Perovskite precursor solution, perovskite solar cell and preparation method thereof, photovoltaic module

Abstract

The present application relates to the field of solar cell technology, and in particular to a perovskite precursor solution, a perovskite solar cell and a preparation method, and a photovoltaic module. The perovskite precursor solution includes: a perovskite material, an additive and an organic solvent; the additive includes an organic acid salt; the perovskite material is an ABX3 structure, A is a monovalent cation; B is a divalent cation; and X is a monovalent anion. The present application can add an additive (organic acid salt) to the perovskite precursor solution. The organic acid radical ions in the organic acid salt can combine with water molecules in the environment to reduce the participation of water molecules in the perovskite crystallization process; the metal cations in the organic acid salt can fill the ion defects in the internal lattice of the perovskite. The metal cations can increase the ion migration barrier through lattice distortion, improve the ion migration phenomenon and the stability of the perovskite material, thereby improving the carrier lifetime of the perovskite material, thereby improving the photoelectric conversion efficiency of the device.

Description

Technical Field

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

[0002] As a clean and renewable energy, solar energy has been internationally recognized as one of the most competitive energy sources due to its unique advantages such as wide distribution, safety and durability. At present, solar cells have developed from crystalline silicon solar cells to perovskite solar cells. Perovskite solar cells have broad research prospects and commercial value due to their high absorption coefficient, adjustable band gap, simple preparation, low cost, and high photoelectric conversion efficiency.

[0003] At present, in commercial applications, the conversion efficiency of large-area perovskite solar cells is low, mainly because the preparation of large-area perovskite cells is in an open environment. Especially when the humidity in the environment is high, the water molecules in the environment will affect the perovskite crystallization and film formation process, resulting in poor performance of large-area perovskite solar cells.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a perovskite precursor solution, a perovskite solar cell and a method for preparing the same, and a photovoltaic module to solve or alleviate one or more of the technical problems raised above.

[0006] In a first aspect, an embodiment of the present application provides a perovskite precursor solution, comprising: Perovskite materials, additives and organic solvents; The additive includes an organic acid salt; Wherein, the perovskite material is an ABX3 structure, A is a monovalent cation; B is a divalent cation; and X is a monovalent anion.

[0007] Optionally, the organic acid salt includes one or more of formates, acetates and propionates.

[0008] Optionally, the formate salt includes one or more of lithium formate, sodium formate, potassium formate, rubidium formate, cesium formate, beryllium formate, magnesium formate, calcium formate, strontium formate, barium formate, europium formate and cerium formate.

[0009] Optionally, the acetate includes one or more of lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, beryllium acetate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, europium acetate and cerium acetate.

[0010] Optionally, the propionate salt includes one or more of lithium propionate, sodium propionate, potassium propionate, rubidium propionate, cesium propionate, beryllium propionate, magnesium propionate, calcium propionate, strontium propionate, barium propionate, europium propionate and cerium propionate.

[0011] Optionally, the organic acid salt includes one or more of sodium formate, potassium formate, rubidium formate, cesium formate, calcium formate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, and calcium acetate.

[0012] Optionally, in the perovskite precursor solution, the concentration of the additive is 0.01-10 mg / ml.

[0013] In a second aspect, an embodiment of the present application provides a perovskite solar cell, comprising: a substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer stacked in sequence; Wherein, the perovskite light-absorbing layer is prepared from the aforementioned perovskite precursor solution.

[0014] In a third aspect, an embodiment of the present application provides a method for preparing a perovskite solar cell, comprising the following steps: providing a substrate; forming a hole transport layer on the upper surface of the substrate; Placing the aforementioned perovskite precursor solution on the upper surface of the hole transport layer to form a perovskite light absorbing layer; An electron transport layer is formed on the perovskite light absorbing layer.

[0015] In a fourth aspect, an embodiment of the present application provides a photovoltaic module, wherein the photovoltaic module includes the aforementioned perovskite solar cell; or The perovskite solar cell is prepared by the aforementioned method for preparing a perovskite solar cell.

[0016] The above technical solution adopted in the embodiment of the present application may have the following advantages: By adding additives (organic acid salts) to the perovskite precursor solution, on the one hand, the organic acid radical ions in the organic acid salts can combine with water molecules in the environment, reducing the participation of water molecules in the perovskite crystallization process, thereby improving the perovskite crystallization quality; on the other hand, the metal cations in the organic acid salts can fill the ion defects in the internal lattice of the perovskite. The metal cations can increase the ion migration barrier through lattice distortion, improve the ion migration phenomenon and the stability of the perovskite material, thereby improving the carrier lifetime of the perovskite material; in addition, the metal cations can also be adsorbed on the surface or grain boundary of the perovskite material to form a protective layer, passivate surface defects, and improve the photoelectric conversion efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0018] Figure 1 It is a schematic diagram of the structure of the perovskite tandem solar cell provided in an embodiment of the present application.

[0019] Description of reference numerals: 1. Intermediate composite layer; 2. First layer; 3. Second layer; 4. Perovskite light absorption layer; 5. Passivation layer; 6. Electron transport layer; 7. Hole blocking layer; 8. First electrode; 9. Second electrode; 10. Transparent conductive layer; 11. First intrinsic amorphous silicon layer; 12. P-type non- / microcrystalline silicon layer; 13. N-type silicon wafer; 14. Second intrinsic amorphous silicon layer; 15. N-type non- / microcrystalline silicon layer. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0021] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present application discloses the existence of the first element, component, region, layer or part.

[0022] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0025] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0026] The embodiment of the present application provides a perovskite precursor solution. The perovskite precursor solution may include: Perovskite materials, additives and organic solvents; Additives include organic acid salts; Among them, the perovskite material has an ABX3 structure, A is a monovalent cation; B is a divalent cation; and X is a monovalent anion.

[0027] In this embodiment, by adding an additive (organic acid salt) to the perovskite precursor solution, on the one hand, the organic acid radical ions in the organic acid salt can combine with water molecules in the environment, reduce the participation of water molecules in the perovskite crystallization process, and thus improve the perovskite crystallization quality; on the other hand, the metal cations in the organic acid salt can fill the ion defects in the internal lattice of the perovskite, and the metal cations can increase the ion migration barrier through lattice distortion. The improvement of the ion migration barrier inhibits the disordered migration of ions (such as I⁻ ion migration), improves the ion migration phenomenon and the stability of the perovskite material, and reduces the non-radiative recombination caused by defect states, thereby improving the carrier lifetime of the perovskite material; in addition, the metal cations can also be adsorbed on the surface or grain boundary of the perovskite material to form a protective layer, passivate surface defects, and improve the photoelectric conversion efficiency of the device.

[0028] It should be noted that large-area perovskite solar cells are usually prepared in an open environment. When the humidity in the environment is high, the water molecules in the environment will react with the perovskite material to destroy the crystal structure. They will also react with the uncoordinated Pb²⁺ and halide vacancies (such as I⁻ vacancies) in the perovskite material to form surface and interface defects. In addition, they will also interfere with the nucleation and growth process of the perovskite crystal, resulting in a decrease in the photoelectric conversion efficiency of the device.

[0029] In an optional embodiment, the organic acid salt includes one or more of formates, acetates and propionates. Organic acid salts can change the hydrophilicity of the perovskite surface and the environment, and reduce water intrusion by forming a hydrophobic protective layer. Formate ions and acetate ions have good hydrophilicity, and can also combine with water molecules through hydrogen bonds, and are more likely to form hydrates, thereby reducing the impact of water molecules in the environment on the preparation of large-area perovskite solar cells, and the combination of acid ions and water molecules evaporates during the perovskite annealing process, and will not cause additional impact on the perovskite; propionate ions have a certain hydrophilicity. When the humidity in the environment is high (that is, when the water molecule content is high), the propionate ions can combine with water molecules, thereby reducing the impact of water molecules on the crystallization of perovskite.

[0030] In an optional embodiment, the formate salt includes one or more of lithium formate, sodium formate, potassium formate, rubidium formate, cesium formate, beryllium formate, magnesium formate, calcium formate, strontium formate, barium formate, europium formate and cerium formate.

[0031] In an optional embodiment, the acetate includes one or more of lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, beryllium acetate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, europium acetate, and cerium acetate.

[0032] In an optional embodiment, the propionate salt includes one or more of lithium propionate, sodium propionate, potassium propionate, rubidium propionate, cesium propionate, beryllium propionate, magnesium propionate, calcium propionate, strontium propionate, barium propionate, europium propionate, and cerium propionate.

[0033] In an optional embodiment, the organic acid salt includes one or more of sodium formate, potassium formate, rubidium formate, cesium formate, calcium formate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, and calcium acetate.

[0034] In this embodiment, the metal cations in the above organic acid salts can not only passivate the defects inside the perovskite, but also slow down the crystallization rate of the precursor by forming a complex with Pb²⁺ or Sn²⁺, thereby improving the grain size distribution of the perovskite film and forming more uniform crystals. Some metal cations (such as Ca²⁺, Mg²⁺) may be selectively adsorbed on the perovskite crystal plane, making the crystal more oriented and helping to improve the photoelectric performance.

[0035] In an optional embodiment, in the perovskite precursor solution, the concentration of the additive is 0.01-10 mg / ml, for example, the concentration of the additive is 0.01 mg / ml, 0.1 g / ml, 1 mg / ml, or 10 mg / ml.

[0036] In this embodiment, when the concentration of the additive is lower than 0.01 mg / ml, the additive cannot effectively interact with the surface or grain boundary of the perovskite material, and water molecules can still penetrate into the perovskite, resulting in film degradation or crystal phase change, and the metal cations in the additive do not react sufficiently with the perovskite lattice defects (such as ion vacancies or grain boundary defects), resulting in increased non-radiative recombination and decreased device performance. When the concentration of the additive is higher than 10 mg / ml, too much additive will excessively passivate the crystal surface, inhibiting the growth of the perovskite crystal, resulting in a perovskite film structure with a small grain size and more grain boundary defects, and the additive will form an overly thick organic layer at the perovskite grain boundary, increasing the resistance to charge transfer, thereby reducing the photoelectric performance of the device.

[0037] In some embodiments, the organic solvent includes one or more of DMF (N,N-dimethylformamide), DMSO (dimethyl sulfoxide), GBL (γ-butyrolactone) and NMP (N-methyl-2-pyrrolidone). The above four organic solvents all have good solubility for perovskite materials, among which DMF has a low boiling point and is easy to volatilize during the spin coating process, which helps to form a preliminary perovskite precursor film; DMSO has a high boiling point and a slow volatilization rate, which can delay the nucleation and growth process of the perovskite film, allowing the grains to have more time to grow and form larger grains, thereby reducing the defect density; GBL has a high boiling point and a slow volatilization rate. During the film formation process, GBL can delay the evaporation of the solvent, ensuring uniform growth of the film and larger grain size; NMP has a high boiling point, which can control the crystallization rate of the perovskite film during the deposition process, allowing larger grains to grow.

[0038] An embodiment of the present application may also provide a perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite light absorbing layer, and an electron transport layer stacked in a set direction; wherein the perovskite light absorbing layer is prepared from the perovskite precursor solution of any of the above embodiments.

[0039] In some embodiments, the perovskite solar cell may be a stacked solar cell, comprising: a substrate including a bottom cell unit and an intermediate composite layer, the bottom cell unit being connected to a hole transport layer through the intermediate composite layer; wherein the bottom cell unit is one of a crystalline silicon bottom cell unit, a CIGS cell, a CdTe cell, a Sb2S3 cell, and a Sb2Se3 cell. CIGS cells, CdTe cells, Sb2S3 cells, and Sb2Se3 cells are all different types of thin-film solar cells that convert solar photons into electrical energy using different materials and processes. CIGS cells have high efficiency and low cost, and perform well in low light intensity environments. CdTe cells have relatively low production costs, and have high photoelectric conversion efficiency and good stability. Sb2S3 cells are an emerging type of solar cell, however, their efficiency and stability are relatively low. Sb2Se3 cells have a higher absorption coefficient and better photoelectric properties.

[0040] The present application may also provide a method for preparing a perovskite solar cell, comprising the following steps: Step S1: providing a substrate; Step S2: forming a hole transport layer on the upper surface of the substrate; Step S3: placing a perovskite precursor solution as described in any of the above embodiments on the upper surface of the hole transport layer to form a perovskite light absorbing layer; Step S4: forming an electron transport layer on the upper surface of the perovskite light absorbing layer.

[0041] In actual implementation, the method for preparing a perovskite solar cell may include: Step S1a: providing a substrate, the substrate may include a bottom battery unit, the bottom battery unit is a crystalline silicon bottom battery unit, and an intermediate composite layer is formed on the upper surface of the bottom battery unit; Step S2a: forming a hole transport layer on the upper surface of the intermediate composite layer; Step S3a: placing a perovskite precursor solution as described in any of the above embodiments on the upper surface of the hole transport layer to form a perovskite light absorbing layer; Step S4a: forming a passivation layer on the upper surface of the perovskite light absorbing layer; Step S5a: forming an electron transport layer on the upper surface of the passivation layer; Step S6a: forming a hole blocking layer on the upper surface of the electron transport layer; Step S7a: forming a first electrode on the upper surface of the hole blocking layer.

[0042] In some embodiments, the substrate may include a bottom battery unit and an intermediate composite layer, wherein the intermediate composite layer is connected to the hole transport layer; the substrate may also be a conductive substrate, and the conductive substrate includes but is not limited to indium tin oxide (ITO) transparent conductive glass, fluorine-doped tin oxide (FTO) transparent conductive glass, tungsten-doped indium oxide (IWO) transparent conductive glass, and aluminum-doped zinc oxide (AZO) transparent conductive glass. The conductive substrate may be cleaned, laser etched, ultraviolet treated, and ozone treated. The step of cleaning the conductive substrate may include: placing the conductive substrate in an ultrasonic cleaning instrument, and ultrasonically cleaning it with deionized water, isopropanol, and ethanol, respectively, with the cleaning time of each link being 20-40 minutes (for example, 20 minutes, 30 minutes, and 40 minutes), and then drying with nitrogen after cleaning. The step of ultraviolet treating the conductive substrate may include: treating the conductive substrate with a UV-zone, wherein the treatment time is 20-40 minutes (for example, 20 minutes, 30 minutes, and 40 minutes). The step of ozone treating the conductive substrate may include: placing the conductive substrate in a reaction chamber of an ozone treatment device for treatment, ensuring that the surface of the substrate is exposed to ozone gas, and the treatment time is 5-10 minutes.

[0043] In some embodiments, the preparation material of the hole transport layer includes organic hole transport materials, inorganic hole transport materials, self-assembled monolayer materials (Self-Assembled Monolayer, referred to as SAM), etc., preferably SAM materials. The preparation materials of the hole transport layer include [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as 2PACZ), (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (abbreviated as MeO-2PACZ), (4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (abbreviated as Me-4PACZ), (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanotitanyl)phosphonic acid (abbreviated as MPA-CPA) and (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)yl)butyl)phosphonic acid (abbreviated as DMAcPA), PEDOT:PSS (poly 3,4-ethylenedioxythiophene:polystyrene sulfonate), NiO x and one or more of CuSCN, placing the hole transport layer solution on the upper surface of the conductive substrate, and then preparing the hole transport layer by solution spin coating. The spin coating speed is 5000~8000rpm (for example, 5000rpm / min, 6500rpm / min, 8000rpm / min), and the time is 40~60s (for example, 40s, 50s, 60s). Finally, an annealing treatment is performed to remove the solvent, and the temperature of the annealing treatment is 100°C and the time is 10min. The solvent used in the hole transport layer solution is one or both of ethanol and isopropanol.

[0044] In some embodiments, the perovskite precursor solution is coated on the surface of the hole transport layer by a one-step spin coating method or a slit coating method to obtain a perovskite light absorbing layer. The coating speed may be 4000-5000rpm / min (e.g., 4000rpm / min, 4500rpm / min, 5000rpm / min), and the coating time may be 30-40s (e.g., 30s, 35s, 40s). The perovskite light absorbing layer includes a perovskite material and an organic solvent, the perovskite material is an ABX3 structure; A is a monovalent cation; B is a divalent cation; X is a monovalent anion; wherein the concentration of B is 200mg / mL to 600mg / mL; wherein A includes one or more of methylamine, formamidine, acetamidine, cesium and rubidium; B also includes one or more of tin, copper and germanium; X includes F - ,I - Br - , Cl - , BF 4- PF 6- and SCN -One or more of; the organic solvent also includes one or more of acetonitrile (ACN), dimethylpyrrolidone (NMP) and 2-methoxyethanol.

[0045] In some embodiments, the preparation material of the electron transport layer includes PCBM ([6,6]-phenyl-C 71 -isomethyl butyrate), TiO2, SnO2, ZnO2, Al2O3, C 60 and ICBA (Indene-C 60 The electron transport layer can be prepared by spin coating, vacuum evaporation, magnetron sputtering, atomic layer deposition and the like. When the vacuum evaporation method is used, the evaporation rate is 0.2Å / s, the evaporation time is 1500s, and the evaporation thickness is 30nm.

[0046] In some embodiments, the hole blocking layer is prepared from materials including BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline), MoO x The buffer layer can be prepared by spin coating, vacuum evaporation, magnetron sputtering, atomic layer deposition and the like. When the vacuum evaporation method is used, the evaporation rate is 0.1Å / s, the evaporation time is 1500s, and the evaporation thickness is 15nm.

[0047] In some embodiments, the material of the electrode includes, but is not limited to, one or more of Au, Ag, Al, Cu, transparent conductive oxide (TCO), graphene, and nanocrystalline silicon. The electrode can be prepared by thermal evaporation, vacuum evaporation, sputtering, atomic layer deposition, 3D printing, screen printing, inkjet printing, etc. The thickness of the electrode can be 60-100 nm.

[0048] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0049] [Example 1] like Figure 1 As shown, the perovskite solar cell can be a perovskite tandem solar cell, and the substrate includes a bottom battery unit and an intermediate composite layer 1. The specific structure of the perovskite tandem solar cell includes a bottom battery unit, an intermediate composite layer 1 and a hole transport layer, a perovskite light absorption layer 4, a passivation layer 5, an electron transport layer 6, a hole blocking layer 7, and a first electrode 8 stacked from bottom to top; The bottom cell unit includes a second electrode 9, a transparent conductive layer 10, a first intrinsic amorphous silicon layer 11, a P-type non- / microcrystalline silicon layer 12, an N-type silicon wafer 13, a second intrinsic amorphous silicon layer 14, and an N-type non- / microcrystalline silicon layer 15, which are stacked in sequence from far away to close to the middle composite layer 1; The hole transport layer may be a composite layer, and the hole transport layer includes a first layer 2 and a second layer 3 which are stacked.

[0050] The specific preparation steps of perovskite solar cells are as follows: Step S1a: providing a substrate, the substrate may include a bottom battery unit, the bottom battery unit is a crystalline silicon bottom battery unit, and an intermediate composite layer 1 is formed on the upper surface of the bottom battery unit, the material of the intermediate composite layer 1 is ITO, and the thickness is 50nm; Step S2a: forming a first layer 2 with a thickness of 30 nm on the upper surface of the intermediate composite layer 1 by magnetron sputtering, wherein the material of the first layer 2 is nickel oxide; Step S3a: forming a second layer 3 with a thickness of 10 nm on the upper surface of the first layer 2 by a slit coating method, wherein the material of the second layer 3 is 2PACz; Step S4a: Perovskite material (Cs 0.05 FA 0.95 Pb(I 0.95 Br 0.05 )3) Dissolve in a mixed organic solvent with a volume ratio of DMF:DMSO=4:1, then add an additive with a concentration of 0.01 mg / ml, the additive is cesium formate, and stir at room temperature until it is completely dissolved to obtain a perovskite precursor solution; Under the condition of an ambient humidity of 20-30%, a perovskite precursor solution is coated on the upper surface of the second layer 3 by a slit coating method for annealing, the annealing temperature is 100° C., the annealing time is 20 min, and a perovskite light absorbing layer 4 with a thickness of 500 nm is formed; Step S5a: forming a passivation layer 5 with a thickness of 2 nm on the upper surface of the perovskite light absorbing layer 4 by a slit coating method, wherein the material of the passivation layer 5 is PDADI; Step S5a: forming an electron transport layer 6 with a thickness of 20 nm on the upper surface of the passivation layer 5 by thermal evaporation, wherein the material of the electron transport layer 6 is C 60 ; Step S6a: forming a hole blocking layer 7 with a thickness of 7 nm on the upper surface of the electron transport layer 6 by a thermal evaporation method, wherein the material of the hole blocking layer 7 is BCP; Step S7a: forming a first electrode 8 on the upper surface of the hole blocking layer 7 by a thermal evaporation method. The material of the first electrode 8 is Ag.

[0051] [Example 2]~[Example 14] The perovskite tandem solar cell of Example 2 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 2, the concentration of the additive cesium formate was 0.1 mg / ml.

[0052] The perovskite tandem solar cell of Example 3 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 3, the concentration of the additive cesium formate was 1 mg / ml.

[0053] The perovskite tandem solar cell of Example 4 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 4, the concentration of the additive cesium formate was 10 mg / ml.

[0054] The perovskite tandem solar cell of Example 5 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 5, the additive was sodium formate, and the concentration of sodium formate was 1 mg / ml.

[0055] The perovskite tandem solar cell of Example 6 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 6, the additive was potassium formate, and the concentration of potassium formate was 1 mg / ml.

[0056] The perovskite tandem solar cell of Example 7 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 7, the additive was rubidium formate, and the concentration of rubidium formate was 1 mg / ml.

[0057] The perovskite tandem solar cell of Example 8 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 8, the additive was rubidium acetate, and the concentration of rubidium acetate was 1 mg / ml.

[0058] The perovskite tandem solar cell of Example 9 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 9, the additive was calcium formate, and the concentration of calcium formate was 1 mg / ml.

[0059] The perovskite tandem solar cell of Example 10 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 10, the additive was europium formate, and the concentration of europium formate was 1 mg / ml.

[0060] The perovskite tandem solar cell of Example 11 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 11, the additive was europium acetate, and the concentration of europium acetate was 1 mg / ml.

[0061] The perovskite tandem solar cell of Example 12 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 12, the additive was barium acetate, and the concentration of barium acetate was 1 mg / ml.

[0062] The perovskite tandem solar cell of Example 13 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 13, the additives were cerium formate and cerium acetate, the concentration of cerium formate was 0.5 mg / ml, and the concentration of cerium acetate was 0.5 mg / ml.

[0063] The perovskite tandem solar cell of Example 14 was prepared by referring to the preparation method of Example 1, except that in step S4a of Example 14, the additive was sodium propionate, and the concentration of sodium propionate was 0.01 mg / ml.

[0064] [Comparative Example 1] The perovskite solar cell of Comparative Example 1 was prepared by referring to the preparation method of Example 1, except that, in step S4a of Comparative Example 1, no additive was added to the perovskite precursor solution, and the ambient humidity was 10-20%.

[0065] [Comparative Example 2] The perovskite solar cell of Comparative Example 2 was prepared by referring to the preparation method of Example 1, except that, in step S4a of Comparative Example 2, no additive was added to the perovskite precursor solution, and the ambient humidity was 20-30%.

[0066] The following is a performance test of the perovskite tandem photovoltaic cells provided in Examples 1-14 of the present application and Comparative Examples 1-2, so as to obtain the short-circuit current density Jsc, open-circuit voltage Voc, fill factor FF, and photoelectric conversion efficiency PCE of the corresponding cell devices. The test results are shown in Table 1.

[0067] Table 1 Performance test results of perovskite solar cells of Examples 1-14 and Comparative Examples 1-2

[0068] It can be seen from Table 1 in combination with Examples 1-14 and Comparative Examples 1-2 that additives are added in Examples 1-14, so that the efficiency of the device prepared is higher during the large-area preparation of perovskite solar cells; while no additives are added in Comparative Examples 1-2, and the preparation of large-area perovskite solar cells in an environment with high humidity is affected by water vapor in the environment, resulting in lower device efficiency; therefore, compared with Comparative Examples 1-2, the short-circuit current density Jsc, open-circuit voltage Voc, fill factor FF, and photoelectric conversion efficiency PCE of the perovskite solar cells prepared by adding additives in Examples 1-14 of the present application are significantly improved, indicating that the addition of additives in Examples 1-14 can, on the one hand, reduce the influence of water molecules in the environment on the perovskite film formation, and on the other hand, can passivate the defects inside the perovskite, thereby improving the performance of the perovskite solar cell.

[0069] The embodiment of the present application may also provide a photovoltaic module (not shown), wherein the photovoltaic module includes the perovskite solar cell as described above. The perovskite solar cell may be connected in series and / or in parallel with one or more other solar cells in a preset manner. Among them, a plurality of cells may form a cell string, and adjacent cells may be connected together by series welding.

[0070] The embodiment of the present application can provide a photovoltaic system, including the photovoltaic components in any of the above embodiments. The advantages of the above photovoltaic components are also possessed by the photovoltaic system, which will not be repeated here. The above photovoltaic system has a wide range of applications, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields where solar energy is required for power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components may form multiple photovoltaic arrays. The photovoltaic array is connected to a junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0071] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0072] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0073] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A perovskite precursor solution, characterized in that: include: Perovskite materials, additives and organic solvents; The additive includes an organic acid salt; Wherein, the perovskite material is an ABX3 structure, A is a monovalent cation; B is a divalent cation; and X is a monovalent anion.

2. The perovskite precursor solution according to claim 1, characterized in that The organic acid salt includes one or more of formates, acetates and propionates.

3. The perovskite precursor solution according to claim 2, characterized in that The formate includes one or more of lithium formate, sodium formate, potassium formate, rubidium formate, cesium formate, beryllium formate, magnesium formate, calcium formate, strontium formate, barium formate, europium formate and cerium formate.

4. The perovskite precursor solution according to claim 2, characterized in that: The acetate includes one or more of lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, beryllium acetate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, europium acetate and cerium acetate.

5. The perovskite precursor solution according to claim 2, characterized in that: The propionate salt includes one or more of lithium propionate, sodium propionate, potassium propionate, rubidium propionate, cesium propionate, beryllium propionate, magnesium propionate, calcium propionate, strontium propionate, barium propionate, europium propionate and cerium propionate.

6. The perovskite precursor solution according to claim 1, characterized in that: The organic acid salt includes one or more of sodium formate, potassium formate, rubidium formate, cesium formate, calcium formate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, and calcium acetate.

7. The perovskite precursor solution according to claim 1, characterized in that: In the perovskite precursor solution, the concentration of the additive is 0.01-10 mg / ml.

8. A perovskite solar cell, characterized in that: include: A substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer are stacked in sequence; Wherein, the perovskite light absorbing layer is prepared from the perovskite precursor solution according to any one of claims 1 to 7.

9. A method for preparing a perovskite solar cell, characterized in that: The steps include: providing a substrate; forming a hole transport layer on the upper surface of the substrate; Placing the perovskite precursor solution according to any one of claims 1 to 7 on the upper surface of the hole transport layer to form a perovskite light absorbing layer; An electron transport layer is formed on the perovskite light absorbing layer.

10. A photovoltaic module, characterized in that: include The perovskite solar cell according to claim 8; or A perovskite solar cell prepared by the method for preparing a perovskite solar cell as claimed in claim 9.

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