A perovskite passivation material, passivation layer and cell thereof

Abstract

The present application provides a kind of for perovskite absorption layer on the surface of passivation layer and its battery.The material of the passivation layer includes formula A compound.By using the formula A compound of the present application to prepare for perovskite absorption layer on the surface of passivation layer, it can more effectively solve perovskite interface charge recombination problem, improve the efficiency and stability of battery.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cells, and particularly to a perovskite passivation material, a passivation layer, and a cell thereof. Background Technology

[0002] Since perovskite solar cells first achieved a photoelectric conversion efficiency of 3.8% in 2009, perovskite materials have become a hot semiconductor material, with the highest photoelectric efficiency exceeding that of silicon cells, reaching 26.7%. However, the poor stability and short lifespan of perovskite solar cells have limited their commercial development.

[0003] In traditional perovskite thin film fabrication methods, solution-based perovskite films typically contain numerous grain boundary defects, allowing water and oxygen from the air to penetrate into the perovskite and cause its decomposition. Simultaneously, the unstable energy of these interface defects makes them susceptible to damage from external factors (such as light, electric fields, and heat), further accelerating perovskite decomposition. To improve stability, various strategies have been developed for perovskite defect passivation and ion migration suppression, such as perovskite composition engineering, antisolvent engineering, and additive engineering. However, unencapsulated perovskite solar cells still exhibit low stability and photoelectric conversion efficiency under high humidity and high temperature conditions. Therefore, designing a perovskite solar cell with good tolerance to high temperature and high humidity has become an urgent problem to be solved.

[0004] While existing technologies have addressed some of the problems of perovskite solar cells, several issues and drawbacks remain. First, current passivation layer materials may not effectively suppress interfacial charge recombination, leading to low cell efficiency. Second, existing passivation layer materials may negatively impact the stability of the perovskite, affecting the long-term performance of the cell. Furthermore, existing passivation layer fabrication methods are complex and costly, hindering large-scale production. Summary of the Invention

[0005] To overcome the limitations of existing passivation layer materials in effectively suppressing interfacial charge recombination, which negatively impacts perovskite stability and leads to low battery efficiency and poor stability, this invention provides a novel passivation layer for the surface of a perovskite absorber layer and its associated battery. By using compound A of this invention to prepare the passivation layer, the perovskite grain radius can be increased, effectively solving the perovskite interfacial charge recombination problem, improving the battery's carrier mobility and defect state density, and enhancing the extraction capability of photogenerated electrons, thereby improving the battery's efficiency and stability.

[0006] Specifically, the first aspect of the present invention provides a passivation layer for the surface of a perovskite absorber layer, the material of the passivation layer comprising a compound of formula A: ; Where L is selected from N + Five- or six-membered heteroaryl groups formed with carbon atoms, or N + (R1)(R2)(R3), wherein R1, R2, and R3 are each independently selected from substituted or unsubstituted C1-10 alkyl groups; Where n takes values ​​from 2 to 20.

[0007] In one or more schemes, n takes the value 3-10.

[0008] In one or more schemes, N + The five- or six-membered heteroaryl group formed with a carbon atom is a pyridyl group.

[0009] In one or more schemes, R1, R2, and R3 are each independently selected from substituted or unsubstituted C1-4 alkyl groups.

[0010] In one or more embodiments, the substituted C1-4 alkyl group is a halo-C1-4 alkyl group.

[0011] In one or more embodiments, the halogenated C1-4 alkyl group is a C1-4 alkyl group with 1-10 or 1-5 halogen substitutions.

[0012] In one or more embodiments, the compound of formula A is selected from compounds of formulas (1) to (4): ; ; ; .

[0013] A second aspect of the present invention provides a method for preparing a passivation layer as described in any embodiment herein or for improving the crystallinity of perovskites and their ability to extract photogenerated electrons, the method comprising the following steps: A passivation layer solution is coated onto the surface of a perovskite absorber layer, and after annealing, the passivation layer is obtained; wherein the passivation layer solution contains a solvent and a compound of formula A as described in any embodiment herein.

[0014] In one or more embodiments, the coating method includes one or more processes selected from spin coating, blade coating, vapor deposition, printing, spraying, spray pyrolysis, and slot coating.

[0015] In one or more embodiments, the mass concentration of compound A in the passivation layer solution is 0.1 mg / ml to 5 mg / ml.

[0016] In one or more embodiments, the solvent is selected from one or more of isopropanol, ethanol, and methanol.

[0017] In one or more of these schemes, the annealing temperature is 50-300℃ and the annealing time is 5-30 min.

[0018] A third aspect of the present invention provides a perovskite solar cell, the perovskite solar cell comprising a conductive glass layer, a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer and an electrode stacked thereon, wherein the material of the passivation layer is selected from compound of formula A as described in any embodiment herein, and optionally, a hole blocking layer is further provided between the electron transport layer and the electrode.

[0019] In one or more embodiments, the material of the electron transport layer is selected from at least one of [6,6]-phenyl-C61-butyrate, C60, and tin oxide.

[0020] In one or more embodiments, the material of the perovskite light-absorbing layer comprises a first perovskite material and a second perovskite material; wherein the first perovskite material is selected from at least one of lead halide salts and tin halide salts, and the second perovskite material is selected from at least one of formamidinium halide salts, methylamine halide salts, and cesium halide salts.

[0021] In one or more embodiments, the material of the hole-blocking layer is selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or zirconium acetylacetonate.

[0022] In one or more embodiments, the material of the electrode is selected from at least one of silver, copper, conductive oxide, and carbon electrodes.

[0023] A fourth aspect of the present invention provides the application of compounds of formula A as described in any embodiment herein in passivating surface and grain boundary defects of perovskite films and / or improving the interfacial contact between the electron transport layer and the perovskite, thereby enhancing the ability to extract photogenerated electrons.

[0024] The fifth aspect of the present invention provides the use of compound of formula A as described in any embodiment herein in the preparation of passivation layers or perovskite solar cells.

[0025] The beneficial effects of this invention are: ① This invention uses a zwitterionic polymer compound A as the passivation layer material for the perovskite absorber layer. This effectively passivates the perovskite surface and suppresses charge recombination at the interface between the perovskite and the electron transport layer, thereby improving the efficiency of perovskite photovoltaic devices. Compared to existing technologies, the perovskite passivation material of this invention can more effectively solve the problem of interfacial charge recombination in the perovskite absorber layer, improving the photoelectric conversion efficiency of the battery.

[0026] ② The zwitterionic polymer material of the present invention, compound A, has a relatively small impact on the stability of perovskite, which is beneficial for maintaining the long-term performance of the battery. Compared with the prior art, the passivation layer material of the present invention can avoid negatively affecting the stability of perovskite and ensure the long-term performance of the battery.

[0027] ③ Compared with the prior art, the passivation layer preparation method of the present invention is simpler, lower in cost, more suitable for large-scale production, and has higher practical value. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the device structure of the perovskite solar cell of the present invention.

[0029] Figure 2 This is an SEM image of the passivation layer obtained in Example 1.

[0030] Figure 3 This is an SEM image of the passivation layer obtained in Example 2.

[0031] Figure 4 This is a SEM image of the passivation layer obtained in Example 3.

[0032] Figure 5 This is an SEM image of the passivation layer obtained in Example 6.

[0033] Figure 6 This is a SEM image of the passivation layer prepared in Comparative Example 1. Detailed Implementation

[0034] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0035] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0036] In this document, the terms “contains,” “includes,” “containing,” and similar terms encompass the meanings of “basically composed of” and “composed of.” For example, when this document discloses “A contains B and C,” “A is basically composed of B and C” and “A is composed of B and C” should be considered as having been disclosed in this document.

[0037] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0038] Unless otherwise specified, percentages refer to mass percentages and proportions refer to mass ratios in this article.

[0039] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the invention to those embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein are covered within the scope defined by the claims.

[0040] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0041] The main objective of this invention is to provide an application of zwitterionic passivating compound A in the passivation of perovskite materials, particularly in the perovskite absorber layer of perovskite solar cells. This invention induces recrystallization of perovskite grains by introducing a passivation layer made of zwitterionic passivating compound A onto the perovskite surface, reducing grain boundaries and passivating surface and grain boundary defects in the perovskite film. Simultaneously, it improves the interfacial contact between the electron transport layer and the perovskite, enhancing the ability to extract photogenerated electrons.

[0042] In some implementation schemes, such as Figure 1 As shown, a perovskite solar cell, from bottom to top, includes a conductive glass layer, a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer, and electrodes.

[0043] Therefore, the present invention provides a passivation layer for the surface of a perovskite absorber layer, comprising a compound of formula A: ; Where L is selected from N + Five- or six-membered heteroaryl groups formed with carbon atoms, or N + (R1)(R2)(R3), wherein R1, R2, and R3 are each independently selected from substituted or unsubstituted C1-10 alkyl groups; n takes the value of 2-20.

[0044] In some implementations, n takes the value 3-10, such as 4-5 or 6-10.

[0045] In some embodiments, R1, R2, and R3 are each independently selected from substituted or unsubstituted C1-4 alkyl groups.

[0046] In some embodiments, the substituted C1-4 alkyl group is a halo-C1-4 alkyl group.

[0047] In some embodiments, the halogenated C1-4 alkyl group is a C1-4 alkyl group with 1-10 or 1-5 halogen substitutions.

[0048] In some specific embodiments, compound A is selected from one or more compounds of formulas (1) to (4): ; ; ; .

[0049] In some embodiments, the compound of formula A is selected from the compounds of formula I, formula II, formula III, or formula IV.

[0050] The passivation layer of this invention can be prepared using a solution method.

[0051] In some embodiments, the present invention provides a method for preparing a passivation layer, comprising: mixing a compound of formula A with a solvent to obtain a passivation layer solution; coating the passivation layer solution onto the surface of a perovskite absorber layer; and annealing to obtain a passivation layer.

[0052] In some embodiments, the compound of formula A and a solvent can be mixed and stirred at room temperature to obtain a passivation layer solution. The type of solvent is not particularly limited and can be selected from organic solvents conventionally used in the art, such as one or more selected from isopropanol, ethanol, and methanol.

[0053] In some implementations, the mass concentration of compound A in the passivation layer solution is 0.1 mg / ml to 5 mg / ml.

[0054] In some embodiments, the compound of formula A is selected from one or more compounds of formulas (1) to (4).

[0055] In some embodiments of this invention, a spin-coating process is used to coat the passivation layer solution onto the surface of the perovskite absorber layer. The coating thickness of the passivation layer solution on the perovskite absorber layer surface can be adjusted according to the target thickness of the passivation layer. In the spin-coating process, the spin-coating rate can be 4500-5000 rpm, and the spin-coating time can be 30-40 s.

[0056] In this invention, the coating method may also include one or more processes such as slot coating, blade coating, spray coating, screen printing, and inkjet printing. The parameters of these processes can be adjusted according to the target thickness of the passivation layer.

[0057] After coating, the coating is annealed. The purpose of annealing is to remove the solvent. The annealing temperature is 50-300°C. An exemplary annealing time can be 5-30 minutes.

[0058] In some implementations, the passivation layer has a thickness of 1-10 nm.

[0059] The present invention also provides a perovskite solar cell comprising a perovskite absorber layer and a passivation layer as described herein disposed on the surface of the perovskite absorber layer.

[0060] This invention also provides a method for fabricating a perovskite solar cell, comprising the steps of sequentially depositing a hole transport layer, a perovskite light-absorbing layer, a passivation layer, an electron transport layer, and an electrode on a conductive transparent glass layer, wherein the passivation layer can be fabricated using the steps described herein. In some embodiments, the method further includes the step of depositing a hole blocking layer between the electron transport layer and the electrode.

[0061] Therefore, the perovskite solar cell of the present invention may include a conductive glass layer, a hole transport layer, a perovskite light-absorbing layer, a passivation layer as described herein, an electron transport layer, and an electrode stacked together. Optionally, a hole blocking layer is further provided between the electron transport layer and the electrode.

[0062] The conductive materials suitable for the conductive glass layer of this invention include, but are not limited to, one or more of FTO, ITO, and IZO. The preparation of the conductive glass layer is not particularly limited; conventional methods for preparing conductive glass layers in the art can be used, such as magnetron sputtering. Process parameters can be adjusted according to the target thickness of the conductive layer.

[0063] Materials suitable for the hole transport layer of this invention include, but are not limited to, NiOx, SAM (self-assembled monolayer material), etc. The type of SAM material is not particularly limited, and includes, but is not limited to, carbazole phosphonic acid. The preparation of the hole transport layer is not particularly limited; conventional methods for preparing hole transport layers in the art can be used, such as spin coating, blade coating, or slot coating processes. Process parameters can be adjusted according to the target thickness of the hole transport layer. In some embodiments, the thickness of the hole transport layer is 2-5 nm.

[0064] The active material of the perovskite active layer applicable to this invention comprises a first perovskite material and a second perovskite material; wherein the first perovskite material is selected from at least one of lead halide salts and tin halide salts, and the second perovskite material is selected from at least one of formamidinium halide salts, methylamine halide salts, and cesium halide salts. In some embodiments, the material of the perovskite absorber layer is lead iodide and methyl iodoamine. The preparation of the perovskite active layer is not particularly limited, and conventional methods for preparing perovskite active layers in the art can be used, including but not limited to one or more of spin coating, blade coating, vapor deposition, printing, spraying, spray pyrolysis, and slot coating. Process parameters can be adjusted according to the target thickness of the perovskite absorber layer. In some embodiments, the thickness of the perovskite absorber layer is 450 nm-550 nm.

[0065] Materials suitable for the electron transport layer of this invention include, but are not limited to, one or more of [6,6]-phenyl-C61-butyrate, C60, and tin oxide. The preparation of the electron transport layer is not particularly limited, and conventional methods in the art can be used, including, but not limited to, spin coating, spray coating, spray pyrolysis, slot coating, and atomic layer deposition. Process parameters can be adjusted according to the target thickness of the electron transport layer. In some embodiments, the thickness of the electron transport layer is 10 nm-100 nm, such as 20-40 nm.

[0066] Materials suitable for the hole-blocking layer of this invention include, but are not limited to, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and zirconium acetylacetonate. The preparation of the hole-blocking layer is not particularly limited, and conventional methods in the art can be used, including, but not limited to, one or more of spin coating, spraying, spray pyrolysis, slot coating, and atomic layer deposition. Process parameters can be adjusted according to the target thickness of the hole-blocking layer. In some embodiments, the thickness of the hole-blocking layer is 1 nm-10 nm, such as 5-8 nm.

[0067] The electrode material suitable for this invention can be selected from one or more of silver, copper, conductive oxides, and carbon electrodes. In some embodiments, the electrode thickness is 90 nm-400 nm, such as 80-150 nm.

[0068] The present invention will be described below by way of specific embodiments. It should be understood that these embodiments are merely illustrative and are not intended to limit the scope of the invention. The methods, reagents, and materials used in the embodiments are conventional methods, reagents, and materials in the art, unless otherwise stated. The raw material compounds in the embodiments are all commercially available.

[0069] Example 1

[0070] 1. The TCO conductive glass was ultrasonically cleaned with deionized water, acetone and isopropanol for 15 min each, and then dried in a drying oven at 75℃ for later use. The dried TCO glass substrate was then treated in an ultraviolet ozone machine for 5 min to remove organic impurities on its surface and optimize its surface wettability. 2. Dissolve 1 mg of 2PACz in 2 mL of chlorobenzene and stir at room temperature until completely dissolved to obtain an organic hole transport material solution; 3. Take 30 μL of organic hole transport material solution, drop it onto the treated TCO glass, spin coat it at 5000 rpm for 30 s, place it on a hot plate and heat it at 100℃ for annealing for 10 min to form a hole transport layer. 4. Dissolve 722.08 mg lead iodide and 238.50 mg methyl iodide solid in 1 mL of N,N-dimethylformamide (DMF) and stir at room temperature until completely dissolved to obtain a perovskite precursor solution. In a nitrogen glove box, take 30 μL of the perovskite precursor solution and drop it onto the ITO conductive glass to form the hole transport layer. First, spin coat at 1000 rpm for 10 s, then spin coat at 5000 rpm for 30 s. During this process, add 125 μL of chlorobenzene rapidly at 25 s. Then, place the TCO glass on a hot stage and heat it at 100 °C for annealing for 40 min to form a 500 nm perovskite light-absorbing layer. 6. Dissolve 2.0 mg of compound SAS (of formula I, where n is 4) in 1 mL of isopropanol and stir at room temperature to obtain the passivation layer solution. 7. Add 75 μL of passivation layer solution dropwise onto the perovskite layer, spin coat at 5000 rpm for 35 s, and anneal at 100°C for 10 min to form the passivation layer; 8. Dissolve 20 mg of methane fullerene phenyl-C61-butyrate methyl ester (PCBM) in 1 mL of chlorobenzene and stir at room temperature to obtain a [6,6]-phenyl-C61-butyrate methyl ester solution; 9. Take 30 μL of methyl [6,6]-phenyl-C61-butyrate solution and drop it onto ITO conductive glass with a passivation layer formed on it. Spin coat it at 3000 rpm for 60 s to form an electron transport layer. 10. Transfer the TCO conductive glass with the electron transport layer, passivation layer, perovskite layer, and hole transport layer formed thereon into a vacuum coating instrument, and wait for the vacuum level to reach 3. 10 -4 A silver electrode is deposited by vapor deposition at Pa to form a silver electrode with a thickness of 100 nm, thus obtaining the electrode layer.

[0071] Example 2

[0072] The only difference between Example 2 and Example 1 is that the compound of Formula I is replaced with the compound of Formula II, Et SAS (where n is 5).

[0073] Example 3

[0074] The only difference between Example 3 and Example 1 is that the compound of Formula I is replaced with the compound of Formula III, Pr SAS (where n is 4).

[0075] Example 4

[0076] The only difference between Example 4 and Example 1 is that the compound of Formula I is replaced with compound of Formula IV, Py SAS (where n is 4).

[0077] Example 5

[0078] The only difference between Example 5 and Example 1 is that n is 10 in the compound of Formula I.

[0079] Comparative Example 1

[0080] The only difference between Example 4 and Example 1 is that no perovskite cell passivation layer is prepared.

[0081] Test Example 1

[0082] Photoelectric testing was performed on the perovskite solar cells prepared in Examples 1-4 and Comparative Examples 1-2. The test temperature was 25 ± 1 °C. The current density-voltage (JV) curves of the devices were obtained using a source meter (Keithley 2400) on an ABET Sun 3000 solar simulator at AM1.5G (100 mW / cm²). 2 The battery area was obtained under illumination and is 0.04907 cm². 2 Before testing, the light intensity was calibrated using a standard silicon cell, and the scan rate was 10mV / s.

[0083] Open-circuit voltage is the terminal voltage of the cell in an open-circuit state. Short-circuit current is the current density that the perovskite solar cell can generate under short-circuit conditions. Fill factor is the ratio of the maximum power of the solar cell to the product of the open-circuit voltage and the short-circuit current. Photovoltaic conversion efficiency can be calculated by measuring the current density-voltage (JV) curves of the solar cell.

[0084] The results are shown in Table 1 below.

[0085] Table 1. Photoelectric test results

[0086] As shown in Table 1, compared with Comparative Example 1, Examples 1-5, using Compound A of the present invention to prepare the passivation layer, can improve the photoelectric conversion efficiency and fill factor of the device. Among them, Example 5 has a certain passivation effect, but the improvement effect is not as good as that of Examples 1-4. This is because when the polymerization rate is too high, the solubility decreases, and the passivation layer film formation effect is relatively worse than that of Examples 1-4, but better than that of the comparative example.

[0087] Test Example 2

[0088] The passivation layers obtained in Examples 1-4 and Comparative Example 1 were observed using an electron microscope, and images were obtained. Figure 2 This is an SEM image of the passivation layer obtained in Example 1. Figure 3 This is an SEM image of the passivation layer obtained in Example 2. Figure 4 This is an SEM image of the passivation layer obtained in Example 3. Figure 5 This is an SEM image of the passivation layer obtained in Example 6. Figure 6 This is a SEM image of the passivation layer prepared in Comparative Example 1.

[0089] Table 1 below shows the maximum grain radius data of the passivation layers in Examples 1-4 and Comparative Example 1.

[0090] Table 1. Maximum grain radius data

[0091] As can be seen from the SEM images of Examples 1-4 and Comparative Example 1 and Table 1, compared with Comparative Example 1, the passivation layer of Examples 1-4 significantly increased the perovskite grain radius and reduced the grain boundaries in the film.

[0092] Test Example 3

[0093] The carrier mobility and defect state density of the perovskite solar cells prepared in Examples 1-4 and Comparative Example 1 were measured.

[0094] Carrier mobility: The pure electronic device model used for SCLC (space charge confined current) mobility testing is ITO / TiO2 / PVK / SAS / PCBM / Ag. The mobility is determined through the SCLC model, and the calculation formula for this model is: J=(8 / 9) µ 0 r ( V 2 / L 3 ); in 0 is the permittivity of free space (8.85 × 10⁻⁶). -12 F m -1 ), r is the dielectric constant of the PCBM (assumed to be 3), μ is the electron mobility, V is the voltage, and L is the film thickness (250 nm). All current-voltage (IV) characteristics of the field-effect transistor (FET) were measured using a Keithley 4200 semiconductor characterization system connected to a probe station in an N2-filled chamber.

[0095] Defect state density test: Trap defect state density (N) t The trap fills the limiting voltage ( V TFL )Decide:

[0096] Where L is the thickness of the perovskite film. V TFL It is the starting voltage of the trap-filling limit region. r It is the relative permittivity of the perovskite thin film. 0 is the vacuum permittivity, and q is the electron charge. V TFL These parameters are obtained from SCLC testing; the remaining parameters are constants.

[0097] The measurement results are shown in Table 2.

[0098] Table 2. Carrier mobility and defect state density data

[0099] As shown in Table 2 above, compared with Comparative Example 1, Examples 1-4 showed increased mobility and decreased defect state density, both indicating enhanced extraction capability of photogenerated carriers and reduced generation of nonradiative recombination.

Claims

1. A method for preparing a passivation layer for use on the surface of a perovskite absorber layer, characterized in that, The method includes the following steps: coating a passivation layer solution onto the surface of a perovskite absorber layer, and annealing to obtain the passivation layer; The passivation layer solution contains a solvent and a compound represented by formula A: ； Where L is selected from N + Five- or six-membered heteroaryl groups or N-membered groups formed with carbon atoms + (R1)(R2)(R3), wherein R1, R2, and R3 are each independently selected from unsubstituted C1-10 alkyl groups; The value of n ranges from 2 to 10; In the passivation layer solution, the mass concentration of compound A is 0.1 mg / ml to 5 mg / ml.

2. The method as described in claim 1, characterized in that, In formula A, n takes values ​​from 3 to 10.

3. The method as described in claim 1, characterized in that, In formula A, R1, R2, and R3 are each independently selected from unsubstituted C1-4 alkyl groups.

4. The method as described in claim 1, characterized in that, The compound of formula A is selected from compounds of formulas (I) to (IV): ; ; ; 。 5. The method as described in claim 1, characterized in that, The coating method includes one or more processes such as spin coating, blade coating, vapor deposition, printing, spraying, spray pyrolysis, and slot coating.

6. The method as described in claim 1, characterized in that, The solvent is selected from one or more of isopropanol, ethanol, and methanol.

7. The method as described in claim 1, characterized in that, The annealing temperature is 50-300℃, and the annealing time is 5-30 minutes.

8. The method as described in claim 1, characterized in that, The perovskite absorber layer comprises a first perovskite material and a second perovskite material; wherein the first perovskite material is selected from at least one of lead halide salts and tin halide salts, and the second perovskite material is selected from at least one of formamidinium halide salts, methylamine halide salts, and cesium halide salts.

9. The method as described in claim 8, characterized in that, The materials of the perovskite absorber layer are lead iodide and methyl iodide.

10. The method as described in claim 1, characterized in that, The thickness of the passivation layer is 1-10 nm.

11. A perovskite solar cell, said perovskite solar cell comprising a conductive glass layer, a hole transport layer, a perovskite absorber layer, a passivation layer, an electron transport layer, and electrodes stacked together, characterized in that, The material of the passivation layer is selected from the compound shown in Formula A: ； Where L is selected from N + Five- or six-membered heteroaryl groups or N-membered groups formed with carbon atoms + (R1)(R2)(R3), wherein R1, R2, and R3 are each independently selected from unsubstituted C1-10 alkyl groups; The value of n is 2-10.

12. The perovskite solar cell according to claim 11, characterized in that, In formula A, n takes values ​​from 3 to 10.

13. The perovskite solar cell according to claim 11, characterized in that, In formula A, R1, R2, and R3 are each independently selected from unsubstituted C1-4 alkyl groups.

14. The perovskite solar cell as claimed in claim 11, characterized in that, The compound of formula A is selected from compounds of formulas (I) to (IV): ; ; ; 。 15. The perovskite solar cell as claimed in claim 11, characterized in that, A hole-blocking layer is also provided between the electron transport layer and the electrode.

16. The perovskite solar cell as described in claim 15, characterized in that: The material of the electron transport layer is selected from at least one of [6,6]-phenyl-C61-butyrate methyl ester, C60, and tin oxide; The perovskite absorber layer comprises a first perovskite material and a second perovskite material; wherein the first perovskite material is selected from at least one of lead halide salts and tin halide salts, and the second perovskite material is selected from at least one of formamidinium halide salts, methylamine halide salts and cesium halide salts; The hole-blocking layer is made of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or zirconium acetylacetonate. The electrode material is selected from at least one of silver, copper, conductive oxide and carbon electrodes.

17. The application of the compound shown in Formula A in passivating surface and grain boundary defects of perovskite films and / or improving the interfacial contact between the electron transport layer and the perovskite, thereby enhancing the ability to extract photogenerated electrons: ； in, L is selected from N + Five- or six-membered heteroaryl groups or N-membered groups formed with carbon atoms + (R1)(R2)(R3), wherein R1, R2, and R3 are each independently selected from unsubstituted C1-10 alkyl groups; The value of n is 2-10.

18. The application as described in claim 17, characterized in that, In formula A, n takes values ​​from 3 to 10.

19. The application as described in claim 17, characterized in that, In formula A, R1, R2, and R3 are each independently selected from unsubstituted C1-4 alkyl groups.

20. The application as described in claim 17, characterized in that, The compound of formula A is selected from compounds of formulas (I) to (IV): ; ; ; 。 21. The application of the compound shown in formula A in the preparation of passivation layers or perovskite solar cells: ； in, L is selected from N + Five- or six-membered heteroaryl groups or N-membered groups formed with carbon atoms + (R1)(R2)(R3), wherein R1, R2, and R3 are each independently selected from unsubstituted C1-10 alkyl groups; The value of n is 2-10.

22. The application as described in claim 21, characterized in that, In formula A, n takes values ​​from 3 to 10.

23. The application as described in claim 21, characterized in that, In formula A, R1, R2, and R3 are each independently selected from unsubstituted C1-4 alkyl groups.

24. The application as described in claim 21, characterized in that, The compound of formula A is selected from compounds of formulas (I) to (IV): ; ; ; 。

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