Photovoltaic material and preparation method and application thereof

Abstract

The invention relates to a photovoltaic material and a preparation method and application thereof, and belongs to the technical field of solar cells. The method comprises the following steps: dissolving a monovalent metal salt and a divalent metal salt in a solvent, carrying out a first reaction, and then removing the solvent to obtain a salt crystal; and mixing the salt crystal with an ammonium salt, and carrying out a second reaction to obtain the photovoltaic material which has a perovskite structure, the monovalent metal salt and the divalent metal salt react to form the mixed metal salt, the mixed metal salt reacts with the ammonium salt to obtain the photovoltaic material with the perovskite structure, the whole photovoltaic material has hydrophobicity due to the addition of the ammonium salt, the molecular structure of the photovoltaic material is good in connectivity, and the photovoltaic material can be applied to the field of photovoltaic devices. And decomposition and structural change are not easy to occur under high temperature, high humidity and intense illumination, and high stability is achieved. And the obtained photovoltaic material has the performance similar to that of a perovskite material.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a photovoltaic material and a preparation method and application thereof. Background Art

[0002] Solar energy has the advantages of being renewable and clean. In recent years, the efficient use of solar energy has been widely studied. The use of solar energy mainly involves photocatalytic technology and photovoltaic technology. Photovoltaic technology is a means of directly converting solar energy into electrical energy using the photovoltaic effect. Among them, silicon-based solar cells are the most developed and widely used solar cells to date. At present, the conversion efficiency of single silicon solar cells has reached 26.1%, which has exceeded the 25% limit of the theoretical model of single-crystal silicon solar cells. The efficiency of polycrystalline silicon cells has also exceeded 22%. However, due to the high cost of using single-crystal silicon and polycrystalline silicon materials, it faces problems such as high cost and high energy consumption, which has affected the further development of silicon solar cells.

[0003] Therefore, perovskite cells were developed. Thanks to the excellent photoelectric properties of organic-inorganic hybrid perovskite materials, the photoelectric conversion efficiency of perovskite cells has been continuously improved, from 3.8% to 24.2% in just a few years. However, its long-term stability and environmental friendliness still need to be improved. Summary of the invention

[0004] The present application provides a photovoltaic material and a preparation method and application thereof to improve the stability of the photovoltaic material.

[0005] In a first aspect, the present application provides a method for preparing a photovoltaic material, the method comprising:

[0006] Dissolving a monovalent metal salt and a divalent metal salt in a solvent, performing a first reaction, and then removing the solvent to obtain salt crystals;

[0007] The salt crystals and the ammonium salt are mixed and subjected to a second reaction to obtain a photovoltaic material having a perovskite structure.

[0008] As an optional embodiment, the monovalent metal salt includes at least one of potassium chloride, sodium chloride, lithium chloride, cesium chloride or silver chloride; and / or

[0009] The divalent metal salt comprises at least one of magnesium chloride, cupric chloride, nickel chloride, ferrous chloride, manganese chloride or calcium chloride; and / or

[0010] The solvent includes at least one of water, ethanol, methanol, dimethyl sulfoxide, NN-dimethylformamide, Y-butyrolactone, N-methylpyrrolidone, dimethyl carbonate, diethyl carbonate, propylene carbonate, ethylene carbonate or ethyl methyl carbonate.

[0011] As an optional embodiment, the mass ratio of the monovalent metal salt to the divalent metal salt is (40-600): (40-60); and / or

[0012] The mass ratio of the sum of the mass of the monovalent metal salt and the divalent metal salt to the mass of the solvent is (2-200):

[0013] (30~1000).

[0014] As an optional embodiment, the temperature of the first reaction is 10°C to 120°C; and / or

[0015] The stirring speed of the first reaction is 100 r / min to 5000 r / min; and / or

[0016] The reaction pressure of the first reaction is no greater than 30 MPa; and / or

[0017] The first reaction time is 30 min to 300 min.

[0018] As an optional implementation, the solvent removal method includes volatilization, and the volatilization temperature is 40°C to 150°C.

[0019] As an optional embodiment, the ammonium salt includes at least one of ammonium formate, ammonium acetate, ammonium chloride, ammonium benzoate, ammonium nitrate or ammonium sulfate; and / or

[0020] The mass ratio of the salt crystals to the ammonium salt is (0.5-1.5):(0.5-1.5).

[0021] As an optional implementation manner, the temperature of the second reaction is 100°C to 1000°C.

[0022] In a second aspect, the present application provides a photovoltaic material, which is prepared by the method provided in the first aspect.

[0023] In a third aspect, the present application provides a perovskite cell, wherein the perovskite cell comprises a perovskite absorption layer, and the material of the perovskite absorption layer comprises the photovoltaic material provided in the second aspect.

[0024] In a fourth aspect, the present application provides a photovoltaic module, comprising the perovskite cell provided in the third aspect.

[0025] In a fifth aspect, the present application provides a photovoltaic power generation system, which includes a plurality of electrically connected photovoltaic components provided in the fourth aspect.

[0026] In a sixth aspect, the present application provides an electrical device comprising a plurality of electrically connected photovoltaic power generation systems provided in the fifth aspect.

[0027] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0028] The method provided in the embodiment of the present application is to react a monovalent metal salt and a divalent metal salt to form a mixed metal salt, and react with an ammonium salt to obtain a photovoltaic material having a perovskite structure. The addition of the ammonium salt can make the entire photovoltaic material hydrophobic, and the molecular structure of the photovoltaic material has good connectivity, so that it is not easy to decompose and change its structure under high temperature, high humidity and strong light, and has high stability. And the photovoltaic material obtained has similar properties to the perovskite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 A schematic diagram of a process for a method provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of the structure of a perovskite battery provided in an embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of a photovoltaic module provided in an embodiment of the present application.

[0034] Reference numerals: 1000 - photovoltaic module;

[0035] 1100-battery string; 1200-front glass; 1300-front encapsulation film; 1400-back encapsulation film; 1500-back glass;

[0036] 100-Perovskite battery;

[0037] 110 - transparent substrate layer; 120 - electron transport layer; 130 - perovskite absorption layer; 140 - hole transport layer; 150 - electrode layer. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0039] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0040] Thanks to the excellent photoelectric properties of organic-inorganic hybrid perovskite materials, the photoelectric conversion efficiency of perovskite cells has been continuously improved, from 3.8% to 24.2% in just a few years. However, its long-term stability and environmental friendliness still need to be improved.

[0041] The present application intends to provide a photovoltaic material with a perovskite-like structure, which has a photoelectric conversion performance similar to that of a perovskite material and has better stability.

[0042] Figure 1 A flow chart of the method provided in the embodiment of the present application is as follows: Figure 1 As shown, the embodiment of the present application provides a method for preparing a photovoltaic material, the method comprising:

[0043] S1. dissolving a monovalent metal salt and a divalent metal salt in a solvent, and performing a first reaction, and then removing the solvent to obtain salt crystals;

[0044] In some embodiments, the monovalent metal salt includes at least one of potassium chloride, sodium chloride, lithium chloride, cesium chloride or silver chloride; the divalent metal salt includes at least one of magnesium chloride, cupric chloride, nickel chloride, ferrous chloride, manganese chloride or calcium chloride; the solvent includes at least one of water, ethanol, methanol, dimethyl sulfoxide, NN-dimethylformamide, γ-butyrolactone, N-methylpyrrolidone, dimethyl carbonate, diethyl carbonate, propylene carbonate, ethylene carbonate or methyl ethyl carbonate. By selecting the above raw materials as monovalent metal salts and divalent metal salts, they do not contain polluting heavy metals such as Pb, so that the prepared photovoltaic material has good environmental friendliness.

[0045] In some embodiments, the mass ratio of the monovalent metal salt to the divalent metal salt is (40-60): (40-60). The mass ratio of the sum of the mass of the monovalent metal salt and the divalent metal salt to the solvent is (2-200): (30-1000). Exemplarily, the mass ratio of the monovalent metal salt to the divalent metal salt can be 40:40, 45:40, 50:40, 55:40, 60:40, 40:50, 45:50, 55:50, 60:50, 40:60, 45:60, 50:60, 55:60, etc. It can also be any value within the range of (40-60): (40-60). The mass ratio of the sum of the mass of the monovalent metal salt and the divalent metal salt to the mass of the solvent can be 2:30, 2:100, 2:200, 2:300, 2:400, 2:500, 2:600, 2:700, 2:800, 2:900, 2:1000, 100:30, 100:100, 100:200, 100:300, 100:400, 100:500, 100:600, 100:700, 100:800, 100:900, 100:1000, 200:30, 200:100, 200:200, 200:300, 200:400, 200:500, 200:600, 200:700, 200:800, 200:900, 200:1000, etc. It can also be any value in the range of (2~200):(30~1000).

[0046] In some embodiments, the temperature of the first reaction is 10°C to 120°C; the stirring speed of the first reaction is 100r / min to 5000r / min; the reaction pressure of the first reaction is not more than 30MPa; the time of the first reaction is 30min to 300min. Exemplarily, the temperature of the first reaction can be 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, etc., and it can also be any value within the range of 10°C to 120°C. The stirring speed of the first reaction can be 100r / min, 500r / min, 1000r / min, 1500r / min, 2000r / min, 2500r / min, 3000r / min, 3500r / min, 4000r / min, 4500r / min, 5000r / min, etc., and it can also be 100r / min~5000r / min. The reaction pressure of the first reaction can be 0MPa, 5MPa, 10MPa, 15MPa, 20MPa, 25MPa, 30MPa, etc., and it can also be any value within the range of not more than 30MPa. The time of the first reaction can be 30min, 50min, 100min, 150min, 200min, 250min, 300min, etc., and it can also be any value within the range of 30min~300min.

[0047] In some embodiments, the solvent removal method includes volatilization. Further, the volatilization temperature is 40°C to 150°C. Exemplarily, the volatilization temperature can be 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc., and it can also be any value within the range of 40°C to 150°C.

[0048] S2. Mixing the salt crystals and the ammonium salt and performing a second reaction to obtain a photovoltaic material having a perovskite structure.

[0049] In some embodiments, the ammonium salt includes at least one of ammonium formate, ammonium acetate, ammonium chloride, ammonium benzoate, ammonium nitrate or ammonium sulfate; the mass ratio of the salt crystals to the ammonium salt is (0.5-1.5): (0.5-1.5).

[0050] In some embodiments, the temperature of the second reaction is 100° C. to 1000° C. For example, the temperature of the second reaction can be 100° C., 200° C., 300° C., 400° C., 500° C., 600° C., 700° C., 800° C., 900° C., 1000° C., etc., and can also be any value within the range of 100° C. to 1000° C.

[0051] The method uses a monovalent metal salt and a divalent metal salt to react to form a mixed metal salt, and then reacts with an ammonium salt to obtain a photovoltaic material with a perovskite structure. The addition of the ammonium salt can make the entire photovoltaic material hydrophobic. The molecular structure of the photovoltaic material has good connectivity, making it less likely to decompose and change its structure under high temperature, high humidity and strong light, and has high stability. The photovoltaic material obtained has similar properties to the perovskite material.

[0052] Based on a general inventive concept, an embodiment of the present application further provides a photovoltaic material, which is prepared by the method provided above.

[0053] The photovoltaic material is prepared based on the above method. The specific steps of the method can refer to the above embodiments. Since the photovoltaic material adopts part or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0054] Figure 2 The schematic diagram of the structure of the perovskite battery provided in the embodiment of the present application is as follows: Figure 2 As shown, based on a general inventive concept, the embodiment of the present application further provides a perovskite cell, the perovskite cell comprising a perovskite absorption layer, the material of the perovskite absorption layer comprising the photovoltaic material provided above.

[0055] The perovskite cell is realized based on the above-mentioned photovoltaic material. The specific content of the photovoltaic material can be referred to the above-mentioned embodiment. Since the perovskite cell adopts part or all of the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0056] Perovskite cells are perovskite solar cells, which usually include functional layers such as a transparent substrate layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer, among which the perovskite light absorption layer is located between the transparent substrate layer and the electrode layer.

[0057] Types of transparent substrate layers include, but are not limited to, FTO (fluorine-doped SnO2 transparent conductive glass), ITO (indium tin oxide transparent conductive glass), AZO (aluminum-doped zinc oxide transparent conductive glass), BZO (boron-doped zinc oxide transparent conductive glass), IZO (indium zinc oxide transparent conductive glass), etc.

[0058] The electron transport material used in the electron transport layer is, for example, but not limited to, at least one of imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, silicon oxide, strontium titanate, calcium titanate, lithium fluoride and calcium fluoride, wherein the metal element in the metal oxide used in the electron transport material includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr.

[0059] The thickness of the electron transport layer is, for example, 5-200 nm, and may be optionally 30-60 nm.

[0060] The thickness of the perovskite absorption layer is, for example, 400-650 nm.

[0061] The hole transport material used in the hole transport layer is, for example but not limited to, at least one of 2,2',7,7'-tetrakis(N,N-p-methoxyanilino)-9,9'-spirobifluorene, methoxytriphenylamine-fluoroformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene), polystyrene sulfonic acid, poly3-hexylthiophene, triphenylamine with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-anilino)carbazole-spirobifluorene, polythiophene, phosphate-based monomers, carbazole-based monomers, sulfonic acid-based monomers, triphenylamine-based monomers, aromatic monomers, metal oxides and cuprous thiocyanate, wherein the metal element in the metal oxide selected in the hole transport material includes at least one of Ni, Mo and Cu.

[0062] The thickness of the hole transport layer is, for example, 5-500 nm, and may be 100-200 nm.

[0063] The material used for the electrode layer is an organic, inorganic or organic-inorganic hybrid conductive material, and the conductive material is at least one of an organic conductive material and an inorganic conductive material, wherein the organic conductive material is, for example, a conductive polymer, and the conductive polymer includes but is not limited to at least one of polyethylene dioxythiophene (PEDOT), polythiophene, and polyacetylene; the inorganic conductive material is, for example, but not limited to, at least one of a transparent conductive oxide, a metal, and a carbon derivative, and specific inorganic conductive materials include, for example, Ag, Cu, C, Au, Al, ITO, AZO, BZO, IZO, etc.

[0064] The structure of the perovskite cell can be a formal structure or a trans structure. For example, when the perovskite cell is a trans structure, the perovskite cell includes a transparent substrate layer, a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode layer stacked in sequence. When the perovskite cell is a formal structure, the perovskite cell includes a transparent substrate layer, an electron transport layer, a perovskite absorption layer, a hole transport layer, and an electrode layer stacked in sequence. The perovskite cell with a formal structure has a simple structure and is easy to prepare.

[0065] Based on the above embodiments, the preparation process of the formal structure perovskite battery exemplarily includes: step 1: etching and cleaning the transparent substrate layer, blowing dry and set aside; step 2: preparing an electron transport layer on the front side of the transparent substrate layer, set aside; step 3: preparing a perovskite absorption layer on the front side of the electron transport layer, set aside; step 4: preparing a hole transport layer on the front side of the perovskite composite layer, set aside; step 5: preparing an electrode layer on the front side of the hole transport layer.

[0066] It can be understood that the preparation methods of the above-mentioned layers include but are not limited to chemical bath deposition, electrochemical deposition, chemical vapor deposition, physical epitaxial growth, thermal evaporation, atomic layer deposition, magnetron sputtering, precursor coating, precursor slit coating, precursor scraping, etc., and technicians in this field can choose according to actual needs. In addition to the above-mentioned settings, a mechanical pressing method can also be used to form at least two interconnected functional layers at one time.

[0067] Optionally, each layer is prepared by thermal evaporation or precursor coating, wherein the precursor coating may be spin coating. The method of preparing the above-mentioned perovskite battery by combining the precursor coating method and vacuum evaporation includes: spin coating the electron transport layer slurry on the front of the cleaned transparent substrate layer at a rotation speed of 4000rpm-6500rpm, and then drying it on a constant temperature hot stage at, for example, 100-200°C to obtain an electron transport layer, and then preparing a perovskite absorption layer on the surface of the electron transport layer, spin coating the hole transport layer slurry on the front of the perovskite absorption layer at a rotation speed of 3000rpm-4000rpm, drying to obtain a hole transport layer, and then in a vacuum coating machine, under a vacuum condition of 5×10-4Pa, evaporating an electrode layer on the front of the hole transport layer.

[0068] Figure 3 The schematic diagram of the structure of the photovoltaic module provided in the embodiment of the present application is as follows: Figure 3 As shown, based on a general inventive concept, an embodiment of the present application further provides a photovoltaic module, including the perovskite cell provided above.

[0069] The photovoltaic module is realized based on the above-mentioned perovskite cell. The specific content of the perovskite cell can refer to the above-mentioned embodiment. Since the photovoltaic module adopts part or all of the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0070] Photovoltaic module refers to a solar cell module, that is, an integral module including multiple perovskite cells, including several cell strings, each of which includes multiple perovskite cells connected in series through connectors such as welding ribbons.

[0071] In a photovoltaic module, in addition to the battery string, it also includes front glass, front packaging film, back packaging film, back glass, etc. As an example, the photovoltaic module includes front glass, front packaging film, battery string, back packaging film and back glass stacked in sequence along the thickness direction.

[0072] According to some embodiments of the present application, the present application also provides a photovoltaic power generation system, which includes a plurality of electrically connected photovoltaic components.

[0073] Several refers to a number of two or more integers.

[0074] Photovoltaic power generation system refers to a power generation system that uses the photovoltaic effect to directly convert solar radiation energy into electrical energy. It is divided into an independent photovoltaic power generation system (Stand-alone PV System) and a grid-connected photovoltaic power generation system (Grid-connected PV System). The independent photovoltaic power generation system consists of a solar photovoltaic array composed of photovoltaic components, a battery pack, a charge controller, a power electronic converter (inverter), a load, etc. The grid-connected photovoltaic power generation system consists of a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter) and a system monitoring part.

[0075] According to some embodiments of the present application, the present application also provides an electrical device, which includes the photovoltaic power generation system provided by the above scheme, and the photovoltaic power generation system is used to provide electrical energy to the electrical device.

[0076] The electrical equipment may be in various forms, such as electric cars, ships, spacecraft, solar water heaters, solar energy, etc.

[0077] The power supply mode of the electric equipment can be a single power supply of photovoltaic modules, or a combination of photovoltaic modules and energy storage batteries, that is, the electric equipment is equipped with photovoltaic modules and energy storage batteries at the same time. The energy storage battery is not limited to primary batteries and secondary batteries, for example, but not limited to lithium-ion secondary batteries, sodium-ion secondary batteries, etc.

[0078] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0079] Example 1

[0080] A photovoltaic material, the preparation steps of which include:

[0081] S1. Weigh the solvent (200 g water, 200 g ethanol, 600 g NMP) and put them into a container and mix them thoroughly.

[0082] S2, weigh 55g of monovalent metal salt (including 25g of silver chloride, 25g of cesium chloride, and 5g of lithium chloride), 45g of divalent metal salt (including 15g of ferrous chloride and 30g of manganese chloride), place in the mixed solvent in step 1, stir and dissolve thoroughly. Reaction temperature 60°C, stirring speed 2000r / min, reaction for 120min under pressure of 1Pa. Then evaporate the solvent to dryness at 80°C.

[0083] S3. Weigh 30 g of the product obtained in step 2 and 30 g of ammonium salt (including 10 g of ammonium formate and 20 g of ammonium benzoate), mix and disperse them, and then transfer them into a high-temperature reactor to react at 300° C. to obtain a perovskite structural material.

[0084] Example 2

[0085] A photovoltaic material, the preparation steps of which include:

[0086] S1. Weigh the solvent (200 g water, 200 g ethanol, 600 g NMP) and put them into a container and mix them thoroughly.

[0087] S2, weigh 58g of monovalent metal salt (including 22g of silver chloride, 30g of cesium chloride and 6g of lithium chloride), 42g of divalent metal salt (including 15g of ferrous chloride and 27g of manganese chloride), place in the mixed solvent in step 1, stir and dissolve thoroughly. Reaction temperature 60°C, stirring speed 2000r / min, reaction for 120min under pressure of 1Pa. Then evaporate the solvent to dryness at 80°C.

[0088] S3. Weigh 30 g of the product obtained in step 2 and 30 g of ammonium salt (including 10 g of ammonium formate and 20 g of ammonium benzoate), mix and disperse them, and then transfer them into a high-temperature reactor to react at 300° C. to obtain a perovskite structural material.

[0089] Example 3

[0090] A photovoltaic material, the preparation steps of which include:

[0091] S1. Weigh the solvent (200 g water, 200 g ethanol, 600 g NMP) and put them into a container and mix them thoroughly.

[0092] S2, weigh 53g of monovalent metal salt (including 23g of silver chloride, 27g of cesium chloride and 3g of lithium chloride), 7g of divalent metal salt (including 20g of ferrous chloride and 27g of manganese chloride), place in the mixed solvent in step 1, stir and dissolve thoroughly. Reaction temperature 60°C, stirring speed 2000r / min, reaction at a pressure of 1Pa for 120min. Then evaporate the solvent to dryness at 80°C.

[0093] S3. Weigh 30 g of the product obtained in step 2 and 30 g of ammonium salt (including 10 g of ammonium formate and 20 g of ammonium benzoate), mix and disperse them, and then transfer them into a high-temperature reactor to react at 300° C. to obtain a perovskite structural material.

[0094] Example 4

[0095] A photovoltaic material, the preparation steps of which include:

[0096] S1. Weigh the solvent (200 g water, 200 g ethanol, 600 g NMP) and put them into a container and mix them thoroughly.

[0097] S2, weigh 56g of monovalent metal salt (including 32g of silver chloride, 20g of cesium chloride, and 4g of lithium chloride), 44g of divalent metal salt (including 24g of ferrous chloride and 20g of manganese chloride), place in the mixed solvent in step 1, stir and dissolve thoroughly. Reaction temperature 60°C, stirring speed 2000r / min, reaction for 120min under pressure of 1Pa. Then evaporate the solvent to dryness at 80°C.

[0098] S3. Weigh 30 g of the product obtained in step 2 and 30 g of ammonium salt (including 10 g of ammonium formate and 20 g of ammonium benzoate), mix and disperse them, and then transfer them into a high-temperature reactor to react at 300° C. to obtain a perovskite structural material.

[0099] Comparative Example 1

[0100] Photovoltaic materials purchased from the market: perovskite material CH3NH3PbI3.

[0101] The photovoltaic materials provided in each embodiment and comparative example are prepared into a photovoltaic cell, which includes a transparent substrate layer, an electron transport layer, a perovskite absorption layer, a hole transport layer and an electrode layer stacked in sequence, wherein the thickness of the electron transport layer is 40nm, the thickness of the hole transport layer is 150nm, and the thickness of the perovskite absorption layer is 500nm. Performance testing is performed.

[0102] Photovoltaic conversion efficiency test (IV test): Use a solar simulator to simulate sunlight irradiating the perovskite cell, measure the cell output power through a power analyzer, and calculate its ratio to the incident light power, i.e. PCE. During the test, keep the component temperature at 25°C, use natural light or a Class B or better simulator that meets the requirements of IEC904-9, at 1000Wm -2 The JV characteristic curve is an important tool for evaluating the performance of solar cells, which can intuitively show the current response of the cell under different voltages.

[0103] Stability test: Under the conditions of temperature: 85℃±2℃ and relative humidity: 85%+5%, the cycle test time is 1000h. The stability of the battery can be evaluated by monitoring the changes in parameters such as open circuit voltage and short circuit current during the thermal cycle.

[0104] The results are shown in the following table:

[0105] Photoelectric conversion efficiency Stability (decay rate) Example 1 25.2％ 1.7％ Example 2 24.5％ 2.3％ Example 3 24.1％ 2.7％ Example 4 25.4％ 1.3％ Comparative Example 1 22.4％ 7.8％

[0106] It can be seen from the above table that the photovoltaic material prepared by the method provided in the embodiment of the present application has good photoelectric conversion efficiency and good stability.

[0107] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0108] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present specification, the terms "including", "comprising", etc. refer to "including but not limited to". In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A, B can be singular or plural. In this article, "at least one" refers to one or more, and "plural" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e. a and b), ac, bc, or abc, where a, b and c can be single or multiple.

[0109] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for preparing a photovoltaic material, characterized in that: The method comprises: Dissolving a monovalent metal salt and a divalent metal salt in a solvent, performing a first reaction, and then removing the solvent to obtain salt crystals; The salt crystals and the ammonium salt are mixed and subjected to a second reaction to obtain a photovoltaic material having a perovskite structure.

2. The method for preparing a photovoltaic material according to claim 1, characterized in that: The monovalent metal salt comprises at least one of potassium chloride, sodium chloride, lithium chloride, cesium chloride or silver chloride; and / or The divalent metal salt comprises at least one of magnesium chloride, cupric chloride, nickel chloride, ferrous chloride, manganese chloride or calcium chloride; and / or The solvent includes at least one of water, ethanol, methanol, dimethyl sulfoxide, NN-dimethylformamide, Y-butyrolactone, N-methylpyrrolidone, dimethyl carbonate, diethyl carbonate, propylene carbonate, ethylene carbonate or ethyl methyl carbonate.

3. The method for preparing a photovoltaic material according to any one of claims 1 to 2, characterized in that: The mass ratio of the monovalent metal salt to the divalent metal salt is (40-60): (40-60); and / or The mass ratio of the sum of the mass of the monovalent metal salt and the divalent metal salt to the mass of the solvent is (2-200):(30-1000).

4. The method for preparing a photovoltaic material according to any one of claims 1 to 2, characterized in that: The temperature of the first reaction is 10°C to 120°C; and / or The stirring speed of the first reaction is 100 r / min to 5000 r / min; and / or The reaction pressure of the first reaction is no greater than 30 MPa; and / or The first reaction time is 30 min to 300 min.

5. The method for preparing a photovoltaic material according to any one of claims 1 to 2, characterized in that: The solvent removal method includes volatilization, and the volatilization temperature is 40°C to 150°C.

6. The method for preparing a photovoltaic material according to any one of claims 1 to 2, characterized in that: The ammonium salt comprises at least one of ammonium formate, ammonium acetate, ammonium chloride, ammonium benzoate, ammonium nitrate or ammonium sulfate; and / or The mass ratio of the salt crystals to the ammonium salt is (0.5-1.5):(0.5-1.5).

7. The method for preparing a photovoltaic material according to any one of claims 1 to 2, characterized in that: The temperature of the second reaction is 100°C to 1000°C.

8. A photovoltaic material, characterized in that: The photovoltaic material is prepared by the method according to any one of claims 1 to 7.

9. A perovskite battery, characterized in that: The perovskite cell comprises a perovskite absorption layer, and the material of the perovskite absorption layer comprises the photovoltaic material according to claim 8.

10. A photovoltaic module, characterized in that: Including the perovskite battery as described in claim 9.

Images