Photovoltaic silver paste and application and use method thereof

Abstract

The invention provides photovoltaic silver paste as well as application and a use method thereof. The photovoltaic silver paste comprises silver powder, organic resin, a solvent and an auxiliary agent, wherein the organic resin comprises a mixture of epoxy resin, a thermal curing agent, acrylate resin and a light curing agent; according to the photovoltaic silver paste disclosed by the invention, by adding the epoxy thermocuring system resin and the acrylate photocuring system resin in a certain proportion, the optimization of low resistivity of the silver paste can be well completed under a low-temperature condition, and meanwhile, the contact performance on an FTO (Fluorine-doped Tin Oxide) base material can be improved, so that the photovoltaic silver paste has excellent electrical conductivity under the low-temperature condition. The perovskite cell can use a silk-screen printing scheme with relatively high mass production efficiency and relatively low cost; according to the photovoltaic silver paste, the resistivity and ohmic contact can be greatly reduced under the condition of low-temperature curing, and the possibility that screen printing mass production can be achieved on perovskite is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of conductive silver paste, and in particular relates to a photovoltaic silver paste and an application and use method thereof. Background Art

[0002] Perovskite (stacked) solar cells, as the third generation of solar cells, are solar cells that use perovskite-type organic metal halide semiconductors as light-absorbing materials. Their biggest advantage is the high theoretical photoelectric conversion rate, which can reach up to 43%, which is much higher than the existing crystalline silicon cell technology. It is very likely to become the next generation of solar energy technology. However, due to the instability of its metal halide semiconductors, the overall cell structure cannot withstand high temperatures exceeding 120°C, which greatly increases the difficulty of its metallization. The existing technical routes are: first, the use of evaporation, which is unacceptable for the efficiency and cost of mass-producing large-scale solar cells; second, the use of conventional low-temperature silver paste for curing at ultra-low temperatures, but its resistivity and contact resistance are difficult to guarantee, resulting in low overall efficiency.

[0003] Therefore, it is urgent to develop a silver paste with lower resistivity and contact resistance so that the efficiency of perovskite (tandem) solar cells can be close to its theoretical photoelectric conversion efficiency and achieve low-cost and high-efficiency mass production. Summary of the invention

[0004] In view of this, the present invention proposes a photovoltaic silver paste and its application and use method to solve the technical problems existing in the prior art.

[0005] In a first aspect, the present invention provides a photovoltaic silver paste, comprising: silver powder, organic resin, solvent, and additive;

[0006] Wherein, the organic resin includes a mixture of epoxy resin, thermal curing agent, acrylate resin and light curing agent.

[0007] Preferably, the epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, alicyclic epoxy resin, and resorcinol epoxy resin;

[0008] And / or, the thermal curing agent includes at least one of IPDA, DICY, AADH, DMP-10, DMP-30, 2E4MZ, and DPEDA;

[0009] And / or, the acrylate resin includes at least one of polyurethane acrylate, polyester acrylate, polyether acrylate, and epoxy acrylate;

[0010] And / or, the photocuring agent includes at least one of photoinitiator 184, photoinitiator 369, photoinitiator 651, photoinitiator 819, photoinitiator 1800, photoinitiator 2020, photoinitiator MBF, photoinitiator TPO, and photoinitiator CTX.

[0011] Preferably, the solvent includes at least one of acetone, butanone, methyl isobutyl ketone, isophorone, ethylene glycol, propylene glycol, ethyl acetate, butyl acetate, xylene, terpineol, ethylene glycol ethyl ether, diethylene glycol butyl ether, dodecanol ester, dibutyl phthalate, dioctyl phthalate, dioctyl adipate, isopropanol, n-butanol, and cyclopentanone;

[0012] And / or, the auxiliary agent includes at least one of BYK055, BYK088, BYK067A, BYK333, BYK373, BYKP-105, Disperbyk-111, Disperbyk-180, and Disperbyk-168.

[0013] Preferably, the photovoltaic silver paste comprises the following components in parts by weight:

[0014] 80-95 parts of silver powder, 3-15 parts of organic resin, 1-30 parts of solvent, and 0.05-5 parts of auxiliary agent.

[0015] Preferably, the silver powder comprises micron silver powder and ultrafine silver powder; wherein the D50 particle size of the micron silver powder is 1 to 5 μm, the D50 particle size of the ultrafine silver powder is 50 to 800 nm, and the mass fraction of the micron silver powder in the silver powder is 50 to 95%;

[0016] And / or, the sum of the mass fractions of the epoxy resin and the thermal curing agent in the organic resin is 50-80%, and the mass of the thermal curing agent is 2-20% of the mass of the epoxy resin;

[0017] The sum of the mass fractions of the acrylate resin and the light curing agent in the organic resin is 20-50%, and the mass of the light curing agent is 0.5-25% of the mass of the acrylate resin.

[0018] Preferably, the photovoltaic silver paste comprises the following components in parts by weight:

[0019] 48-70 parts of micron silver powder, 15-40 parts of ultrafine silver powder, 3-7 parts of epoxy resin, 0.2-0.6 parts of thermal curing agent, 2-3 parts of acrylate resin, 0.03-0.3 parts of light curing agent, 6-15 parts of solvent, and 0.3-1 parts of auxiliary agent.

[0020] Preferably, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the acrylic resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts;

[0021] Or, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the thermal curing agent is 0.2-0.3 parts, the weight of the acrylic resin is 2.5-3 parts, the weight of the light curing agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts;

[0022] Or, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the acrylic resin is 2-2.5 parts, the weight of the photocuring agent is 0.03-0.04 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts;

[0023] Or, the D50 particle size of the micron silver powder is 1-2 μm, the weight of the micron silver powder is 48-50 parts, the ultrafine silver powder includes ultrafine silver powder with a D50 particle size of 180-220 nm and ultrafine silver powder with a D50 particle size of 60-100 nm, the weight of the ultrafine silver powder with a D50 particle size of 180-220 nm is 15-25 parts, the weight of the ultrafine silver powder with a D50 particle size of 60-100 nm is 15-25 parts, the weight of the acrylate resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts;

[0024] Or, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the acrylate resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes ethylene glycol ethyl ether and diethylene glycol butyl ether, the weight of the ethylene glycol ethyl ether is 2-4 parts, the weight of the diethylene glycol butyl ether is 4-6 parts, the auxiliary agent includes BYK055 and Disperbyk-180, the weight of BYK055 is 0.05-0.1 parts, and the weight of the Disperbyk-180 is 0.8-0.9 parts.

[0025] In a second aspect, the present invention also provides an application of the photovoltaic silver paste in the preparation of perovskite solar cells.

[0026] In a third aspect, the present invention further provides a method for using the photovoltaic silver paste, comprising the following steps:

[0027] Silver powder, organic resin, solvent and additive are mixed and printed on a fluorine-doped tin oxide FTO substrate, the solvent is dried at 50-80°C, and then thermally cured at 80-100°C, and then UV light cured.

[0028] Preferably, during the UV curing process, the UV intensity is 1000-5000 mJ / cm 2 .

[0029] The photovoltaic silver paste and its application and use method of the present invention have the following beneficial effects compared with the prior art:

[0030] 1. The photovoltaic silver paste of the present invention can optimize the low resistivity of the silver paste under low temperature conditions by adding a certain proportion of epoxy thermosetting system resin and acrylate photocuring system resin, and can also improve the contact performance on the FTO substrate, so that under low temperature conditions, the perovskite battery can use a screen printing solution with high mass production efficiency and low cost;

[0031] 2. The photovoltaic silver paste of the present invention can significantly reduce the resistivity and ohmic contact under low-temperature curing conditions, making it possible to realize mass production by screen printing on perovskite. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to better understand the present invention but not to limit the scope of the present invention, all the numbers used in this application to express the amount, percentage, and other numerical values ​​should be understood as modified by the word "about" in all cases. Therefore, unless otherwise specified, the numerical parameters listed in the specification and the appended claims are approximate values, which may be changed according to the different ideal properties attempted to be obtained. Each numerical parameter should at least be regarded as obtained based on the reported significant figures and by conventional rounding methods.

[0034] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present invention may be in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the numbered range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0035] The present invention provides a photovoltaic silver paste, comprising: silver powder, organic resin, solvent, and additive;

[0036] Wherein, the organic resin includes a mixture of epoxy resin, thermosetting agent, acrylate resin and light curing agent.

[0037] The photovoltaic silver paste of the present invention adds a photocurable acrylate resin and a photocuring agent to the conventional heat-curing system epoxy resin and heat-curing agent, so that the silver paste uses a low-temperature curing resin as a skeleton on the basis of a low degree of low-temperature curing, and with the support of the acrylate resin, the photocuring effect is supplemented, and the shrinkage performance of the resin is further improved, thereby compacting the gaps between the silver powders and reducing the volume resistivity. At the same time, the silver powders are also pushed toward the surface of the conductive substrate fluorine-doped tin oxide FTO to reduce the contact resistivity. The silver paste can be used for screen printing, which is not much different from the metallization method of traditional battery cells, and can achieve efficient mass production of metallization without replacing the equipment.

[0038] In some embodiments, the epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, alicyclic epoxy resin, and resorcinol epoxy resin. According to the needs of the product, one or more epoxy resins commonly used in the industry may be added, for example, NPEL-128E (i.e., Nan Ya NPEL-128E epoxy resin, CAS: 25068-38-6), NPSN-901X75 (i.e., NPC Nan Ya epoxy resin NPSN-901X75), NPES-903 (i.e., Nan Ya solid bisphenol A epoxy resin NPES-903), NPEF-170 (i.e., Nan Ya NPEF-170 bisphenol F type liquid epoxy resin), 8240E (i.e., Huntsman 8240 novolac epoxy resin), EPALLOY 8250, EPALLOY 8280, EPALLOY 8330, EPALLOY8350, EPALLOY 8370, EPALLOY9000; NPCN-704 (i.e. Nan Ya o-cresol epoxy resin NPCN-704), NPER-133L (i.e. Nan Ya NPER-133L epoxy resin), etc.

[0039] In some embodiments, the thermal curing agent includes IPDA (i.e., isophorone diamine), DICY (i.e., dicyandiamide), AADH (i.e., adipic acid dihydrazide), DMP-10 (i.e., dimethylaminomethylphenol), DMP-30 (i.e., 2,4,6-tris(dimethylaminomethyl)phenol, molecular formula C 15 H 27 At least one of N3O), 2E4MZ (i.e. 1-cyanoethyl-2-ethyl-4-methylimidazole), and DPEDA (i.e. diphenyl ether tetraacid dianhydride).

[0040] In some embodiments, the acrylate resin includes at least one of polyurethane acrylate, polyester acrylate, polyether acrylate, and epoxy acrylate; wherein, since light curing and heat curing need to be performed simultaneously, acrylate must be added, and one or more commonly used acrylate resins in the industry will be added according to product requirements, for example, Miki acrylic resin BS 962, Sartomer CN2254NS difunctional polyester acrylate, Sartomer CN2003 epoxy acrylate, Sartomer CN1073NS isocyanate urethane acrylate resin, Sartomer CN983 NS urethane diacrylate resin, Sartomer CN980NS urethane acrylate resin, Sartomer CN970A60NS triacrylate resin, Sartomer CN969 NS acrylate resin, Sartomer CN120NS bisphenol A difunctional epoxy acrylate, Sartomer CN115 NS epoxy acrylate resin, Sartomer UV resin oligomer CN9001NS, Sartomer CN1074NS tackifier acrylate oligomer, DPGDA (dipropylene glycol diacrylate), TMPTA (MIRAMER M300 TMPTA), TEGDA (triethylene glycol diacrylate), DPPA (dipentaerythritol pentaacrylate), DPHA (dipentaerythritol hexaacrylate), etc.

[0041] In some embodiments, the photocuring agent includes at least one of photoinitiator 184 (i.e., IGM photosensitizer Omnirad 184, CAS: 947-19-3), photoinitiator 369 (i.e., IGM photoinitiator Omnirad369), photoinitiator 651 (i.e., IGM photoinitiator Omnirad 651), photoinitiator 819 (i.e., IGM photoinitiator Omnirad 819), photoinitiator 1800 (i.e., Irgacure 1800), photoinitiator 2020, photoinitiator MBF (BASF photoinitiator Irgacure MBF), photoinitiator TPO (i.e., (2,4,6-trimethylbenzoyl) diphenylphosphine oxide), and photoinitiator CTX (i.e., 2-chlorothioxanthone).

[0042] In some embodiments, the solvent mainly plays the role of dissolving and dispersing silver powder and organic resin, and can also assist screen printing to be more efficient; the solvent includes at least one of acetone, butanone, methyl isobutyl ketone, isophorone, ethylene glycol, propylene glycol, ethyl acetate, butyl acetate, xylene, terpineol, ethylene glycol ethyl ether, diethylene glycol butyl ether, dodecanol ester, dibutyl phthalate, dioctyl phthalate, dioctyl adipate, isopropyl alcohol, n-butanol, and cyclopentanone.

[0043] In some embodiments, the auxiliary agent is mainly used to adjust the state of the slurry to make it more in line with the requirements of fast screen printing; the auxiliary agent is generally added with one or more of the following to adjust the effect of screen printing, for example: BYK055 (i.e., German BYK-055 defoamer), BYK088 (i.e., German BYK088 defoamer), BYK067A (i.e., German BYK-067A defoamer), BYK333 (i.e., German BYK-333 anti-shrinkage leveling agent), BYK373 (i.e., German BYK coating auxiliary leveling agent BYK-373), BYKP-105 (i.e., German BYK-P At least one of Disperbyk-105 wetting and dispersing agent), Disperbyk-111 (i.e., German BYK DISPERBYK-111 wetting and dispersing agent for solvent-based system), Disperbyk-180 (i.e., German BYK DISPERBYK-180 wetting and dispersing agent), and Disperbyk-168 (i.e., German BYK wetting and dispersing agent DISPERBYK-168).

[0044] In some embodiments, the photovoltaic silver paste includes the following components in parts by weight:

[0045] 80-95 parts of silver powder, 3-15 parts of organic resin, 1-30 parts of solvent, and 0.05-5 parts of auxiliary agent.

[0046] In some embodiments, the silver powder includes micron silver powder and ultrafine silver powder; wherein the D50 particle size of the micron silver powder is 1-5 μm, the D50 particle size of the ultrafine silver powder is 50-800 nm, the mass fraction of the micron silver powder in the silver powder is 50-95%, and the rest is ultrafine silver powder.

[0047] Silver powder is the main body of silver paste conductivity, and its main function is to conduct electricity. The addition amount is generally 80-95 parts. If too many parts are added, the viscosity will be too high and it will be inconvenient to print; if too few parts are added, the conductivity will not meet the requirements. Among them, the D50 particle size (i.e., the average particle size) of micron silver powder is 1-5μm, which plays the role of building the overall conductive framework and is the main body. The amount to be added is 50-95% of the mass of the silver powder. The rest is ultrafine silver powder with a D50 particle size of 50-800nm, which fills the gaps between the silver powders.

[0048] In some embodiments, the sum of the mass fractions of the epoxy resin and the thermal curing agent in the organic resin is 50-80%, and the mass of the thermal curing agent is 2-20% of the mass of the epoxy resin;

[0049] Organic resin mainly plays the role of curing and shrinking under the action of heat and light, and can also improve printing stability during printing. The added amount is generally 3 to 15 parts; epoxy resin and thermosetting agent work together as a thermal curing system. The general added amount accounts for 50 to 80% of the total mass of organic resin, playing the role of supporting the overall resin system skeleton; and the thermosetting agent is generally based on the curing efficiency and the expected degree of curing, generally accounting for 2 to 20% of the epoxy resin. Adding too little will make it difficult to cure, and adding too much will cause the resin to become brittle, affecting adhesion and aging.

[0050] In some embodiments, the sum of the mass fractions of the acrylate resin and the photocuring agent in the organic resin is 20-50%, and the mass of the photocuring agent is 0.5-25% of the mass of the acrylate resin.

[0051] Acrylate resin and photocuring agent work together as a photocuring system. Generally, the added mass accounts for 20-50% of the total organic resin, which plays a role in further enhancing the curing effect in the part where the thermosetting resin cannot be cured. The photocuring agent is generally added at 0.5-25% of the acrylate resin, depending on the curing efficiency and curing depth. Adding too little will make it difficult to cure, and adding too much will cause the resin to become brittle, affecting adhesion and aging.

[0052] Solvents mainly dissolve and disperse silver powder and organic resins, and can also help screen printing to be more efficient. The amount of solvent added is generally adjusted according to the required viscosity, usually 1 to 30 parts. If too much is added, the viscosity will be too high, affecting the printing line width. If too little is added, the organic resin system cannot be dissolved well, resulting in printing anomalies.

[0053] Additives are mainly used to adjust the state of the paste to make it more suitable for fast screen printing. The amount added is generally 0.05 to 5 parts. If too much is added, the resistivity of the silver paste will be affected. If too little is added, the effect of auxiliary printing will not be obvious.

[0054] In some embodiments, the photovoltaic silver paste includes the following components in parts by weight:

[0055] 48-70 parts of micron silver powder, 15-40 parts of ultrafine silver powder, 3-7 parts of epoxy resin, 0.2-0.6 parts of thermal curing agent, 2-3 parts of acrylate resin, 0.03-0.3 parts of light curing agent, 6-15 parts of solvent, and 0.3-1 parts of auxiliary agent.

[0056] In some embodiments, the D50 particle size of the micron silver powder is 2 to 3 μm, the weight of the micron silver powder is 60 to 70 parts, the D50 particle size of the ultrafine silver powder is 250 to 350 nm, the weight of the ultrafine silver powder is 15 to 25 parts, the weight of the acrylic resin is 2.5 to 3 parts, the weight of the photocuring agent is 0.25 to 3 parts, the solvent includes butanone and butyl acetate, the weight of butanone is 5 to 6 parts, the weight of butyl acetate is 7 to 8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3 to 0.4 parts.

[0057] In some embodiments, the D50 particle size of the micron silver powder is 2 to 3 μm, the weight of the micron silver powder is 60 to 70 parts, the D50 particle size of the ultrafine silver powder is 250 to 350 nm, the weight of the ultrafine silver powder is 15 to 25 parts, the weight of the thermal curing agent is 0.2 to 0.3 parts, the weight of the acrylic resin is 2.5 to 3 parts, the weight of the photocuring agent is 0.25 to 3 parts, the solvent includes butanone and butyl acetate, the weight of butanone is 5 to 6 parts, the weight of butyl acetate is 7 to 8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3 to 0.4 parts.

[0058] In some embodiments, the D50 particle size of the micron silver powder is 2 to 3 μm, the weight of the micron silver powder is 60 to 70 parts, the D50 particle size of the ultrafine silver powder is 250 to 350 nm, the weight of the ultrafine silver powder is 15 to 25 parts, the weight of the acrylate resin is 2 to 2.5 parts, the weight of the photocuring agent is 0.03 to 0.04 parts, the solvent includes butanone and butyl acetate, the weight of butanone is 5 to 6 parts, the weight of butyl acetate is 7 to 8 parts, and the additive is Disperbyk-111, and the weight of the additive is 0.3 to 0.4 parts.

[0059] In some embodiments, the D50 particle size of the micron silver powder is 1-2 μm, the weight of the micron silver powder is 48-50 parts, the ultrafine silver powder includes ultrafine silver powder with a D50 particle size of 180-220 nm and ultrafine silver powder with a D50 particle size of 60-100 nm, the weight of the ultrafine silver powder with a D50 particle size of 180-220 nm is 15-25 parts, the weight of the ultrafine silver powder with a D50 particle size of 60-100 nm is 15-25 parts, the weight of the acrylic resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of butanone is 5-6 parts, the weight of butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts.

[0060] In some embodiments, the D50 particle size of the micron silver powder is 2 to 3 μm, the weight of the micron silver powder is 60 to 70 parts, the D50 particle size of the ultrafine silver powder is 250 to 350 nm, the weight of the ultrafine silver powder is 15 to 25 parts, the weight of the acrylate resin is 2.5 to 3 parts, the weight of the photocuring agent is 0.25 to 3 parts, the solvent includes ethylene glycol ethyl ether and diethylene glycol butyl ether, the weight of ethylene glycol ethyl ether is 2 to 4 parts, the weight of diethylene glycol butyl ether is 4 to 6 parts, the additives include BYK055 and Disperbyk-180, the weight of BYK055 is 0.05 to 0.1 parts, and the weight of Disperbyk-180 is 0.8 to 0.9 parts.

[0061] The photovoltaic silver paste of the present invention can optimize the low resistivity of the silver paste under low temperature conditions by adding a certain proportion of epoxy thermosetting system resin and acrylate photocuring system resin, and can also improve the contact performance on the FTO substrate, so that under low temperature conditions, the perovskite battery can use a screen printing solution with high mass production efficiency and low cost; by using the thermosetting photocuring system of the present invention, the resistivity and ohmic contact can be greatly reduced under low temperature curing, so that the possibility of realizing screen printing mass production on perovskite can be achieved.

[0062] Based on the same inventive concept, the present invention also provides an application of the above-mentioned photovoltaic silver paste in the preparation of perovskite solar cells.

[0063] Specifically, when used, the photovoltaic silver paste is printed on the fluorine-doped tin oxide FTO substrate of the perovskite solar cell, the solvent is dried at 50-80°C, and then thermally cured at 80-100°C, and then UV light cured.

[0064] Based on the same inventive concept, the present invention also provides a method for using the above photovoltaic silver paste, comprising the following steps:

[0065] Silver powder, organic resin, solvent and additive are mixed and printed on a fluorine-doped tin oxide FTO substrate, the solvent is dried at 50-80°C, and then thermally cured at 80-100°C, and then UV light cured.

[0066] In some embodiments, during the UV curing process, the UV intensity is 1000 to 5000 mJ / cm 2 .

[0067] Specifically, in the above embodiments, the curing method of photovoltaic silver paste after printing also has certain requirements. After printing, the solvent needs to be dried at a low temperature, and the temperature is generally selected to be 50-80°C, and the solvent can be dried; then thermal curing is performed. This step is the key to the curing of thermally cured epoxy resin. The temperature needs to reach the temperature of the ring-opening reaction of the epoxy functional group, which is generally set at 80-100°C. If the curing temperature is too high, the stability of the perovskite will be destroyed and the photoelectric conversion efficiency will be affected; if the curing temperature is too low, the ring cannot be opened, and the degree of curing reaction is too low, resulting in incomplete curing; after thermal curing, light curing is also required. Light curing requires an overall demand for energy, which needs to reach 1000-5000mJ / cm 2 If the energy is insufficient, the photocuring will be incomplete. If the energy is too high, excessive heat will be generated, which will affect the photoelectric conversion efficiency of the substrate.

[0068] The photovoltaic silver paste of the present application and its application and use method are further described below with specific examples. This section further illustrates the content of the present invention in conjunction with specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0069] Example 1

[0070] The embodiment of the present application provides a photovoltaic silver paste, comprising the following components in parts by weight: 65 parts of micron silver powder, 20 parts of ultrafine silver powder, 5 parts of epoxy resin, 0.4 parts of thermal curing agent, 2.7 parts of acrylate resin, 0.27 parts of light curing agent, 12.5 parts of solvent, and 0.3 parts of auxiliary agent;

[0071] Among them, the D50 particle size of micron silver powder is 2.5μm, and the D50 particle size of ultrafine silver powder is 300nm;

[0072] The epoxy resin is NPEL-128E (i.e. Nan Ya NPEL-128E epoxy resin, CAS: 25068-38-6), and the thermal curing agent is DICY (i.e. dicyandiamide);

[0073] The acrylate resin includes 2.5 parts by weight of Sartomer CN115 NS epoxy acrylate resin and 0.2 parts by weight of Sartomer CN980NS urethane acrylate resin;

[0074] The photocuring agent is photoinitiator 184 (i.e. IGM photosensitizer Omnirad 184, CAS: 947-19-3);

[0075] The solvent includes 5 parts by weight of butanone (i.e., methyl ethyl ketone, molecular formula C4H8O) and 7.5 parts by weight of butyl acetate (i.e., n-butyl acetate, molecular formula CH3COO(CH2)3CH3);

[0076] The additive is Disperbyk-111 (i.e., the wetting and dispersing agent for the German BYK DISPERBYK-111 solvent-based system).

[0077] This embodiment also provides a method for using the photovoltaic silver paste in the above embodiment 1, comprising the following steps:

[0078] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, epoxy resin, thermal curing agent, acrylate resin, light curing agent, solvent, and additive into a blender and mix well to obtain a slurry;

[0079] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm 2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0080] Example 2

[0081] The embodiment of the present application provides a photovoltaic silver paste, comprising the following components in parts by weight: 65 parts of micron silver powder, 20 parts of ultrafine silver powder, 4 parts of epoxy resin, 0.25 parts of thermal curing agent, 2.7 parts of acrylate resin, 0.27 parts of light curing agent, 12.5 parts of solvent, and 0.3 parts of auxiliary agent;

[0082] Among them, the D50 particle size of micron silver powder is 2.5μm, and the D50 particle size of ultrafine silver powder is 300nm;

[0083] The epoxy resin includes 3 parts by weight of Huntsman EPALLOY 8240 novolac epoxy resin and 1 part by weight of NPCN-704 (i.e. Nan Ya o-cresol novolac epoxy resin NPCN-704);

[0084] The thermal curing agent is 2E4MZ (i.e. 1-cyanoethyl-2-ethyl-4-methylimidazole);

[0085] The acrylate resin includes 2.5 parts by weight of Sartomer CN115 NS epoxy acrylate resin and 0.2 parts by weight of Sartomer CN980NS urethane acrylate resin;

[0086] The photocuring agent is photoinitiator 184 (i.e. IGM photosensitizer Omnirad 184, CAS: 947-19-3);

[0087] The solvent includes 5 parts by weight of butanone (i.e., methyl ethyl ketone, molecular formula C4H8O) and 7.5 parts by weight of butyl acetate (i.e., n-butyl acetate, molecular formula CH3COO(CH2)3CH3);

[0088] The additive is Disperbyk-111 (i.e., the wetting and dispersing agent for the German BYK DISPERBYK-111 solvent-based system).

[0089] This embodiment also provides a method for using the photovoltaic silver paste in the above embodiment 2, comprising the following steps:

[0090] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, epoxy resin, thermal curing agent, acrylate resin, light curing agent, solvent, and additive into a blender and mix well to obtain a slurry;

[0091] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm 2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0092] Example 3

[0093] The embodiment of the present application provides a photovoltaic silver paste, comprising the following components in parts by weight: 65 parts of micron silver powder, 20 parts of ultrafine silver powder, 5 parts of epoxy resin, 0.4 parts of thermal curing agent, 2 parts of acrylate resin, 0.03 parts of light curing agent, 12.5 parts of solvent, and 0.3 parts of auxiliary agent;

[0094] Among them, the D50 particle size of micron silver powder is 2.5μm, and the D50 particle size of ultrafine silver powder is 300nm;

[0095] The epoxy resin is NPEL-128E (i.e. Nan Ya NPEL-128E epoxy resin, CAS: 25068-38-6), and the thermal curing agent is DICY (i.e. dicyandiamide);

[0096] The acrylate resin includes 1.5 parts by weight of Sartomer CN970A60 NS triacrylate resin and 0.5 parts by weight of Sartomer CN115 NS epoxy acrylate resin;

[0097] The photocuring agent is photoinitiator 651 (i.e., IGM photoinitiator Omnirad 651);

[0098] The solvent includes 5 parts by weight of butanone (i.e., methyl ethyl ketone, molecular formula C4H8O) and 7.5 parts by weight of butyl acetate (i.e., n-butyl acetate, molecular formula CH3COO(CH2)3CH3);

[0099] The additive is Disperbyk-111 (i.e., the wetting and dispersing agent for the German BYK DISPERBYK-111 solvent-based system).

[0100] This embodiment also provides a method for using the photovoltaic silver paste in the above embodiment 3, comprising the following steps:

[0101] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, epoxy resin, thermal curing agent, acrylate resin, light curing agent, solvent, and additive into a blender and mix well to obtain a slurry;

[0102] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm 2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0103] Example 4

[0104] The embodiment of the present application provides a photovoltaic silver paste, comprising the following components in parts by weight: 48 parts of micron silver powder, 40 parts of ultrafine silver powder, 5 parts of epoxy resin, 0.4 parts of thermal curing agent, 2.7 parts of acrylate resin, 0.27 parts of light curing agent, 12.5 parts of solvent, and 0.3 parts of auxiliary agent;

[0105] The micron silver powder has a D50 particle size of 1.5 μm, and the ultrafine silver powder includes 20 parts by weight of ultrafine silver powder with a D50 particle size of 200 nm and 20 parts by weight of ultrafine silver powder with a D50 particle size of 80 nm.

[0106] The epoxy resin is NPEL-128E (i.e. Nan Ya NPEL-128E epoxy resin, CAS: 25068-38-6), and the thermal curing agent is DICY (i.e. dicyandiamide);

[0107] The acrylate resin includes 2.5 parts by weight of Sartomer CN115 NS epoxy acrylate resin and 0.2 parts by weight of Sartomer CN980NS urethane acrylate resin;

[0108] The photocuring agent is photoinitiator 184 (i.e. IGM photosensitizer Omnirad 184, CAS: 947-19-3);

[0109] The solvent includes 5 parts by weight of butanone (i.e., methyl ethyl ketone, molecular formula C4H8O) and 7.5 parts by weight of butyl acetate (i.e., n-butyl acetate, molecular formula CH3COO(CH2)3CH3);

[0110] The additive is Disperbyk-111 (i.e., the wetting and dispersing agent for the German BYK DISPERBYK-111 solvent-based system).

[0111] This embodiment also provides a method for using the photovoltaic silver paste in the above embodiment 4, comprising the following steps:

[0112] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, epoxy resin, thermal curing agent, acrylate resin, light curing agent, solvent, and additive into a blender and mix well to obtain a slurry;

[0113] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm 2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0114] Example 5

[0115] The embodiment of the present application provides a photovoltaic silver paste, comprising the following components in parts by weight: 65 parts of micron silver powder, 20 parts of ultrafine silver powder, 5 parts of epoxy resin, 0.4 parts of thermal curing agent, 2.7 parts of acrylate resin, 0.27 parts of light curing agent, 6 parts of solvent, and 0.9 parts of auxiliary agent;

[0116] Among them, the D50 particle size of micron silver powder is 2.5μm, and the D50 particle size of ultrafine silver powder is 300nm;

[0117] The epoxy resin is NPEL-128E (i.e. Nan Ya NPEL-128E epoxy resin, CAS: 25068-38-6), and the thermal curing agent is DICY (i.e. dicyandiamide);

[0118] The acrylate resin includes 2.5 parts by weight of Sartomer CN115 NS epoxy acrylate resin and 0.2 parts by weight of Sartomer CN980NS urethane acrylate resin;

[0119] The photocuring agent is photoinitiator 184 (i.e. IGM photosensitizer Omnirad 184, CAS: 947-19-3);

[0120] The solvent includes 2 parts by weight of ethylene glycol ethyl ether (molecular formula C4H 10O2) and 4 parts by weight of diethylene glycol butyl ether (molecular formula C8H 18 O3);

[0121] The additives include 0.05 parts by weight of BYK055 (ie, German BYK-055 defoamer) and 0.85 parts by weight of Disperbyk-180 (ie, German BYK DISPERBYK-180 wetting and dispersing agent).

[0122] This embodiment also provides a method for using the photovoltaic silver paste in the above embodiment 5, comprising the following steps:

[0123] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, epoxy resin, thermal curing agent, acrylate resin, light curing agent, solvent, and additive into a blender and mix well to obtain a slurry;

[0124] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm 2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0125] Comparative Example 1

[0126] This comparative example provides a photovoltaic silver paste, comprising the following components in parts by weight: 65 parts of micron silver powder, 20 parts of ultrafine silver powder, 5 parts of epoxy resin, 0.4 parts of thermal curing agent, 12.5 parts of solvent, and 0.3 parts of auxiliary agent;

[0127] Among them, the D50 particle size of micron silver powder is 2.5μm, and the D50 particle size of ultrafine silver powder is 300nm;

[0128] The epoxy resin is NPEL-128E (i.e. Nan Ya NPEL-128E epoxy resin, CAS: 25068-38-6), and the thermal curing agent is DICY (i.e. dicyandiamide);

[0129] The solvent includes 5 parts by weight of butanone (i.e., methyl ethyl ketone, molecular formula C4H8O) and 7.5 parts by weight of butyl acetate (i.e., n-butyl acetate, molecular formula CH3COO(CH2)3CH3);

[0130] The additive is Disperbyk-111 (i.e., the wetting and dispersing agent for the German BYK DISPERBYK-111 solvent-based system).

[0131] This embodiment also provides a method for using the photovoltaic silver paste in the above comparative example 1, comprising the following steps:

[0132] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, epoxy resin, thermosetting agent, solvent and additive into a blender and mix well to obtain a slurry;

[0133] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm 2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0134] Comparative Example 2

[0135] This comparative example provides a photovoltaic silver paste, comprising the following components in parts by weight: 65 parts of micron silver powder, 20 parts of ultrafine silver powder, 2.7 parts of acrylate resin, 0.27 parts of photocuring agent, 12.5 parts of solvent, and 0.3 parts of auxiliary agent;

[0136] Among them, the D50 particle size of micron silver powder is 2.5μm, and the D50 particle size of ultrafine silver powder is 300nm;

[0137] The acrylate resin includes 2.5 parts by weight of Sartomer CN115 NS epoxy acrylate resin and 0.2 parts by weight of Sartomer CN980NS urethane acrylate resin;

[0138] The photocuring agent is photoinitiator 184 (i.e. IGM photosensitizer Omnirad 184, CAS: 947-19-3);

[0139] The solvent includes 5 parts by weight of butanone (i.e., methyl ethyl ketone, molecular formula C4H8O) and 7.5 parts by weight of butyl acetate (i.e., n-butyl acetate, molecular formula CH3COO(CH2)3CH3);

[0140] The additive is Disperbyk-111 (i.e., the wetting and dispersing agent for the German BYK DISPERBYK-111 solvent-based system).

[0141] This embodiment also provides a method for using the photovoltaic silver paste in the above comparative example 2, comprising the following steps:

[0142] S1. Add the above-mentioned micron silver powder, ultrafine silver powder, acrylate resin, light curing agent, solvent and additive into a blender and mix well to obtain slurry;

[0143] S2. The slurry is printed on the fluorine-doped tin oxide FTO substrate by a screen printer, dried at 50°C for 30 minutes, and then thermally cured at 100°C for 30 minutes. After thermal curing, UV light curing is performed. During the UV light curing process, the ultraviolet light intensity is 4000mJ / cm2 ; After curing, the resistivity and ohmic contact of the silver layer were tested.

[0144] According to the methods in Examples 1 to 5 and Comparative Examples 1 to 2 above, the resistivity and ohmic contact of the silver layer were tested after curing. The results are shown in Table 1 below.

[0145] Table 1 - Resistivity of the silver layer and ohmic contact after curing in different examples

[0146] Example Resistivity (μΩ·cm) <![CDATA[Ohmic contact (mΩ·cm 2 )]]> Example 1 3.98 1.71 Example 2 3.74 1.56 Example 3 3.71 1.42 Example 4 3.62 1.21 Example 5 3.86 1.65 Comparative Example 1 52.01 5.60 Comparative Example 2 220.12 10.51

[0147] As can be seen from Table 1 above, by adding silver powder, epoxy resin, thermal curing agent, acrylate resin, light curing agent, solvent, and additives, the resistivity of the silver layer after curing is less than 4μΩ·cm, which has very excellent resistivity performance, while maintaining less than 2mΩ·cm 2 The contact resistance is low and the comprehensive electrical properties are excellent. In Example 2, a mixed epoxy resin system is used, and the amount of a certain resin is reduced, which is helpful for improving the resistivity. In Example 3, the proportion of epoxy resin and acrylate resin is increased, which can effectively improve the connection between the thermosetting system and the photocuring system, thereby improving the electrical performance; in Example 4, a higher proportion of nano-sized silver powder is added, and the size of the silver powder is reduced, which has a very obvious effect on improving the resistivity; in Example 5, the amount of solvent is reduced, and a solvent with better solubility is used, and the use of defoaming aids is increased, which can effectively reduce the holes in the system, thereby improving the contact performance; in Example 1, after the photocuring system is removed, due to the insufficient degree of curing reaction of the thermosetting system itself, it is difficult to ensure reactivity and density, resulting in a significant increase in resistance and poor contact with the substrate; in Example 2, after the heat-curing system is removed, due to the insufficient curing depth and poor resin coating of the photocuring system alone, the problem of resistance is further exposed, and at the same time, when the density cannot be guaranteed, the contact increases exponentially.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic silver paste, characterized in that: include: Silver powder, organic resin, solvent, additives; Wherein, the organic resin includes a mixture of epoxy resin, thermosetting agent, acrylate resin and light curing agent.

2. The photovoltaic silver paste according to claim 1, characterized in that: The epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, alicyclic epoxy resin, and resorcinol epoxy resin; And / or, the thermal curing agent includes at least one of IPDA, DICY, AADH, DMP-10, DMP-30, 2E4MZ, and DPEDA; And / or, the acrylate resin includes at least one of polyurethane acrylate, polyester acrylate, polyether acrylate, and epoxy acrylate; And / or, the photocuring agent includes at least one of photoinitiator 184, photoinitiator 369, photoinitiator 651, photoinitiator 819, photoinitiator 1800, photoinitiator 2020, photoinitiator MBF, photoinitiator TPO, and photoinitiator CTX.

3. The photovoltaic silver paste according to claim 1, characterized in that: The solvent includes at least one of acetone, butanone, methyl isobutyl ketone, isophorone, ethylene glycol, propylene glycol, ethyl acetate, butyl acetate, xylene, terpineol, ethylene glycol ethyl ether, diethylene glycol butyl ether, dodecanol ester, dibutyl phthalate, dioctyl phthalate, dioctyl adipate, isopropanol, n-butanol, and cyclopentanone; And / or, the auxiliary agent includes at least one of BYK055, BYK088, BYK067A, BYK333, BYK373, BYKP-105, Disperbyk-111, Disperbyk-180, and Disperbyk-168.

4. The photovoltaic silver paste according to any one of claims 1 to 3, characterized in that: The photovoltaic silver paste comprises the following components in parts by weight: 80-95 parts of silver powder, 3-15 parts of organic resin, 1-30 parts of solvent, and 0.05-5 parts of auxiliary agent.

5. The photovoltaic silver paste according to claim 4, characterized in that: The silver powder includes micron silver powder and ultrafine silver powder; wherein the D50 particle size of the micron silver powder is 1 to 5 μm, the D50 particle size of the ultrafine silver powder is 50 to 800 nm, and the mass fraction of the micron silver powder in the silver powder is 50 to 95%; And / or, the sum of the mass fractions of the epoxy resin and the thermal curing agent in the organic resin is 50-80%, and the mass of the thermal curing agent is 2-20% of the mass of the epoxy resin; The sum of the mass fractions of the acrylate resin and the light curing agent in the organic resin is 20-50%, and the mass of the light curing agent is 0.5-25% of the mass of the acrylate resin.

6. The photovoltaic silver paste according to claim 5, characterized in that: The photovoltaic silver paste comprises the following components in parts by weight: 48-70 parts of micron silver powder, 15-40 parts of ultrafine silver powder, 3-7 parts of epoxy resin, 0.2-0.6 parts of thermal curing agent, 2-3 parts of acrylate resin, 0.03-0.3 parts of light curing agent, 6-15 parts of solvent, and 0.3-1 parts of auxiliary agent.

7. The photovoltaic silver paste according to claim 6, characterized in that: The D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the acrylic resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts; Or, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the thermal curing agent is 0.2-0.3 parts, the weight of the acrylic resin is 2.5-3 parts, the weight of the light curing agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts; Or, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the acrylic resin is 2-2.5 parts, the weight of the photocuring agent is 0.03-0.04 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts; Or, the D50 particle size of the micron silver powder is 1-2 μm, the weight of the micron silver powder is 48-50 parts, the ultrafine silver powder includes ultrafine silver powder with a D50 particle size of 180-220 nm and ultrafine silver powder with a D50 particle size of 60-100 nm, the weight of the ultrafine silver powder with a D50 particle size of 180-220 nm is 15-25 parts, the weight of the ultrafine silver powder with a D50 particle size of 60-100 nm is 15-25 parts, the weight of the acrylate resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes butanone and butyl acetate, the weight of the butanone is 5-6 parts, the weight of the butyl acetate is 7-8 parts, the auxiliary agent is Disperbyk-111, and the weight of the auxiliary agent is 0.3-0.4 parts; Or, the D50 particle size of the micron silver powder is 2-3 μm, the weight of the micron silver powder is 60-70 parts, the D50 particle size of the ultrafine silver powder is 250-350 nm, the weight of the ultrafine silver powder is 15-25 parts, the weight of the acrylate resin is 2.5-3 parts, the weight of the photocuring agent is 0.25-3 parts, the solvent includes ethylene glycol ethyl ether and diethylene glycol butyl ether, the weight of the ethylene glycol ethyl ether is 2-4 parts, the weight of the diethylene glycol butyl ether is 4-6 parts, the auxiliary agent includes BYK055 and Disperbyk-180, the weight of BYK055 is 0.05-0.1 parts, and the weight of the Disperbyk-180 is 0.8-0.9 parts.

8. Use of the photovoltaic silver paste according to any one of claims 1 to 7 in the preparation of perovskite solar cells.

9. A method for using the photovoltaic silver paste according to any one of claims 1 to 7, characterized in that: The following steps are involved: Silver powder, organic resin, solvent and additive are mixed and printed on a fluorine-doped tin oxide FTO substrate, the solvent is dried at 50-80°C, and then thermally cured at 80-100°C, and then UV light cured.

10. The method for using the photovoltaic silver paste according to claim 9, characterized in that: During UV curing, the UV intensity is 1000~5000mJ / cm 2 .