Preparation method for perovskite light absorption layer

Abstract

A preparation method for a perovskite light absorption layer, comprising: spreading perovskite ink on a screen mesh, and forming a layer of liquid film on the screen mesh; pressing the screen mesh to cause the liquid film to pass through the mesh openings of the screen mesh to be transferred to a printing substrate arranged below the screen mesh in parallel, thus obtaining the printing substrate loaded with the perovskite ink; and carrying out crystallization treatment on the printing substrate loaded with the perovskite ink, so as to obtain a perovskite light absorption layer. The preparation method for a perovskite light absorption layer has the characteristics of compatibility with traditional screen printing equipment, large-area film formation, high uniformity, simplicity, ease of scaling-up, low cost, etc.

Description

A method for preparing a perovskite light-absorbing layer Technical Field

[0001] The present invention belongs to the field of perovskite solar cell preparation and relates to a method for preparing a perovskite light-absorbing layer. Background Art

[0002] The perovskite light-absorbing layer is the core of perovskite solar cells. The quality of the film determines the product's performance, directly affecting its carrier transport and the cell's photoelectric conversion performance. The preparation process has a significant impact on cell performance. Rapidly and cost-effectively preparing high-quality, large-area perovskite films is a crucial issue for the industrialization of perovskite solar cells.

[0003] The substrates for perovskite films include dense substrates and porous substrates. Currently, the mainstream process methods for making perovskite liquid films on dense substrates are: spin coating, slit coating, inkjet printing, etc. Spin coating is not suitable for enlarging the battery area. When spin coating a large area, uneven film formation will occur in the middle and around the edges, and the solution waste is too large, with most of the spin coating liquid being thrown away. Although slit coating and inkjet printing are suitable for large-scale production, the coating head or nozzle requires high precision, and currently it still relies on imports, and the equipment cost is expensive. Chinese Patent Publication No. CN111048667A discloses a coating process and device suitable for uniformly coating a perovskite light-absorbing layer on a large-area substrate. Chinese Patent Publication No. CN111282772B discloses a coating process and device that can adjust the coating gap in real time and uniformly coat a perovskite light-absorbing layer on a large-area substrate. However, the core component of the coating process and device, the coating head, has high processing technology requirements, and after the size is enlarged, due to the processing precision, the price of equipment suitable for large-area coating is very high.

[0004] The porous skeleton substrate can also be used as the substrate for the perovskite film, which usually uses a screen printing process to prepare a variety of film layers on a transparent conductive substrate, usually in the order of a dense layer, a mesoporous (porous) electron transport layer, a mesoporous (porous) insulating layer, a mesoporous (porous) hole transport layer, and a mesoporous (porous) carbon electrode layer. Since a screen printer can be used to prepare these key film layers, the preparation process of perovskite solar cells becomes very simple and efficient. However, the current screen printing process is still unable to achieve screen printing coating of the perovskite precursor solution. At present, the perovskite precursor solution is mainly infiltrated into the porous skeleton layer by the drip coating method, which poses a great obstacle to the compatibility of the manufacturing process. In addition, the drip coating method is not suitable for the preparation of large-area batteries, and it is impossible to achieve the simultaneous drip coating of the perovskite precursor solution in the entire battery by manual methods. For example, when making a battery with a size of 600 mm x 600 mm, the time interval between adding the first drop of ink and adding the last drop of ink is more than half an hour. During this period, it is easy to cause uneven penetration of the perovskite solution, affecting the filling effect. On the other hand, the perovskite precursor solution infiltrated by the drip coating method makes the perovskite penetration uniformity poor after crystallization. A significant color difference can be observed between the position where the droplet lands and the droplet diffusion area around it. And through testing, it can be found that there is a significant difference in the battery power generation performance between the position where the droplet lands and the droplet diffusion area. If the drip coating process is to be amplified, it is necessary to use high-precision inkjet printing equipment. However, high-precision inkjet printing equipment requires high processing precision of the inkjet head and is expensive. In order to improve the uniformity problem of forming a large-area thin film in porous pores by drip coating, Chinese Patent Publication No. CN111048667A discloses a method of setting an auxiliary outer frame around the edges of the top electrode and the spacing area between adjacent top electrodes. The auxiliary outer frame method has a good effect on the penetration of the perovskite precursor solution into the porous skeleton layer, but it requires an additional auxiliary outer frame as a jig.

[0005] Therefore, how to quickly and cost-effectively prepare perovskite films on dense substrates, and how to achieve low-cost and uniform penetration of perovskite precursor solutions over a large area on porous skeleton substrates to prepare perovskite films, have become urgent problems to be solved in the industrialization of perovskite solar cells. Summary of the Invention

[0006] In order to solve the above technical problems, the purpose of the present invention is to provide a method for preparing a perovskite light-absorbing layer that is simple, easy to scale up, and low-cost, without changing the components of the perovskite ink itself. The present invention breaks the inherent thinking of the existing technology and uses a traditional screen to support the low-viscosity ink and form a liquid film above the screen. The liquid film is transferred to a dense substrate and then uses the surface tension of the ink to self-spread into a film; or by forming a liquid bridge between the screen and the substrate, the liquid is transferred and penetrated into the porous substrate under the action of capillary force. It has the characteristics of compatibility with traditional screen printing equipment, high uniformity of large-area film formation, simplicity and ease of scale up, and low cost.

[0007] Specifically, the present invention provides a method for preparing a perovskite light-absorbing layer, comprising: (1) applying perovskite ink to a screen, and forming a liquid film on the screen by utilizing the surface tension of the perovskite ink and the adhesion between the mesh wall of the screen and the perovskite ink; the surface tension coefficient of the perovskite ink is greater than 5 millinewtons per meter; and the mesh diameter of the screen is 18 to 250 micrometers; (2) by squeezing the screen, the liquid film leaks from the mesh of the screen and is transferred to a printing substrate arranged parallel to the bottom of the screen to obtain a printing substrate loaded with perovskite ink; the printing substrate is a first printing substrate having a dense layer on the surface or a second printing substrate having a porous layer on the surface; when the printing substrate is the first printing substrate, the perovskite ink leaking from the mesh of the screen is re-spread into a film on the surface of the first printing substrate under the action of surface tension or capillary force; when the printing substrate is the second printing substrate, the perovskite ink leaking from the mesh of the screen forms a liquid bridge between the mesh of the screen and the second printing substrate, and is sucked in under the action of capillary force and penetrates into the porous layer of the second printing substrate; (3) the printing substrate loaded with perovskite ink is crystallized to obtain the titanium ore light absorption layer.

[0008] Specifically, on the one hand, the present invention provides a method for preparing a perovskite light-absorbing layer by a pseudo-screen printing process, comprising: (1) spreading perovskite ink on a screen, and forming a liquid film on the screen by utilizing the surface tension of the perovskite ink and the adhesion between the mesh wall of the screen and the perovskite ink; (2) squeezing the screen so that the liquid film descends from the mesh to form a liquid bridge between the screen and the printing substrate, and penetrates into the printing substrate under the action of capillary force, and then undergoes crystallization treatment to obtain a perovskite light-absorbing layer; the surface of the printing substrate is a porous layer.

[0009] On the other hand, the present invention also provides a method for preparing a high-quality perovskite light-absorbing layer, comprising: (1) spreading perovskite ink on a silk screen, and utilizing the surface tension of the perovskite ink and the adhesion between the mesh wall of the silk screen and the perovskite ink to form a uniform liquid film on the silk screen; (2) squeezing the silk screen so that the liquid film leaks from the mesh to the printed substrate, and is re-spread into a film under the action of surface tension, and then subjected to crystallization treatment to obtain a high-quality perovskite light-absorbing layer; the surface of the printed substrate is a dense layer.

[0010] Preferably, the wire mesh includes: a middle mesh area provided with the mesh holes, and a non-porous area surrounding the middle mesh area and having no mesh holes; the wire mesh is made of stainless steel, tungsten or polyester.

[0011] In the present invention, perovskite ink is dripped onto a non-porous area of ​​a screen, and a scraper is used to spread the ink from the non-porous area on one side of the screen to the non-porous area on the opposite side. Due to surface tension, the ink penetrates into the mesh of the screen, and the adhesion between the screen mesh wall and the ink is used to maintain the perovskite ink on the screen to form a liquid film, preventing leakage. The scraper is then pressed against the screen, moving from the non-porous area on one side of the screen to the non-porous area on the opposite side of the screen. During this movement, downward pressure is applied to the scraper, squeezing the liquid film in the mesh and causing it to descend from the mesh. When the printing substrate is a dense substrate, the liquid film re-spreads onto the surface of the printing substrate under the action of surface tension to form a film, resulting in a dense printing substrate loaded with perovskite ink. When the printing substrate is a porous substrate (porous layer or porous skeleton layer), the liquid film first forms a liquid bridge between the surface of the printing substrate and the lower surface of the screen mesh, and then, under the action of capillary force, penetrates into the porous printing substrate, thus obtaining a porous printing substrate loaded with perovskite ink. The two types of printing substrates loaded with perovskite ink were crystallized separately, ultimately forming a perovskite light-absorbing layer.

[0012] In the present invention, the surface tension coefficient of the perovskite ink is greater than 5 millinewtons per meter; the mesh diameter of the screen is 18 to 250 micrometers, thereby ensuring that the surface tension of the perovskite ink, the adhesion to the mesh wall, and the mesh size match each other. If the adhesion between the ink and the mesh wall is too small, the ink will not be able to be retained in the hole and will leak out directly; or when the amount of ink filled in the same mesh is too much, causing the gravity of the ink to be greater than the vertical upward component of its adhesion to the hole wall, the ink will also leak out directly. Compared with commonly used methods, this method does not require changing the components of the perovskite ink itself, is compatible with traditional screen printing equipment, has high film uniformity, is simple and easy to scale up, and has low cost. It is applicable to both dense and porous substrates.

[0013] Preferably, the chemical composition of the perovskite material in the perovskite ink is ABX3, wherein A is a monovalent cation, A is [CH(NH2)2]+ 、[NH3NH2] + 、[(CH2)3NH2] + , [NH3OH] + 、[C3N2H5] + 、[(CH3CH2)NH3] + 、[(CH3)2NH2] + 、[(NH2)3C] + 、[(CH3)4N] + 、[C3H4NS] + , [NC4H8] + 、[C7H7] + , K + , Rb + 、Cs + At least one of; B is Pb 2+ 、Sn 2+ 、Co 2+ 、Mn 2+ 、Ge 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Cu 2+ 、Fe 2+ 、Pd 2+ 、Eu 2+ 、Ni 2+ and Bi 3+ At least one of; X is F - 、Cl - Br - , I - and SCN -- At least one of the following: the solvent of the perovskite ink is selected from at least one of dimethylformamide, N-methylformamide, dimethyl sulfoxide, γ-valerolactone, γ-butyrolactone, N-methyl-2-pyrrolidone methanol, isopropyl alcohol, ethylene glycol, water, ethyl acetate, triethyl phosphate, 2-methoxyethanol, cyclopentyl methyl ether, and N-hydroxymethyl acrylamide; the concentration of the perovskite ink is 0.5 to 2.0 mol / L. The perovskite ink includes, but is not limited to, a perovskite solution, a perovskite colloidal dispersion, and a perovskite turbid solution.

[0014] Preferably, the first printed substrate includes: a first substrate and a first dense layer, the first dense layer is a first transparent conductive layer, or a first dense electron transport layer, or a first dense hole transport layer, or a composite dense layer formed by the first transparent conductive layer and one of the first dense electron transport layer or the first dense hole transport layer.

[0015] Preferably, the second printed substrate includes, in sequence: a second substrate, a second transparent conductive layer, a second dense layer, a porous composite layer and a porous top electrode layer, or a second substrate, a second dense layer, a porous composite layer and a transparent porous top electrode layer, and one side of the porous top electrode layer or the transparent porous top electrode layer is placed parallel to the screen; the porous composite layer includes a second porous electron transport layer, a porous insulating layer and a second porous hole transport layer.

[0016] Furthermore, preferably, the material of the first substrate and / or the second substrate includes at least one of a metal material, an inorganic non-metallic material and a polymer material; the thickness of the first substrate and / or the second substrate is 0.001 to 5 mm; the material of the first transparent conductive layer and / or the second transparent conductive layer includes indium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), vanadate, graphene and its derivatives; the thickness of the first transparent conductive layer and / or the second transparent conductive layer is 2 to 300 nanometers.

[0017] The material of the first dense electron transport layer includes: at least one of titanium oxide and its dopants, tin oxide and its dopants, indium oxide and its dopants, zinc oxide and its dopants, cadmium sulfide and its dopants, zinc sulfide and its dopants, zinc selenide and its dopants, fullerenes and their derivatives, graphene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane; the thickness of the first dense electron transport layer is 2 to 100 nanometers.

[0018] The material of the first dense hole transport layer includes: nickel oxide, cuprous oxide, poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine], [2- (3,6-dimethoxy-9H-carbazol-9-yl) ethyl] phosphonic acid, dimethoxydiphenylamine substituted carbazole functionalized with phosphonic acid and at least one of arylamino-cyanovinylphosphonic acid; the thickness of the first dense hole transport layer is 2 to 300 nanometers.

[0019] The second dense layer comprises a metal oxide film; the thickness of the second dense layer is 2 to 100 nanometers; the material of the metal oxide film comprises at least one of titanium oxide and its dopants, tin oxide and its dopants, and zinc oxide and its dopants.

[0020] The material of the second porous electron transport layer includes at least one of titanium oxide, tin oxide, indium oxide, zinc oxide, cadmium sulfide, zinc sulfide, zinc selenide, fullerene and its derivatives, graphene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), and doped compounds thereof; the thickness of the second porous electron transport layer is 0.002 to 2 microns; the pore diameter of the second porous electron transport layer is 5 to 100 nanometers, and the porosity is 10 to 80%.

[0021] The material of the porous insulating layer includes at least one of aluminum oxide, zirconium oxide and magnesium oxide; the thickness of the porous insulating layer is 0.1 to 4 microns; the pore size of the porous insulating layer is 0.001 to 1 micron, and the porosity is 10 to 80%.

[0022] The material of the second porous hole transport layer includes at least one of copper oxide, copper iodide, copper sulfide, cuprous thiocyanate, copper antimony sulfide, tungsten oxide, nickel oxide, molybdenum oxide, cerium oxide, vanadium oxide, manganese oxide, cobalt oxide, tungsten sulfide and molybdenum sulfide; the thickness of the second porous hole transport layer is 0.05 to 20 microns; the pore size of the second porous hole transport layer is 0.001 to 1 micron, and the porosity is 10 to 80%.

[0023] The porous top electrode layer is made of at least one of graphite, carbon black, carbon nanotubes, carbon fibers, and graphene; the thickness of the porous top electrode layer is 1 to 200 microns; the pore size of the porous top electrode layer is 0.001 to 6.5 microns, and the porosity is 10 to 90%. The transparent porous top electrode layer is made of at least one of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, indium tin oxide, aluminum zinc oxide, indium zinc oxide, fluorine-doped tin oxide, and vanadate; the thickness of the transparent porous top electrode layer is 1 to 200 microns; the pore size of the transparent porous top electrode layer is 0.001 to 6.5 microns, and the porosity is 10 to 90%.

[0024] Furthermore, preferably, the inorganic non-metallic material of the first substrate and / or the second substrate includes crystalline silicon cells.

[0025] Preferably, the distance between the screen and the printing substrate is 0 to 3 mm and is not zero.

[0026] Preferably, the perovskite ink is spread onto the screen by a scraper; the parameters of the scraper include: a moving speed of 0 to 300 mm / s and not 0, a gap between the scraper and the screen of 0 to 0.5 mm, an angle between the scraper and the screen of >0 degrees and <180 degrees, and a pressure between the scraper and the screen of 0 Pa; the perovskite ink is dropped onto a non-porous area without mesh holes on one side of the screen, and the perovskite ink is spread from the non-porous area on one side of the screen to the non-porous area on the opposite side of the screen by using the scraper.

[0027] Preferably, the liquid is applied by squeezing the screen with a scraper, and the parameters of the scraper include: a pressing pressure of 0.01 to 0.6 MPa, a moving speed of 0 to 300 mm / s and not 0, and an angle between the scraper and the screen of >0 degrees and <180 degrees.

[0028] Preferably, when the printed substrate is the first printed substrate, the crystallization treatment includes two steps: pretreatment and annealing treatment, and the pretreatment includes at least one of air knife blowing treatment, vacuum crystallization, and infrared flash burning; the temperature of the air knife blowing treatment is room temperature to 300 degrees Celsius, the time is 5 to 100 seconds, and the angle between the wind curtain and the spread perovskite liquid film is 0 to 60 degrees; the temperature of the vacuum crystallization is room temperature, and the time is 2 to 20 minutes; the temperature of the infrared flash burning is 60 to 300 degrees Celsius, and the time is 1.5 to 600 seconds; the temperature of the annealing treatment is 60 to 300 degrees Celsius, and the time is 2 to 60 minutes.

[0029] Preferably, when the printed substrate is the second printed substrate, the temperature of the crystallization treatment is room temperature to 300 degrees Celsius, and the time is 2 to 1440 minutes.

[0030] In another aspect, the present invention provides a perovskite light-absorbing layer prepared according to the above method.

[0031] In another aspect, the present invention provides a perovskite solar cell, comprising: a perovskite light-absorbing layer prepared by the above method.

[0032] Beneficial Effects of the Invention: This invention provides a method for fabricating a perovskite light-absorbing layer that does not require changes to the perovskite ink composition, is compatible with conventional screen printing equipment, and can produce uniform, simple, easily scalable, and low-cost films over large areas of printed substrates. The following detailed description, combined with reference to the accompanying drawings, will provide a better understanding of the present invention and its objectives, features, and advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a cross-sectional view of an example of a formal perovskite solar cell prepared by forming a perovskite light-absorbing layer on a printed substrate having a dense layer on its surface; Figure 2 is a top view of an example screen and scraper used in the method of the present invention; Figure 3 is a schematic diagram of a liquid spreading process for forming a perovskite light-absorbing layer on a printed substrate having a dense layer on its surface; Figure 4 is a schematic diagram of one of the example liquid dispensing processes for forming a perovskite light-absorbing layer on a printed substrate having a dense layer on its surface; in this example, after liquid dispensing, the perovskite ink attracts each other and spreads itself to form a liquid film under the action of surface tension; Figures 3 and 4 are side cross-sectional views; Figure 5 is a schematic diagram of another example liquid dispensing process for forming a perovskite light-absorbing layer on a printed substrate having a dense layer on its surface; in this example, after liquid dispensing, the perovskite ink forms a liquid film under the action of capillary force formed between the upper surface of the printed substrate and the lower surface of the screen; Figure 6 shows a comparison of the photoelectric conversion performance of photovoltaic cells prepared using the methods of Example 1, Example 3, Example 6, Example 7 and Comparative Example 1; Figure 7 shows the photoelectric conversion performance of a photovoltaic cell light-absorbing layer produced using the method of Example 5; Figure 8 shows a comparison of the photoelectric conversion performance of a photovoltaic cell light-absorbing layer produced using the methods of Example 6 and Comparative Example 2; Figure 9 shows a comparison of the photoelectric conversion performance of a photovoltaic cell light-absorbing layer produced using the methods of Example 7, Comparative Example 3, and Comparative Example 4; Figure 10 shows a comparison of the photoelectric conversion performance of a photovoltaic cell light-absorbing layer produced using the methods of Example 8 and Comparative Example 5; Figure 11 (Table 1) shows the performance parameters of Examples 1-8 and Comparative Examples 1-5; Figure 12 is a cross-sectional view of an example of a formal perovskite solar cell prepared by forming a perovskite light-absorbing layer on a printed substrate having a porous layer on its surface; Figure 13 is a top view of another example screen and scraper used in the method of the present invention; Figure 14 is a schematic diagram of the process of spreading the liquid to form a perovskite light-absorbing layer on a printed substrate having a porous layer on its surface; Figure 15 is a schematic diagram of one example of the liquid-dissolving process for forming a perovskite light-absorbing layer on a printed substrate having a dense layer on its surface; Figures 14 and 15 are side cross-sectional views; Figure 16 shows a comparison of the electroluminescence test performance of batteries using the methods of Example 9 and Comparative Example 6 to manufacture perovskite light-absorbing layers; Figure 17 shows a comparison of the photoelectric conversion performance of batteries using the methods of Example 9 and Comparative Example 6 to manufacture perovskite light-absorbing layers; Figure 18 shows a comparison of the photoelectric conversion performance of batteries using the methods of Examples 10 to 14 to manufacture perovskite light-absorbing layers; Figure 19 (Table 2) shows the performance parameters of Examples 9-14 and Comparative Example 6.

[0034] Figure numerals: 1, 1': substrate; 2, 2': transparent conductive layer; 3': dense layer 0, 0': printing base; 4, 4': perovskite light-absorbing layer; 4a, 4a': perovskite ink (hereinafter referred to as ink); 4b, 4b': liquid film; 4c, 4c': residual liquid; 5a: electron transport layer; 5b: hole transport layer; 5b': porous composite layer (electron transport layer, hole transport layer, insulating layer); 6, 6': top electrode layer; 7, 7': current collecting bar; 8, 8': insulating area; 10, 10': silk screen; 10a, 10': mesh; 10b, 10b': non-porous area; 12, 12b': scraper.

[0035] The perovskite light-absorbing layer 4 (4') and perovskite ink 4a (4a'), liquid film 4b (4b'), and residual liquid 4c (4c') in the accompanying drawings are different stages of the ink film formation process, so the same figure marks are used in the drawings, but different explanatory texts are used; the top electrode layer in the accompanying drawings may belong to the printed substrate, but because the graphic size is different from the printed substrate, additional annotations are used; the shapes of the ink and mesh in the accompanying drawings are only for the convenience of distinction and are not limited to this; the amount of ink penetration in the hole in the accompanying drawings is only for illustration and is not limited to this; the front and back perspectives of the ink and mesh hole walls in the accompanying drawings are only for the convenience of distinction and are not limited to this; there is no current collection bar in Figure 15 for the convenience of graphical observation and is not limited to this. DETAILED DESCRIPTION

[0036] The present invention is further described below through the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, rather than to limit the present invention.

[0037] In this application, perovskite ink is spread on a silk screen, and the surface tension of the ink and the adhesion between the mesh wall of the silk screen and the ink are used to make the perovskite ink stay in the mesh of the silk screen without leaking, thereby spreading on the silk screen to form a liquid film. The silk screen is then squeezed by a scraper, so that the liquid film is dropped from the mesh to a printed substrate placed parallel to the bottom of the silk screen, or a liquid bridge is formed between the silk screen and the printed substrate, so that the perovskite ink is re-spread into a film on a printed substrate with a dense layer under the action of surface tension or capillary force, or the capillary force is used to penetrate into a printed substrate with a porous layer on the surface, so that a simple and controllable method can be used to transfer the perovskite ink using a silk screen and load it onto the printed substrate. Thus, a method for preparing a high-quality perovskite light-absorbing layer on a printed substrate over a large area without changing the components of the perovskite ink itself, which is simple, easy to scale up, and low-cost, is provided.

[0038] In the present application, the surface of the printing substrate can be a dense layer or a porous layer. Here, the printing substrate with a dense layer on the surface is referred to as the first printing substrate, and the printing substrate with a porous layer on the surface is referred to as the second printing substrate.

[0039] The first printed substrate may include a first substrate and a first dense layer. In one example, the first dense layer may be a first transparent conductive layer, in which case a perovskite absorption layer may be formed on the first transparent conductive layer, and then a charge transport layer (electron transport layer or hole transport layer) and a top electrode layer (counter electrode) may be formed thereon. In another example, the first dense layer may be a composite dense layer consisting of a first transparent conductive layer and a first dense electron transport layer, in which case a perovskite absorption layer may be formed on the composite dense layer, and then a hole transport layer and a top electrode layer (counter electrode) may be formed thereon. In yet another example, the first dense layer may be a composite dense layer consisting of a first transparent conductive layer and a first dense hole transport layer, in which case a perovskite absorption layer may be formed on the composite dense layer, and then an electron transport layer and a top electrode layer (counter electrode) may be formed thereon. It should be understood that the top electrode layer may also serve as a hole transport layer.

[0040] The second printing substrate may include, in order: a second substrate, a second transparent conductive layer, a second dense layer, a porous composite layer, and a porous top electrode layer, or a second substrate, a second dense layer, a porous composite layer, and a transparent porous top electrode layer, with one side of the porous top electrode layer or the transparent porous top electrode layer facing the screen and placed parallel to the screen; the porous composite layer may include a second porous electron transport layer, a porous insulating layer, and a second porous hole transport layer. It should be understood that the porous top electrode layer may also be part of the porous composite layer.

[0041] The first substrate and / or the second substrate are selected from at least one of metal materials, inorganic non-metallic materials (preferably crystalline silicon solar cells) and polymer materials, and the thickness can be 0.001 to 5 mm.

[0042] The transparent conductive layer (the first transparent conductive layer or the second transparent conductive layer) is selected from indium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), vanadate, graphene and its derivatives, and the thickness can be 2 to 300 nanometers.

[0043] The material of the second dense layer can be selected from metal oxide films, preferably at least one of titanium oxide and its dopants, tin oxide and its dopants, and the thickness can be 2 to 100 nanometers.

[0044] The material of the electron transport layer (first dense electron transport layer or second porous electron transport layer) is selected from at least one of titanium oxide and its dopants, tin oxide and its dopants, indium oxide and its dopants, zinc oxide and its dopants, cadmium sulfide and its dopants, zinc sulfide and its dopants, zinc selenide and its dopants, fullerenes and their derivatives, graphene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), and their doped compounds. The first dense electron transport layer can have a thickness of 2 to 100 nanometers. The second porous electron transport layer can have a thickness of 0.002 to 2 microns, a pore size of 5 to 100 nanometers, and a porosity of 10 to 80%, preferably 25 to 75%.

[0045] The material of the first dense hole transport layer can be selected from at least one of nickel oxide, cuprous oxide, poly(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), dimethoxydiphenylamine-substituted carbazole functionalized with phosphonic acid (V1036), and arylaminocyanovinylphosphonic acid (MPA-CPA). The thickness of the first dense hole transport layer can be 2 to 300 nanometers.

[0046] In the present application, the doping element in the titanium oxide dopant includes at least one of an alkali (earth) metal element, a non-metallic element, and an element with a transition metal property, with the total doping content not exceeding 10 mol%. Among them, the alkali (earth) metal elements include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, etc. Non-metallic elements include nitrogen, carbon, sulfur, fluorine, chlorine, bromine, iodine, boron, phosphorus, silicon, etc. Transition metal elements include iron, cobalt, nickel, manganese, copper, zinc, cadmium, niobium, tantalum, aluminum, gallium, germanium, antimony, bismuth, indium, tin, vanadium, chromium, molybdenum, silver, platinum, etc. The doping element in the tin oxide dopant includes at least one of an alkali (earth) metal element, a non-metallic element, and an element with a transition metal property, with the total doping content not exceeding 10 mol%. Among them, the alkali (earth) metal elements include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, etc. Non-metallic elements include nitrogen, carbon, sulfur, fluorine, chlorine, bromine, iodine, boron, phosphorus, and silicon. Transition metal elements include titanium, iron, cobalt, nickel, manganese, copper, zinc, cadmium, niobium, tantalum, aluminum, gallium, germanium, antimony, bismuth, indium, vanadium, chromium, molybdenum, silver, and platinum. The doping element in indium oxide includes at least one of an alkali (earth) metal element, a non-metallic element, and an element with transition metal properties, with the total doping content not exceeding 10 mol%. Alkali (earth) metal elements include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and barium. Non-metallic elements include nitrogen, carbon, sulfur, fluorine, chlorine, bromine, iodine, boron, phosphorus, and silicon. Transition metal elements include titanium, iron, cobalt, nickel, manganese, copper, zinc, cadmium, niobium, tantalum, aluminum, gallium, germanium, antimony, bismuth, tin, vanadium, chromium, molybdenum, silver, and platinum. The doping elements in zinc oxide include at least one of alkali (earth) metal elements, non-metallic elements, and transition metal elements, with the total doping content not exceeding 10 mol%. Among them, alkali (earth) metal elements include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, etc. Non-metallic elements include nitrogen, carbon, sulfur, fluorine, chlorine, bromine, iodine, boron, phosphorus, silicon, etc. Transition metal elements include titanium, iron, cobalt, nickel, manganese, copper, cadmium, niobium, tantalum, aluminum, gallium, germanium, antimony, bismuth, indium, tin, vanadium, chromium, molybdenum, silver, platinum, etc. The doping elements in cadmium sulfide include at least one of zinc, magnesium, calcium, strontium, barium, copper, silver, barium, gallium, thallium, aluminum, cobalt, nickel, manganese, germanium, tin, silicon, selenium, and tellurium, with the total doping content not exceeding 10 mol%. The doping elements in zinc sulfide include at least one of cadmium, magnesium, calcium, strontium, barium, copper, silver, barium, gallium, thallium, aluminum, cobalt, nickel, manganese, germanium, tin, silicon, selenium, and tellurium, with the total doping content not exceeding 10 mol%. The doping elements in zinc selenide include at least one of cadmium, magnesium, calcium, strontium, barium, copper, silver, barium, gallium, thallium, aluminum, cobalt, nickel, manganese, germanium, tin, silicon, sulfur, and tellurium, with the total doping content not exceeding 10 mol%. Fulene derivatives include [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C71-butyric acid methyl ester, and fullerene.Graphene derivatives include: chlorided graphene, fluorinated graphene, graphene oxide, reduced graphene oxide, carboxylated graphene, aminated graphene, nitrogen-doped graphene, phosphorus-doped graphene, sulfur-doped graphene, boron-doped graphene, etc.

[0047] The porous insulating layer may be made of at least one of aluminum oxide, zirconium oxide and magnesium oxide, may have a thickness of 0.1 to 4 micrometers, a pore size of 0.001 to 1 micrometer, and a porosity of 10 to 80%, preferably 25 to 75%.

[0048] The material of the second porous hole transport layer can be selected from at least one of copper oxide, copper iodide, copper sulfide, cuprous thiocyanate, copper antimony sulfide, tungsten oxide, nickel oxide, molybdenum oxide, cerium oxide, vanadium oxide, manganese oxide, cobalt oxide, tungsten sulfide and molybdenum sulfide. The thickness can be 0.05 to 20 microns, the pore size can be 0.001 to 1 micron, and the porosity can be 10 to 80%, preferably 25 to 75%.

[0049] The porous top electrode layer can be made of at least one of graphite, carbon black, carbon nanotubes, carbon fibers, and graphene, and can have a thickness of 1 to 200 microns, a pore size of 0.001 to 6.5 microns, and a porosity of 10 to 90%, preferably 15 to 90%. The transparent porous top electrode layer can be made of at least one of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, indium tin oxide, aluminum zinc oxide, indium zinc oxide, fluorine-doped tin oxide, and vanadate, and can have a thickness of 1 to 200 microns, a pore size of 0.001 to 6.5 microns, and a porosity of 10 to 90%.

[0050] In an optional embodiment, in order to produce a more uniform liquid film, the pore size of the screen is preferably 18 to 250 microns. The perovskite ink with a certain surface tension can be a perovskite solution, a perovskite turbid solution, a perovskite colloidal dispersion, or the like.

[0051] In an optional embodiment, the scraper must be made of a material that matches the perovskite ink's composition to avoid corrosion that could affect the ink's performance. Preferably, it is made of at least one of a metal, an inorganic non-metallic material, or a polymer. In an optional embodiment, the scraper can be used for both spreading and dispensing, or two scrapers made of different materials can be used, one for spreading and one for dispensing.

[0052] In an optional embodiment, during the liquid spreading process of the scraper, the scraper is used to spread the ink from the non-porous area on one side of the screen to the non-porous area on the opposite side of the screen. Due to the effect of surface tension, the ink penetrates and fills the mesh holes of the screen. At the same time, due to the adhesion between the mesh wall and the ink, the ink dispersed into each mesh hole stays in the mesh hole and forms a liquid film without leaking out.

[0053] In an optional embodiment, during the spreading process of the scraper, the amount of liquid spread is controlled by controlling various parameters of the scraper, including: the movement speed, the gap between the scraper and the screen, the angle between the scraper and the screen, and the scraper material, to prevent the ink from leaking directly into the printing substrate during the process of spreading the ink to form a liquid film due to the ink's own gravity being greater than the adhesion between the mesh wall and the ink. Preferably, the movement speed can be set to 0-300 mm / s and is not 0, the gap between the scraper and the screen can be set to 0-0.5 mm, the angle between the scraper and the screen can be set to within 0-180 degrees (for example, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, etc.), and the scraper material can be selected from at least one of metal materials, inorganic non-metallic materials, or polymer materials.

[0054] In an alternative embodiment, the scraper can be used to spread the ink from a non-porous area on one side of the screen to a non-porous area on the opposite side of the screen during the spreading process. Furthermore, in the present invention, the scraper can be used to press the screen during the spreading process, thereby changing the adhesion between the perovskite ink remaining in the mesh and the mesh walls, thereby transferring the ink to the printing substrate.

[0055] In an optional embodiment, during the liquid application process of the scraper, the amount of liquid applied is controlled by controlling various parameters, including: the downward pressure of the scraper, the moving speed, the angle between the scraper and the screen, the material of the scraper, and the gap between the porous layer and the screen. Preferably, the downward pressure of the scraper can be set at 0.01 to 0.6 MPa, preferably 0.1 to 0.4 MPa, the moving speed can be set at 0 to 300 mm / s and not 0, the angle between the scraper and the screen can be set within 0 to 180 degrees (for example, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, etc.), the gap between the porous layer and the screen can be set at 0 to 3 mm, and the scraper material can be selected from non-rigid polymer materials, preferably, silica gel and fluororesin.

[0056] In the present invention, the screen is elastic; the mesh wire material must be compatible with the perovskite ink to avoid corrosion that could affect the ink's performance. The sides of the screen are imperforate, preventing liquid from flowing through, while the center is a perforated area where liquid can flow through. Preferably, the screen is made of at least one of a metal or a polymer (chemical fiber or natural fiber). The mesh wire can be made of stainless steel, polyester, or tungsten.

[0057] In an optional embodiment, the perovskite ink on the first printing substrate having a dense layer on its surface is re-spread into a film under the action of surface tension. The liquid film may be formed by mutual attraction and self-spreading on the printing substrate under the action of its own surface tension, or by the capillary force formed between the upper surface of the printing substrate and the lower surface of the screen.

[0058] The following exemplifies a method for producing a high-quality perovskite light-absorbing layer on a first printing substrate having a dense layer on its surface, comprising: 1) dripping perovskite ink onto a non-porous area on one side of a screen; 2) using a scraper to spread the ink from the non-porous area on one side of the screen to the non-porous area on the opposite side of the screen; 3) during the spreading process of the ink, the ink penetrates into the mesh of the screen due to the action of surface tension; utilizing the adhesion between the mesh wall of the screen and the ink, a liquid film is formed on the screen without leakage; 4) during the liquid dispersing process, downward pressure is applied to the scraper to squeeze the mesh, thereby changing the adhesion between the ink that penetrates the inside of the mesh and the mesh wall, causing the liquid film to leak from the mesh to the printing substrate; 5) the ink on the printing substrate is re-spread into a film under the action of surface tension or the capillary force formed between the upper surface of the printing substrate and the lower surface of the screen; 6) after a crystallization process, a high-quality perovskite light-absorbing layer is obtained.

[0059] When using the above-mentioned method for making a perovskite light-absorbing layer, the core process is to use the surface tension of the ink itself to achieve: spreading to form a liquid film, penetrating into the mesh of the screen; adhering to the mesh without leaking; transferring to the printing substrate, under the action of surface tension, attracting each other to spread and form a liquid film, or forming a liquid film under the action of the capillary force formed between the upper surface of the printing substrate and the lower surface of the screen, so the film quality is higher. In an optional embodiment, the solvent of the perovskite ink needs to have the characteristic of not being easy to volatilize, to ensure that in mass production, the mesh will not be blocked due to the ink drying in the mesh, so it is better to use a solvent with a low saturated vapor pressure. In an optional embodiment, the surface tension of the ink can be increased by adding non-surface active substances, such as inorganic salts, non-volatile acids, and bases, or reduced by adding surfactants, such as short-chain fatty acids, alcohols, and aldehydes. If the contact angle between the ink and the substrate is too large (the wettability of the ink and the substrate is poor), the wettability of the ink on the printed substrate surface can be improved by UV treatment and / or plasma treatment of the substrate.

[0060] Figure 1 is a front view of a perovskite solar cell fabricated using a method for fabricating a high-quality perovskite light-absorbing layer according to an embodiment of the present invention. Figure 2 is a top view of the screen and squeegee used in an embodiment of the present invention. Figure 3 is a side view of the entire liquid spreading process, from spreading to the point of liquid application. Figure 4 is a side view of the entire liquid application process. After application, the inks, under the action of surface tension, attract each other and spread to form a liquid film. Figure 5 is a side view of the entire liquid application process. After application, the inks form a liquid film under the action of capillary forces formed between the upper surface of the printed substrate and the lower surface of the screen. Figure 6 compares the photoelectric conversion performance of perovskite solar cells fabricated using the methods of Examples 1 to 4 and Comparative Example 1. Figure 7 is a photoelectric conversion performance curve for a perovskite solar cell fabricated using Example 5. Figure 8 compares the photoelectric conversion performance of photovoltaic cell light-absorbing layers fabricated using the methods of Example 6 and Comparative Example 2. Figure 9 compares the photoelectric conversion performance of photovoltaic cell light-absorbing layers fabricated using the methods of Example 7, Comparative Example 3, and Comparative Example 4. Figure 10 compares the photoelectric conversion performance of photovoltaic cells produced using the methods of Example 8 and Comparative Example 5. Table 1 compares the specific parameters of the cells produced using the methods of Example 8 and Comparative Example 5. To address the aforementioned technical issues, the present invention provides a method for producing a high-quality, simple, easily scalable, low-cost perovskite light-absorbing layer on a printed substrate without modifying the components of the perovskite ink itself.

[0061] This embodiment and subsequent embodiments will be described in detail. As shown in FIG1 , an insulating region 8 is formed on the transparent conductive layer 2 of the substrate 1 to distinguish the positive and negative electrodes of the battery, rendering the transparent conductive layer 2 discontinuous. An electron transport layer 5a is formed on the transparent conductive layer 2. A high-quality perovskite light-absorbing layer 4 is formed on the electron transport layer 5a using the method of the present invention. A hole transport layer 5b and an electrode layer 6 are sequentially formed on the perovskite light-absorbing layer 4. The electrode layer 6 crosses the insulating region 8 and contacts the conductive layer 2 to the right of the insulating region 8. Finally, current collector strips 7 are formed on the outermost edges of the transparent conductive layer 2 to serve as the positive and negative electrodes of the battery. As shown in FIG1 , the resulting perovskite solar cell is completed.

[0062] Using the screen shown in FIG2 , the liquid spreading process (as shown in FIG3 ) and the liquid dispensing process (as shown in FIG4 and FIG5 ) are started.

[0063] As shown in Figure 3, the perovskite ink 4a to be infiltrated is applied to the non-porous area 10b of the screen 10. A scraper 12 is used to spread the ink 4a from the non-porous area 10b on one side of the screen 10 to the non-porous area 10b on the opposite side. During the spreading process, the ink 4a penetrates into the mesh 10a of the screen 10 due to surface tension, forming a liquid film 4b. This liquid film adheres to the pore walls, preventing it from leaking out.

[0064] As shown in Figure 4, the liquid film 4b penetrates into the mesh 10a of the screen 10, and the remaining residual liquid 4c is scraped by the scraper 12 to the non-porous area 10b on the other side of the screen 10. When the liquid is discharged, the scraper 12 is close to the screen 10, moving from the non-porous area 10b on one side of the screen 10 to the non-porous area 10b on the opposite side of the screen 10. During this process, downward pressure is applied to the scraper 12 to squeeze the screen 10, changing the adhesion between the ink liquid inside the mesh 10a and the pore wall, so that the liquid film 4b leaks from the mesh 10a to the printing substrate 0 (the printing substrate 0 in this figure includes, from bottom to top: substrate 1, transparent conductive layer 2 and electron transport layer 5a). The perovskite liquid film 4b on the printing substrate 0 is re-spread into a continuous perovskite liquid film 4b under the action of surface tension. In addition, during the liquid discharge process, the scraper 12 can avoid the residual liquid 4c or not.

[0065] As shown in Figure 5, the liquid film 4b penetrates into the mesh 10a of the screen 10, and the remaining residual liquid 4c is scraped by the scraper 12 onto the non-porous area 10b of the screen 10. When the liquid is discharged, the scraper 12 is closely attached to the screen 10, moving from the non-porous area 10b on one side of the screen 10 to the non-porous area 10b on the opposite side of the screen 10. During this process, downward pressure is applied to the scraper 12 to squeeze the screen 10, changing the adhesion between the ink inside the mesh 10a and the pore walls, causing the liquid film 4b to leak out of the mesh 10a and onto the substrate 0 (the substrate 0 in this figure includes, from bottom to top, the substrate 1, the transparent conductive layer 2, and the electron transport layer 5a). Under the action of the capillary force formed between the upper surface of the substrate 0 and the lower surface of the mesh 10a of the screen 10, a new liquid film 4b is formed. In addition, during the liquid discharge process, the scraper 12 can avoid the residual liquid 4c, or it can not avoid the residual liquid 4c.

[0066] After crystallization treatment, a high-quality perovskite light-absorbing layer is formed. The crystallization treatment includes two steps: pretreatment and annealing. Among them, the pretreatment includes at least one of air knife blowing treatment, vacuum crystallization, and infrared flash burning. The temperature of the air knife blowing treatment is room temperature to 300 degrees Celsius, the time is 5 to 100 seconds, and the angle between the wind curtain and the spread perovskite liquid film is 0 to 60 degrees. The temperature of the vacuum crystallization is room temperature, and the time is 2 to 20 minutes. The temperature of the infrared flash burning is 60 to 300 degrees Celsius, and the time is 1.5 to 600 seconds. The temperature of the annealing treatment is 60 to 300 degrees Celsius, and the time is 2 to 60 minutes.

[0067] In the present invention, the process of the perovskite ink penetrating into the second printing substrate having a porous layer on its surface may be a process of synchronous point and line penetration and from line to surface penetration during the movement of the scraper; or the perovskite ink may be penetrated into the entire surface under the action of the capillary force formed between the upper surface of the printing substrate and the lower surface of the screen.

[0068] The following exemplifies a method for producing a high-quality perovskite light-absorbing layer on a second printing substrate having a porous layer on its surface, comprising: 1) sequentially producing a dense layer and a porous layer (the porous layer comprises an electron transport layer, an insulating layer, a hole transport layer, and a top electrode layer) on a transparent conductive layer on a substrate as a printing substrate; 2) dropping perovskite ink onto a non-porous area on one side of a screen; 3) using a scraper to spread the ink from the non-porous area on one side of the screen to the non-porous area on the opposite side of the screen; 4) during the ink spreading process, the surface tension of the perovskite ink and the adhesion between the mesh wall of the screen and the perovskite ink are utilized to form a liquid film on the screen without leaking; 5) applying downward pressure on the scraper to squeeze the liquid film in the mesh, changing the adhesion between the ink penetrating into the mesh and the mesh wall, causing the liquid film to descend from the mesh, and forming a liquid bridge between the upper surface of the printing substrate and the lower surface of the screen mesh; 6) the perovskite ink penetrates into the printing substrate under the action of capillary force; 7) After crystallization treatment, a high-quality perovskite light-absorbing layer is obtained.

[0069] In the present invention, the method of preparing the perovskite light-absorbing layer using the above-mentioned pseudo-screen printing process utilizes the surface tension of the ink itself to achieve the following core processes: spreading to form a liquid film, penetrating into the mesh of the screen; adsorbing in the holes without leaking; and penetrating into the printed substrate under the action of capillary force, thereby achieving higher film quality.

[0070] In the present invention, the solvent of the perovskite ink may also be non-volatile to ensure that the ink does not dry in the mesh and cause clogging during mass production. Therefore, a solvent with a low saturated vapor pressure may be preferably selected.

[0071] In the present invention, the surface tension of the ink can be increased by adding non-surfactant substances, such as inorganic salts, non-volatile acids, and bases, or reduced by adding surfactants, such as short-chain fatty acids, alcohols, and aldehydes.

[0072] In the present invention, if the contact angle between the ink and the porous layer is too large (the wettability of the ink to the porous layer is poor), the wettability of the ink on the surface of the porous layer can be improved by ultraviolet treatment and / or plasma treatment.

[0073] Figure 12 is a front view of a perovskite solar cell after perovskite ink has been infiltrated into a porous layer according to an embodiment of the present invention. Figure 13 is a top view of the screen and scraper used in an embodiment of the present invention. Figure 14 is an enlarged side view of the entire liquid spreading process, from spreading to the point of liquid dispensing. Figure 15 is an enlarged side view of the entire liquid dispensing process without a current collector strip. Figure 16 compares the electroluminescence performance of cells with perovskite light-absorbing layers fabricated using the methods of Example 9 and Comparative Example 6. Figure 17 compares the photoelectric conversion performance of cells with perovskite light-absorbing layers fabricated using the methods of Example 9 and Comparative Example 6. Figure 18 compares the photoelectric conversion performance of cells with perovskite light-absorbing layers fabricated using the methods of Examples 10 to 14. Figure 19 (Table 2) compares the specific parameters of the cells in the Examples and Comparative Examples. To address the above-mentioned technical problems, the present invention has invented a method for producing a high-quality perovskite light-absorbing layer on a printed substrate that is simple, easily scalable, and low-cost, with high film uniformity.

[0074] This embodiment and subsequent embodiments will be described in detail. As shown in Figure 12 , an insulating region 8' is formed on the transparent conductive layer 2' of the substrate 1' to distinguish the positive and negative electrodes of the battery, making the transparent conductive layer 2' discontinuous. A dense layer 3', a porous composite layer 5' (including a porous electron transport layer, a porous insulating layer, and a porous hole transport layer), and a top electrode layer 6' are sequentially formed on the conductive layer 2'. The above 1'-6' are defined as the printed substrate 0'. The top electrode layer 6' is formed above the porous composite layer 5' and crosses the insulating region 8' to contact the transparent conductive layer 2' to the right of the insulating region 8'. Current collector bars 7' are formed on the outermost edges of the transparent conductive layer 2' to serve as the positive and negative electrodes of the battery. Using the screen shown in Figure 13, perovskite ink 4a' to be infiltrated is applied to the non-porous areas 10b' of screen 10'. Using a scraper 12', ink 4a' is spread from the non-porous areas 10b' on one side of screen 10' to the non-porous areas 10b' on the opposite side. During this spreading process, ink 4a' spreads across screen 10' due to surface tension, forming a liquid film 4b'. Adhesion to the pore walls prevents leakage. Then, a scraper 12' is moved against the screen 10', from a non-porous area 10b' on one side of the screen 10' to a non-porous area 10b' on the opposite side. During this process, downward pressure is applied to the scraper 12', squeezing the screen 10'. This changes the adhesion between the liquid inside the mesh 10a' and the pore walls, causing the liquid film 4b' to descend from the mesh 10a' and form a liquid bridge between the upper surface of the top electrode 6' and the lower surface of the mesh 10a'. Under the action of capillary forces, the liquid film 4b' penetrates into the porous layer 5'; as shown in the lower figure in Figure 1, it finally undergoes a crystallization process to form a perovskite light-absorbing layer.

[0075] As shown in FIG14 , when the ink 4a' is scraped through the mesh 10a' of the screen 10' using a scraper 12', the ink 4a' forms a liquid film 4b' in the mesh 10a' due to the surface tension during the scraping process, and does not leak due to the adhesion force with the hole wall.

[0076] As shown in FIG15 , the liquid film 4b' has penetrated the mesh 10a' of the screen 10', and the remaining liquid 4c' is scraped by the scraper 12' to the non-porous area 10b' of the screen 10'. When the liquid is to be deposited, the scraper 12' is closely attached to the screen 10' and moves from the non-porous area 10b' on one side of the screen 10' to the non-porous area 10b' on the opposite side of the screen 10'. During this process, downward pressure is applied to the scraper 12' to squeeze the screen 10', changing the adhesion between the liquid inside the mesh 10a' and the pore wall, causing the liquid film 4b' to descend from the mesh 10a' and form a liquid bridge between the upper surface of the porous layer 5' and the lower surface of the mesh 10a' of the screen 10'. The liquid bridge in the figure is discontinuous, but this is not limited to this. A continuous liquid bridge can also be formed, thereby achieving simultaneous point and line deposition, line and surface deposition, liquid bridge formation, and simultaneous penetration of the entire surface liquid bridge. The liquid film 4b' permeates into the porous layer 5' under the action of capillary force.

[0077] The following examples are further given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, and are not limited to the specific numerical values ​​exemplified below.

[0078] Comparative Example 1: A formal perovskite solar cell with tin oxide as the electron transport layer is produced, and the perovskite light-absorbing layer is formed by a spin coating process: 1) An insulating area is made on the ITO conductive layer on the glass substrate by laser etching to make the ITO conductive layer discontinuous, and the two sides of the insulating area serve as the positive and negative electrode areas of the battery respectively; 2) The ITO glass is ultrasonically cleaned with acetone, alkaline detergent, deionized water, and acetone for 15 minutes respectively, and finally blown dry; 3) Tin oxide is spin-coated on the ITO conductive layer as an electron transport layer. The purchased tin oxide solution and deionized water were mixed in a volume ratio of 1:3, ultrasonicated at room temperature for 30 minutes, spin-coated at a speed of 2000 rpm for 20 seconds, and annealed on a hot plate at 150 degrees Celsius for 40 minutes; 4) 461 mg of lead iodide (PbI2) powder, 159 mg of methylamine iodide (CH3NH3I) powder, and 78 mg of dimethyl sulfoxide (DMSO) were mixed in 600 mg of N,N-dimethylformamide (DMF) and stirred at room temperature for 1 hour to form methylamine lead iodide (CH3NH3PbI3) perovskite ink; 5) Using this ink as a spin coating liquid, a perovskite light absorbing layer was prepared on the tin oxide electron transport layer by spin coating at a speed of 5000 rpm for 20 seconds; 6) Annealed at 100 degrees Celsius for 5 minutes to form a crystallized perovskite light absorbing layer; 7) Spin-coat 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) as a hole transport layer on the perovskite light-absorbing layer at a speed of 4000 rpm for 30 seconds. 8) Evaporate silver as a counter electrode on the hole transport layer to fabricate a perovskite solar cell.

[0079] Example 1 The method of the present invention is used to form a perovskite light-absorbing layer on a tin oxide electron transport layer; finally, the liquid film leaks down to the printed substrate and uses surface tension to self-spread into a film: 1) The preparation method 1) to 4) is the same as that of Comparative Example 1; 2) The printed substrate (the printed substrate in this embodiment includes, from bottom to top, a glass substrate, ITO and tin oxide) is placed on a horizontal table; 3) Stainless steel wire is used to make a screen with mesh, the screen frame size is 380 mm × 380 mm, the middle mesh area is 100 mm × 100 mm, and the screen mesh number is 325 mesh (mesh size is 45 microns). Place the screen above the printed substrate and adjust the gap between the lower surface of the screen and the upper surface of the printed substrate to 0.3 mm. 4) Add 0.5 ml of perovskite ink to the non-porous area on one side of the screen. Once the ink has spread, use a 150 mm long stainless steel scraper to directly contact and apply no pressure to the screen, moving the ink from the non-porous area on one side of the screen to the non-porous area on the other side at a constant speed. The movement speed is 50 mm / s, the angle between the scraper and the screen is 90 degrees, and the pressure between the scraper and the screen is 0 Pa. At this point, the ink penetrates the mesh and, due to the adhesion to the mesh pore walls, does not leak out. 5) Use another 150 mm long silicone scraper to directly contact the screen and apply a pressure of 0.14 MPa above it. Move the scraper from the non-porous area on one side of the screen to the non-porous area on the other side of the screen at a constant speed, without avoiding any residual liquid. The movement speed is 50 mm / s, and the angle between the scraper and the screen is 60 degrees. When passing through the mesh area, the scraper squeezes the screen, and the adhesion between the ink in the mesh and the hole wall of the screen changes, causing the liquid film to leak from the mesh to the tin oxide electron transport layer. The perovskite ink on the tin oxide electron transport layer attracts each other under the action of its own surface tension and self-spreads on the electron transport layer to form a liquid film; 6) The liquid film of the light-absorbing layer is placed in a vacuum exhaust device and vacuum crystallized for 2 minutes to form a pretreated perovskite light-absorbing layer; 7) The pretreated perovskite light-absorbing layer is placed on a hot plate and annealed at 150 degrees Celsius for 20 minutes to form a crystallized perovskite light-absorbing layer; 8) On the perovskite light-absorbing layer, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) is spin-coated as a hole transport layer. The spin coating speed is 4000 rpm and the time is 30 seconds; 9) silver is evaporated on the hole transport layer as a counter electrode to produce a perovskite solar cell.

[0080] Example 2: Using the method of the present invention, a perovskite light-absorbing layer was formed on the tin oxide electron transport layer. Finally, the liquid film that leaked onto the printed substrate formed a liquid film under the action of capillary forces between the upper surface of the substrate and the lower surface of the screen: 1) The preparation methods 1) to 4) were the same as those in Example 1. The gap between the lower surface of the screen and the upper surface of the printed substrate was adjusted to 0.1 mm. 2) A second 150 mm long silicone scraper was used to directly contact the screen and apply a pressure of 0.1 MPa above it. The scraper was moved at a constant speed from a non-porous area on one side of the screen to a non-porous area on the other side of the screen. The movement speed was 50 mm / s, and the angle between the scraper and the screen was 60 degrees. When passing through the mesh area, the scraper squeezes the screen, changing the adhesion between the ink in the screen mesh and the hole wall, causing the liquid film to leak from the mesh onto the tin oxide electron transport layer. The ink forms a liquid film under the action of the capillary force formed between the upper surface of the tin oxide electron transport layer and the lower surface of the screen. 3) Fix the printing substrate and adjust the gap between the lower surface of the screen and the upper surface of the printing substrate to 0.5 mm. The liquid film formed between the upper surface of the tin oxide electron transport layer and the lower surface of the screen is separated, carrying away the excess perovskite ink. 4) 6) to 9) Same as Example 1

[0081] Example 3 A perovskite light-absorbing layer was formed on a tin oxide electron transport layer using the method of the present invention. Finally, a liquid film was dripped onto a printed substrate and self-spread into a film using surface tension. The production method was the same as in Example 1. The only differences were: 1) in step 3), a screen with a mesh size of 165 (a mesh size of 93 μm) was used; and 2) during step 5), a pressure of 0.12 MPa was applied above the scraper when the liquid was dripped.

[0082] Example 4 Using the method of the present invention, a perovskite light-absorbing layer is formed on the tin oxide electron transport layer; finally, the liquid film that leaks onto the substrate uses surface tension to self-spread into a film: the preparation method is the same as that of Example 1; the only differences are: 1) in step 3), a screen with a mesh size of 400 (a mesh size of 38 microns) is used; 2) in step 5), a pressure of 0.18 MPa is applied above the scraper when the liquid is deposited.

[0083] Example 5 The method of the present invention is used to form a perovskite light-absorbing layer on a flexible substrate tin oxide electron transport layer; finally, the liquid film that leaks onto the printed substrate uses surface tension to self-spread into a film. The production method is the same as that of Example 1, with the only difference being: 1) the substrate used comprises, from bottom to top, a flexible polyethylene naphthalate (PEN) substrate, ITO, and tin oxide; 2) when adding liquid in step 5), avoid residual liquid.

[0084] Comparative Example 2: Fabrication of an inverse perovskite solar cell with poly(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) as the hole transport layer. The perovskite light absorbing layer was formed using a spin coating process: 1) 1) to 2) were the same as those in Comparative Example 1; 2) Preparation of PTAA ink: Commercially available PTAA was dissolved in chlorobenzene (6 mg / ml) and spin-coated at 3000 rpm for 30 seconds. The ink was then annealed on a hot plate at 100°C for 10 minutes. 3) 753.7 mg of lead iodide (PbI2) powder and 256.4 mg of formamidine hydroiodide (CH5IN2) powder were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio = 4:1); 275.3 mg of lead bromide (PbBr2) powder and 83.9 mg of methylammonium bromide (CH3NH3Br) powder were dissolved in 1 mL of a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio = 4:1); 395.7 mg of cesium iodide (CsI) powder was dissolved in 1 mL of dimethyl sulfoxide (DMSO); after heating and stirring at 60 degrees Celsius overnight, the three bottles of ink were mixed to form a perovskite ink; 4) Using this ink as a spin coating solution, a perovskite light-absorbing layer was prepared on the PTAA hole-transport layer by spin coating at a speed of 2000 rpm for 30 seconds. 6) Annealing was performed at 100°C for 5 minutes to form a crystallized perovskite light-absorbing layer. 7) [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) was spin-coated on the perovskite light-absorbing layer as an electron-transport layer at a speed of 3000 rpm for 30 seconds. 8) Fullerene (C60), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and copper as a counter electrode were sequentially evaporated on the hole-transport layer to fabricate a perovskite solar cell.

[0085] Example 6 The method of the present invention is used to form a perovskite light-absorbing layer on the PTAA hole transport layer; finally, the liquid film leaks down to the printed substrate and uses surface tension to self-spread into a film: 1) The preparation method 1) to 3) is the same as that of Comparative Example 2, and the same perovskite ink is used; 2) The printed substrate (the printed substrate in this embodiment includes, from bottom to top, a glass substrate, ITO and PTAA) is placed on a horizontal table; 3) A mesh screen is made of stainless steel wire, the outer frame size of the screen is 380 mm × 380 mm, the middle mesh area is 100 mm × 100 mm, and the mesh number of the screen is 325 meshes (the mesh size is 45 microns). Place the screen above the printing substrate and adjust the gap between the bottom surface of the screen and the top surface of the substrate to 0.2 mm. 4) Add 0.5 ml of perovskite ink to the non-porous area on one side of the screen. Once it has spread, use a 150 mm long stainless steel scraper to directly contact and apply no pressure to the screen. Scrape the ink from the non-porous area on one side of the screen to the non-porous area on the other side of the screen at a constant speed of 30 mm / s. The angle between the scraper and the screen is 90 degrees, and the pressure between the scraper and the screen is 0 Pa. At this point, the ink penetrates the mesh and is prevented from leaking due to the adhesion to the mesh pore wall. 5) Use another 150 mm long silicone scraper to directly contact the screen and apply a pressure of 0.18 MPa above it. Move the scraper from the non-porous area on one side of the screen to the non-porous area on the other side of the screen at a constant speed of 30 mm / s. The angle between the scraper and the screen is 60 degrees. When passing through the mesh area, the scraper squeezes the screen, changing the adhesion between the ink in the mesh and the hole wall, causing the liquid film to leak from the mesh onto the PTAA hole transport layer. Under the action of its own surface tension, the ink attracts each other and spreads itself on the PTAA hole transport layer to form a liquid film; 6) Set the temperature of the hot air gun to 100 degrees Celsius and blow dry the liquid film in a direction parallel to the surface of the liquid film; 7) Place the printed substrate after the liquid film is blown dry on a hot plate and anneal at 100 degrees Celsius for 5 minutes to produce a high-quality perovskite light-absorbing layer; 8) Spin-coat [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM) on the perovskite light-absorbing layer as an electron transport layer. The spin coating speed is 3000 rpm for 30 seconds; 9) Fullerene (C60), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and copper are sequentially deposited on the hole transport layer as a counter electrode to produce a perovskite solar cell.

[0086] Comparative Example 3: A formal perovskite solar cell with titanium oxide as the electron transport layer was prepared, and the perovskite light-absorbing layer was formed by a doctor blade coating process: 1) FTO glass was ultrasonically cleaned with an alkaline detergent, deionized water, and ethanol for 15 minutes respectively, and finally blown dry; 2) On the FTO conductive layer, a titanium oxide electron transport layer was screen-printed, which included the following ingredients: 1.5 ml of tetraisopropyl titanate, 3.5 g of ethyl cellulose, and 80 ml of terpineol. Sintering was performed in a muffle furnace at 510°C for 30 minutes. 3) 2.88 g of lead iodide (PbI2) powder and 975 mg of methylamine iodide (CH3NH3I) powder were mixed in a mixture of 4 ml of γ-butyrolactone (GBL) and 1 ml of N-methylpyrrolidone (NMP) and stirred at room temperature for 1 hour to form a methylamine lead iodide (CH3NH3PbI3) perovskite ink. 4) This ink was used as the perovskite ink for a doctor blade coating process at a speed of 1 mm / s to prepare a perovskite light-absorbing layer. 6) A hot air gun was set to 120°C and the film was dried parallel to the surface. 7) Annealing was performed at 125°C for 10 minutes to form a crystallized perovskite light-absorbing layer. 8) A low-temperature carbon paste was screen-printed on the perovskite light-absorbing layer as an electrode layer (also serving as a hole transport layer). The solids content (mass fraction) was 37%, and the solvent was terpineol.

[0087] Comparative Example 4 A formal perovskite solar cell with titanium oxide as the electron transport layer is prepared, and the perovskite light-absorbing layer is formed using a screen printing process: 1) 1) to 2) The preparation method is the same as that of Comparative Example 3; 2) 2.88 grams of lead iodide (PbI2) powder and 975 milligrams of methylammonium iodide (CH3NH3I) powder are measured and dissolved in 5 milliliters of methylamine acetate (MAAC) ionic liquid, and stirred continuously for 12 hours in a nitrogen atmosphere at 60 degrees Celsius to form methylamine lead iodide (CH3NH3PbI3) perovskite slurry; 3) The printed substrate (the printed substrate in this embodiment includes, from bottom to top, a glass substrate, FTO and titanium oxide) is placed on a horizontal platform; 4) A mesh with mesh is made using stainless steel wire, the outer frame size of the mesh is 380 mm × 380 mm, the middle mesh area is 100 mm × 100 mm, and the mesh number of the mesh is 325 mesh (mesh size is 45 microns). Place the screen above the printed substrate and adjust the gap between the lower surface of the screen and the upper surface of the printed substrate to 2 mm; 4) Pour 10 ml of perovskite slurry on the non-porous area on one side of the screen, use a 150 mm long silicone scraper to directly contact the screen, and apply a pressure of 0.3 MPa on it. Move the scraper from the non-porous area on one side of the screen to the non-porous area on the other side of the screen at a constant speed. The moving speed is 30 mm / s, and the angle between the scraper and the screen is 60 degrees. When passing through the mesh area, the scraper squeezes the perovskite slurry from the screen holes to the titanium oxide electron transport layer. In this process, the scraper, slurry, screen, and titanium oxide electron transport layer are in linear direct contact; 5) Place it on a hot plate and anneal at 120 degrees Celsius for 10 minutes to form a crystallized perovskite light-absorbing layer; 6) Screen-print low-temperature carbon slurry on the perovskite light-absorbing layer as an electrode layer (also a hole transport layer). The solid content (mass fraction) is 37%, and the solvent is terpineol.

[0088] Example 7 A perovskite light absorbing layer is prepared on a titanium oxide electron transport layer using the method of the present invention; finally, the liquid film leaks onto the printed substrate and self-spreads into a film using surface tension: 1) 1) to 3) are prepared in the same manner as in Comparative Example 3; 2) 2) to 3) are prepared in the same manner as in Example 1. The mesh size is 165 mm × 165 mm, the central mesh area is 10 mm × 15 mm, and the mesh size is 400 mesh (mesh size is 38 μm). 3) 180 μL of perovskite ink is dropped onto a non-porous area on one side of the mesh. After spreading, a 60 mm long stainless steel scraper is used to scrape the ink from the non-porous area on one side of the mesh to the non-porous area on the other side of the mesh without applying pressure. The movement speed is 20 mm / s, the angle between the scraper and the mesh is 90 degrees, and the pressure between the scraper and the mesh is 0 Pa. At this point, the ink penetrates the mesh and is prevented from leaking due to the adhesion force with the mesh pore walls. 4) A 60 mm long silicone scraper is used to directly contact the mesh and apply a pressure of 0.14 MPa. The scraper is moved at a constant speed from the non-porous area on one side of the mesh to the non-porous area on the other side of the mesh. The moving speed is 30 mm / s, and the angle between the scraper and the screen is 60 degrees. When passing through the mesh area, the scraper squeezes the screen, changing the adhesion between the ink in the screen mesh and the hole wall, causing the liquid film to leak from the mesh onto the titanium oxide electron transport layer. The ink forms a liquid film under the action of the capillary force formed between the upper surface of the titanium oxide electron transport layer and the lower surface of the screen. 5) Fix the printed substrate and adjust the gap between the lower surface of the screen and the upper surface of the printed substrate to 0.5 mm. The liquid film formed between the upper surface of the titanium oxide electron transport layer and the lower surface of the screen is separated, carrying away the excess perovskite ink. 6) Set the heat gun temperature to 120 degrees Celsius and blow dry the liquid film in a direction parallel to the surface of the liquid film. 7) Place the printed substrate after the liquid film is blown dry on a hot plate and anneal at 125 degrees Celsius for 10 minutes to produce a high-quality perovskite light-absorbing layer. 8) On the perovskite light-absorbing layer, a low-temperature carbon paste is screen-printed as an electrode layer (also serving as a hole transport layer) with a solid content (mass fraction) of 37% and terpineol as the solvent.

[0089] Comparative Example 5: A formal perovskite solar cell with tin oxide as the electron transport layer was prepared, and a spin coating process of a formamidinium lead iodide perovskite colloidal dispersion was used to form a film: 1) 1) to 3) The preparation method is the same as that of Comparative Example 1; 2) 884.8 mg of formamidinium lead iodide (CH4N2PbI3) powder was measured and dissolved in 1 ml of N-methylpyrrolidone (NMP) solvent, and stirred at 70 degrees Celsius for 1 hour to form a formamidinium lead iodide (CH4N2PbI3) perovskite colloidal dispersion; 3) Using this ink as a spin coating liquid, a perovskite light absorbing layer was prepared on the tin oxide electron transport layer by spin coating. Step 1: Spin coating speed of 1000 rpm for 10 seconds; Step 2: Spin coating speed of 5000 rpm for 40 seconds; 4) Annealing at 120 degrees Celsius for 60 minutes to form a crystallized perovskite light absorbing layer; 5) Spin-coat Spiro-OMeTAD as a hole transport layer on the perovskite light-absorbing layer at a speed of 4000 rpm for 30 seconds. 6) Evaporate silver as a counter electrode on the hole transport layer to create a perovskite solar cell.

[0090] Example 8 A perovskite light-absorbing layer was prepared on a tin oxide electron transport layer using the method of the present invention. Finally, the liquid film leaked onto the printed substrate was self-spread into a film using surface tension. The preparation method was the same as that of Example 1, with the only difference being: 1) a formamidinium lead iodide perovskite colloidal dispersion was used as the perovskite ink.

[0091] Figures 6 to 10 show a comparison of the performance of a perovskite solar cell produced using the method of the present invention and a conventional perovskite solar cell. Figures 6, 8, 9, and 10 demonstrate that the method of the present invention for producing a perovskite light-absorbing layer achieves superior performance compared to conventional processes.

[0092] Example 9 1) An insulating area was made on the FTO conductive layer of the glass substrate by laser etching to make the FTO conductive layer discontinuous, and the two sides of the insulating area served as the positive and negative electrode areas of the battery respectively; 2) The FTO glass was ultrasonically cleaned with acetone, alkaline detergent, deionized water, and acetone for 15 minutes respectively, and finally blown dry; 3) A TiO2 dense layer was prepared by screen printing on the FTO conductive layer, and a screen printing slurry comprising the following components: 1.5 ml of tetraisopropyl titanate, 3.5 g of ethyl cellulose, and 80 ml of pine alcohol was printed and coated on the FTO conductive layer, and sintered at 510 degrees Celsius in a muffle furnace for 30 minutes to form a TiO2 dense layer; 4) On the dense layer, titanium dioxide slurry (solid content mass fraction of 10%, solvent is pine alcohol) was screen printed, and sintered at 510 degrees Celsius in a muffle furnace for 30 minutes to form an electron transport layer with a porous structure; 5) On the electron transport layer, screen-print zirconium dioxide slurry (solid content mass fraction of 5%, solvent is pine alcohol) and sintered at 510 degrees Celsius in a muffle furnace for 30 minutes to form a porous insulating layer; 6) On the insulating layer, screen-print nickel oxide slurry (solid content mass fraction of 5%, solvent is pine alcohol) and sintered at 510 degrees Celsius in a muffle furnace for 30 minutes to form a porous hole transport layer; 7) On the hole transport layer, screen-print carbon slurry (solid content mass fraction of 37%, solvent is pine alcohol) and sintered at 430 degrees Celsius in a muffle furnace for 30 minutes to form a porous top electrode. The above 4) to 7) layers are called porous layers before perovskite infiltration; 8) On the FTO conductive layer, a tinned copper tape is pasted as a current collection strip; 9) Weigh 15.3 mg of 5-aminovaleric acid hydroiodide (5-AVAI), 576 mg of lead iodide (PbI2), and 195 mg of methylammonium iodide (CH3NH3I) powder, measure 1 ml of a mixed solvent (γ-valerolactone (GVL) and ethanol 4:1), and stir at 60 degrees Celsius for 6 hours to form CH3NH3PbI3 perovskite ink (concentration of 1.25 mol / L, surface tension coefficient of approximately 26 mN / m); 10) Place the printed substrate on a horizontal platform; 11) Use stainless steel wire to make a mesh screen with a mesh frame size of 550 mm × 550 mm, a middle mesh area of ​​180 mm × 180 mm, and a mesh count of 165 (mesh size of 93 μm).Place the screen above the printed substrate and adjust the gap between the lower surface of the screen and the upper surface of the printed substrate to 0.4 mm. 12) Apply 1.0 ml of perovskite ink to a non-porous area on one side of the screen. Once the ink has spread, use a 250 mm long stainless steel scraper to directly contact and apply no pressure to the screen, moving the ink from the non-porous area on one side of the screen to the non-porous area on the other side at a constant speed of 80 mm / s, with the scraper at a 90-degree angle to the screen and a pressure of 0 Pa between the scraper and the screen. At this point, the ink penetrates the mesh and adheres to the mesh wall, preventing it from leaking out. 13) Use another 250 mm long silicone scraper to directly contact the screen and apply a pressure of 0.24 MPa above it. Move the scraper from the non-porous area on one side of the screen to the non-porous area on the other side of the screen at a constant speed of 80 mm / s, with the scraper at a 60-degree angle to the screen. As the scraper squeezes the mesh, the adhesion between the liquid in the mesh and the pore walls changes, causing the liquid film to descend from the mesh and form a liquid bridge between the upper surface of the carbon layer and the lower surface of the mesh. Capillary forces allow the perovskite ink to penetrate the printed substrate. 14) The perovskite ink was allowed to stand for 20 minutes to allow for full penetration, and then crystallized at 50 degrees Celsius for 2 hours to create a perovskite solar cell.

[0093] Example 10 A perovskite light-absorbing layer was prepared using the method of the present invention. The preparation method was the same as that of Example 9, with the only difference being that a wire mesh with a mesh size of 400 (a mesh size of 38 microns) was used.

[0094] Example 11 A perovskite light-absorbing layer was prepared using the method of the present invention. The preparation method was the same as that of Example 9, with the only difference being that a 100-mesh screen (with a mesh size of 150 μm) was used.

[0095] Example 12 A perovskite light absorbing layer was prepared using the method of the present invention. The preparation method was the same as that of Example 9, with the only difference being that in step 13), when adding the liquid, a scraper pressure of 0.35 MPa was used.

[0096] Example 13 The perovskite light absorbing layer was prepared using the method of the present invention. The preparation method was the same as that of Example 9, except that a screen with a mesh size of 80 (a mesh size of 180 μm) was used. In step 13), when adding the liquid, the scraper pressure was 0.12 MPa.

[0097] Example 14 A perovskite light-absorbing layer was prepared using the method of the present invention. The preparation method was the same as that of Example 9, except that in step 9), γ-butyrolactone (GBL) was used instead of γ-valerolactone (GVL), and the ratio remained unchanged (concentration was 1.25 mol / L, and the surface tension coefficient was approximately 33 mN / m).

[0098] Comparative Example 6 1) Steps 1) to 9) are the same as those in Example 9 2) A fixed amount of perovskite ink is precisely dripped onto the carbon layer using a pipette gun, left to stand for 20 minutes to allow for full penetration and filling, and then crystallized at 50 degrees Celsius for 2 hours to produce a perovskite solar cell.

[0099] Figure 16 shows a comparison of the electroluminescence performance of a perovskite solar cell fabricated using the present invention's perovskite light-absorbing layer and a conventional perovskite solar cell. The perovskite solar cell fabricated using the present invention's perovskite light-absorbing layer exhibits superior electroluminescence uniformity to that produced using the conventional dropwise addition method.

[0100] Figures 17-18 show a comparison of the photoelectric conversion performance of a perovskite solar cell produced using the method of the present invention and a conventional perovskite solar cell. The photoelectric conversion performance of the perovskite solar cell produced using the method of the present invention for producing a perovskite light-absorbing layer is superior to that of the perovskite solar cell produced using the conventional dropwise addition method. As can be seen from Figure 19 (Table 2) and Figures 17-18, the open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF), and photoelectric conversion efficiency (Eff) of the cell produced using the method of the present invention are all higher than those of Comparative Example 6.

[0101] Among Examples 9-13, Example 9 has the best performance, because under the premise of using the same perovskite ink and the same porous material (that is, the concentration and surface tension coefficient of the ink are fixed values, and the porosity and pore size of the porous material are fixed values), the optimal amount of liquid can be controlled by adjusting the mesh size (that is, the pore size) and / or the pressure of the liquid drop. The amount of liquid drop directly affects the battery performance. In Example 12, the pressure of the liquid drop was increased, so the amount of liquid drop was too much, and its performance was poor compared with Examples 9-11. Therefore, with the method of Example 13, as long as the mesh size of the screen is also adjusted accordingly, the battery performance can be further improved on the existing basis.

[0102] The above specific embodiments further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not limited to the scope of protection of the present invention. Without departing from the purpose of the basic characteristics of the present invention, the present invention can be embodied in various forms. Therefore, the embodiments of the present invention are used for illustration rather than limitation. Since the scope of the present invention is defined by the claims rather than the specification, and all changes that fall within the scope defined by the claims or the equivalent range of the scope defined by the claims should be understood to be included in the claims. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a perovskite light-absorbing layer, characterized in that: include: (1) applying perovskite ink to a screen, and forming a liquid film on the screen by utilizing the surface tension of the perovskite ink and the adhesion between the mesh wall of the screen and the perovskite ink; the surface tension coefficient of the perovskite ink is greater than 5 mN / m; and the mesh diameter of the screen is 18 to 250 μm; (2) squeezing the screen to allow the liquid film to leak from the mesh of the screen and transfer to a printing substrate arranged parallel to the bottom of the screen to obtain a printing substrate loaded with perovskite ink; The printing substrate is a first printing substrate having a dense layer on its surface or a second printing substrate having a porous layer on its surface; When the printing substrate is the first printing substrate, the perovskite ink leaking from the mesh of the screen is re-spread into a film on the surface of the first printing substrate under the action of surface tension or capillary force; when the printing substrate is the second printing substrate, the perovskite ink leaking from the mesh of the screen forms a liquid bridge between the mesh of the screen and the second printing substrate, and is sucked in under the action of capillary force, penetrating into the porous layer of the second printing substrate; (3) performing a crystallization treatment on the printed substrate loaded with the perovskite ink to obtain the titanium ore light absorbing layer.

2. The preparation method according to claim 1, characterized in that The wire mesh includes: a middle mesh area provided with the mesh holes, and a non-porous area surrounding the middle mesh area and having no mesh holes; the wire mesh is made of stainless steel, tungsten or polyester.

3. The preparation method according to claim 1, characterized in that The chemical composition of the perovskite material in the perovskite ink is ABX3; wherein A is a monovalent cation, including [CH(NH2)2] + 、[NH3NH2] + 、[(CH2)3NH2] + , [NH3OH] + 、[C3N2H5] + 、[(CH3CH2)NH3] + 、[(CH3)2NH2] + 、[(NH2)3C] + 、[(CH3)4N] + 、[C3H4NS] + 、[NC4H8] + 、[C7H7] + , K + , Rb + 、Cs + At least one of; B is Pb 2+ 、Sn 2+ 、Co 2+ 、Mn 2+ 、Ge 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Cu 2+ 、Fe 2+ 、Pd 2+ 、Eu 2+ 、Ni 2+ and Bi 3+ At least one of; X is F - 、Cl - Br - , I - and SCN - At least one of; The solvent of the perovskite ink is selected from at least one of dimethylformamide, N-methylformamide, dimethyl sulfoxide, γ-valerolactone, γ-butyrolactone, N-methyl-2-pyrrolidone methanol, isopropyl alcohol, ethylene glycol, water, ethyl acetate, triethyl phosphate, 2-methoxyethanol, cyclopentyl methyl ether and N-hydroxymethyl acrylamide; The concentration of the perovskite ink is 0.5 to 2.0 mol / L.

4. The preparation method according to any one of claims 1 to 3, characterized in that The first printed substrate includes: a first substrate and a first dense layer, wherein the first dense layer is a first transparent conductive layer, or a first dense electron transport layer, or a first dense hole transport layer, or a composite dense layer formed by the first transparent conductive layer and one of the first dense electron transport layer or the first dense hole transport layer.

5. The preparation method according to any one of claims 1 to 3, characterized in that The second printed substrate includes, in sequence: a second substrate, a second transparent conductive layer, a second dense layer, a porous composite layer and a porous top electrode layer, or a second substrate, a second dense layer, a porous composite layer and a transparent porous top electrode layer, and one side of the porous top electrode layer or the transparent porous top electrode layer is placed parallel to the screen; the porous composite layer includes a second porous electron transport layer, a porous insulating layer and a second porous hole transport layer.

6. The preparation method according to claim 4 or 5, characterized in that The material of the first substrate and / or the second substrate includes: at least one of a metal material, an inorganic non-metallic material and a polymer material; the thickness of the first substrate and / or the second substrate is 0.001 to 5 mm; the material of the first transparent conductive layer and / or the second transparent conductive layer includes indium tin oxide, aluminum zinc oxide, indium zinc oxide, fluorine-doped tin oxide, vanadate, graphene and its derivatives; the thickness of the first transparent conductive layer and / or the second transparent conductive layer is 2 to 300 nanometers.

7. The preparation method according to claim 4, characterized in that The material of the first dense electron transport layer includes: at least one of titanium oxide and its dopants, tin oxide and its dopants, indium oxide and its dopants, zinc oxide and its dopants, cadmium sulfide and its dopants, zinc sulfide and its dopants, zinc selenide and its dopants, fullerene and its derivatives, graphene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane; the thickness of the first dense electron transport layer is 2 to 100 nanometers; The material of the first dense hole transport layer includes: nickel oxide, cuprous oxide, poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine], [2- (3,6-dimethoxy-9H-carbazol-9-yl) ethyl] phosphonic acid, dimethoxydiphenylamine substituted carbazole functionalized with phosphonic acid and at least one of arylamino-cyanovinylphosphonic acid; the thickness of the first dense hole transport layer is 2 to 300 nanometers.

8. The preparation method according to claim 5, characterized in that The second dense layer comprises a metal oxide film; the thickness of the second dense layer is 2 to 100 nanometers; the material of the metal oxide film comprises at least one of titanium oxide and its dopants, tin oxide and its dopants, and zinc oxide and its dopants; The material of the second porous electron transport layer includes at least one of titanium oxide, tin oxide, indium oxide, zinc oxide, cadmium sulfide, zinc sulfide, zinc selenide, fullerene and its derivatives, graphene and its derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), and doped compounds thereof; the thickness of the second porous electron transport layer is 0.002 to 2 microns; the pore size of the second porous electron transport layer is 5 to 100 nanometers, and the porosity is 10 to 80%; The porous insulating layer is made of at least one of aluminum oxide, zirconium oxide, and magnesium oxide; the thickness of the porous insulating layer is 0.1 to 4 micrometers; the pore size of the porous insulating layer is 0.001 to 1 micrometer, and the porosity is 10 to 80%; The material of the second porous hole transport layer includes: at least one of copper oxide, copper iodide, copper sulfide, cuprous thiocyanate, copper antimony sulfide, tungsten oxide, nickel oxide, molybdenum oxide, cerium oxide, vanadium oxide, manganese oxide, cobalt oxide, tungsten sulfide and molybdenum sulfide; the thickness of the second porous hole transport layer is 0.05 to 20 microns; the pore size of the second porous hole transport layer is 0.001 to 1 micron, and the porosity is 10 to 80%; the material of the porous top electrode layer includes: at least one of graphite, carbon black, carbon nanotubes, carbon fiber, and graphene; the thickness of the porous top electrode layer is 1 to 200 microns; the pore size of the porous top electrode layer is 0.001 to 6.5 microns, and the porosity is 10 to 90%.

9. The preparation method according to claim 5, characterized in that The transparent porous top electrode layer is made of at least one of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, indium tin oxide, aluminum zinc oxide, indium zinc oxide, fluorine-doped tin oxide, and vanadate; the transparent porous top electrode layer has a thickness of 1 to 200 microns; a pore size of 0.001 to 6.5 microns, and a porosity of 10 to 90%.

9. The preparation method according to claim 4, wherein the inorganic non-metallic material of the first substrate and / or the second substrate comprises a crystalline silicon cell.

10. The preparation method according to any one of claims 1 to 9, characterized in that The distance between the screen and the first printing substrate or the second printing substrate is 0 to 3 mm and is not zero.

11. The preparation method according to any one of claims 1 to 10, characterized in that The perovskite ink is spread onto the screen by a scraper, wherein the scraper parameters include: a moving speed of 0 to 300 mm / s and not 0, a gap between the scraper and the screen of 0 to 0.5 mm, an angle between the scraper and the screen of >0 degrees and <180 degrees, and a pressure between the scraper and the screen of 0 Pa; The perovskite ink was dropped onto a non-porous area without mesh holes on one side of the screen, and the perovskite ink was spread from the non-porous area on one side to the non-porous area on the opposite side by using a scraper.

12. The preparation method according to any one of claims 1 to 11, characterized in that The screen is squeezed by a scraper, and the parameters of the scraper include: a downward pressure of 0.01 to 0.6 MPa, a moving speed of 0 to 300 mm / s and not 0, and an angle between the scraper and the screen greater than 0 degree and less than 180 degrees.

13. The preparation method according to any one of claims 1 to 12, characterized in that When the printed substrate is a first printed substrate, the crystallization treatment includes two steps: pretreatment and annealing treatment, and the pretreatment includes at least one of air knife blowing treatment, vacuum crystallization, and infrared flash burning; The air knife blowing treatment is performed at a temperature of room temperature to 300 degrees Celsius for 5 to 100 seconds, and an angle between the air curtain and the spread perovskite liquid film is 0 to 60 degrees. The vacuum crystallization temperature is room temperature and the time is 2 to 20 minutes; The infrared flashing temperature is 60 to 300 degrees Celsius and the time is 1.5 to 600 seconds; The annealing treatment is performed at a temperature of 60 to 300 degrees Celsius and for a time of 2 to 60 minutes.

14. The preparation method according to any one of claims 1 to 12, characterized in that When the printed substrate is the second printed substrate, the crystallization treatment is performed at a temperature of room temperature to 300 degrees Celsius, and for a time of 2 to 1440 minutes.

15. A perovskite light-absorbing layer prepared according to the preparation method according to any one of claims 1 to 14.

16. A perovskite battery, characterized in that: include: The perovskite light-absorbing layer according to claim 15.

Images