation of the silicon wafers after the induction period, and the silicon wafers are suspended on the surface of the liquid in a water floating manner, which is slow and time-consuming.

[0029] Therefore, the embodiment provides an etching solution activator which can effectively overcome the above problems.

[0030] The embodiment provides an etching solution activator for manufacturing a crystalline silicon solar cell, and the activator comprises silicon powder and a mixed solution, and the mixed solution comprises a surfactant, a catalyst, a dispersing agent and water.

[0031] Specifically, the purity of the silicon powder is greater than 99.99%. The silicon powder reacts with nitric acid in the mixed acid solution to form nitrous acid salt, thereby enhancing the activity of the mixed acid solution.

[0032] In the etching liquid activator, the catalyst can include acetate salts, the acetate salts including at least one of palladium acetate, silver acetate, and lead acetate. For example, the catalyst can include any one, a mixture of two, or a mixture of three of palladium acetate, silver acetate, and lead acetate. The acetate salts can release hydrogen ions, adjust the pH value of the etching liquid, and provide suitable conditions for the silicon powder reaction. In addition, palladium ions, silver ions, and lead ions have strong oxidizing properties, which can promote the reaction of silicon powder and nitric acid to generate more nitrogen oxides, thereby accelerating the reaction rate of silicon powder and nitric acid.

[0033] The dispersant can include at least one of tri-tert-butyl phosphate, alkyl phosphate, aryl phosphate, fatty alcohol polyoxyethylene ether phosphate, alkyl phenol polyoxyethylene ether phosphate, alkyl alcohol amide phosphate, imidazoline phosphate, polyphosphate, and siloxane phosphate. For example, the dispersant can be a mixture of any one, two, three, or all of the above. Preferably, the dispersant includes tri-tert-butyl phosphate, which includes tri-tert-butylphosphonium tetrafluoroborate (C 12 H 28 PBF4). The dispersant and other components work together to increase the wettability of the silicon powder, facilitate uniform dispersion of the silicon powder, and facilitate the reaction of the silicon powder and nitric acid.

[0034] The surfactant can include at least one of dimethyl dodecyl amine oxide, N,N-dimethyl dodecyl amine oxide, N,N-dimethyl tetradecyl amine oxide, N,N-dimethyl hexadecyl amine oxide, N,N-dimethyl octadecyl amine oxide, N,N-dihydroxyethyl dodecyl amine oxide, N,N-dihydroxyethyl tetradecyl amine oxide, N,N-dihydroxyethyl hexadecyl amine oxide, N,N-dimethyl dodecyl acylpropyl amine oxide, N,N-dipolyoxyethylene ether tetradecyl amine oxide, N,N-dimethyl o-cresol amine oxide, and N,N-dimethyl alkyl benzene sulfonic acid propyl amine oxide. For example, the surfactant can be a mixture of any one, two, or all of the above. Preferably, the surfactant includes dimethyl dodecyl amine oxide. Through the cooperation between the surfactant and other components, the bubbles generated in the reaction are quickly enlarged and detached from the surface of the silicon powder, thereby facilitating the continuous reaction of the remaining silicon powder and nitric acid and accelerating the activation efficiency.

[0035] Optionally, the mass ratio of the surfactant, the catalyst, and the dispersant to water is (4-6):(1-2):(3-4):40, such as 4:1:3:40, 5:1:3:40, 6:1:3:40, 5:1.5:3.5:40, 5:2:4:40, 6:1.5:3.5:40, or 6:2:4:40, etc.

[0036] Preferably, the mass ratio of the surfactant, the catalyst, the dispersant, and the water is 5: (1-2): (3-4): 40. In this way, the effects of mutual matching among the surfactant, the catalyst, the dispersant, and the water can be best, and the effects of each component can be fully exerted.

[0037] Optionally, the mass ratio of the silicon powder and the mixed solution is (40-70): 2000, such as 40:2000, 60:2000, or 70:2000, etc. In this way, the ratio between the silicon powder and the mixed solution can achieve the best effect, so as to fully exert the effects of the silicon powder and the mixed solution, and enable the silicon powder to quickly react with nitric acid in the etching solution.

[0038] Preferably, the mass ratio of the silicon powder and the mixed solution is 50:2000.

[0039] Optionally, the particle size of the silicon powder is less than or equal to 0.3 mm, and exemplarily, the particle size of the silicon powder is 0.3 mm, 0.2 mm, 0.1 mm, 80 μm, 40 μm, or 35 μm, etc. In this way, the silicon powder can be quickly reacted with nitric acid in the etching solution.

[0040] Preferably, the particle size of the silicon powder is 45 μm-70 μm. Exemplarily, the particle size of the silicon powder is 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, or 70 μm, etc.

[0041] In some embodiments, the etching solution activator includes silicon powder and a mixed solution with a mass ratio of 50:2000, and the mixed solution includes dimethyl dodecyl amine oxide, palladium acetate, tri-tert-butyl phosphate, and water with a mass ratio of 5: (1-2): (3-4): 40.

[0042] Based on the above, the etching liquid activator provided by the embodiment of the present application is added to the etching liquid for the crystalline silicon solar cell in use, the wettability of the surface of the silicon powder can be improved by the dispersant, which is beneficial to the uniform dispersion of the silicon powder in the etching liquid activator, and further beneficial to the rapid reaction of the silicon powder and nitric acid in the etching liquid. Moreover, the specific surface area of the silicon powder is greater than that of the silicon wafer, which makes the reaction speed of the silicon powder and nitric acid greater than that of the silicon wafer and nitric acid. The cooperation between the catalyst and other components is beneficial to catalytic acceleration of the reaction of the silicon powder and nitric acid. The cooperation between the surfactant and other components is beneficial to the rapid increase and separation of the bubbles generated in the reaction from the surface of the silicon powder, and further beneficial to the continuous reaction of the remaining silicon powder and nitric acid, and beneficial to the acceleration of the activation efficiency. The etching liquid activator can quickly activate the etching liquid, the activation time is reduced to 15-20 minutes, which is beneficial to the improvement of the equipment productivity. Moreover, the amount of the silicon powder is much less than that of the damaged or poor-quality silicon wafer, and the cost of the silicon powder is much lower than that of the damaged or poor-quality silicon wafer, which is beneficial to the reduction of the activation cost.

[0043] The embodiment of the present application also provides a preparation method of the etching liquid activator, and the preparation method comprises the following steps:

[0044] S01, dissolving the surfactant, the catalyst and the dispersant in water to obtain a mixed solution.

[0045] Specifically, the surfactant, the catalyst and the dispersant are added to water, and stirring and ultrasonic treatment are performed to uniformly dissolve the surfactant, the catalyst and the dispersant in water. The water is deionized water, and the temperature of the deionized water can be 65 DEG C during the dissolving.

[0046] Optionally, the ultrasonic treatment condition is that the ultrasonic power is 3000 W, the frequency is 20 KHz, the temperature is 40 DEG C, and the ultrasonic time is 40 min.

[0047] S02, adding the silicon powder to the mixed solution to obtain the etching liquid activator for the crystalline silicon solar cell.

[0048] The preparation method of the etching liquid activator provided by the embodiment of the present application can obtain the mixed solution by dissolving the surfactant, the catalyst and the dispersant in water, and can obtain the etching liquid activator by adding the silicon powder to the mixed solution. The preparation method is simple and convenient for preparation, and is beneficial to application in the production of the solar cell assembly.

[0049] The embodiment of the present application also provides the application of the above-mentioned etching liquid activator or the etching liquid activator prepared by the above-mentioned preparation method in the preparation of the crystalline silicon solar cell, which comprises the following steps:

[0050] Before etching the edge of the silicon wafer with the etching solution, the etching solution activator is added to the etching solution and stirred uniformly to activate the etching solution. The etching solution can be activated after 15-20 minutes of adding the etching solution activator, which is short in activation time and conducive to improving the equipment productivity.

[0051] In order to more clearly understand the effect of the etching solution activator provided by the embodiments of the present application, the following examples are given.

[0052] Embodiment 1: The present embodiment provides a production method of a monocrystalline silicon solar cell, which comprises:

[0053] S11, texturing treatment.

[0054] Specifically, an alkali solution is used to perform texturing treatment on the surface of the monocrystalline silicon wafer. The alkali solution can be a NaOH solution with a mass concentration of 2.1%. A tank-type texturing machine can be used to perform texturing reaction on the silicon wafer at a temperature of 82℃ and a mass concentration of NaOH of 2.1% for 420s to obtain a textured surface.

[0055] S12, diffusion treatment.

[0056] Specifically, a tube-type diffusion furnace is used to perform diffusion treatment on the silicon wafer at a temperature of 850℃, a negative pressure of 100mBar, and a nitrogen flow rate of 1000sccm / min to form a PN junction.

[0057] S13, laser doping treatment.

[0058] A laser is used for local re-doping to reduce the contact resistance at the position of the grid line. Specifically, a laser beam with a wavelength of 532nm, a pulse of 40ns, and a power of 30W can be used in an SE laser device to perform local laser re-doping treatment on the surface of the silicon wafer, so that the diffusion layer of the surface of the silicon wafer has a local re-doping region.

[0059] S14, wet etching treatment.

[0060] After the etching solution is prepared in the wet etching tank, the etching solution is activated by the etching solution activator. Specifically, after the etching solution is prepared in the wet etching tank, the silicon powder is first mixed with the mixed solution for 5min to obtain the etching solution activator, and then the etching solution activator is added to the etching tank. The etching solution activator for crystalline silicon solar cell is added to the etching tank and mixed for 20min and stirred uniformly, and the laser-doped silicon wafer is loaded for wet etching production to etch the back surface and the edge of the silicon wafer.

[0061] In the embodiment, the etching liquid activator comprises 50 g of silicon powder and 2 kg of a mixed solution, the mixed solution comprises dimethyl dodecyl amine oxide, lead acetate, tri-tert-butyl phosphine tetrafluoroborate and water, and the mass ratio of dimethyl dodecyl amine oxide, lead acetate, tri-tert-butyl phosphine tetrafluoroborate and water is 5:1:3:40. The particle size of the silicon powder is 0.07 mm, and the purity of the silicon powder is greater than 99.99%.

[0062] S15, coating treatment.

[0063] Specifically, after the back surface of the silicon wafer after wet etching, a layer of Al2O3 with a thickness of 3-5 nm is deposited by ALD (Atomic Layer Deposition), and then a layer of SiN with a thickness of 80 nm is deposited by PECVD (Plasma Enhanced Chemical Vapor Deposition). x A passivation film is formed on the back surface of the silicon wafer, and then a layer of SiN with a thickness of 75 nm is deposited on the front surface of the silicon wafer by PECVD. x A passivation film is formed on the back surface of the silicon wafer, and then a layer of SiN with a thickness of 75 nm is deposited on the front surface of the silicon wafer by PECVD.

[0064] S16, printing electrodes to obtain the monocrystalline silicon solar cell provided in Embodiment 1.

[0065] Specifically, this step includes printing grid lines on the front surface and the back surface of the silicon wafer after coating and sintering to obtain front surface electrodes and back surface electrodes.

[0066] The etching liquid activator in Embodiment 1 can quickly activate the etching liquid in the wet etching tank, shorten the activation time, and directly produce without using a large number of silicon wafer running pieces to activate the etching liquid. The weight loss of a silicon wafer with an initial mass of 10 g after etching is 0.291 g, the back surface reflectivity of the silicon wafer after etching is 27.10%, the conversion efficiency of the production sample is 22.92%, and the weight loss reflectivity of the silicon wafer after etching is normal. The efficiency of the normal sample activated by the broken silicon wafer and the like is flat. The electrical performance test data are shown in Table 1.

[0067] Table 1

[0068]

[0069] Embodiment 2: The embodiment provides a production method of a monocrystalline silicon solar cell, which is different from Embodiment 1 in that:

[0070] In the embodiment, the mixed solution is composed of dimethyl dodecyl amine oxide, palladium acetate, tri-tert-butyl phosphine tetrafluoroborate and water, and the mass percentage of each component in the mixed solution is 10% dimethyl dodecyl amine oxide, 4% palladium acetate, 6% tri-tert-butyl phosphine tetrafluoroborate and 80% deionized water.

[0071] The etching liquid activator in Example 2 can quickly activate the etching liquid in the wet etching tank, shorten the activation time, and directly produce after activating the etching liquid without using a large number of silicon wafer running pieces for activating the etching liquid. The weight loss of a silicon wafer with an initial mass of 10 g after etching is 0.30 g, the backside etching reflectivity of the silicon wafer is 27.30%, the conversion efficiency is 22.93%, and the electrical performance test data are shown in Table 2.

[0072] Table 2

[0073]

[0074] Example 3: The present example provides a production method of a single crystal silicon solar cell, which is different from Example 1 in that:

[0075] In the present example, the mixed solution is composed of dimethyl dodecyl amine oxide, silver acetate and water, and the mass ratio of dimethyl dodecyl amine oxide, silver acetate, tri-tert-butyl phosphine tetrafluoroborate and water is 5:2:4:40.

[0076] The etching liquid activator in Example 3 can quickly activate the etching liquid in the wet etching tank, shorten the activation time, and directly produce after activating the etching liquid without using a large number of silicon wafer running pieces for activating the etching liquid. The weight loss of a silicon wafer with an initial mass of 10 g after etching is 0.298 g, the backside reflectivity of the silicon wafer is 27.15%, the conversion efficiency is 22.93%, and the electrical performance test data are shown in Table 3.

[0077] Table 3

[0078]

[0079]

[0080] Example 4: The present example provides a production method of a polycrystalline silicon solar cell, which comprises:

[0081] S41, texturing treatment.

[0082] Specifically, a mixed acid solution is used to perform texturing treatment on the surface of a single crystal silicon wafer. The mixed acid solution comprises hydrofluoric acid, nitric acid and water in a volume ratio of 3:1:2.7. Alternatively, a chain texturing machine can be used to perform texturing treatment on the silicon wafer at a temperature of 10°C.

[0083] S42, diffusion treatment.

[0084] Specifically, a tube-type diffusion furnace is used to perform diffusion treatment on the silicon wafer at a temperature of 820°C, a negative pressure of 100 mBar and a nitrogen flow rate of 1200 sccm / min to form a PN junction.

[0085] S43, wet etching treatment.

[0086] After the wet etching tank auxiliary tank circulating pump is opened for 5 minutes, the etching solution activator for the crystalline silicon solar cell is added to the etching tank under the condition that the solution fills the etching tank. The etching solution activator for the crystalline silicon solar cell includes 40 g of silicon powder and 2 kg of a mixed solution composed of dimethyl dodecyl amine oxide, lead acetate, tri-tert-butyl phosphine tetrafluoroborate and water, and the mass ratio of dimethyl dodecyl amine oxide, lead acetate, tri-tert-butyl phosphine and water is 6:2:3:40. After the etching solution activator for the crystalline silicon solar cell is added to the etching tank and mixed for 10 minutes, the silicon wafer after diffusion is loaded for normal wet etching production.

[0087] The silicon powder can be added to the etching tank first, and then the mixed solution is added to the etching tank.

[0088] S44, annealing treatment.

[0089] The silicon wafer after the wet etching treatment is placed in a hot oxygen furnace tube, and high-temperature annealing is performed under the condition of high temperature (>700℃) and oxygen atmosphere (>1000sccm) for 40 minutes to grow a layer of SiO2 on the front surface of the silicon wafer.

[0090] S45, coating treatment. This step specifically includes depositing a layer of SiN passivation film on the front surface of the silicon wafer.

[0091] S46, printing electrodes to obtain the crystalline silicon solar cell provided in Example 4.

[0092] Specifically, this step includes printing grid lines on the front surface and the back surface of the silicon wafer after coating and sintering to obtain front electrodes and back electrodes.

[0093] The etching solution activator in Example 4 can quickly activate the etching solution in the wet etching tank, shorten the activation time, and directly produce after activating the etching solution without using a large number of silicon wafers for activation. The weight loss of the silicon wafer after etching is 0.25 g, the back surface reflectivity of the silicon wafer is 30.10%, the conversion efficiency is 18.21%, the weight loss reflectivity is normal, and the efficiency is flat with the efficiency of the sample activated by the dummy wafer. The electrical performance test data is shown in Table 4.

[0094] Table 4

[0095]

[0096] Comparative Example 1: The present comparative example provides a production method of a single crystalline silicon solar cell, which is different from Example 1 in that:

[0097] In the present comparative example, the etching solution activator for crystalline silicon solar cell is not used to activate the etching solution in the wet etching step, but 8000 broken silicon wafers are used to activate the etching solution for 90 minutes.

[0098] In Comparative Example 1, the weight of the silicon wafer with an initial mass of 10 g is reduced by 0.287 g after wet etching, the back surface reflectivity of the silicon wafer is 26.8%, the production sample efficiency is 22.92%, and the electrical performance test data are shown in Table 5.

[0099] Table 5

[0100]

[0101] Comparative Example 2: The present comparative example provides a production method of a polycrystalline silicon solar cell, which is different from Example 4 in that:

[0102] In the present comparative example, the etching solution activator for crystalline silicon solar cell is not used to activate the etching solution in the wet etching step, but 6000 broken silicon wafers are used to activate the etching solution for 90 minutes.

[0103] In Comparative Example 2, the weight of the silicon wafer with an initial mass of 10 g is reduced by 0.247 g after wet etching, the back surface reflectivity is 29.90%, the production sample efficiency is 18.19%, and the electrical performance test data are shown in Table 6.

[0104] Table 6

[0105]

[0106] Based on the above, the conversion efficiency, open circuit voltage, short circuit current, fill factor, series resistance, and parallel resistance of the crystalline silicon solar cell produced by activating the etching solution with the activator having a mass ratio of surfactant, catalyst, dispersant, and water of (4-6):(1-2):(3-4):40 in Example 1 and Example 4 are similar to those of the crystalline silicon solar cell produced by the running wafer method in Comparative Example 1 and Comparative Example 2. It can be seen that the method of activating the etching solution with the activator does not affect the electrical performance of the produced crystalline silicon solar cell, and the etching time is shortened.

[0107] In addition, the price of silicon powder is 180 yuan / kg, and 40-60 g of silicon powder is used in Example 1 to Example 4, with a cost of 7.2 yuan-10.8 yuan. The cost of one broken silicon wafer is about 6 yuan. Comparative Example 1 requires 48000 yuan, and Comparative Example 2 requires 36000 yuan, which is much higher than the cost of using the activator provided in the present example.

[0108] In summary, the etching liquid activator provided by the embodiment of the present application is added into the etching liquid for the crystalline silicon solar cell in use, can quickly activate the etching liquid, reduce the activation time to 15-20 minutes, is beneficial to improve the equipment productivity, and the amount of the silicon powder is far less than the amount of the damaged or poor quality silicon wafer, the cost of the silicon powder is far lower than the cost of the damaged or poor quality silicon wafer, and the activation cost is reduced.

[0109] Of course, the above-mentioned embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any modification made according to the spirit and essence of the main technical solution of the present application should be covered within the protection scope of the present application.

Claims

1. An etching liquid activator characterized by comprising: The application relates to an etching liquid activator for manufacturing a crystalline silicon solar cell, wherein the activator comprises silicon powder and a mixed solution, and the mass ratio of the silicon powder to the mixed solution is (40-70):2000. The mixed solution comprises a surfactant, a catalyst, a dispersant and water, and the mass ratio of the surfactant, the catalyst, the dispersant and water is (4-6):(1-2):(3-4):

40. The specific surface area of the silicon powder is greater than that of a silicon wafer. The particle size of the silicon powder is 45-70 microns.

2. The etchant activator according to claim 1, wherein The surfactant comprises at least one of dimethyl dodecyl amine oxide, N,N-dimethyl dodecyl amine oxide, N,N-dimethyl tetradecyl amine oxide, N,N-dimethyl hexadecyl amine oxide, N,N-dimethyl octadecyl amine oxide, N,N-dihydroxyethyl dodecyl amine oxide, N,N-dihydroxyethyl tetradecyl amine oxide, N,N-dihydroxyethyl hexadecyl amine oxide, N,N-dimethyl dodecyl acyl propyl amine oxide, N,N-dimethyl tetradecyl amine oxide, N,N-dimethyl o-cresol amine oxide and N,N-dimethyl alkyl benzene sulfonic acid propyl amine oxide. The catalyst comprises at least one of palladium acetate, silver acetate and lead acetate. The dispersant comprises at least one of tri-tert-butyl phosphate, alkyl phosphate, aryl phosphate, fatty alcohol polyoxyethylene ether phosphate, alkyl phenol polyoxyethylene ether phosphate, alkyl alcohol amide phosphate, imidazoline phosphate, polyphosphate and siloxane phosphate.

3. The etchant activator according to claim 2, wherein The dispersant comprises tri-tert-butyl phosphate, and the tri-tert-butyl phosphate comprises tri-tert-butyl phosphine tetrafluoroborate.

4. The etchant activator according to claim 1, wherein The mass ratio of the surfactant, the catalyst, the dispersant and water is 5:(1-2):(3-4):

40.

5. The etchant activator of claim 1, wherein The mass ratio of the silicon powder to the mixed solution is 50:2000.

6. The etchant activator of claim 1, wherein The surfactant comprises dimethyl dodecyl amine oxide, the catalyst comprises acetate and the dispersant comprises tri-tert-butyl phosphate.

7. A method for producing an etching liquid activator, characterized by, The method comprises: dissolving a surfactant, a catalyst and a dispersant in water to obtain a mixed solution, and the mass ratio of the surfactant, the catalyst, the dispersant and water is (4-6):(1-2):(3-4):40; adding silicon powder into the mixed solution to obtain an etching liquid activator, and the mass ratio of the silicon powder to the mixed solution is (40-70):2000, and the specific surface area of the silicon powder is greater than that of a silicon wafer; the particle size of the silicon powder is 45-70 microns.

8. The production method according to claim 7, characterized by, The method specifically comprises: dissolving a surfactant, a catalyst and a dispersant in water, stirring and ultrasonic treatment to uniformly dissolve the surfactant, the catalyst and the dispersant in water to obtain a mixed solution.

9. The use of the etching liquid activator according to any one of claims 1-6 in the preparation of a crystalline silicon solar cell, comprising: adding the etching liquid activator into the etching liquid and stirring uniformly before etching the edge junction of a silicon wafer by using the etching liquid to activate the etching liquid.

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