Low-dimensional layered wide-bandgap perovskite material, wide-bandgap perovskite solar cell and preparation method thereof

Abstract

This invention discloses a low-dimensional layered wide-bandgap perovskite material, a wide-bandgap perovskite solar cell, and a method for preparing the same. The chemical formula of the low-dimensional layered wide-bandgap perovskite material is A2B. n‑ 1Pb n X 3n+1 Where A is at least one of 4-fluoro-phenylethylammonium ion, phenylethylammonium ion, butammonium ion, and octylammonium ion; B is at least one of methylamine ion, formamidinium ion, and cesium ion; X is at least one halide ion; and n is greater than 1 and less than 10. The low-dimensional layered wide-bandgap perovskite material provided by this invention exhibits excellent environmental stability, with a bandgap reaching 1.70 eV. The open-circuit voltage of perovskite solar cells based on this low-dimensional layered wide-bandgap perovskite material can reach 1.27 V at 0.1 cm⁻¹. 2 It achieves a photoelectric conversion efficiency of 20.18% within the effective area and exhibits good stability.

Description

Technical Field

[0001] This invention relates to the field of perovskite materials technology, and in particular to a low-dimensional layered wide-bandgap perovskite material, a wide-bandgap perovskite solar cell, and a method for preparing the same. Background Technology

[0002] Inorganic-organic perovskite materials have attracted much attention due to their excellent energy conversion efficiency and tunable bandgap. Wide bandgap cells absorb short-wavelength light, while narrow bandgap cells absorb long-wavelength light. Among them, mixed halide perovskite cells with a bandgap >1.65 eV are generally defined as wide bandgap perovskite cells.

[0003] To meet the requirements of different bandgap ranges, introducing a mixture of bromides and iodides is a common strategy for wide-bandgap perovskite thin films. A larger bromide-to-iodine ratio naturally leads to phase separation, which is considered a major cause of photoinstability. On the other hand, wide-bandgap perovskite solar cells exhibit more severe open-circuit voltage losses compared to conventional bandgap perovskite solar cells. One approach to improve related performance is to form two-dimensional / three-dimensional perovskite heterojunctions.

[0004] This strategy can be broadly categorized into two types. One type involves adding long-chain molecules to the surface passivator to construct two-dimensional / three-dimensional heterostructures at the interface. The other type uses a small amount of long-chain molecules as bulk additives to form a small number of two-dimensional / three-dimensional heterostructures at the bulk grain boundaries. Long-chain molecules can hinder ion migration and suppress charge recombination, improving the stability of the cell. However, they can also hinder carrier transport, thereby reducing the cell's performance. Therefore, existing methods struggle to simultaneously achieve the goals of efficiency and stability in wide-bandgap perovskite solar cells.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a low-dimensional layered wide-bandgap perovskite material, a wide-bandgap perovskite solar cell and a method for preparing the same, in order to solve the problem that existing wide-bandgap perovskite solar cells cannot simultaneously have good efficiency and stability.

[0007] The technical solution of the present invention is as follows:

[0008] In a first aspect, the present invention provides a low-dimensional layered wide-bandgap perovskite material, wherein the chemical formula of the low-dimensional layered wide-bandgap perovskite material is A2B. n-1 Pb n X 3n+1Where A is at least one of 4-fluoro-phenylethylammonium ion, phenylethylammonium ion, butammonium ion, and octylammonium ion, B is at least one of methylamine ion, formamidinium ion, and cesium ion, X is at least one halide ion, and n is greater than 1 and less than 10.

[0009] Optionally, the low-dimensional layered wide-bandgap perovskite material is in powder or thin film form.

[0010] Optionally, the chemical formula of the low-dimensional layered wide-bandgap perovskite material is (4F-PEA)2(FA). 0.73 Cs 0.27 ) 5.5 Pb 6.5 (I 0.78 Br 0.22 ) 20.5 4F-PEA is 4-fluoro-phenylethylammonium ion, and FA is formamidinium ion.

[0011] A second aspect of the present invention provides a method for preparing the low-dimensional layered wide-bandgap perovskite material of the present invention as described above, comprising the following steps:

[0012] Press A2B n-1 Pb n X 3n+1 The stoichiometric ratio of each element is determined by mixing Al, BX, and PbX in an organic solvent or by mixing ABr, BX, and PbX in an organic solvent to obtain a precursor solution; wherein Al is at least one of 4-fluoro-phenylethylammonium iodide, phenylethylammonium iodide, butylammonium iodide, and octylammonium iodide; ABr is at least one of 4-fluoro-phenylethylammonium bromide and phenylethylammonium bromide; BX is at least one of methylamine halide, formamidinium halide, and cesium halide; and PbX is at least one lead halide.

[0013] The precursor solution is reacted to obtain a powdered low-dimensional layered wide-bandgap perovskite material; or, the perovskite precursor solution is coated and annealed to obtain a thin film low-dimensional layered wide-bandgap perovskite material.

[0014] Optionally, the annealing temperature is 105–120°C, and the annealing time is 20–40 min.

[0015] Optionally, the coating method includes one of spin coating, blade coating, and slot coating;

[0016] The organic solvent includes at least one of N,N-dimethylformamide and dimethyl sulfoxide.

[0017] A third aspect of the present invention provides a wide-bandgap perovskite solar cell, wherein the wide-bandgap perovskite solar cell comprises a first electrode, a perovskite light-absorbing layer and a second electrode stacked sequentially, and the perovskite light-absorbing layer comprises the low-dimensional layered wide-bandgap perovskite material described above and / or the low-dimensional layered wide-bandgap perovskite material prepared by the preparation method described above.

[0018] Optionally, the wide-bandgap perovskite solar cell further includes a hole transport layer disposed between the first electrode and the perovskite light-absorbing layer, and an electron transport layer and a hole blocking layer disposed between the perovskite light-absorbing layer and the second electrode; the electron transport layer is disposed close to the perovskite light-absorbing layer, and the hole blocking layer is disposed close to the second electrode.

[0019] A fourth aspect of the present invention provides a method for fabricating a wide-bandgap perovskite solar cell, wherein the method for fabricating the wide-bandgap perovskite solar cell includes the following steps:

[0020] Provide the first electrode;

[0021] A perovskite light-absorbing layer is formed on the first electrode. The perovskite light-absorbing layer includes the low-dimensional layered wide-bandgap perovskite material of the present invention as described above and / or the low-dimensional layered wide-bandgap perovskite material prepared by the preparation method of the present invention as described above.

[0022] A second electrode is formed on the perovskite light-absorbing layer to obtain the wide-bandgap perovskite solar cell.

[0023] Optionally, the method for fabricating the wide-bandgap perovskite solar cell further includes the following steps:

[0024] A hole transport layer is formed between the first electrode and the perovskite light-absorbing layer;

[0025] An electron transport layer and a hole blocking layer are formed between the perovskite light-absorbing layer and the second electrode. The electron transport layer is disposed close to the perovskite light-absorbing layer, and the hole blocking layer is disposed close to the second electrode.

[0026] Beneficial effects: The low-dimensional layered wide-bandgap perovskite material provided by this invention exhibits excellent environmental stability, with a bandgap reaching 1.70 eV. The open-circuit voltage of perovskite solar cells based on this low-dimensional layered wide-bandgap perovskite material can reach 1.27 V, and the voltage can be measured at 0.1 cm⁻¹. 2 It achieves a photoelectric conversion efficiency of 20.18% within the effective area and exhibits good stability. Attached Figure Description

[0027] Figure 1The image shows the XRD pattern of the low-dimensional layered wide-bandgap perovskite light-absorbing layer in Example 1.

[0028] Figure 2 The image shows the GIWAXS test results of the low-dimensional layered wide-bandgap perovskite light-absorbing layer in Example 1, where (a) represents the intensity-q. z The graph, (b) is q z -q xy Line graph.

[0029] Figure 3 This is a current density-voltage curve of the wide-bandgap perovskite solar cell in Example 1.

[0030] Figure 4 The figure shows the external quantum efficiency test results of the wide-bandgap perovskite solar cell in Example 1.

[0031] Figure 5 The figure shows the stability test results of the wide-bandgap perovskite solar cell in Example 1, where (a) is J sc - Time curve, (b) is the normalized PCE-time curve. Detailed Implementation

[0032] This invention provides a low-dimensional layered wide-bandgap perovskite material, a wide-bandgap perovskite solar cell, and a method for preparing the same. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0034] This invention provides a low-dimensional layered wide-bandgap perovskite material (belonging to the RP-type perovskite, which is a layered perovskite structure), wherein the chemical formula of the low-dimensional layered wide-bandgap perovskite material is A2B. n-1 Pb n X 3n+1 Where A is at least one of 4-fluoro-phenylethylammonium ion, phenylethylammonium ion, butammonium ion, and octylammonium ion, B is at least one of methylamine ion, formamidinium ion, and cesium ion, X is at least one halide ion, and n is a value greater than 1 and less than 10 (n is the number of restricted lead halide octahedra).

[0035] The low-dimensional layered wide-bandgap perovskite material provided in this invention exhibits excellent environmental stability, with a bandgap reaching 1.70 eV. The open-circuit voltage of perovskite solar cells based on this material can reach 1.27 V at a depth of 0.1 cm⁻¹. 2 It achieves a photoelectric conversion efficiency of 20.18% within the effective area and exhibits good stability.

[0036] In some implementations, the value of n is greater than or equal to 5 and less than or equal to 7, for example, it can be 5, 5.5, 6, 6.5 or 7, etc.

[0037] In some embodiments, the low-dimensional layered wide-bandgap perovskite material is in powder or thin film form.

[0038] In some embodiments, the chemical formula of the low-dimensional layered wide-bandgap perovskite material is (4F-PEA)2(FA). 0.73 Cs 0.27 ) 5.5 Pb 6.5 (I 0.78 Br 0.22 ) 20.5 4F-PEA is 4-fluoro-phenylethylammonium ion, and FA is formamidinium ion.

[0039] This invention also provides a method for preparing the low-dimensional layered wide-bandgap perovskite material as described above, comprising the following steps:

[0040] S11, Press A2B n-1 Pb n X 3n+1 The stoichiometric ratios of each element are determined by mixing Al, BX, and PbX in an organic solvent, or by mixing ABr, BX, and PbX in an organic solvent to obtain a precursor solution; wherein, Al is at least one of 4-fluoro-phenylethyl ammonium iodide (4F-PEAI), phenylethyl ammonium iodide (PEAI), butyl ammonium iodide (BAI), and octyl ammonium iodide (OAI); and ABr is 4-fluoro-phenylethyl ammonium bromide (4F-PEABr) or phenylethyl ammonium bromide (PE... BX is at least one of the following: ABr; BX is at least one of the following: methyl halides (e.g., methyl chloride, abbreviated as MABr; methyl iodide, abbreviated as MAI, etc.), formamidine halides (e.g., formamidine chloride, abbreviated as FACl; formamidine bromide, abbreviated as FABr; formamidine iodide, abbreviated as FAI, etc.), cesium halides (e.g., CsCl, CsBr, CsI, etc.), and PbX is at least one of the following: PbCl2, PbBr2, PbI2, etc.

[0041] S12. After reacting the precursor solution, a low-dimensional layered wide-bandgap perovskite material in powder form is obtained; or, the perovskite precursor solution is coated and annealed to obtain a low-dimensional layered wide-bandgap perovskite material in thin film form (i.e., a low-dimensional layered wide-bandgap perovskite thin film).

[0042] The preparation method provided by this invention is simple and can prepare low-dimensional layered wide-bandgap perovskite materials in powder form or thin film form.

[0043] In some embodiments, the annealing temperature is 105-120°C (e.g., 105°C, 110°C, 115°C, or 120°C), and the annealing time is 20-40 min (e.g., 20 min, 25 min, 30 min, 35 min, or 40 min).

[0044] In some embodiments, the coating method includes, but is not limited to, spin coating, blade coating, and slot coating.

[0045] In some embodiments, the organic solvent includes at least one of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), but is not limited thereto.

[0046] This invention also provides a wide-bandgap perovskite solar cell, wherein the wide-bandgap perovskite solar cell includes a first electrode, a perovskite light-absorbing layer and a second electrode stacked sequentially, and the perovskite light-absorbing layer includes the low-dimensional layered wide-bandgap perovskite material described in this invention embodiment and / or the low-dimensional layered wide-bandgap perovskite material prepared by the preparation method described in this invention embodiment.

[0047] The present invention does not limit the structural type of wide-bandgap perovskite solar cells; they can be either inverted (pin-type) or conventional (nip-type) structures.

[0048] The first electrode includes a flexible substrate or a rigid substrate and an electrode material layer located on the surface of the flexible substrate or the rigid substrate. The flexible substrate includes one of polystyrene (PET) substrate and polynaphthalene dicarboxylic acid (PEN). The rigid substrate includes glass. The electrode material layer includes a transparent conductive oxide, which includes fluorine-doped tin oxide (FTO), indium tin oxide (ITO), and aluminum-doped zinc oxide (AZO). For example, the first electrode is ITO conductive glass.

[0049] In some embodiments, the second electrode includes at least one of silver, copper, aluminum and gold, but is not limited thereto. The thickness of the second electrode is 60 to 150 nm, for example, it can be 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or 150 nm.

[0050] Of course, the first electrode can also be at least one of silver, copper, aluminum and gold, but is not limited to this. In this case, the second electrode is a flexible substrate or a rigid substrate and an electrode material layer located on the surface of the flexible substrate or the rigid substrate. The selection of the electrode material layer is described above.

[0051] In some embodiments, the thickness of the perovskite light-absorbing layer is 300–600 nm, for example, it can be 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm or 600 nm.

[0052] In some embodiments, the wide-bandgap perovskite solar cell further includes a hole transport layer disposed between the first electrode and the perovskite light-absorbing layer, and an electron transport layer and a hole blocking layer disposed between the perovskite light-absorbing layer and the second electrode; the electron transport layer is disposed close to the perovskite light-absorbing layer, and the hole blocking layer is disposed close to the second electrode.

[0053] In some embodiments, the thickness of the hole transport layer is 5 to 25 nm, for example, it can be 5 nm, 10 nm, 15 nm, 20 nm or 25 nm.

[0054] In some embodiments, the hole transport layer includes a hole transport material, which includes an organic polymer or a self-assembled monolayer (SAM) material, etc. The organic polymer includes, but is not limited to, at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS); the self-assembled monolayer (SAM) material includes, but is not limited to, at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), and [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB).

[0055] In some embodiments, the thickness of the electron transport layer is 20–50 nm, for example, it can be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm.

[0056] In some embodiments, the electron transport layer includes an electron transport material, which includes at least one of organic electron transport materials and inorganic electron transport materials, wherein the organic electron transport material includes [6,6]-phenyl-C 61 The inorganic electron transport material comprises, but is not limited to, at least one of methyl butyrate (PC61BM) and C60, and includes at least one of titanium dioxide (TiO2) and tin dioxide (SnO2).

[0057] In some embodiments, the thickness of the hole blocking layer is 4 to 8 nm, for example, it can be 4 nm, 5 nm, 6 nm, 7 nm or 8 nm.

[0058] In some embodiments, the hole-blocking layer includes a hole-blocking material, which includes, but is not limited to, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, also known as copper bath) and 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI).

[0059] This invention also provides a method for fabricating a wide-bandgap perovskite solar cell (taking a pin-type cell as an example), wherein the method for fabricating the wide-bandgap perovskite solar cell includes the following steps:

[0060] S21, Provide the first electrode;

[0061] S22. A hole transport layer is formed on the first electrode;

[0062] S23. A perovskite light-absorbing layer is formed on the hole transport layer; the perovskite light-absorbing layer includes the low-dimensional layered wide-bandgap perovskite material described in the embodiments of the present invention and / or the low-dimensional layered wide-bandgap perovskite material prepared by the preparation method described in the embodiments of the present invention.

[0063] S24. An electron transport layer is formed on the perovskite light-absorbing layer;

[0064] S25. A hole blocking layer is formed on the electron transport layer;

[0065] S26. A second electrode is formed on the hole blocking layer to obtain the wide-bandgap perovskite solar cell.

[0066] In step S22, a hole transport layer can be prepared by spin coating. Specifically, the hole transport material can be mixed with a solvent and then spin coated.

[0067] In step S24, the electron transport layer can be prepared by spin coating. Specifically, the electron transport material can be mixed with a solvent and then spin coated. Alternatively, the electron transport layer can be prepared by thermal evaporation deposition, for example, in… At a certain evaporation rate, C60 is deposited through thermal evaporation to form an electron transport layer.

[0068] In step S25, a hole-blocking layer can be formed using a thermal evaporation deposition method.

[0069] In step S26, a second electrode can be formed using a thermal evaporation deposition method.

[0070] The present invention will be further described below through specific embodiments.

[0071] Example 1

[0072] This embodiment provides a method for fabricating a wide-bandgap perovskite solar cell, comprising the following steps:

[0073] (1) Processing of ITO conductive glass

[0074] The ITO conductive glass was ultrasonically cleaned sequentially in diluted detergent, deionized water, and isopropanol for 20 minutes each. After drying, the cleaned ITO conductive glass was treated with ultraviolet ozone for 30 minutes to obtain clean ITO conductive glass.

[0075] (2) Fabrication of a hole transport layer on ITO conductive glass

[0076] A 4PADCB solution (4PADCB solution in ethanol, concentration 1.0 mg / mL) was spin-coated onto ITO conductive glass at 3000 rpm for 30 seconds, followed by annealing at 100°C for 10 minutes to obtain a hole transport layer with a thickness of 5 nm.

[0077] (3) Fabrication of a low-dimensional layered wide-bandgap perovskite light-absorbing layer on the hole transport layer

[0078] 64.1 mg of 4F-PEAI, 82.6 mg of FAI, 276.6 mg of PbI2, 66.0 mg of PbBr2, 38.4 mg of CsBr, and 4.6 mg of MACl (as an additive) were added to a mixed solution of 570 μL of DMF and 30 μL of DMSO and shaken for 8 hours to obtain the precursor solution.

[0079] 45 μL of precursor solution was dropped onto the hole transport layer and spin-coated at 5000 rpm for 60 s. During spin-coating, the perovskite wet film was blown with nitrogen gas at 0.3 MPa to accelerate solvent evaporation. Then, it was annealed at 110 °C for 30 min on a heating stage to obtain a low-dimensional layered wide-bandgap perovskite light-absorbing layer with a thickness of 430 nm. The chemical formula of the low-dimensional layered wide-bandgap perovskite is (4F-PEA)₂(FA). 0.73 Cs 0.27 ) 5.5 Pb 6.5 (I 0.78 Br 0.22 ) 20.5 The band gap is 1.70 eV.

[0080] (4) Fabrication of an electron transport layer, a hole blocking layer and a silver electrode on a low-dimensional layered wide-bandgap perovskite light-absorbing layer

[0081] A PC61BM solution (PC61BM dissolved in chlorobenzene, with a concentration of 10 mg / mL) was spin-coated on a low-dimensional layered wide-bandgap perovskite light-absorbing layer at 3000 rpm for 30 s to obtain a PC61BM layer with a thickness of 35 nm.

[0082] exist At an evaporation rate of 10 nm, a C60 layer with a thickness of 10 nm was deposited on the PC61BM layer by thermal evaporation deposition method to obtain an electron transport layer (including the stacked PC61BM layer and C60 layer).

[0083] exist At an evaporation rate of 5 nm, a hole-blocking layer was obtained by depositing a 5 nm thick BCP on a C60 layer using a thermal evaporation deposition method.

[0084] exist At an evaporation rate of 0.5, a silver electrode with a thickness of 90 nm was deposited on the hole-blocking layer by thermal evaporation deposition.

[0085] test:

[0086] (1) X-ray diffraction (XRD) was performed on the low-dimensional layered wide-bandgap perovskite light-absorbing layer in Example 1, and the results are as follows: Figure 1 As shown, a peak with n=2 is observed, confirming that it is a low-dimensional layered perovskite material.

[0087] (2) Grazing incidence wide-angle X-ray scattering (GIWAXS) was performed on the low-dimensional layered wide-bandgap perovskite light-absorbing layer in Example 1, and the results are as follows: Figure 2 As shown (where q) z q represents an out-of-plane vector. xy (representing in-plane vectors), it can be seen that this low-dimensional layered wide-bandgap perovskite has good orientation.

[0088] (3) A transient scan was performed on the wide-bandgap perovskite solar cell in Example 1, and its current density-voltage curve is shown below. Figure 3 As shown, its photoelectric conversion efficiency (PCE) is 20.18%, its fill factor (FF) is 78.88%, and its short-circuit current (J) is... sc The value is 20.16 mA·cm. -2 Open circuit voltage (V) oc The voltage is 1.27V.

[0089] (4) The external quantum efficiency of the wide-bandgap perovskite solar cell in Example 1 was tested, and the results are as follows: Figure 4 As shown, its band gap Eg = 1.70 eV (for wide band gap perovskite materials) is approximately 90%.

[0090] (5) The stability of the wide-bandgap perovskite solar cell in Example 1 was tested, and the results are as follows: Figure 5 As shown, the steady-state output efficiency of the wide-bandgap perovskite solar cell in Example 1 is 19.9%, and the PCE remains basically unchanged after 500 hours of operation, demonstrating good stability.

[0091] In summary, this invention provides a low-dimensional layered wide-bandgap perovskite material, a wide-bandgap perovskite solar cell, and a method for fabricating the same. The low-dimensional layered wide-bandgap perovskite material provided by this invention exhibits excellent environmental stability, with a bandgap reaching 1.70 eV. The perovskite solar cell based on this low-dimensional layered wide-bandgap perovskite material achieves an open-circuit voltage of 1.27 V at 0.1 cm⁻¹. 2 It achieves a photoelectric conversion efficiency of 20.18% within the effective area and exhibits good stability.

[0092] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A low-dimensional layered wide-bandgap perovskite material, characterized in that, The chemical formula of the low-dimensional layered wide-bandgap perovskite material is (4F-PEA)2(FA). 0.73 Cs 0.27 ) 5.5 Pb 6.5 (I 0.78 Br 0.22 ) 20.5 4F-PEA is 4-fluoro-phenylethylammonium ion, and FA is formamidinium ion; The band gap of the low-dimensional layered wide-bandgap perovskite material is 1.70 eV.

2. The low-dimensional layered wide-bandgap perovskite material according to claim 1, characterized in that, The low-dimensional layered wide-bandgap perovskite material is in powder or thin film form.

3. A method for preparing the low-dimensional layered wide-bandgap perovskite material according to claim 1, characterized in that, Includes the following steps: Press (4F-PEA)2(FA) 0.73 Cs 0.27 ) 5.5 Pb 6.5 (I 0.78 Br 0.22 ) 20.5 The stoichiometric ratio of each element was determined by adding 4F-PEAI, FAI, PbI2, PbBr2 and CsBr to an organic solvent and mixing them to obtain a precursor solution. After reacting the precursor solution, a low-dimensional layered wide-bandgap perovskite material in powder form is obtained. Alternatively, the precursor solution can be coated and annealed to obtain a low-dimensional layered wide-bandgap perovskite material in thin film morphology.

4. The preparation method according to claim 3, characterized in that, The annealing temperature is 105~120℃, and the annealing time is 20~40 min.

5. The preparation method according to claim 3, characterized in that, The coating method includes one of spin coating, blade coating, and slot coating; The organic solvent includes at least one of N,N-dimethylformamide and dimethyl sulfoxide.

6. A wide-bandgap perovskite solar cell, characterized in that, The wide-bandgap perovskite solar cell includes a first electrode, a perovskite light-absorbing layer, and a second electrode stacked sequentially. The perovskite light-absorbing layer includes the low-dimensional layered wide-bandgap perovskite material according to any one of claims 1-2 and / or the low-dimensional layered wide-bandgap perovskite material prepared by the preparation method according to any one of claims 3-5.

7. The wide-bandgap perovskite solar cell according to claim 6, characterized in that, The wide-bandgap perovskite solar cell further includes a hole transport layer disposed between the first electrode and the perovskite light-absorbing layer, and an electron transport layer and a hole blocking layer disposed between the perovskite light-absorbing layer and the second electrode; the electron transport layer is disposed close to the perovskite light-absorbing layer, and the hole blocking layer is disposed close to the second electrode.

8. A method for fabricating a wide-bandgap perovskite solar cell, characterized in that, The fabrication method of the wide-bandgap perovskite solar cell includes the following steps: Provide the first electrode; A perovskite light-absorbing layer is formed on the first electrode, wherein the perovskite light-absorbing layer comprises the low-dimensional layered wide-bandgap perovskite material according to any one of claims 1-2 and / or the low-dimensional layered wide-bandgap perovskite material prepared by the preparation method according to any one of claims 3-5. A second electrode is formed on the perovskite light-absorbing layer to obtain the wide-bandgap perovskite solar cell.

9. The preparation method according to claim 8, characterized in that, The method for fabricating the wide-bandgap perovskite solar cell further includes the following steps: A hole transport layer is formed between the first electrode and the perovskite light-absorbing layer; An electron transport layer and a hole blocking layer are formed between the perovskite light-absorbing layer and the second electrode. The electron transport layer is disposed close to the perovskite light-absorbing layer, and the hole blocking layer is disposed close to the second electrode.

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