Two-dimensional perovskite material, preparation method, solar cell and application
By designing two-dimensional perovskite materials with specific structures and preparing single crystals using solution methods, the problem of low stability of two-dimensional perovskite materials has been solved, enabling the application of high-efficiency and stable solar cells, especially in the field of optoelectronics.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-04-14
AI Technical Summary
Existing two-dimensional perovskite materials have low stability in atmospheric environments, which affects their stability and efficiency in solar cells.
A two-dimensional perovskite material with a specific structure, [NH3-(CH2)m1-C6H10-(CH2)m2-NH3]p[(B)n-1MnX3n+1]q, was used to prepare single crystals by controlling the arrangement of metal clusters and spacer cations, combined with a solution method. These crystals were then applied in the light-absorbing layer to optimize the structure of solar cells.
High conversion efficiency and stability of two-dimensional perovskite materials were achieved. The single crystal exhibited superior humidity, thermal and light stability. The unencapsulated solar cell device still maintained 90% of its initial efficiency after 1400 hours at 60°C.
Smart Images
Figure CN121850874A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional materials and perovskite solar cell technology, specifically relating to a two-dimensional perovskite material, its preparation method, a solar cell, and its application. Background Technology
[0002] Compared to three-dimensional perovskites, two-dimensional perovskites have attracted increasing attention due to their superior intrinsic structural stability and desirable photophysical properties. Compared to Ruddlesden-Popper (RP) perovskites, Dion... Jacobson (DJ) type perovskites with diamine cations at the bis-position are thought to enhance the connections between inorganic layers and increase overall structural stiffness, potentially improving stability. However, most of these promising DJ perovskites have not shown the expected stability improvements. Studies of the RP and DJ series even indicate that DJ perovskites have relatively low stability in atmospheric environments. Therefore, a systematic study of the key factors affecting the stability of DJ materials and guiding the design of stable DJ perovskites is crucial for the fabrication of stable, efficient, and scalable solar cells and modules. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a two-dimensional perovskite material, a preparation method, a solar cell, and an application, which have high conversion efficiency and good stability.
[0004] This invention provides a two-dimensional perovskite material with the structural formula [NH3-(CH2)]. m1 -C6H 10 -(CH2) m2 -NH3] p [(B) n-1 M n X 3n+1 ] q ; Among them, -C6H 10 - is a cyclohexene group; B is methylamine, ethylamine, formamidinium, cesium or guanidine, M is Pb and / or Sn, and X is a halogen; m1 and m2 are 0-10 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10), and m1 and m2 are not both 0. Preferably, 1,3-cyclohexanedimethylamine is used. n is 1-60, for example, 1, 2, 3, 4, 5, 6, 10, 17, 60. q:p is (1-60):1, for example, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 10:1, 17:1, 60:1.
[0005] NH3-(CH2) m1 -C6H 10 -(CH2)m2 -NH3 is a spacer cation, (B) n-1 M n X 3n+1 The metal clusters are arranged with any two metal clusters separated by the spacer cations.
[0006] Metal clusters include at least a metal halide inorganic layer M. n X 3n+1 And optional B + Wherein, n is the number of layers of the metal halide inorganic layer, n≥1; X is selected from halogens, such as Cl, Br, I, preferably I; M is a divalent metal ion, selected from Pb and / or Sn, preferably Pb.
[0007] B + The filling cations are used to fill the metal halide inorganic layer to form the metal clusters when n≥2.
[0008] Preferably, [NH3-(CH2)] m1 -C6H 10 -(CH2) m2 The structural formula of [-NH3] is: .
[0009] Preferably, B is formamidin.
[0010] Preferably, M is Pb.
[0011] Preferably, X is I.
[0012] Preferably, the two-dimensional perovskite material is a single crystal; its structural formula is (NH3-CH2-C6H 10 The crystal is (NH3-CH2-NH3)PbI4, belonging to the orthorhombic crystal system, space group Pnma. Preferably, the unit cell parameters of the single crystal are a = 9.0501(3) Å, b = 24.9061(9) Å, c = 8.3721(3) Å; β = 90°; and the unit cell volume is 1887.09(11) Å. The structural formula is (NH3-CH2-C6H)PbI4. 10 -CH2-NH3)(CH3NH3)Pb2I7, which belongs to the orthorhombic crystal system, space group Cmm2, preferably, the unit cell parameters of the single crystal are: a=12.5811(7) Å, b=12.7802(9) Å, c=17.7483(12) Å; β=90 °; the unit cell volume is 2853.7(3) Å. Or (NH3-CH2-C6H 10-CH2-NH3)(H2N=CHNH2)2Pb2I7 belongs to the orthorhombic crystal system, space group Cmmm. Preferably, the unit cell parameters of the single crystal are: a = 9.0379(18) Å, b = 9.0379(18) Å, c = 17.708(4) Å; β = 90°, and the unit cell volume is 1446.4(5) Å. Or it is (C8H 20 N2)(H2N=CHNH2) n-1 Pb n I 3n+1 n=5, 17, 60.
[0013] This invention provides a method for preparing the two-dimensional perovskite material, comprising mixing an aqueous solution of a spacer compound, a filler compound, a metal compound, and hydrogen halide, heating (to dissolve, preferably at 100°C), and cooling (preferably slowly, wherein the slow cooling refers to controlling the cooling rate according to the required crystal mass and size, which is 0.0001-10°C / min, for example, 5°C / min is preferred for ordinary crystal materials, and 0.0001-0.002°C / min is preferred for high-quality large single crystal materials) to obtain the two-dimensional perovskite material; The spacer compound is NH2-(CH2). m1 -C6H 10 -(CH2) m2 -NH2, NH2-(CH2) m1 and (CH2) m2 -NH2 can be para, or adjacent, or meta, preferably meta, i.e. .
[0014] The filling compound is methylamine, ethylamine, formamidinium, cesium, or guanidine, preferably formamidinium. The metal compound is a halide, oxide, carbonate, or nitrate of M, taking lead as an example, such as lead iodide, lead bromide, lead chloride, lead oxide, lead carbonate, or lead nitrate, preferably lead oxide.
[0015] The hydrogen halide is HCl, HBr, or HI, preferably HI. According to embodiments of the present invention, the amount of hydrogen halide used is not specifically limited, and amounts known in the art can be used. According to embodiments of the present invention, the concentration of the hydrogen halide in the aqueous solution can be selected from concentrations known in the art, and the present invention does not impose specific limitations.
[0016] The molar ratio of the metal compound to the spacer compound is (1-60):1, for example, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 10:1, 17:1, or 60:1.
[0017] The molar ratio of the metal compound to the filler compound is r: (r-1), where r is selected from 1 to 60, for example, 1:0, 2:1, 3:2, 4:3, 5:4, 6:5, 10:9, 17:16, 60:59.
[0018] Preferably, the operation of mixing the spacer compound, the filler compound, the metal compound, and the aqueous solution of hydrogen halide is as follows: the spacer compound, the filler compound, and the metal compound are dissolved in the aqueous solution of hydrogen halide to obtain the halide of the spacer cation, the halide of the filler cation, and the metal halide, respectively; then the halide of the spacer cation, the halide of the filler cation, and the metal halide are dissolved in an organic solvent, wherein the organic solvent is N,N-dimethylformamide and / or dimethyl sulfoxide, preferably N,N-dimethylformamide and dimethyl sulfoxide, in a volume ratio of r:(10-r), where r is selected from 1-10, for example 9:1, 8:2, 7:3.
[0019] The spacer cation halides, cation-filling halides, and metal halides can be prepared using methods known in the art, and are not specifically limited herein. Exemplarily, the preparation method of the spacer cation halides includes dissolving the spacer cations in a hydrogen halide solution, reacting them, and subsequently recrystallizing and drying them. Exemplarily, the preparation method of the cation-filling halides includes dissolving the cations in a hydrogen halide solution, reacting them, and subsequently recrystallizing and drying them. Exemplarily, the preparation method of the metal halides includes dissolving the metal compound in a hydrogen halide solution, reacting it, and subsequently recrystallizing and drying it.
[0020] This invention provides a solar cell comprising the aforementioned two-dimensional perovskite material, wherein the two-dimensional perovskite material serves as the light-absorbing layer of the solar cell.
[0021] The light-absorbing layer is obtained by depositing the two-dimensional perovskite material on a substrate using methods known in the art, such as spin coating, blade coating, or vapor deposition.
[0022] According to an embodiment of the present invention, the substrate is selected from ITO (indium tin oxide) coated glass.
[0023] According to an exemplary embodiment of the present invention, the method for preparing the light-absorbing layer includes: A1) The above two-dimensional perovskite material is dissolved in an organic solvent to obtain a precursor solution, and the precursor solution is spin-coated onto the substrate surface to obtain the light-absorbing layer; Alternatively, A1') according to stoichiometric ratio, the spacer compound, filler compound and metal compound are dissolved in an aqueous solution of hydrogen halide to obtain the halide of the spacer cation, the halide of the filler cation and the metal halide, respectively. The halide of the spacer cation, the halide of the filler cation and the metal halide are then dissolved in an organic solvent to obtain a mixed solution. The mixed solution is then spin-coated onto the surface of a substrate to obtain the light-absorbing layer.
[0024] According to an embodiment of the present invention, the concentration of the two-dimensional perovskite material in the precursor solution is 0.1-1.8 mol / mL, for example, 0.1 mol / mL, 0.2 mol / mL, 0.3 mol / mL, 0.4 mol / mL, 0.5 mol / mL, 0.9 mol / mL, 1 mol / mL, 1.1 mol / mL, 1.2 mol / mL, 1.3 mol / mL, 1.4 mol / mL, 1.5 mol / mL, 1.6 mol / mL, 1.7 mol / mL, or 1.8 mol / mL.
[0025] Preferably, the organic solvent is selected from at least one of dimethylformamide and dimethyl sulfoxide, and more preferably two of them. Exemplarily, the organic solvent includes dimethylformamide and dimethyl sulfoxide in a volume ratio of r : (10-r), for example, 9:1, 8:2, or 7:3.
[0026] According to an embodiment of the present invention, the spin-coating volume of the precursor solution is 20-100 μL, for example, 60 μL.
[0027] According to an embodiment of the present invention, the thickness of the light-absorbing layer is 300-450 nm, for example, 350 nm.
[0028] According to an embodiment of the present invention, in step A1'), the stoichiometric ratio has the meaning as described above.
[0029] According to an embodiment of the present invention, in step A1'), after spin coating, the spin-coated film also needs to be annealed. The annealing process described in the present invention can be performed using methods known in the art, such as annealing on a hot plate at 120°C for 10 minutes.
[0030] This invention provides an application of the aforementioned two-dimensional perovskite material in the optoelectronic field. It is preferably used in photodetectors and integrated optoelectronic devices, such as solar cells.
[0031] This invention provides an optimization method for solar cells, which involves dissolving 1,3-cyclohexanedimethylamine iodide in a solvent (such as ethanol or isopropanol) to obtain a passivation solution, and using the passivation solution to passivate the upper interface of the light-absorbing layer. 1,3-cyclohexanedimethylamine binds to vacancies on the upper surface of the light-absorbing layer, thereby improving the stability of the light-absorbing layer. The light-absorbing layer includes any perovskite material or a two-dimensional perovskite material as described above.
[0032] The beneficial effects of this invention are that it obtains single crystals of two-dimensional perovskite materials through a solution method, and obtains single crystals of different sizes by controlling the growth rate.
[0033] The two-dimensional perovskite material of this invention, both in single crystal and thin film, exhibits superior humidity stability, thermal stability, and light stability. As a light-absorbing layer, the two-dimensional perovskite material of this invention can be used to fabricate perovskite solar cells over large areas. For example, perovskite solar cells prepared by spin-coating can achieve a maximum conversion efficiency of 20.16%. Furthermore, unencapsulated solar cell devices retain 90% of their initial efficiency after 1400 hours at 60°C. The single crystal of the two-dimensional perovskite material of this invention has enormous application potential in the fields of optics and optoelectronics. Attached Figure Description
[0034] Figure 1 The images show the single-crystal growth of the two-dimensional perovskite materials in Examples 1-3.
[0035] Figure 2 The diagram shows the structural schematics of the two-dimensional perovskite materials in Examples 1-3.
[0036] Figure 3 This is a schematic diagram of the structure of the solar cell device used in Example 1.
[0037] Figure 4 A comparison chart showing the efficiency of two-dimensional perovskite solar cells in Application Examples 1-2 and Application Example 2.
[0038] Figure 5 The thermal stability test diagrams of the two-dimensional perovskite solar cells in Application Examples 1-2 and Application Example 2 are shown for comparison.
[0039] Figure 6 The graph shows the thermal stability test results of the perovskite solar cell used in Example 1.
[0040] Figure 7 This is a comparison of the current-voltage characteristic curves of the solar cell in Application Example 1. Detailed Implementation
[0041] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.
[0042] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.
[0043] Example 1 (C8H) 20 N2)(CH3NH3) n-1 Pb n I 3n+1 (n=1) A method for preparing two-dimensional perovskite single crystal materials, including the following steps: 1. Using an aqueous solution of hydroiodic acid (hydroiodic acid concentration of 57 wt.%) as the solvent, add 1 mol of 1,3-cyclohexanedimethylamine (meta-position) and 1 mol of inorganic lead oxide to 10 mL of the aqueous solution of hydroiodic acid, heat to 100 °C, and stir to ensure that the raw materials are completely dissolved in the hydroiodic acid solution.
[0044] 2. Then, by slowly cooling (at a rate of 1℃ / min), (NH3-CH2-C6H) is obtained. 10 (CH2-NH3)PbI4 single crystal material, which is a yellow, plate-like crystal. The crystal structure is as follows: Figure 1 As shown.
[0045] Analysis using X-ray single-crystal diffraction revealed that the (NH3-CH2-C6H) prepared in this embodiment... 10 (-CH2-NH3)PbI4 single crystal, belonging to the orthorhombic crystal system. Pnma Space group. The unit cell parameters of the single crystal are: a = 9.0501(3) Å, b = 24.9061(9) Å, c = 8.3721(3) Å; β = 90 °; the unit cell volume is 1887.09(11) Å.
[0046] Example 2 Based on the filling cation being methylamine (C8H) 20 N2)(CH3NH3) n-1 Pb n I 3n+1(n=2) The preparation method of the two-dimensional perovskite single crystal material is basically the same as in Example 1, except that methylamine, methylamine and 1,3-cyclohexanedimethylamine (meta-position), and inorganic lead oxide are added to the aqueous solution of hydroiodic acid. The molar ratio of 1,3-cyclohexanedimethylamine (meta-position): methylamine: lead oxide is 1:1:2. The single crystal obtained is (NH3-CH2-C6H 10 -CH2-NH3)(CH3NH3)Pb2I7, this single crystal material is a red, plate-like crystal.
[0047] Analysis using X-ray single-crystal diffraction revealed that the (NH3-CH2-C6H) prepared in this embodiment... 10 -CH2-NH3)(CH3NH3)Pb2I7 single crystal, belonging to the orthorhombic crystal system. Cmm 2. Space group. Preferably, the unit cell parameters of the single crystal are: a = 12.5811(7) Å, b = 12.7802(9) Å, c = 17.7483(12) Å; β = 90 °; and the unit cell volume is 2853.7(3) Å.
[0048] Example 3 Based on formamidinium as the filling cation (C8H) 20 N2)(H2N=CHNH2) n-1 Pb n I 3n+1 (n = 2) The preparation method of the two-dimensional perovskite single crystal material is basically the same as in Example 1, except that formamidin is added. Formamidin and 1,3-cyclohexanedimethylamine (meta-position), and inorganic lead oxide are added to the aqueous solution of hydroiodic acid. The molar ratio of 1,3-cyclohexanedimethylamine:formamidin:lead oxide is 1:1:2. The single crystal obtained is (NH3-CH2-C6H 10 -CH2-NH3)(H2N=CHNH2) Pb2I7, this single crystal material is a red, plate-like crystal.
[0049] Analysis using X-ray single-crystal diffraction revealed that the (NH3-CH2-C6H) prepared in this embodiment... 10 -CH2-NH3)(H2N=CHNH2)Pb2I7 single crystal, belonging to the orthorhombic crystal system. Cmmm Space group. Preferably, the unit cell parameters of the single crystal are: a = 9.0379(18) Å, b = 9.0379(18) Å, c = 17.708(4) Å; β = 90 °, and the unit cell volume is 1446.4(5) Å.
[0050] Example 4 The preparation method of the two-dimensional perovskite single crystal material in this embodiment is basically the same as that in Example 3, except that 1,3-cyclohexanedimethylamine (meta-position), formamidinium, and lead oxide are dissolved in an aqueous solution of hydroiodic acid, and 1,3-cyclohexanedimethylamine iodine, formamidinium iodine, and lead iodide are prepared under recrystallization purification and drying conditions, respectively. The above-mentioned 1,3-cyclohexanedimethylamine iodine, formamidinium iodine, and lead iodide are added to 2 mL of N,N-dimethylformamide, and after heating and stirring to completely dissolve the solute, single crystals are obtained by slow cooling (cooling rate of 1-60℃ / hour, selected as 0.5℃ / min).
[0051] Tests show that the crystal structure of the single crystal prepared in this embodiment is basically the same as that in Example 3.
[0052] Example 5 Stability comparison of materials with different n values Preparation of two-dimensional perovskite films with different n values: 1,3-cyclohexanedimethylamine iodine, formamidinium iodine, and lead iodide prepared in Example 4 were dissolved in an organic solvent to obtain a precursor solution. According to the general chemical formula (C8H... 20 N2)(H2N=CHNH2) n-1 Pb n I 3n+1 Two-dimensional perovskite precursor solutions were prepared according to different raw material ratios with different n values (n = 5, 17, or 60). The solubility of the precursor solution was 1.0 mol / L (based on the proportion of lead in the solution), and the organic solvents were dimethylformamide and dimethyl sulfoxide. In this application example, the volume ratio of dimethylformamide to dimethyl sulfoxide in the mixed solvent was 9:1.
[0053] Preparation conditions for spin-coated films: spin coater speed of 6000 r / s, spin time of 40s, antisolvent CB added dropwise in the last 10s; precursor solution volume of 60 μL; annealing temperature of 120℃.
[0054] Application Example 1 Spin-coating process for fabricating light-absorbing layers and perovskite solar cells 1) Spin-coating process for preparing the light-absorbing layer: Using 1,3-cyclohexanedimethylamine iodine, formamidinium iodine, and lead iodide prepared in Example 4 as raw materials, according to the general chemical formula (C8H... 20 N2)(H2N=CHNH2) n-1 Pb n I 3n+1The precursor solution is prepared by dissolving raw materials in an organic solvent according to different n values (n = 5, 17, or 60). The solubility of the precursor solution is 1.0 mol / L. The organic solvent is a mixture of dimethylformamide and dimethyl sulfoxide. By adjusting different ratios, a precursor solution with higher solubility is used for spin coating processes. In this application example, the mixed solvent contains dimethylformamide and dimethyl sulfoxide, with a volume ratio of dimethylformamide to dimethyl sulfoxide of 9:1.
[0055] The conditions for preparing the light-absorbing thin film by spin coating were as follows: the spin coater speed was 6000 r / s, the rotation time was 40s, and the antisolvent CB was added dropwise in the last 10s; the amount of precursor solution used was 60 μL; and the annealing temperature was 120℃.
[0056] 2) Fabrication of perovskite solar cells: This application example uses, as shown in the example... Figure 2 The configuration of the inverted perovskite solar cell shown is as follows: the substrate is glass with an ITO coating; the hole transport layer is 4-(n-propylammonium)dicyanophenyl bromide (4PADCB); the light-absorbing layer is the solution prepared in step 1); a two-dimensional perovskite thin film is obtained by spin coating; the electron transport layer is C60; the blocking layer is 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline; and the metal electrode is copper. The structure is as follows. Figure 3 As shown.
[0057] Application Example 2 Spin-coating process for fabricating light-absorbing layers and perovskite solar cells 1) Spin-coating process for preparing the light-absorbing layer: Using 1,3-cyclohexanedimethylamine iodine, formamidinium iodine, and lead iodide prepared in Example 4 as raw materials, a (C8H) light-absorbing layer was prepared. 20 (N2)PbI4 and (H2N=CHNH2)PbI3 are dissolved in an organic solvent to obtain a precursor solution, which is then used according to [(C8H 20 [N2)PbI4] p [(H2N=CHNH2)PbI3] q Perovskite precursor solutions with different n values were obtained. When q:p was 4:1, n=5; when q:p was 16:1, n=17; and when q:p was 59:1, n=60.
[0058] The precursor solution for the two-dimensional perovskite thin film has a solubility of 1.0 mol / L. The organic solvent is a mixture of dimethylformamide and dimethyl sulfoxide. By adjusting different ratios, precursor solutions with higher solubility are used in spin-coating processes. In this application example, the volume ratio of dimethylformamide to dimethyl sulfoxide in the mixed solvent is 9:1.
[0059] The conditions for preparing the light-absorbing thin film by spin coating were as follows: the spin coater speed was 6000 r / s, the rotation time was 40s, and the antisolvent CB was added dropwise in the last 10s; the amount of precursor solution used was 60 μL; and the annealing temperature was 120℃.
[0060] 2) Fabrication of perovskite solar cells: This application example uses, as shown in the example... Figure 2 The configuration of the inverted perovskite solar cell shown is as follows: the substrate is glass with an ITO coating; the hole transport layer is 4-(n-propylammonium)dicyanophenyl bromide (4PADCB); the light-absorbing layer is the solution prepared in step 1); a two-dimensional perovskite thin film is obtained by spin coating; the electron transport layer is C60; the blocking layer is 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline; and the metal electrode is copper.
[0061] Comparative Application Example 1 1,3-Diaminopropane Two-Dimensional Perovskite Solar Cells 1) Preparation of precursor solution: The preparation of the precursor solution for the two-dimensional perovskite solar cell containing spacer cations in this comparative application example is basically the same as that in application example 2 (n=17), except that 1,3-cyclohexanedimethylamine is replaced with 1,3-diaminopropane.
[0062] 2) Fabrication of perovskite solar cells: The 1,3-diaminopropane two-dimensional perovskite solar cell in this comparative application example is basically the same as step 2 in application example 1).
[0063] Comparative Application Example 2 1,3-Phenylenediamine two-dimensional perovskite solar cells 1) Preparation of precursor solution: The preparation of the precursor solution for the two-dimensional perovskite solar cell based on the benzene ring spacer cation in this comparative application example is basically the same as that in application example 2 (n=17), except that 1,3-cyclohexanedimethylamine is replaced with 1,3-phenylenediamine.
[0064] 2) Fabrication of perovskite solar cells: The two-dimensional perovskite solar cells containing benzene ring spacer cations in this comparative application example are basically the same as step 2 in application example 1.
[0065] The cell performance of the two-dimensional perovskite solar cells obtained in Application Examples 1-2 and 2 (n=17) was compared and tested, and the cell efficiency was increased by... Figure 4 It is known that the energy conversion efficiency of two-dimensional perovskite films containing benzene ring spacer cations and chain spacer cations is lower than that of cyclic spacer cations.
[0066] The two-dimensional perovskite solar cells obtained in Application Examples 1-2 and Application Example 2 (n=17) were tested and compared in a nitrogen glove box at 60°C. Figure 5It can be seen that the thermal stability of two-dimensional perovskite films containing benzene ring spacer cations and chain spacer cations is greatly reduced at 60℃.
[0067] Test Example 1 Thermal stability test of two-dimensional perovskite solar cell devices at 60°C The solar cell prepared in Application Example 1 was placed in a glove box under a nitrogen atmosphere and kept at 60°C, with its efficiency continuously monitored. The stability test results are as follows: Figure 6 As shown, by Figure 6 It can be seen that when placed in an environment of 60℃ for more than 1400 hours, the n=17 film still maintains 90% of the initial efficiency, the n=5 film maintains 70% of the initial efficiency, while the n=60 film has a conversion efficiency of less than 30% of the initial efficiency after 700 hours.
[0068] In Application Example 1, the efficiency of n=17 decreased to 90% of the initial efficiency after 1400 hours at 60°C, indicating that the solar cell using the cyclohexanediamine-based two-dimensional perovskite material with n=17 in this invention has better thermal stability.
[0069] Test Example 2 The performance of the solar cell used in Application Example 1 was tested. J - V Curve test results as follows Figure 7 As shown, the solar cells made of cyclohexanediamine-based two-dimensional perovskite material with n=17 exhibit better energy conversion efficiency.
[0070] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.
[0071] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.
Claims
1. A two-dimensional perovskite material, characterized in that, The structural formula of the two-dimensional perovskite material is [NH3-(CH2)]. m1 -C6H 10 -(CH2) m2 -NH3] p [(B) n-1 M n X 3n+1 ] q ; Among them, -C6H 10 - is a cyclohexene group; B is methylamine, ethylamine, formamidinium, cesium or guanidine, M is Pb and / or Sn, and X is a halogen; m1 and m2 are 0-10, and m1 and m2 are not both 0 at the same time, n is 1-60, and q:p is (1-60):
1.
2. The two-dimensional perovskite material as described in claim 1, characterized in that, [NH3-(CH2) m1 -C6H 10 -(CH2) m2 The structural formula of [-NH3] is: .
3. The two-dimensional perovskite material as described in claim 1, characterized in that, B stands for formamidin.
4. The two-dimensional perovskite material as described in claim 1, characterized in that, M is Pb.
5. The two-dimensional perovskite material as described in claim 1, characterized in that, X is I.
6. The two-dimensional perovskite material as described in claim 1, characterized in that, The two-dimensional perovskite material is a single crystal; its structural formula is (NH3-CH2-C6H). 10 -CH2-NH3)PbI4,(NH3-CH2-C6H 10 -CH2-NH3)(CH3NH3)Pb2I7, (NH3-CH2-C6H 10 -CH2-NH3)(H2N=CHNH2)2Pb2I7, or (C8H 20 N2)(H2N=CHNH2) n-1 Pb n I 3n+1 n=5, 17, 60.
7. A method for preparing a two-dimensional perovskite material as described in any one of claims 1-6, characterized in that, A two-dimensional perovskite material is obtained by mixing a spacer compound, a filler compound, a metal compound, and an aqueous solution of hydrogen halide, heating, and cooling. The spacer compound is NH2-(CH2). m1 -C6H 10 -(CH2) m2 -NH2, wherein the filling compound is methylamine, ethylamine, formamidinium, cesium or guanidine, and the metal compound is a halide, oxide, carbonate or nitrate of M.
8. The preparation method according to claim 7, characterized in that, The operation of mixing the spacer compound, the filler compound, the metal compound, and the aqueous solution of hydrogen halide is as follows: the spacer compound, the filler compound, and the metal compound are dissolved in the aqueous solution of hydrogen halide to obtain the halide of the spacer cation, the halide of the filler cation, and the metal halide, respectively; then the halide of the spacer cation, the halide of the filler cation, and the metal halide are dissolved in an organic solvent, wherein the organic solvent is N,N-dimethylformamide and / or dimethyl sulfoxide.
9. A solar cell, characterized in that, Includes the two-dimensional perovskite material as described in any one of claims 1-6.
10. An application of a two-dimensional perovskite material as described in any one of claims 1-6 in the field of optoelectronics.
11. An optimization method for solar cells, characterized in that, A passivation solution is obtained by dissolving 1,3-cyclohexanedimethylamine iodide in a solvent, and the passivation solution is used to passivate the upper interface of the light-absorbing layer. 1,3-cyclohexanedimethylamine combines with vacancies on the upper surface of the light-absorbing layer, thereby improving the stability of the light-absorbing layer. The light-absorbing layer includes any perovskite material or a two-dimensional perovskite material as described in any one of claims 1-6.