Perovskite ink suitable for meniscus coating, preparation method and application thereof

Abstract

The application discloses a perovskite ink suitable for meniscus coating, a preparation method and application thereof, the perovskite ink comprises a perovskite material, a polymer additive and a solvent; the polymer additive is selected from one or more of polymethyl methacrylate, polydimethylsiloxane, polyethylene naphthalate, polyethylene terephthalate, polyimide, polycarbonate, polyurethane, natural rubber or silicone polymer. The application adopts a polymer additive to regulate the shape of perovskite precursor micelles in a solution, and prepares perovskite precursor ink. The ink shows uniform film morphology and single crystal orientation after blade coating. The high-quality perovskite film prepared by using the perovskite ink improves the performance of a perovskite battery.

Description

Technical Field

[0001] This invention relates to the field of perovskite materials technology, and in particular to a perovskite ink suitable for meniscus coating, its preparation method, and its application in photovoltaics. Background Technology

[0002] Perovskite solar cells have achieved certified power conversion efficiencies exceeding 26% in laboratory-scale spin-coating fabrication, a level approaching that of silicon-based photovoltaics. Despite these remarkable advancements in recent years, a performance gap remains between scalable perovskite solar modules and laboratory-fabricated solar cells. Currently, most high-efficiency perovskite solar modules are still produced using spin-coating, which limits their scalability for large-scale production.

[0003] Blade coating, as a scalable thin-film deposition method, has shown great potential for large-area perovskite thin film deposition. However, due to the low solvent extraction rate and complex rheological behavior, the perovskite solar module films prepared by blade coating have poor morphology, resulting in low photoelectric conversion efficiency. Recently, the rheological factors of inks, such as viscosity, surface tension, meniscus shape, and colloidal distribution, have attracted extensive research, as these factors affect the film morphology during the blade coating process. However, the complex rheological behavior of inks often leads to uncontrolled film morphology in blade coating, resulting in degraded solar cell performance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a perovskite ink suitable for meniscus coating, its preparation method, and its application in photovoltaics. The perovskite ink is prepared by controlling the micelle morphology of the perovskite precursor in solution using polymeric additives. This perovskite ink is suitable for meniscus coating methods such as blade coating, slot coating, wire rod coating, or dip coating, and can be used in the fabrication of perovskite solar cells.

[0005] In a first aspect, the present invention provides a perovskite ink comprising a perovskite material, a polymeric additive, and a solvent;

[0006] The polymeric additive is selected from one or more of polymethyl methacrylate, polydimethylsiloxane, polyethylene naphthalate, polyethylene terephthalate, polyimide, polycarbonate, polyurethane, natural rubber, or silicone polymers.

[0007] According to an embodiment of the present invention, the solvent is at least selected from solvent A, which is selected from at least one of dimethyl sulfoxide, N,N-dimethylformamide, 2-methoxyethanol, γ-butyrolactone or N-methylpyrrolidone.

[0008] According to an embodiment of the present invention, the solvent may also be selected from solvent B, which is selected from at least one of acetonitrile, ethanol or tetrahydrofuran.

[0009] According to an embodiment of the present invention, the solvent is selected from a mixture of solvent A and solvent B, wherein the volume ratio of solvent A to solvent B is 1:9-9:1, preferably 1:9-5:5, and even more preferably 8:2-9:1.

[0010] According to an embodiment of the present invention, the perovskite material is selected from compounds with the chemical formula ABX3 and Cs. x FA 1- x PbI3, Cs x FA 1-x Pb(I y Cl 1-y 3. Cs x FA 1-x Pb(I y Br 1-y 3. Cs x FA 1-x Pb(I y Br z Cl 1-y-z 3. MAPb(I) x Cl 1-x 3. MAPb(I) x Br 1-x 3. MAPb(I) x Br y Cl 1-x-y 3. MA x FA 1-x PbI3, MA x FA 1-x Pb(I y Cl 1-y 3. MA x FA 1-x Pb(I y Br 1-y 3. MA x FA 1-x Pb(I y Br z Cl 1-y-z At least one of the following three;

[0011] x is a number between 0 and 1, y is a number between 0 and 1, and z is a number between 0 and 1;

[0012] In ABX3, A is one of MA, FA or Cs, B is Pb, and X is one of I, Br or Cl; MA is methylamine cation, and FA is formamidin cation.

[0013] According to an embodiment of the present invention, the concentration of perovskite material in the perovskite ink is 0.5-6 mol / L, preferably 1-2 mol / L.

[0014] According to an embodiment of the present invention, the concentration of the polymeric additive in the perovskite ink is 0.1-2 mg / mL, preferably 0.1-1 mg / mL.

[0015] Secondly, the present invention also provides a method for preparing the above-mentioned perovskite ink, comprising the following steps:

[0016] The perovskite ink is prepared by mixing perovskite material, polymer additives, and solvents.

[0017] According to an embodiment of the present invention, the mixing temperature is 16-80°C and the mixing time is 1-8 hours.

[0018] According to one embodiment of the present invention, the method for preparing the perovskite ink specifically includes:

[0019] 1) Mix solvent A and solvent B, then add the polymer additive and mix again;

[0020] 2) Add perovskite material to the mixture in step 1) and mix to prepare the perovskite ink.

[0021] According to an embodiment of the present invention, the instrument used for mixing in step 1) and / or step 2) is a vortex mixer and / or a magnetic stirrer.

[0022] Thirdly, the present invention also provides a perovskite thin film, which is obtained by heat annealing the above-mentioned perovskite ink.

[0023] According to an embodiment of the present invention, the average grain size of the perovskite thin film is greater than or equal to 500 nm.

[0024] According to an embodiment of the present invention, the thickness of the perovskite thin film is 50-1000 nm.

[0025] According to an embodiment of the present invention, the heat annealing temperature is 50-150°C, preferably 110-150°C; the heat annealing time is 5-120 min, preferably 10-60 min, for example 15 min.

[0026] Fourthly, the present invention also provides a method for preparing a perovskite thin film, comprising the following steps:

[0027] The perovskite ink described above was coated onto a substrate and then subjected to thermal annealing to obtain the perovskite film.

[0028] According to an embodiment of the present invention, the coating method is at least one of blade coating, slot coating, filament coating or lift coating, preferably blade coating.

[0029] According to an embodiment of the present invention, the substrate is selected from at least one of silicon, silicon dioxide, soda-lime glass, borosilicate glass, quartz glass, indium tin oxide glass (ITO glass), polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polyimide (PI) film, fluorine-doped tin oxide glass (FTO glass), ITO / PET, ITO / PEN, etc.

[0030] According to an embodiment of the present invention, the substrate may be treated with ultraviolet light or oxygen plasma before coating.

[0031] As an exemplary embodiment of the present invention, the method for preparing the perovskite thin film is specifically as follows:

[0032] 1) The above substrate is cleaned under ultraviolet light or oxygen plasma;

[0033] 2) Use a blade coating tool to coat the above perovskite ink onto the substrate to form a wet film;

[0034] 3) The wet film is purged with nitrogen gas;

[0035] 4) The membrane from step 3) is subjected to heat treatment to obtain the perovskite thin film.

[0036] Fifthly, the present invention also provides a perovskite photovoltaic device, which sequentially comprises a substrate, a hole transport layer, the perovskite thin film, an electron transport layer and a top electrode; or, sequentially comprises a substrate, an electron transport layer, the perovskite thin film, a hole transport layer and a top electrode.

[0037] According to an embodiment of the present invention, the substrate is selected from at least one of silicon, silicon dioxide, soda-lime glass, borosilicate glass, quartz glass, indium tin oxide glass (ITO glass), polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, polyimide (PI) film, fluorine-doped tin oxide glass (FTO glass), ITO / PET, ITO / PEN, etc.

[0038] According to an embodiment of the present invention, the hole transport layer is selected from at least one of the following: poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene / polystyrene sulfonate) (PEDOT:PSS), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), [N,N-di(4-methoxyphenyl)amino]spirodifluorene (Spiro-MeOTAD), phthalocyanine blue (CuPc), nickel oxide, molybdenum trioxide, cuprous iodide, [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), and [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz);

[0039] According to an embodiment of the present invention, the electron transport layer is selected from at least one of titanium dioxide, tin dioxide, fullerene, [6,6]-phenyl C 61 butyrate methyl ester (PC61BM), etc.

[0040] According to an embodiment of the present invention, the top electrode is selected from at least one of gold, silver, copper, calcium, barium, and chromium.

[0041] Sixthly, the present invention also provides a method for fabricating the above-mentioned perovskite photovoltaic device, the method comprising the following steps:

[0042] The coating is applied layer by layer according to the device structure of substrate, hole transport layer, perovskite thin film, electron transport layer and top electrode, or substrate, electron transport layer, perovskite thin film, hole transport layer and top electrode.

[0043] Preferably, the coating method is selected from at least one of spin coating, blade coating, spray coating, wire rod coating, slot coating, screen printing, chemical vapor deposition, or physical vapor deposition.

[0044] The beneficial effects of this invention are:

[0045] This invention utilizes polymeric additives to regulate the shape of perovskite precursor micelles in solution, thereby formulating a perovskite precursor ink. This ink, after blade coating, exhibits a uniform film morphology and a single crystal orientation. The high-quality perovskite films prepared using this perovskite ink enhance the performance of perovskite solar cells. Attached Figure Description

[0046] Figure 1 These are small-angle X-ray scattering diagrams of Example 1 and Comparative Example 1.

[0047] Figure 2 This is a diagram showing the crystal orientation results in wide-angle X-ray scattering of the inks of Example 1 and Comparative Example 1.

[0048] Figure 3This is a scanning electron microscope image of the perovskite thin film of Example 2.

[0049] Figure 4 These are the current density-voltage curves of the solar cells of Example 3 and Comparative Example 3. Detailed Implementation

[0050] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0051] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0052] Example 1

[0053] Preparation and characterization of micelle shape of perovskite ink

[0054] 1) Mix 150 μL of N-methylpyrrolidone, 150 μL of acetonitrile, and 700 μL of 2-methoxyethanol evenly;

[0055] 2) Dissolve 0.4 mg of the polymer additive polymethyl methacrylate in the mixed solvent described in 1), and after mixing evenly, add 1.1 mmol of FA. 0.95 Cs 0.05 PbI3 perovskite powder was stirred at 60°C for 3 hours using a magnetic stirrer to obtain a homogeneous and clear perovskite ink.

[0056] Comparative Example 1

[0057] The difference between Comparative Example 1 and Example 1 is that no high molecular weight additive, polymethyl methacrylate, was added.

[0058] The perovskite ink solutions of Example 1 and Comparative Example 1 were characterized by small-angle X-ray scattering to obtain the shape of the perovskite precursor micelles. The test results are as follows: Figure 1 As shown, Figure 1 This indicates that perovskite micelles without polymer additives are spherical, while those with polymer additives are ellipsoidal.

[0059] Example 2 and Comparative Example 2

[0060] Preparation and Orientation Observation of Perovskite Thin Films

[0061] 1) Clean the surface of the soda-lime glass substrate under ultraviolet light or oxygen plasma.

[0062] 2) The perovskite inks in Example 1 and Comparative Example 1 were coated using blade coating, and dry nitrogen was used to purge the coating process. Then, the films were heat-annealed at 150 degrees Celsius for 15 minutes to promote film crystallization.

[0063] In the ink of Example 1, the polymeric additives have a beneficial effect on the crystallization of the perovskite film. For example... Figure 2 As shown, the perovskite film containing polymer additives exhibits a more uniform vertical orientation in the wide-angle X-ray scattering characterization results.

[0064] Figure 3 This is a scanning electron microscope image of the perovskite thin film in Example 2. Figure 3 It can be seen that the average grain size of the perovskite film can reach over 600 nm. By adding the polymer additive of this invention, the crystallization rate can be controlled, the grain size of the perovskite film can be increased, and the quality of the obtained perovskite film can be further improved.

[0065] Example 3 and Comparative Example 3

[0066] Fabrication of perovskite solar cells

[0067] (1) Select ITO glass as the substrate. Clean the substrate in oxygen plasma for 200 seconds.

[0068] (2) A 0.5 mg / mL MeO-2PACz ethanol solution was coated onto the substrate using a blade coating method at a coating speed of 10 mm / s. The substrate was then annealed at 100 °C for 10 minutes. After annealing, the substrate was allowed to cool to room temperature.

[0069] (2) The perovskite inks of Example 1 and Comparative Example 1 were coated onto the MeO-2PACz layer at a coating speed of 15 mm / s using a blade coating method. After annealing at 110°C for 15 minutes and cooling to room temperature, a 20 mg / mL PC61BM chlorobenzene solution was coated onto the perovskite layer at a coating speed of 10 mm / s using a blade coating method.

[0070] (3) Finally, 100 nm copper was deposited on the PC61BM layer by physical vapor deposition to obtain the desired perovskite solar cell.

[0071] The current density-voltage curves of the solar cells in Example 3 and Comparative Example 3 are shown below. Figure 4 As shown, the photoelectric conversion efficiency of the solar cell is 24.20% after adding the polymer additive. Compared with the solar cell without the polymer additive, the photoelectric conversion efficiency is significantly improved.

[0072] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A perovskite ink, characterized in that, It includes perovskite materials, polymer additives, and solvents; The polymeric additive is selected from one or more of polymethyl methacrylate, polydimethylsiloxane, polyethylene naphthalate, polyethylene terephthalate, polyimide, polycarbonate, polyurethane, natural rubber, or silicone polymers.

2. The perovskite ink according to claim 1, characterized in that, The solvent is at least selected from solvent A, which is selected from at least one of dimethyl sulfoxide, N,N-dimethylformamide, 2-methoxyethanol, γ-butyrolactone or N-methylpyrrolidone. Preferably, the solvent is further selected from solvent B, which is selected from at least one of acetonitrile, ethanol or tetrahydrofuran. Preferably, the solvent is selected from a mixture of solvent A and solvent B, and the volume ratio of solvent A to solvent B is 1:9-9:

1.

3. The perovskite ink according to claim 1, characterized in that, The perovskite material is selected from compounds with the chemical formula ABX3 and Cs. x FA 1-x PbI3, Cs x FA 1-x Pb(I y Cl 1-y 3. Cs x FA 1-x Pb(I y Br 1-y 3. Cs x FA 1-x Pb(I y Br z Cl 1-y-z 3. MAPb(I) x Cl 1-x 3. MAPb(I) x Br 1-x 3. MAPb(I) x Br y Cl 1-x-y 3. MA x FA 1-x PbI3, MA x FA 1-x Pb(I y Cl 1-y 3. MA x FA 1-x Pb(I y Br 1-y 3. MA x FA 1-x Pb(I y Br z Cl 1-y-z At least one of the following three; x is a number between 0 and 1, y is a number between 0 and 1, and z is a number between 0 and 1; In ABX3, A is one of MA, FA or Cs, B is Pb, and X is one of I, Br or Cl; MA is methylamine cation, and FA is formamidin cation.

4. The perovskite ink according to claim 1, characterized in that, In perovskite ink, the concentration of perovskite material is 0.5-6 mol / L. Preferably, in the perovskite ink, the concentration of the polymeric additive is 0.1-2 mg / mL.

5. The method for preparing perovskite ink according to any one of claims 1-4, characterized in that, Includes the following steps: The perovskite ink is prepared by mixing perovskite material, polymer additives, and solvents.

6. The method according to claim 5, characterized in that, The preparation method of the perovskite ink specifically includes: 1) Mix solvent A and solvent B, then add the polymer additive and mix again; 2) Add perovskite material to the mixture in step 1) and mix to prepare the perovskite ink.

7. A perovskite thin film, characterized in that, It is obtained by heat annealing the perovskite ink as described in any one of claims 1-4. Preferably, the heat annealing temperature is 50-150℃ and the heat annealing time is 5-120min.

8. The method for preparing perovskite thin films according to claim 7, characterized in that, It includes the following steps: The perovskite ink described above was coated onto a substrate and then subjected to thermal annealing to obtain the perovskite film. Preferably, the coating method is at least one of blade coating, slot coating, wire rod coating, or lift coating.

9. A perovskite photovoltaic device, characterized in that, It comprises, in sequence, a substrate, a hole transport layer, the perovskite thin film of claim 7, an electron transport layer, and a top electrode; or, it comprises, in sequence, a substrate, an electron transport layer, the perovskite thin film of claim 7, a hole transport layer, and a top electrode.

10. The method for fabricating the perovskite photovoltaic device according to claim 9, characterized in that, The method includes the following steps: The coating is applied layer by layer according to the device structure of substrate, hole transport layer, perovskite thin film, electron transport layer and top electrode, or substrate, electron transport layer, perovskite thin film, hole transport layer and top electrode.

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