Perovskite solar cell preparation method based on passivation additive and perovskite solar cell

Abstract

The invention provides a passivation additive-based perovskite solar cell preparation method and a perovskite solar cell. The preparation method comprises the following steps: forming the hole transport layer on the surface of one side of the conductive substrate layer; coating a perovskite precursor solution containing N-(2-aminoethyl) maleimide trifluoroacetate and / or 1-(2-aminoethyl) maleimide hydrochloride on the surface of one side, far away from the conductive substrate layer, of the hole transport layer, and forming a perovskite light absorption layer on the surface of the hole transport layer; and sequentially preparing an electron transport layer and a metal electrode layer on the surface of one side, far away from the hole transport layer, of the perovskite light absorption layer to obtain the perovskite solar cell. The passivation additive is added into the perovskite precursor solution, a five-membered ring structure of a maleimide group with a substituent group in the structure of the passivation additive has a certain steric hindrance effect, a strain adjusting effect is achieved, deformation of a perovskite crystal structure is inhibited, and therefore the quality of the thin film is improved.

Description

Technical Field

[0001] The present invention relates to the field of perovskite solar cells, and in particular to a method for preparing a perovskite solar cell based on a passivation additive and a perovskite solar cell. Background Art

[0002] As a new type of high-efficiency solar cell, the photoelectric conversion efficiency of perovskite solar cells has been significantly improved in recent years. Among the solar cell module materials, halide perovskite materials have attracted extensive attention at home and abroad due to their excellent optical properties and low-cost preparation process.

[0003] At present, the average photoelectric conversion efficiency of perovskite solar cells still needs to be improved, and the efficiency stability is poor. The main reason is that the grain boundaries, domain boundaries, defects, etc. in the perovskite light-absorbing layer will cause interlayer interface charge recombination, resulting in reduced photoelectric conversion efficiency and stability. In particular, perovskite films prepared based on the solution method still have a high degree of defect states, which is an important reason for limiting the further improvement of its efficiency and stability. Therefore, improving the quality of perovskite films and reducing the density of film defect states are very important for obtaining efficient and stable perovskite solar cells.

[0004] Therefore, how to provide a method for preparing a solar cell with high photoelectric conversion efficiency based on an additive that can passivate defects is one of the important technical problems that need to be solved in this field. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for preparing a perovskite solar cell based on a passivation additive and a perovskite solar cell, so as to solve the problem of low photoelectric conversion efficiency of perovskite solar cells in the prior art.

[0006] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a method for preparing a perovskite solar cell based on a passivation additive, comprising: step S1, providing a conductive substrate layer, and forming a hole transport layer on one side surface of the conductive substrate layer; step S2, preparing a perovskite precursor solution containing a passivation additive; step S3, coating the perovskite precursor solution on the side surface of the hole transport layer away from the conductive substrate layer, and after heat treatment, forming a perovskite light absorption layer on the surface of the hole transport layer; step S4, sequentially preparing an electron transport layer and a metal electrode layer on the side surface of the perovskite light absorption layer away from the hole transport layer to obtain a perovskite solar cell; wherein the passivation additive is N-(2-aminoethyl)maleimide trifluoroacetate and / or 1-(2-aminoethyl)maleimide hydrochloride.

[0007] Furthermore, the passivation additive is a mixture of N-(2-aminoethyl)maleimide trifluoroacetate and 1-(2-aminoethyl)maleimide hydrochloride in a molar ratio of (1.8-2.0):1.

[0008] Furthermore, the crystal structure of perovskite in the perovskite light absorbing layer is ABX3, where A + Including MA + , FA + and Cs + , B 2+ Pb 2+ , X － Selected from I － Br － and Cl － One or more of; Preferably, the crystal structure formula of the perovskite in the perovskite light absorbing layer is (FA 0.95 MA 0.05 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3.

[0009] Further, step S2 comprises: dissolving a perovskite precursor source and a passivation additive in an organic solvent at a molar ratio of 100:(1-10) to obtain a perovskite precursor solution; preferably, in the perovskite precursor solution, the molar concentration of the perovskite precursor source is 0.5 mol / L-2.0 mol / L, more preferably 1.5 mol / L-2.0 mol / L.

[0010] Furthermore, the organic solvent is selected from one or more of DMF, DMSO and PC; preferably, the organic solvent is a mixed solvent formed by DMF and DMSO in a volume ratio of (1-4):1; more preferably, the organic solvent is a mixed solvent formed by DMF, DMSO and PC in a volume ratio of (3-4):1:(0.1-0.5).

[0011] Further, in step S3, the temperature of the heat treatment is 100°C to 200°C, and the time is 5 min to 60 min; preferably, the temperature of the heat treatment is 100°C to 150°C, and the time is 25 min to 30 min.

[0012] Furthermore, in step S1, the hole transport layer is selected from NiO x The hole transport layer is formed by one of a Me-4PACz layer, a MeO-4PACz layer and a 4PADCB layer, and the hole transport layer is formed by a method selected from a magnetron sputtering method, a spin coating method and a blade coating method, preferably a spin coating method.

[0013] Further, in step S4, the electron transport layer is selected from a TiO2 layer, a SnO2 layer, a PCBM layer and a C 60 and / or the metal electrode layer is selected from one or more of a gold electrode layer, a silver electrode layer and a copper electrode layer; preferably, the electron transport layer and the metal electrode layer are formed by each independently selected from one of vacuum evaporation, magnetron sputtering, atomic layer deposition, spin coating, blade coating and chemical bath deposition.

[0014] A second aspect of the present invention provides a perovskite solar cell, which is prepared by the above-mentioned perovskite solar cell preparation method based on passivation additives, and the perovskite solar cell includes a conductive substrate layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer and a metal electrode layer stacked in sequence.

[0015] Furthermore, the thickness of the hole transport layer is 10nm to 40nm; and / or the thickness of the perovskite light absorption layer is 200nm to 600nm; and / or the thickness of the electron transport layer is 20nm to 50nm; and / or the thickness of the metal electrode layer is 50nm to 150nm; preferably, the conductive substrate layer is a FTO glass sheet or an ITO glass sheet.

[0016] By applying the technical solution of the present invention, by adding an additive as a passivation defect in the perovskite precursor solution, namely N-(2-aminoethyl)maleimide trifluoroacetate and / or 1-(2-aminoethyl)maleimide hydrochloride, the maleimide group with an amino substituent can passivate the defects in the perovskite lattice due to Pb by coordination. 2+ The defects caused by insufficient coordination and positively charged defect sites enhance the crystallinity of the perovskite film and reduce its defect density. At the same time, the five-membered ring structure of the maleimide group has a certain steric hindrance, plays a strain regulation role, suppresses the deformation of the perovskite crystal structure, and improves the quality of the film. The amino and / or carboxyl groups in its structure can interact with the perovskite to passivate the defects therein. At the same time, the interaction between the perovskite and the passivation additive can further achieve grain boundary stitching, further passivate grain boundary defects, thereby significantly improving the crystallization quality and stability of the perovskite film, and improving the photoelectric conversion efficiency and working life of the perovskite solar cell. In addition, the method is simple in process, can effectively improve the photoelectric performance of perovskite photovoltaic materials, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1The photoelectric conversion efficiency test result curve of the perovskite solar cell obtained in Example 1;

[0019] Figure 2 The photoelectric conversion efficiency test result curve of the perovskite solar cell obtained in Example 4;

[0020] Figure 3 This is a curve showing the photoelectric conversion efficiency test results of the perovskite solar cell obtained in Comparative Example 1. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0022] As described in the background technology, the perovskite solar cell in the prior art has the problem of low photoelectric conversion efficiency. In order to solve the above technical problems, the first aspect of the present invention provides a method for preparing a perovskite solar cell based on a passivation additive, comprising: step S1, providing a conductive substrate layer, and forming a hole transport layer on one side surface of the conductive substrate layer; step S2, preparing a perovskite precursor solution containing a passivation additive; step S3, coating the perovskite precursor solution on the side surface of the hole transport layer away from the conductive substrate layer, and after heat treatment, forming a perovskite light absorption layer on the surface of the hole transport layer; step S4, sequentially preparing an electron transport layer and a metal electrode layer on the side surface of the perovskite light absorption layer away from the hole transport layer to obtain a perovskite solar cell; wherein the passivation additive is N-(2-aminoethyl) maleimide trifluoroacetate and / or 1-(2-aminoethyl) maleimide hydrochloride.

[0023] In the preparation method provided by the present invention, N-(2-aminoethyl)maleimide trifluoroacetate and / or 1-(2-aminoethyl)maleimide hydrochloride are added to the perovskite precursor solution as additives for passivating defects. The amino and / or carboxyl groups in the structure can react with the perovskite to passivate the defects. Specifically, the maleimide group with an amino substituent can passivate the defects in the perovskite lattice due to Pb by coordination. 2+ The defects caused by insufficient coordination and positively charged defect sites enhance the crystallinity of the perovskite film and reduce its defect density. At the same time, the five-membered ring structure of the maleimide group has a certain steric hindrance, plays a strain regulation role, inhibits the deformation of the perovskite crystal structure, and thus improves the quality of the film. In addition, the amino group can neutralize the positive charge generated by defects in the perovskite material, such as halide vacancies (I － Br －The capture of carriers by defects is reduced by balancing the charge. For trifluoroacetate, it has strong electron affinity and coordination ability, and can form stable chemical bonds with unpaired metal ions or positively charged defect sites on the surface of perovskite materials, thereby sealing defects and reducing non-radiative recombination paths of carriers, thereby reducing defect density and improving material quality. In addition, the highly electronegative F atoms in N-(2-aminoethyl)maleimide trifluoroacetate can adjust the electronic structure of perovskite materials, help optimize the band structure of perovskites, and improve light absorption efficiency and carrier transport performance.

[0024] In particular, the N-(2-aminoethyl) maleimide trifluoroacetate and / or 1-(2-aminoethyl) maleimide hydrochloride passivation additives used in the present invention contain special (2-aminoethyl) maleimide groups substituted or not substituted by N in their chemical structures, which are stable cyclic structures, thereby providing additional rigidity and stability for the entire additive structure, thereby helping to maintain the structural integrity of the molecule in the perovskite film, and ultimately acting more effectively with defect sites. More importantly, the maleimide groups in these two additives can form more stable coordination bonds with cations and halogen ions in the perovskite material, and this coordination helps to position the amino and / or carboxyl groups on the perovskite surface or near the defect sites, enhancing the passivation effect, and ultimately improving the photoelectric conversion efficiency of the solar cell where the perovskite light absorption layer is located.

[0025] In summary, the perovskite solar cell prepared by the above technical solution of the present invention has significantly improved efficiency, stability and durability, showing higher photoelectric conversion efficiency and longer working life, providing strong technical support for the commercial application of perovskite solar cells. In addition, the method is simple in process, can effectively improve the photoelectric performance of perovskite photovoltaic materials, and effectively reduce the preparation cost of the battery, promoting its wide application in the photovoltaic field.

[0026] In several typical embodiments, the inventors use N-(2-aminoethyl) maleimide trifluoroacetate and 1-(2-aminoethyl) maleimide hydrochloride as passivation additives in order to effectively utilize the complementary effects of the two additives in defect passivation, structural optimization and performance improvement. Specifically, the preferred passivation additive is a mixture of N-(2-aminoethyl) maleimide trifluoroacetate and 1-(2-aminoethyl) maleimide hydrochloride in a molar ratio of (1.8 to 2.0): 1, and the amino groups in the two structures can effectively neutralize positive charge defects, and the carboxyl groups can close metal ion site defects through coordination. The coordinated use of the above two passivation additives can also form a composite passivation layer on the surface of the perovskite, further stitching grain boundaries, reducing grain boundary defects, and improving the crystallinity and uniformity of the film. In particular, the inventors have optimized the above molar ratio relationship through a large number of experiments, so as to better balance the distribution of the two additives in the perovskite film to achieve a more superior defect passivation effect. At this molar ratio, the two additives can cover the perovskite surface more evenly to form a complementary passivation layer, further reducing non-radiative recombination, increasing carrier lifetime, and ultimately more significantly improving the photoelectric performance and stability of perovskite solar cells.

[0027] Furthermore, it is preferred that the crystal structure of the perovskite in the perovskite light absorbing layer is ABX3, wherein A + Including MA + , FA + and Cs + , B 2+ Pb 2+ , X － Selected from I － Br － and Cl － One or more of the above, so as to obtain a perovskite solar cell with higher photoelectric conversion efficiency. And more preferably A + Medium, MA + , FA + and Cs + The stoichiometric ratio of X is (18-20): (0.9-1.0): 1; and / or, X － middle, I － and Br － The stoichiometric ratio of is (18-20):1, thereby forming a perovskite light-absorbing layer with higher crystallinity. In order to better adapt to the above two passivation additives, obtain a more superior defect passivation effect, and more effectively improve the photoelectric conversion efficiency of the solar cell in which it is located, the crystal structure formula of the perovskite in the perovskite light-absorbing layer is further preferably (FA 0.95 MA 0.05 ) 0.95 Cs 0.05 Pb(I 0.95Br 0.05 )3.

[0028] In order to more finely adjust the passivation effect of the above two passivation additives on the defects in the perovskite layer, the preferred step S2 further includes: dissolving the perovskite precursor source and the passivation additive in an organic solvent at a molar ratio of 100: (1-10) to obtain a perovskite precursor solution. That is to say, the molar ratio of N-(2-aminoethyl) maleimide trifluoroacetate and / or 1-(2-aminoethyl) maleimide hydrochloride to the perovskite precursor source is (1-10): 100, so as to provide a more appropriate amount of amino and carboxyl functional groups to participate in the reaction, thereby more fully passivating the defects on the surface and grain boundaries of the perovskite material, reducing the non-radiative recombination of carriers, and also avoiding the destruction of the film structure or performance degradation caused by excessive additives. The perovskite light-absorbing layer prepared within this molar ratio range has higher film quality, and the photoelectric conversion efficiency and stability of the solar cell in which it is located are also better. Preferably, in the perovskite precursor solution, the molar concentration of the perovskite precursor source is 0.5 mol / L to 2.0 mol / L, more preferably 1.5 mol / L to 2.0 mol / L. The perovskite precursor solution within the above molar concentration range can be more uniformly crystallized during subsequent spin coating crystallization, improve the photoelectric performance of the obtained perovskite light absorbing layer, and also help optimize the film quality, promote its formation of a denser structure, reduce pinholes, improve the uniformity of grain size, and ultimately obtain a more efficient solar cell.

[0029] Furthermore, for the solution system formed by the above-mentioned precursor source and the passivation additive, the organic solvent is preferably selected from one or more of DMF (N,N-dimethylformamide), DMSO (dimethyl sulfoxide) and PC (propylene carbonate). In several typical embodiments, the organic solvent is a mixed solvent formed by DMF and DMSO in a volume ratio of (1 to 4): 1. In this solvent system, DMF has a strong solubility, which is conducive to the uniform dispersion of the precursor; DMSO can regulate the film formation process, delay crystallization, make the perovskite film grow more uniformly, and reduce defects. When the two are mixed as a solvent in the above-mentioned proportion, the properties of the perovskite precursor solution can be more effectively improved, the formation of high-quality films can be promoted, a perovskite light-absorbing layer with fewer defects can be obtained, and the performance of the solar cell in which it is located can be improved. In several more typical embodiments, the organic solvent is a mixed solvent formed by DMF, DMSO and PC in a volume ratio of (3-4):1:(0.1-0.5). In this solvent system, propylene carbonate can be adsorbed on the surface of the lead halide octahedron, promote the formation of point-sharing octahedrons, inhibit the yellow phase, and cooperate with DMF and DMSO to finally obtain a phase-pure perovskite film.

[0030] After the precursor film is obtained by spin coating, the temperature of the heat treatment in step S3 is further set to 100°C to 200°C, and the time is 5min to 60min, and the temperature is more preferably 100°C to 150°C, and the time is 25min to 30min. Thereby more effectively promoting the full crystallization of the perovskite material, forming a stable phase, and optimizing the film structure, improving its photoelectric performance and stability. The coating is carried out by spin coating, and preferably the spin coating includes the first spin coating and the second spin coating carried out in sequence. Among them, two-stage spin coating is adopted, and the first spin coating is carried out at a lower speed (1500rpm to 2000rpm) and time (8s to 10s), which helps the precursor solution to spread evenly and form the initial layer of the film. Subsequently, the second spin coating is carried out at a high speed (5000rpm to 6000rpm) and a longer time (40s to 50s), so as to effectively control the film thickness, remove the solvent, promote crystallization, obtain a dense and uniform perovskite film, and then obtain a solar cell with better performance. In order to more effectively balance the uniformity and thickness of the titanite film and further improve the photoelectric performance of the battery, it is more preferred that the volume of the perovskite precursor solution used for coating is 80 μL to 100 μL.

[0031] Furthermore, the hole transport layer is selected from NiO x The hole transport layer is one of a Me-4PACz layer, a MeO-4PACz layer, and a 4PADCB layer, and the hole transport layer is formed by a method selected from a magnetron sputtering method, a spin coating method, and a blade coating method, preferably a spin coating method.

[0032] Specifically, Me-4PACz is [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, MeO-4PACz is [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, and 4PADCB is (4-(7H-dibenzo[c,g]carbazole-7-yl)butyl)phosphonic acid.

[0033] In several typical embodiments, in order to further improve the performance of the obtained perovskite solar cell, preferably in step S1, the step of forming the hole transport layer includes: spin coating a nickel oxide dispersion with a concentration of 10 mg / mL to 30 mg / mL on one surface of the conductive substrate layer, and obtaining the hole transport layer after annealing at 80°C to 150°C.

[0034] After the perovskite light absorbing layer is prepared, the electron transport layer is further preferably selected from a TiO2 layer, a SnO2 layer, a PCBM layer and a C 60One of the layers; and / or, the metal electrode layer is selected from one or more of a gold electrode layer, a silver electrode layer and a copper electrode layer. The two work synergistically with the perovskite light-absorbing layer passivated by additives, which can effectively improve the carrier extraction efficiency and reduce interface recombination. At the same time, the above two layers of materials have better electron affinity, and when in contact with the perovskite interface, they can more effectively promote the rapid transfer of electrons from the perovskite to the transport layer, thereby making the resulting solar cell show a higher photoelectric conversion efficiency. In several typical embodiments, the formation methods of the electron transport layer and the metal electrode layer are independently selected from one of vacuum evaporation, magnetron sputtering, atomic layer deposition, spin coating, blade coating and chemical bath deposition.

[0035] The second aspect of the present invention provides a perovskite solar cell, which is prepared by the above-mentioned perovskite solar cell preparation method based on passivation additives, and the perovskite solar cell includes a conductive substrate layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer and a metal electrode layer stacked in sequence. The perovskite solar cell prepared by the above method has fewer defects in the perovskite light absorption layer, and thus exhibits a higher photoelectric conversion efficiency.

[0036] Furthermore, the thickness of the hole transport layer is 10nm to 40nm; and / or the thickness of the perovskite light absorption layer is 200nm to 600nm; and / or the thickness of the electron transport layer is 20nm to 50nm; and / or the thickness of the metal electrode layer is 50nm to 150nm. The thickness setting of the above layers can further optimize the structure of the perovskite solar cell and improve its photoelectric conversion efficiency, while also making it more stable and longer in use. In several more preferred embodiments, the conductive substrate layer is a FTO glass sheet or an ITO glass sheet.

[0037] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0038] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0039] Example 1

[0040] A method for preparing perovskite solar cells based on passivation additives:

[0041] (1) A 2.2 mm thick FTO glass substrate was cleaned with acetone, deionized water, and isopropanol in turn, dried, and treated with ultraviolet light for 15 minutes to be used as a conductive base layer. A 20 mg / mL nickel oxide isopropanol solution was added to the FTO glass substrate and spin-coated at 3000 rpm for 30 seconds, followed by annealing at 100°C for 20 minutes to obtain a 20 nm thick NiO x layer.

[0042] (2) According to the stoichiometric ratio, weigh 232.8 mg FAI (formamidine iodide), 7.98 mg MABr (potassium ammonium bromide), 19.49 mg CsI (cesium iodide), 27.53 mg PbBr2 (lead bromide), 676.6 mg PbI2 (lead iodide) and 30.38 mg MACl (methylammonium chloride). Then add N-(2-aminoethyl)maleimide trifluoroacetate as a passivation additive, and its molar ratio with the above-mentioned precursor source is 1:100. Afterwards, add 800 μL of DMF, 200 μL of DMSO and 100 μL of PC (i.e., DMF:DMSO:PC=4:1:0.5, volume ratio) as a mixed solvent to the reagent bottle containing the above-mentioned chemicals to obtain (FA) with a molar concentration of 1.5 mol / L. 0.95 MA 0.05 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3Perovskite precursor solution.

[0043] (3) Take 100 μL of the above precursor solution and apply it on the surface of the hole transport layer that has been formed away from the conductive substrate layer. Then, the first spin coating is performed at a speed of 2000 rpm for 10 seconds; the second spin coating is performed at a speed of 5000 rpm for 40 seconds, and 200 μL of chlorobenzene is quickly added as an anti-solvent 15 seconds before the end of the second spin coating. Then, the formed perovskite film is heat-treated on a hot stage at 100°C for 30 minutes to obtain a perovskite light-absorbing layer with a thickness of 400 nm.

[0044] (4) On the surface of the perovskite light absorbing layer away from the hole transport layer, a 40 nm thick electron transport layer C is prepared by vacuum evaporation. 60 , and then vacuum evaporation is used again to prepare a gold electrode layer with a thickness of 100 nm on the surface of the electron transport layer away from the perovskite light absorbing layer, and finally a perovskite solar cell is obtained.

[0045] Example 2

[0046] A method for preparing perovskite solar cells based on passivation additives:

[0047] (1) A 2.2 mm thick FTO glass substrate was cleaned with acetone, isopropanol, and deionized water in turn, and then dried and used as a conductive base layer. A 20 mg / mL nickel oxide isopropanol solution was added to the FTO glass substrate and spin-coated at 3000 rpm for 30 seconds, followed by annealing at 100°C for 20 minutes to obtain a 40 nm thick NiO x layer.

[0048] (2) According to the stoichiometric ratio, weigh 232.8 mg FAI (formamidine iodide), 7.98 mg MABr (potassium ammonium bromide), 19.49 mg CsI (cesium iodide), 27.53 mg PbBr2 (lead bromide), 676.6 mg PbI2 (lead iodide) and 30.38 mg MACl (methylammonium chloride). Then add 1-(2-aminoethyl)maleimide hydrochloride as a passivation additive, and its molar ratio with the above-mentioned precursor source is 1:100. Then, add 800 μL of DMF, 200 μL of DMSO and 20 μL of PC (i.e., DMF:DMSO:PC=4:1:0.1, volume ratio) as a mixed solvent to the reagent bottle containing the above-mentioned chemicals to obtain (FA) with a molar concentration of 1.5 mol / L. 0.95 MA 0.05 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3Perovskite precursor solution.

[0049] (3) Take 100 μL of the above precursor solution and apply it on the surface of the hole transport layer that is formed away from the conductive substrate layer. Then, the first spin coating is performed at a speed of 1500 rpm for 8 seconds; the second spin coating is performed at a speed of 6000 rpm for 50 seconds, and 200 μL of chlorobenzene is quickly added as an anti-solvent 15 seconds before the end of the second spin coating. Then, the formed perovskite film is heat-treated on a hot stage at 150°C for 25 minutes to obtain a perovskite light-absorbing layer with a thickness of 300 nm.

[0050] (4) On the surface of the perovskite light absorbing layer away from the hole transport layer, a 50 nm thick electron transport layer SnO2 is prepared by vacuum evaporation, and then a 120 nm thick silver electrode layer is prepared by vacuum evaporation again on the surface of the electron transport layer away from the perovskite light absorbing layer, and finally a perovskite solar cell is obtained.

[0051] Example 3

[0052] A method for preparing perovskite solar cells based on passivation additives:

[0053] The only difference between this embodiment and embodiment 1 is that N-(2-aminoethyl)maleimide trifluoroacetate and 1-(2-aminoethyl)maleimide hydrochloride are used together as passivation additives, the total molar amount of the two remains unchanged, and the molar ratio of N-(2-aminoethyl)maleimide trifluoroacetate:1-(2-aminoethyl)maleimide hydrochloride is 2:1.

[0054] Example 4

[0055] A method for preparing perovskite solar cells based on passivation additives:

[0056] The only difference between this embodiment and embodiment 1 is that in the process of preparing the perovskite precursor solution in step (2), the molar ratio of N-(2-aminoethyl)maleimide trifluoroacetate to the precursor source is changed to 5:100.

[0057] Example 5

[0058] A method for preparing perovskite solar cells based on passivation additives:

[0059] The only difference between this embodiment and embodiment 1 is that in the process of preparing the perovskite precursor solution in step (2), the molar ratio of N-(2-aminoethyl)maleimide trifluoroacetate to the precursor source is changed to 0.5:100.

[0060] Example 6

[0061] A method for preparing perovskite solar cells based on passivation additives:

[0062] The only difference between this embodiment and embodiment 1 is that in the process of preparing the perovskite precursor solution in step (2), the molar ratio of N-(2-aminoethyl)maleimide trifluoroacetate to the precursor source is changed to 20:100.

[0063] Example 7

[0064] A method for preparing perovskite solar cells based on passivation additives:

[0065] The only difference between this embodiment and embodiment 1 is that in the process of preparing the perovskite precursor solution in step (2), the mixed solvent used does not include PC.

[0066] Example 8

[0067] A method for preparing perovskite solar cells based on passivation additives:

[0068] The only difference between this embodiment and embodiment 1 is that during the heat treatment in step (3), the heat treatment temperature is changed to 200° C. and the time is changed to 5 minutes.

[0069] Comparative Example 1

[0070] A method for preparing perovskite solar cells based on passivation additives:

[0071] The only difference between this comparative example and Example 1 is that in the process of preparing the perovskite precursor solution in step (2), N-(2-aminoethyl)maleimide trifluoroacetate is not added.

[0072] Comparative Example 2

[0073] A method for preparing perovskite solar cells based on passivation additives:

[0074] The difference between this comparative example and Example 1 is that in the process of preparing the perovskite precursor solution in step (2), an equimolar amount of cesium trifluoroacetate is used to replace N-(2-aminoethyl)maleimide trifluoroacetate.

[0075] Comparative Example 3

[0076] A method for preparing perovskite solar cells based on passivation additives:

[0077] The difference between this comparative example and Example 1 is that in the process of preparing the perovskite precursor solution in step (2), an equimolar amount of cyclohexylmethylamine hydrochloride is used to replace N-(2-aminoethyl)maleimide trifluoroacetate.

[0078] Test Method

[0079] At room temperature, using a 3A solar simulator, at 100mW / cm 2 The photoelectric conversion efficiency of the perovskite solar cells prepared in each embodiment and comparative example was tested under a light intensity of , and the effective area of ​​the tested perovskite solar cell samples was 0.09 cm 2 .

[0080] The test result curve of the perovskite solar cell obtained in Example 1 is shown in Figure 1 The test result curve of the perovskite solar cell obtained in Example 4 is shown in Figure 2 The test result curve of the perovskite solar cell obtained in Comparative Example 1 is shown in Figure 3 .

[0081] In addition, the short-circuit current density, open-circuit voltage, fill factor and photoelectric conversion efficiency data results of the perovskite solar cells obtained in the above-mentioned test process are shown in Table 1.

[0082] Table 1

[0083] <![CDATA[Short-circuit current density (mA / cm 2 )]]> Open circuit voltage(V) Fill factor (%) Photoelectric conversion efficiency (%) Example 1 25.59 1.133 85.18 24.71 Example 2 26.03 1.145 81.60 24.25 Example 3 26.03 1.133 84.82 25.02 Example 4 25.76 1.133 84.34 24.62 Example 5 25.74 1.105 81.30 23.12 Example 6 25.52 1.100 77.40 21.72 Example 7 25.57 1.112 78.20 22.28 Example 8 25.44 1.109 77.33 21.87 Comparative Example 1 25.15 1.090 77.23 21.24 Comparative Example 2 25.09 1.111 76.72 21.43 Comparative Example 3 25.28 1.108 76.32 21.37

[0084] From the above description, it can be seen that the above-mentioned embodiments of the present invention add additives as passivation defects, namely N-(2-aminoethyl)maleimide trifluoroacetate and / or 1-(2-aminoethyl)maleimide hydrochloride, to the perovskite precursor solution, which significantly improves the crystallization quality and stability of the prepared perovskite film, and improves the short-circuit current density and photoelectric conversion efficiency of the perovskite solar cell when in use.

[0085] Specifically, the perovskite solar cells containing appropriate amounts of N-(2-aminoethyl)maleimide trifluoroacetate and / or 1-(2-aminoethyl)maleimide hydrochloride passivators (Examples 1-8) have higher open circuit voltage and fill factor than the solar cells without additives (Comparative Example 1) or the solar cells with other types of additives (Comparative Example 2, Comparative Example 3), and ultimately achieve higher photoelectric conversion efficiency.

[0086] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application 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 described herein, for example.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a perovskite solar cell based on a passivation additive, characterized in that: include: Step S1, providing a conductive substrate layer, and forming a hole transport layer on one surface of the conductive substrate layer; Step S2, preparing a perovskite precursor solution containing the passivation additive; Step S3, coating the perovskite precursor solution on the surface of the hole transport layer away from the conductive substrate layer, and forming a perovskite light absorption layer on the surface of the hole transport layer after heat treatment; Step S4, sequentially preparing an electron transport layer and a metal electrode layer on a surface of the perovskite light absorbing layer away from the hole transport layer to obtain the perovskite solar cell; Wherein, the passivation additive is N-(2-aminoethyl)maleimide trifluoroacetate and / or 1-(2-aminoethyl)maleimide hydrochloride.

2. The method for preparing a perovskite solar cell based on a passivation additive according to claim 1, characterized in that: The passivation additive is a mixture of N-(2-aminoethyl)maleimide trifluoroacetate and 1-(2-aminoethyl)maleimide hydrochloride in a molar ratio of (1.8-2.0):

1.

3. The method for preparing a perovskite solar cell based on a passivation additive according to claim 1 or 2, characterized in that: The crystal structure formula of the perovskite in the perovskite light absorbing layer is ABX3, wherein A + Including MA + , FA + and Cs + , B 2+ Pb 2 + , X － Selected from I － Br － and Cl － One or more of; Preferably, the crystal structure formula of the perovskite in the perovskite light absorbing layer is (FA 0.95 MA 0.05 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3.

4. The method for preparing a perovskite solar cell based on a passivation additive according to any one of claims 1 to 3, characterized in that: The step S2 comprises: dissolving a perovskite precursor source and the passivation additive in an organic solvent at a molar ratio of 100:(1-10) to obtain the perovskite precursor solution; Preferably, in the perovskite precursor solution, the molar concentration of the perovskite precursor source is 0.5 mol / L to 2.0 mol / L, more preferably 1.5 mol / L to 2.0 mol / L.

5. The method for preparing a perovskite solar cell based on a passivation additive according to claim 4, characterized in that: The organic solvent is selected from one or more of DMF, DMSO and PC; Preferably, the organic solvent is a mixed solvent formed by DMF and DMSO in a volume ratio of (1-4):1; More preferably, the organic solvent is a mixed solvent formed by DMF, DMSO and PC in a volume ratio of (3-4):1:(0.1-0.5).

6. The method for preparing a perovskite solar cell based on a passivation additive according to any one of claims 1 to 5, characterized in that: In step S3, the heat treatment temperature is 100°C to 200°C, and the time is 5min to 60min; Preferably, the heat treatment is performed at a temperature of 100° C. to 150° C. and for a time of 25 min to 30 min.

7. The method for preparing a perovskite solar cell based on a passivation additive according to any one of claims 1 to 6, characterized in that: In the step S1, the hole transport layer is selected from NiO x The hole transport layer is one of a Me-4PACz layer, a MeO-4PACz layer and a 4PADCB layer, and the hole transport layer is formed by a method selected from a magnetron sputtering method, a spin coating method and a blade coating method, preferably a spin coating method.

8. The method for preparing a perovskite solar cell based on a passivation additive according to any one of claims 1 to 7, characterized in that: In step S4, the electron transport layer is selected from a TiO2 layer, a SnO2 layer, a PCBM layer and a C 60 and / or the metal electrode layer is selected from one or more of a gold electrode layer, a silver electrode layer and a copper electrode layer; Preferably, the electron transport layer and the metal electrode layer are formed by methods independently selected from one of vacuum evaporation, magnetron sputtering, atomic layer deposition, spin coating, blade coating and chemical bath deposition.

9. A perovskite solar cell, characterized in that: The perovskite solar cell is prepared by the perovskite solar cell preparation method based on a passivation additive according to any one of claims 1 to 8, and the perovskite solar cell includes the conductive substrate layer, the hole transport layer, the perovskite light absorption layer, the electron transport layer and the metal electrode layer stacked in sequence.

10. The perovskite solar cell according to claim 9, characterized in that: The thickness of the hole transport layer is 10nm to 40nm; and / or the thickness of the perovskite light absorption layer is 200nm to 600nm; and / or the thickness of the electron transport layer is 20nm to 50nm; and / or the thickness of the metal electrode layer is 50nm to 150nm; Preferably, the conductive substrate layer is a FTO glass sheet or an ITO glass sheet.

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