Preparation method of lead adsorption coating applied to perovskite solar cell

Abstract

The present invention discloses a preparation method of a lead adsorption coating applied to a perovskite solar cell, belonging to the technical field of perovskite solar cells. The present invention provides a lead adsorption coating prepared from modified polyvinyl alcohol. This coating can be combined with traditional packaging materials of perovskite solar cells to prepare a generally applicable packaging material with lead adsorption function. After obtaining a lead adsorption coating precursor solution by modifying polyvinyl alcohol with a modifier, it is blade-coated on the surface of the packaging material to prepare a lead adsorption coating with high uniformity. This coating has excellent light transmittance and lead adsorption ability. The lead leakage amount of the encapsulated damaged perovskite solar device is reduced, and at the same time, the coating will not cause any damage to the perovskite solar cell. After encapsulating with the packaging material containing this coating, a perovskite solar cell with a low lead leakage rate can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and particularly relates to a preparation method of a lead adsorption coating applied to perovskite solar cells. Background Art

[0002] Metal halide perovskite materials have become an excellent class of materials widely used in the optoelectronic field due to their unique optical and electrical properties. Therefore, perovskite optoelectronic devices with low cost and high efficiency have become a new research hotspot, and the technical research is continuously deepening. At present, there are still certain technical defects in perovskite optoelectronic devices.

[0003] The unique electron arrangement configuration of lead makes it an essential component for constructing perovskite optoelectronic devices with high efficiency and good stability. Lead is one of the most toxic heavy elements in the environment. Due to its non-biodegradable nature, it is extremely easy to accumulate in the human body through the food chain and cause harm. Therefore, to achieve the large-scale commercialization of perovskite optoelectronic devices, the toxicity of lead must be solved. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of lead leakage existing after the perovskite solar cell encapsulation device is damaged, reduce the public health risk brought by the leakage of lead ions into the environment, improve the safety and environmental protection ability of the perovskite solar cell, promote the commercialization process of the perovskite solar cell, and facilitate the integrated integration of perovskite photovoltaics and buildings. The lead adsorption coating prepared by the present invention can be combined with a variety of encapsulation materials, has good compatibility, reduces the risk of lead leakage after the device is damaged while retaining the advantages of the original encapsulation materials, and can obtain a low-pollution perovskite solar cell without increasing the device preparation steps.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention:

[0007] The present invention provides a preparation method of a lead adsorption coating applied to perovskite solar cells, comprising the following steps:

[0008] Adding a modifier to an aqueous solution of polyvinyl alcohol, stirring evenly, and standing to remove bubbles to obtain a mixed solution;

[0009] Cleaning and drying the encapsulation material, laying it flat on a substrate, after ultraviolet ozone treatment, scraping the mixed solution on the encapsulation material, drying to constant weight, and removing the coating from the substrate to obtain a lead adsorption coating applied to perovskite solar cells.

[0010] Furthermore, the preparation method of the polyvinyl alcohol aqueous solution is as follows: Add polyvinyl alcohol to deionized water and heat to dissolve it to obtain a polyvinyl alcohol aqueous solution. Heating is to make polyvinyl alcohol dissolve better in deionized water. The present invention does not limit the heating temperature, and the heating temperature is sufficient to dissolve polyvinyl alcohol, for example, the heating temperature can be 75 °C, 80 °C or 90 °C.

[0011] Furthermore, the modifier is sulfosuccinic acid or mercaptosuccinic acid. The modifier of the present invention is a succinic acid compound with functional groups. The modification principle is that the succinic acid in the modifier crosslinks with the hydroxyl groups existing in polyvinyl alcohol. The ester groups generated after crosslinking modification increase the water resistance of the modified polyvinyl alcohol, and the functional groups and the generated ester groups provide adsorption sites for lead ions, thereby reducing the leakage of lead ions.

[0012] Furthermore, the mass ratio of polyvinyl alcohol to the modifier is (3 - 4)∶(1.5 - 2.75).

[0013] Furthermore, the encapsulation material includes one of ethylene-vinyl acetate copolymer (EVA), ethylene-octene copolymer (POE), polyvinyl fluoride composite film (TPT), glass, epoxy resin, and polydimethylsiloxane (PDMS).

[0014] Furthermore, the time of ultraviolet ozone treatment is 10 min.

[0015] The present invention provides a lead adsorption coating for perovskite solar cells prepared according to the above method.

[0016] The present invention also provides the application of the lead adsorption coating in preventing lead leakage in perovskite solar cells. By combining a coating with chemical adsorption effect on lead ions to the encapsulation layer, the present invention can effectively solve the problem of lead ion leakage in damaged perovskite optoelectronic devices, reduce its environmental pollution, and promote the commercialization process of perovskite optoelectronic devices.

[0017] The present invention also provides a method for encapsulating a perovskite solar cell using the lead adsorption coating, and uses the lead adsorption coating to perform edge encapsulation on the perovskite solar cell.

[0018] Furthermore, an encapsulation adhesive is also used during encapsulation.

[0019] Furthermore, the encapsulation adhesive is one of UV adhesive, hot melt adhesive, and silicone.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] The present invention provides a lead adsorption coating prepared from modified polyvinyl alcohol, which can be combined with traditional packaging materials of perovskite solar cells to prepare a generally applicable packaging material with lead adsorption function. After obtaining the lead adsorption coating precursor solution by modifying polyvinyl alcohol with a modifier, it is spin-coated on the surface of the packaging material to prepare a lead adsorption coating with high uniformity. This coating has excellent light transmittance and lead adsorption ability. The lead leakage of the damaged perovskite solar device after encapsulation is reduced, and at the same time, the coating will not cause any damage to the perovskite solar cell. After encapsulating with the packaging material containing this coating, a perovskite solar cell with a low lead leakage rate can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0023] Figure 1 is a schematic diagram of the encapsulation structure of the perovskite solar cell of the present invention;

[0024] Figure 2 are the long-term operation stability results of the perovskite solar cells of the p-i-n type devices without encapsulation, encapsulated with the coating of Example 1 (Example 1 encapsulation), and encapsulated only with PDMS in Comparative Example 1 (PDMS encapsulation);

[0025] Figure 3 are the long-term operation stability results of the perovskite solar cells of the n-i-p type devices without encapsulation, encapsulated with the coating of Example 1 (Example 1 encapsulation), and encapsulated only with PDMS in Comparative Example 1 (PDMS encapsulation);

[0026] Figure 4 are the long-term operation stability results of the perovskite solar cells of the p-i-n type devices without encapsulation, encapsulated with the coating of Example 7 (Example 7 encapsulation), and encapsulated only with PDMS in Comparative Example 1 (PDMS encapsulation). DETAILED DESCRIPTION OF THE INVENTION

[0027] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation to the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0028] It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded within the range.

[0029] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although only preferred methods and materials are described in this invention, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0030] Without departing from the scope or spirit of this invention, various improvements and changes can be made to the specific embodiments of the description of this invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of this invention are obvious to those skilled in the art. The description and examples of this invention are merely exemplary.

[0031] Regarding the use of "comprising", "including", "having", "containing", etc. in this article, they are all open-ended terms, meaning including but not limited to.

[0032] Each raw material used in the embodiments of this invention is obtained by purchasing from the market.

[0033] Some embodiments of this invention provide a method for preparing a lead adsorption coating applied to a perovskite solar cell, including the following steps:

[0034] Add a modifier to an aqueous solution of polyvinyl alcohol, stir evenly, and let stand to remove bubbles to obtain a mixed solution;

[0035] Clean and dry the encapsulation material, lay it flat on a substrate, after ultraviolet ozone treatment, scrape the mixed solution on the encapsulation material, dry to constant weight, and remove the coating from the substrate to obtain a lead adsorption coating applied to a perovskite solar cell.

[0036] In some embodiments of this invention, the preparation method of the aqueous solution of polyvinyl alcohol is as follows: Add polyvinyl alcohol to deionized water and heat to dissolve to obtain an aqueous solution of polyvinyl alcohol. Heating is to make polyvinyl alcohol dissolve better in deionized water. This invention places no limitation on the heating temperature, as long as the heating temperature is sufficient to dissolve polyvinyl alcohol, for example, the heating temperature can be 75 °C, 80 °C or 90 °C.

[0037] In some embodiments of the present invention, the modifier is sulfosuccinic acid or mercaptosuccinic acid. The succinic acid in such succinic acid compounds with functional groups can crosslink with the hydroxyl groups present in polyvinyl alcohol. The ester groups formed after crosslinking modification increase the water resistance of the modified polyvinyl alcohol, and the functional groups and the formed ester groups provide adsorption sites for lead ions, thereby reducing the leakage of lead ions. The sulfosuccinic acid (70 wt% aqueous solution) (CAS No.: 5138-18-1, product number: S922175) and mercaptosuccinic acid (CAS No.: 70-49-5, product number: M813490) in the embodiments of the present invention are purchased from Shanghai Macklin Biochemical Co., Ltd.

[0038] In some embodiments of the present invention, the mass ratio of polyvinyl alcohol to the modifier is (3 - 4)∶(1.5 - 2.75). For example, when the mass of polyvinyl alcohol is 3 g, the mass of the modifier can be 2 g or 1.5 g; when the mass of polyvinyl alcohol is 4 g, the mass of the modifier can be 2.5 g or 2.75 g.

[0039] In some embodiments of the present invention, the encapsulation material includes one of ethylene-vinyl acetate copolymer (EVA), ethylene-octene copolymer (POE), polyvinyl fluoride composite film (TPT), glass, epoxy resin, and polydimethylsiloxane (PDMS). The above encapsulation materials are well-known to those skilled in the art, and commercially available products can be used. In the embodiments of the present invention, PDMS with a thickness of 0.5 mm is taken as an example for illustration.

[0040] In some embodiments of the present invention, after the mixed solution is scrape-coated on the encapsulation material, the scrape-coating thickness is 0.5 - 1.2 mm.

[0041] In some embodiments of the present invention, the time of ultraviolet ozone treatment is 10 min.

[0042] In some embodiments of the present invention, a lead adsorption coating applied to a perovskite solar cell prepared according to the above method is provided. The lead adsorption coating of the present invention applied to a perovskite solar cell is a new coating of modified polyvinyl alcohol coated on the existing encapsulation material. Currently, most of the research on preventing lead leakage in perovskite solar cells focuses on internal adsorption. Internal adsorption increases the device manufacturing process, and the amount of adsorption material used is small, making it difficult to balance the adsorption efficiency and device efficiency. The new coating of the present invention uses external chemical adsorption, integrating the adsorption layer on the encapsulation material, reducing the pollution of perovskite solar cells without increasing the device manufacturing process. Moreover, the coating preparation process of the present invention is simple and suitable for large-area preparation.

[0043] In some embodiments of the present invention, there is provided an application of the described lead adsorption coating in preventing lead leakage in perovskite solar cells. By combining a coating with a chemical adsorption effect on lead ions into the encapsulation layer, the present invention can effectively solve the problem of lead ion leakage in damaged perovskite optoelectronic devices, reduce its environmental pollution, and promote the commercialization process of perovskite optoelectronic devices.

[0044] Some embodiments of the present invention also provide a method for encapsulating a perovskite solar cell using the described lead adsorption coating, and the edge of the perovskite solar cell is encapsulated using the lead adsorption coating.

[0045] In some embodiments of the present invention, an encapsulation adhesive is also used during encapsulation.

[0046] In some embodiments of the present invention, the encapsulation adhesive is one of UV glue, hot melt glue, and silicone. The above encapsulation adhesives are well-known to those skilled in the art, and commercially available products can be used. In the embodiments of the present invention, silicone sealant is taken as an example for illustration. The area of the perovskite solar cell in each embodiment of the present invention is 2.5 * 2.5 cm 2 , and the schematic diagram of the encapsulation structure is as Figure 1 shown (the upper and lower sides of the perovskite solar cell are closely attached to the lead adsorption coating applied to the perovskite solar cell, and a sealant is coated around the device to achieve edge encapsulation). Two types of perovskite solar cell devices, n-i-p and p-i-n, are used to test the versatility of the adsorption coating. Among them, the n-i-p type device structure: FTO conductive glass / tin dioxide (SnO2) / perovskite layer ((FA 0.65 MA 0.20 Cs 0.15 )Pb(I 0.8 Br 0.2 )3) / 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-OMeTAD) / (gold electrode) Au. The n-i-p type device structure: ITO conductive glass / [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) / perovskite layer (FA 0.8 MA 0.15 Cs 0.05 PbI3) / lithium fluoride (LiF) / fullerene (C60) / 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) / silver electrode (Ag).

[0047] The encapsulation method involved in the embodiments of the present invention is a conventional technical means of the present invention and is not the focus of the present invention, so it will not be elaborated here.

[0048] In the embodiments of the present invention, the equipment used for "ultraviolet ozone treatment" is an ultraviolet ozone cleaning machine, and the specific model is UC100-SE of Jiangsu Leibo Scientific Instruments Co., Ltd.

[0049] The technical solutions of the present invention will be further described below through embodiments.

[0050] Example 1

[0051] 1. Add 3 g of polyvinyl alcohol to 8 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous solution of polyvinyl alcohol (PVA).

[0052] 2. Add 2 mL of sulfosuccinic acid (70 wt% aqueous solution, where sulfosuccinic acid is 2 g) to the above aqueous solution of polyvinyl alcohol, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0053] 3. After cleaning and drying the encapsulation material (PDMS with a thickness of 0.5 mm, the same below), lay it flat on the substrate. After ultraviolet ozone treatment for 10 min, scrape the above mixed solution on the encapsulation material with a scraping thickness of 1.2 mm, and place it in an oven, and heat and dry it at 35 °C until the weight no longer changes (that is, dry to constant weight).

[0054] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to the perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device (the upper and lower sides of the perovskite solar cell are closely attached to the lead adsorption coating applied to the perovskite solar cell, and sealant is coated around the device to achieve edge encapsulation, the same below).

[0055] Example 2

[0056] 1. Add 3 g of polyvinyl alcohol to 8 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous solution of polyvinyl alcohol.

[0057] 2. Add 2 mL of sulfosuccinic acid (70 wt% aqueous solution, where sulfosuccinic acid is 2 g) to the above aqueous solution of polyvinyl alcohol, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0058] 3. After cleaning and drying the encapsulation material, lay it flat on the substrate. After ultraviolet ozone treatment for 10 min, scrape the above mixed solution on the encapsulation material with a scraping thickness of 1 mm, and place it in an oven, and heat and dry it at 35 °C until the weight no longer changes.

[0059] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to the perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device.

[0060] Example 3

[0061] 1. Add 3 g of polyvinyl alcohol to 8 mL of deionized water, heat to dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0062] 2. Add 1.5 mL of sulfosuccinic acid (70 wt% aqueous solution, where sulfosuccinic acid is 1.5 g) to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0063] 3. Clean and dry the encapsulating material, lay it flat on the substrate, after ultraviolet ozone treatment for 10 min, scrape and coat the above mixed solution on the encapsulating material with a scraping thickness of 1.2 mm, place it in a drying oven, and heat and dry it at 35 °C until the weight no longer changes.

[0064] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to a perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device.

[0065] Example 4

[0066] 1. Add 3 g of polyvinyl alcohol to 8 mL of deionized water, heat to dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0067] 2. Add 1.5 mL of sulfosuccinic acid (70 wt% aqueous solution, where sulfosuccinic acid is 1.5 g) to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0068] 3. Clean and dry the encapsulating material, lay it flat on the substrate, after ultraviolet ozone treatment for 10 min, scrape and coat the above mixed solution on the encapsulating material with a scraping thickness of 1 mm, place it in a drying oven, and heat and dry it at 35 °C until the weight no longer changes.

[0069] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to a perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device.

[0070] Example 5

[0071] 1. Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat to dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0072] 2. Add 2.75 g of mercaptosuccinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0073] 3. Clean and dry the encapsulating material, lay it flat on the substrate, after ultraviolet ozone treatment for 10 min, scrape and coat the above mixed solution on the encapsulating material with a scraping thickness of 0.5 mm, place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h.

[0074] 4. Remove the coating from the substrate to obtain a lead adsorption coating for perovskite solar cells, and perform edge encapsulation on the perovskite optoelectronic device.

[0075] Example 6

[0076] 1. Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0077] 2. Add 2.75 g of mercapto succinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0078] 3. Clean and dry the encapsulation material, lay it flat on the substrate, after ultraviolet ozone treatment for 10 min, scrape the above mixed solution on the encapsulation material, with a scraping thickness of 0.6 mm, place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h.

[0079] 4. Remove the coating from the substrate to obtain a lead adsorption coating for perovskite solar cells, and perform edge encapsulation on the perovskite optoelectronic device.

[0080] Example 7

[0081] 1. Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0082] 2. Add 2.75 g of mercapto succinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0083] 3. Clean and dry the encapsulation material, lay it flat on the substrate, after ultraviolet ozone treatment for 10 min, scrape the above mixed solution on the encapsulation material, with a scraping thickness of 0.7 mm, place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h.

[0084] 4. Remove the coating from the substrate to obtain a lead adsorption coating for perovskite solar cells, and perform edge encapsulation on the perovskite optoelectronic device.

[0085] Example 8

[0086] 1. Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0087] 2. Add 2.5 g of mercapto succinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0088] 3. After cleaning and drying the encapsulating material, lay it flat on the substrate. After ultraviolet ozone treatment for 10 min, scrape and coat the above mixed solution on the encapsulating material with a scraping thickness of 0.5 mm. Place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h.

[0089] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to the perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device.

[0090] Example 9

[0091] 1. Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0092] 2. Add 2.5 g of mercapto succinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0093] 3. After cleaning and drying the encapsulating material, lay it flat on the substrate. After ultraviolet ozone treatment for 10 min, scrape and coat the above mixed solution on the encapsulating material with a scraping thickness of 0.6 mm. Place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h.

[0094] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to the perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device.

[0095] Example 10

[0096] 1. Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution.

[0097] 2. Add 2.5 g of mercapto succinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution.

[0098] 3. After cleaning and drying the encapsulating material, lay it flat on the substrate. After ultraviolet ozone treatment for 10 min, scrape and coat the above mixed solution on the encapsulating material with a scraping thickness of 0.7 mm. Place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h.

[0099] 4. Remove the coating from the substrate to obtain a lead adsorption coating applied to the perovskite solar cell, and perform edge encapsulation on the perovskite optoelectronic device.

[0100] Comparative Example 1

[0101] The perovskite solar cells are encapsulated only with PDMS, that is, the upper and lower sides of the perovskite solar cells are closely attached to the PDMS layer, and a sealant is coated around the device to achieve edge encapsulation.

[0102] Comparative Example 2

[0103] Same as Example 1, except that in Step 2, the modifier sulfosuccinic acid is not added, and only the PVA aqueous solution is spin-coated on the PDMS, and the device is encapsulated.

[0104] To test the lead leakage of the encapsulated device under the worst conditions, the falling ball experiment was used to simulate hail and other severe weather or physical impacts, and then the encapsulation layer was scratched with a knife to obtain a damaged perovskite solar cell encapsulated device, and the damaged device was used to simulate the rainfall experiment and the immersion experiment.

[0105] Falling ball experiment: A 400 g steel ball was dropped from a height of 20 cm above the encapsulated device.

[0106] Simulated rainfall experiment: The damaged encapsulated device was placed in a funnel and tilted at an angle of 20°. Deionized water was dripped above the damaged device at a dripping rate of 31.25 L / h for 1.5 h. The contaminated water under the funnel was collected and the lead ion concentration in the contaminated water was measured. To simulate the harsh natural environment, the lead leakage rates of the dripping experiments were tested at pH = 5.6 and pH = 5.6 in the presence of Ca 2+ 、Mg 2+ competitive ions (2 ppm).

[0107] Immersion experiment: The damaged encapsulated device was placed in 50 mL of deionized water, and the lead ion concentration in the contaminated water was detected. To simulate the harsh natural environment, the lead leakage rates of the immersion experiments were tested at pH = 5.6 and pH = 5.6 in the presence of Ca 2+ 、Mg 2+ competitive ions (2 ppm).

[0108] The Shimadzu AA-7000 atomic absorption spectrometer was used to measure the lead ion concentration in the contaminated water of the damaged encapsulated device in the simulated rainfall and immersion experiments to determine the lead leakage amount.

[0109] The Keithley 2400 was used to measure the power conversion efficiency (PCE) of the encapsulated perovskite solar cell device. The conditions were as follows: in a glove box filled with nitrogen, an AM1.5G light source with a light intensity of 100 mW·cm -2 was used to simulate sunlight, and the effective area of the active layer was 0.09 cm 2 .

[0110] To test the long-term operation stability of the encapsulated perovskite solar cells, the perovskite solar cells were subjected to maximum power point tracking (MPP Tracking) inside a glove filled with nitrogen at a temperature of 50 °C ± 5, using an LED lamp as a simulated light source with an intensity of 100 mW cm -2 .

[0111] The above lead leakage test results are shown in Tables 1 to 4, and the long-term operation stability results of the unencapsulated and differently coated perovskite solar cells are shown in Figures 2 to 4 . It can be seen that the new coating of the present invention has good compatibility, reduces the risk of lead leakage after device breakage while retaining the advantages of the original encapsulation material, improves the stability of the battery on the basis of the PDMS layer, and can obtain perovskite solar cells with low pollution and high stability without increasing the device preparation steps.

[0112] Table 1 Photovoltaic conversion efficiency (PCE) of n-i-p type and p-i-n type devices before and after encapsulation

[0113]

[0114] Table 2 Lead leakage of damaged encapsulated n-i-p type devices in the immersion experiment

[0115]

[0116] Table 3 Lead leakage of damaged encapsulated p-i-n type devices in the immersion experiment

[0117]

[0118] Table 4 Lead leakage of damaged encapsulated n-i-p type and p-i-n type devices in the simulated rainfall experiment

[0119]

[0120] In summary, the present invention provides a lead adsorption coating prepared from modified polyvinyl alcohol. This coating can be combined with traditional encapsulation materials of perovskite solar cells to prepare a generally applicable encapsulation material with lead adsorption function. After using a modifier to modify polyvinyl alcohol to obtain a lead adsorption coating precursor solution, it is spin-coated on the surface of the encapsulation material to prepare a lead adsorption coating with high uniformity. This coating has excellent light transmittance and lead adsorption ability, reduces the lead leakage amount of the damaged perovskite solar device after encapsulation, and at the same time the coating does not cause any damage to the perovskite solar cell. A perovskite solar cell with a low lead leakage rate can be obtained after encapsulation with the encapsulation material containing this coating.

[0121] The above are only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A preparation method of a lead adsorption coating applied to a perovskite solar cell, characterized in that, Including the following steps: (1) Add 4 g of polyvinyl alcohol to 10 mL of deionized water, heat and dissolve it at a heating temperature of 90 °C to obtain an aqueous polyvinyl alcohol solution; (2) Add 2.75 g of mercaptosuccinic acid to the above aqueous polyvinyl alcohol solution, stir evenly, and let it stand to remove bubbles to obtain a mixed solution; (3) After cleaning and drying the encapsulation material, lay it flat on the substrate. After ultraviolet ozone treatment for 10 min, scrape the above mixed solution on the encapsulation material with a scraping thickness of 0.7 mm, place it in a drying oven, heat and dry it at 50 °C until the weight no longer changes, and then heat it at 100 °C for 2 h; (4) Remove the coating from the substrate to obtain a lead adsorption coating applied to a perovskite solar cell.

2. A method for encapsulating a perovskite solar cell using the lead adsorption coating described above, characterized in that, Use the lead adsorption coating in Claim 1 to perform edge encapsulation on the perovskite solar cell.

3. The method for encapsulating a perovskite solar cell using the lead adsorption coating according to claim 2, wherein An encapsulation adhesive is also used during encapsulation.

4. The method for encapsulating a perovskite solar cell using the lead adsorption coating according to claim 3, characterized in that, The encapsulation adhesive is one of UV glue, hot melt glue, and silicone.

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