Broadband-gap perovskite solar cell and preparation method and application thereof

Abstract

The invention provides a wide-band-gap perovskite solar cell and a preparation method and application thereof. The wide-band-gap perovskite solar cell comprises a conductive substrate, a hole transport layer, a perovskite active layer, an electron transport layer and an electrode layer which are sequentially stacked. The perovskite active layer comprises an organic phosphate ester compound. According to the wide-band-gap perovskite solar cell, the organophosphate compound is introduced into the perovskite layer, Br / I competitive crystallization and component distribution are regulated and controlled, phase homogenization of wide-band-gap perovskite is achieved, the ion migration potential barrier is improved, non-radiative recombination, component degradation and crystalline phase segregation are restrained, and the performance of the solar cell is improved. Therefore, the photoelectric properties and stability of the wide-band-gap perovskite solar cell and the perovskite-organic laminated solar cell are improved, and the problems of non-uniform phase distribution, high defect density, poor stability and the like caused by ion mismatching and crystallization kinetics problems of wide-band-gap perovskite are solved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, and relates to a wide-bandgap perovskite solar cell, its preparation method and application. Background Technology

[0002] Solar energy, as a clean and renewable energy source, has received widespread attention for its development and utilization. Solar cells, as a key technology for converting solar energy into electricity, have conversion efficiency and cost-effectiveness as crucial factors driving their commercial application. Traditional single-junction solar cells are limited by the Shockley-Queisser limit, making further improvements in conversion efficiency difficult. To overcome this limitation, existing technologies have begun to explore multi-junction tandem solar cell technology, which achieves wider spectrum utilization and higher photoelectric conversion efficiency by stacking cell materials with different band gaps. In recent years, perovskite solar cells have attracted widespread attention due to their excellent photoelectric conversion efficiency and low-cost solution processing characteristics. Significant progress has also been made in tandem solar cells based on perovskite solar cells. The certified efficiencies of perovskite / crystalline silicon tandem solar cells, perovskite / perovskite tandem solar cells, perovskite-organic tandem solar cells, and perovskite / CIGS tandem solar cells have reached 34.6%, 30.1%, 25.7%, and 24.6%, respectively, showing promising application prospects in future energy supply and cost reduction. Compared with other perovskite-based tandem solar cells, perovskite organic tandem solar cells have a simpler solution-based fabrication process. They also combine the UV filtering function of perovskite with the encapsulation function of organic semiconductors, resulting in complementary stability improvements and excellent flexibility, demonstrating great potential for future development.

[0003] Although tandem solar cells based on perovskite materials have shown great potential in reducing thermal radiation loss and improving spectral utilization, their low photoelectric conversion efficiency and poor stability have limited the commercialization of the technology. Wide-bandgap perovskites are typically composed of mixed formamidinium-cesium (FA-Cs) cations and mixed bromine-iodine (Br-I) anions, making it difficult to achieve a uniform distribution of cations and halide anions under rapid non-equilibrium crystallization conditions. The smaller ionic radius of Br... - and Cs + With a larger radius I - and FA + The growth of thin films introduces differences in crystallization kinetics. Due to the mismatch in crystallization rates, the subsequent annealing process further amplifies the heterogeneity of these phase structures. These compositional deviations form non-stoichiometric structural domains, thereby amplifying defect density and ion migration, accelerating phase segregation and lattice strain. This technical defect severely affects the performance of wide-bandgap perovskite solar cells and the fabricated tandem solar cells, and also accelerates the aging process of the cells, significantly impacting their lifespan.

[0004] Based on the above research, there is a need to provide a wide-bandgap perovskite solar cell that can regulate the competitive crystallization and compositional distribution of Br / I in wide-bandgap perovskite. Summary of the Invention

[0005] The purpose of this invention is to provide a wide-bandgap perovskite solar cell, its preparation method, and its application. The wide-bandgap perovskite solar cell achieves phase homogenization of the perovskite by introducing organophosphate compounds into the perovskite layer, regulating Br / I competitive crystallization and composition distribution, thereby increasing the ion migration barrier and suppressing non-radiative recombination, component degradation, and phase segregation. This improves the photoelectric performance and stability of the wide-bandgap perovskite solar cell and the perovskite-organic tandem solar cell, and solves the problems of uneven phase distribution, high defect density, and poor stability caused by ion mismatch and crystallization kinetics in wide-bandgap perovskites.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a wide-bandgap perovskite solar cell, the wide-bandgap perovskite solar cell comprising a conductive substrate, a hole transport layer, a perovskite active layer, an electron transport layer and an electrode layer stacked sequentially.

[0008] The perovskite active layer includes organophosphate compounds.

[0009] Because wide-bandgap perovskites have mismatched ionic radii when used in tandem solar cells (e.g., Br₂... - With I-, Cs + with FA + Problems with phase distribution and crystallization kinetics can lead to uneven phase distribution and defects, which limit device performance and stability. This invention addresses these issues by adding organophosphate compounds to the perovskite active layer. Through a phosphate ligand isomerization strategy, it regulates the uniform phase distribution during the crystallization process of wide-bandgap perovskite, suppresses halide ion migration through competitive coordination, constructs a stable geometric structure with six-membered hydrogen bonds (which stabilize cations), increases the ion migration barrier, suppresses component degradation and phase segregation, and reduces non-radiative recombination and defect density. This significantly improves the photoelectric conversion efficiency and stability of wide-bandgap perovskite solar cells and perovskite-organic tandem solar cells. Simultaneously, it solves the problem of halide anion and cation phase distribution, effectively suppresses phase segregation, reduces open-circuit voltage loss in the cell, and significantly improves the cell's operational stability and photoelectric conversion efficiency.

[0010] Preferably, the organophosphate compound includes any one or a combination of at least two of phenyl phosphate, diphenyl phosphate, triphenyl phosphate, diethyl phosphate, or triethyl phosphate, with triphenyl phosphate being the most preferred.

[0011] The organophosphate compounds described in this invention are preferably triphenyl phosphates. Compared with other organophosphate compounds, the three phenyl groups in the molecular structure of triphenyl phosphates enhance the rigidity of the molecular skeleton through a conjugation effect. This not only effectively improves the interaction with perovskite, but also inhibits the migration of small molecules through steric hindrance, thereby improving the operating stability and photoelectric conversion efficiency of the battery.

[0012] Preferably, in the perovskite precursor solution used to prepare the perovskite active layer, the concentration of the organophosphate compound is 0.05-2 mg / mL, for example, it can be 0.05 mg / mL, 0.075 mg / mL, 0.1 mg / mL, 0.25 mg / mL, 0.5 mg / mL, 0.75 mg / mL, 1 mg / mL, 1.25 mg / mL, 1.5 mg / mL, 1.75 mg / mL or 2 mg / mL, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] The content of organophosphate compounds in this invention affects its effectiveness.

[0014] Preferably, in the perovskite active layer, the general chemical formula of the perovskite active layer formulation is Cs. x FA 1-x PbI y Br z Where x is 0.1-0.3, for example, it can be 0.1, 0.15, 0.2, 0.25 or 0.3; y is 1.5-2.1, for example, it can be 1.6, 1.7, 1.8, 1.9, 2.0 or 2.1; z is 0.9-1.5, for example, it can be 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, and y+z=3.

[0015] Preferably, a passivation layer is further included between the perovskite active layer and the electron transport layer.

[0016] Preferably, the passivation layer is made of PDAI (1,3-propanediamine diiodide).

[0017] Preferably, the hole transport layer is made of Me-2PACz (2-(3,6-dimethyl-9H-carbazole-9-yl)ethylphosphonic acid).

[0018] Preferably, the material of the electron transport layer includes C.60 (Fullerene).

[0019] Preferably, the electrode layer is made of Ag.

[0020] In a second aspect, the present invention provides a method for preparing a wide-bandgap perovskite solar cell as described in the first aspect, the method comprising the following steps:

[0021] A conductive substrate, a hole transport layer, a perovskite active layer, an electron transport layer, and an electrode layer are sequentially fabricated on the surface of a conductive substrate.

[0022] The perovskite precursor solution used to prepare the perovskite active layer includes organophosphate compounds.

[0023] Preferably, the conductive substrate comprises an indium tin oxide (ITO) glass substrate, which is subsequently cleaned in an ultrasonic bath with detergent, deionized water, acetone, and isopropanol for 15-20 minutes each, for example, 15 minutes, 17 minutes, 19 minutes, or 20 minutes. Then, the ITO glass substrate is dried with a nitrogen gas stream and treated with ultraviolet ozone for 15-20 minutes, for example, 15 minutes, 17 minutes, 19 minutes, or 20 minutes. Before use, the ITO glass substrate is transferred to a nitrogen-filled glove box.

[0024] Preferably, the method for preparing the hole transport layer includes spin-coating a hole transport layer solution and then annealing it.

[0025] Preferably, the concentration of the organophosphate compound in the perovskite precursor solution is 0.05-2 mg / mL, for example, it can be 0.05 mg / mL, 0.075 mg / mL, 0.1 mg / mL, 0.25 mg / mL, 0.5 mg / mL, 0.75 mg / mL, 1 mg / mL, 1.25 mg / mL, 1.5 mg / mL, 1.75 mg / mL or 2 mg / mL, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0026] In the perovskite precursor solution described in this invention, the concentration of organophosphate compounds affects the content of organophosphate compounds in the perovskite active layer, thereby affecting the effectiveness of organophosphate compounds. If there are too few organophosphate compounds, the regulation effect on perovskite crystallization and ion migration will decrease; if there are too many organophosphate compounds, it will easily cause an imbalance in crystallization kinetics.

[0027] Preferably, the method for preparing the perovskite active layer includes spin-coating a perovskite precursor solution, adding an anti-solvent during the spin-coating process, and then annealing.

[0028] Preferably, a passivation layer is prepared after the perovskite active layer is prepared and before the electron transport layer is prepared.

[0029] Preferably, the method for preparing the passivation layer includes spin coating and annealing.

[0030] Preferably, the methods for preparing the electron transport layer and the electrode layer are each independently vapor deposition methods.

[0031] Thirdly, the present invention provides a perovskite-organic tandem solar cell, which is prepared by stacking a top cell and a bottom cell at both ends using an end-to-end stacking method;

[0032] The top cell includes a wide-bandgap perovskite solar cell as described in the first aspect, and the bottom cell includes a narrow-bandgap organic cell.

[0033] For example, the method for preparing the narrow bandgap organic battery includes the following steps:

[0034] (1) Clean the indium tin oxide glass substrate sequentially in an ultrasonic bath with detergent, deionized water, acetone and isopropanol for 15-20 minutes each. Then, dry the ITO glass substrate with nitrogen gas and treat it with ultraviolet ozone for 15-20 minutes.

[0035] (2) A PEDOT:PSS hole transport layer was deposited on a glass ITO substrate by spin coating at 3000 rpm for 30 seconds, and then annealed in air at 150°C for 15 minutes; or a 20 nm MoO3 layer was thermally evaporated on the substrate as a hole transport layer, followed by the deposition of a 2PACz layer.

[0036] For bulk heterojunction (PM6:BTP-eC9:ICBA = 1:1.0:0.2) devices, the active layer solution was dynamically spin-coated onto the substrate at 3000 rpm, followed by annealing at 100°C for 10 minutes. The film thickness was controlled to be approximately 110 nm.

[0037] (3) After cooling, take 30 μL of a solution with a concentration of 1 mg·mL⁻¹. -1 The PDINO methanol solution was spin-coated onto the organic active layer at 3000 rpm for 30 seconds. Finally, at 6 × 10⁻⁶... -4 A 100 nm Ag electrode was deposited under vacuum at Pa.

[0038] Preferably, the perovskite-organic tandem solar cell includes a conductive substrate, a hole transport layer, a perovskite active layer, an interconnect layer, a narrow bandgap organic active layer, an electron transport layer, and an electrode layer.

[0039] Preferably, the method for preparing the perovskite-organic tandem solar cell includes the following steps:

[0040] In the process of preparing a wide-bandgap perovskite solar cell as described in the first aspect, after preparing the perovskite active layer, an interconnect layer, a narrow-bandgap organic active layer, an electron transport layer, and an electrode layer are prepared sequentially.

[0041] Preferably, the material of the interconnect layer includes C. 60 SnO2, Au and MoO3.

[0042] Preferably, the material of the narrow bandgap organic active layer includes PM6 (poly[[4,4-bis(2-ethylhexyl)-4H-cyclopentano[2,1-b:3,4-b']dithiophene-2,6-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl), BTP-eC9 (2,2'-[[12,13-bis(2-butyloctyl)]... 12,13-dihydro-3,9-dinonylbisthiopheno[2”,3”:4’,5’]thiopheno[2’,3’:4,5]pyrrole[3,2-e:2’,3’-g][2,1,3]benzothiadiazole-2,10-diyl]bis[methylmethylene(5,6-chloro-3-oxo-1H-indene-2,1(3H)-dimethylene)]]bis[malononitrile) and ICBA(C 60 derivative).

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] This invention significantly improves the photoelectric conversion efficiency and stability of wide-bandgap perovskite solar cells and perovskite-organic tandem solar cells by adding organophosphate compounds to the perovskite active layer. This is achieved through a phosphate ligand isomerization strategy to regulate the uniform phase distribution during the crystallization process of wide-bandgap perovskite, suppressing halide ion migration through competitive coordination, constructing a stable six-membered hydrogen bond geometry, increasing the ion migration barrier, inhibiting component degradation and phase segregation, and reducing non-radiative recombination and defect density. Simultaneously, it addresses the issue of halide anion and cation phase distribution, effectively suppressing phase segregation and thus reducing open-circuit voltage loss in the cell, significantly improving the cell's operational stability and photoelectric conversion efficiency. Attached Figure Description

[0045] Figure 1 This is an anion distribution diagram of the perovskite active layer described in Comparative Example 1 of the present invention.

[0046] Figure 2 This is an anion distribution diagram of the perovskite active layer described in Example 1 of the present invention.

[0047] Figure 3 This is a cation depth distribution diagram of the perovskite active layer described in Comparative Example 1 and Example 1 of the present invention, wherein the standard sample refers to Comparative Example 1, and the modified sample refers to Example 1.

[0048] Figure 4 The diagram shows the bandgap and photoelectric conversion efficiency of the wide bandgap perovskite solar cells described in Embodiments 1 and 2 of the present invention. The dots represent the common efficiencies of different bandgap types in the prior art in recent years, and the asterisks represent Embodiments 1 and 2 of the present invention, respectively.

[0049] Figure 5 This is a graph showing the photoelectric conversion efficiency of the perovskite-organic tandem solar cell described in Example 2 of the present invention.

[0050] Figure 6 This is a schematic diagram of the perovskite-organic tandem solar cell described in Embodiment 1 of the present invention.

[0051] The structure consists of: 1-ITO glass substrate, 2-SAM / Al2O3 layer, 3-perovskite active layer, 4-interconnect layer, 5-narrow bandgap active layer, 6-electron transport layer, and 7-metal Ag electrode layer. Detailed Implementation

[0052] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] Example 1

[0054] This embodiment provides a wide-bandgap perovskite solar cell, which includes a conductive substrate, a hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, and an electrode layer stacked sequentially.

[0055] The perovskite active layer includes triphenyl phosphate;

[0056] The fabrication method of the wide-bandgap perovskite solar cell includes the following steps:

[0057] (1) The indium tin oxide glass substrate was cleaned in the ultrasonic bath of detergent, deionized water, acetone and isopropanol for 17 minutes each. Then, the ITO glass substrate was dried with nitrogen gas flow and treated with ultraviolet ozone for 20 minutes.

[0058] (2) Before use, transfer the ITO glass substrate to a nitrogen-filled glove box. Spin-coat Me-2PACz (2-(3,6-dimethyl-9H-carbazole-9-yl)ethylphosphonic acid, at a concentration of 0.5 mg / mL in ethanol) at 4000 rpm for 30 seconds, followed by heat annealing at 100°C for 10 minutes. Then, spin-coat the Al2O3 / IPA dispersion at 5000 rpm for 30 seconds, followed by annealing at 80°C for 5 minutes.

[0059] (3) By dissolving 62.4 mg of CsI, 165.2 mg of FAI, 304.4 mg of PbI2, and 198.1 mg of PbBr2 in 1 mL of a mixed solvent of DMF and DMSO with a volume ratio of 4:1, a stoichiometric ratio of CsI was prepared. 0.2 FA 0.8 Pb(I 0.7 Br 0.3 )3 Perovskite precursor solution. Triphenyl phosphate was added to the perovskite precursor solution at a concentration of 0.3 mg / mL.

[0060] (4) A uniformly dispersed perovskite precursor solution was spin-coated onto the substrate at 5000 rpm for 40 seconds. Twenty seconds before the end of the spin-coating, 200 μL of chlorobenzene was added to the substrate as an anti-solvent. After spin-coating the perovskite precursor solution, the substrate was annealed at 100°C for 10 minutes to form a perovskite film. PDAI (1 mg·mL⁻¹) was then added. -1 Dissolved in a mixed solvent of isopropanol, the solution was spin-coated onto the prepared perovskite film at 5000 rpm for 30 seconds, and then annealed at 80°C for 5 minutes.

[0061] (5) After spin coating and brief cooling, all samples were transferred to a thermal evaporation chamber under a vacuum of 5 × 10⁻⁶. - 4 C20nm of carbon is thermally evaporated in the evaporation chamber of Pa. 60 7nm BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and 100nm Ag.

[0062] This embodiment also provides a perovskite-organic tandem solar cell, which is prepared by stacking a wide-bandgap perovskite solar cell as the top cell and a narrow-bandgap organic solar cell as the bottom cell using a two-end stacking method.

[0063] A schematic diagram of the perovskite-organic tandem solar cell is shown below. Figure 6 As shown, it includes an ITO glass substrate 1, a SAM / Al2O3 layer 2, a perovskite active layer 3, an interconnect layer 4, a narrow bandgap active layer 5, an electron transport layer 6, and a metal Ag electrode layer 7, which are stacked sequentially.

[0064] The method for fabricating the perovskite-organic tandem solar cell includes the following steps:

[0065] After the preparation in step (4) of this embodiment is completed, C is deposited sequentially. 60A 20 nm SnO2 layer, a 1 nm Au layer, and a 20 nm MoO3 layer were spin-coated, followed by the deposition of an organic active layer with a BHJ structure, an electron transport layer, and an Ag electrode.

[0066] The step of depositing the organic active layer with the BHJ structure includes: dynamically spin-coating the active layer solution at 3000 rpm, then annealing it at 100°C for 10 minutes, controlling the film thickness to 110 nm; the step of preparing the electron transport layer includes preparing 30 μL of a 1 mg·mL⁻¹ solution. -1 The PDINO methanol solution was spin-coated onto the organic active layer at a speed of 3000 rpm for 30 seconds.

[0067] Example 2

[0068] This embodiment provides a wide-bandgap perovskite solar cell. The wide-bandgap perovskite solar cell, except for step (3) of its preparation method, involves dissolving 52.0 mg CsI, 137.6 mg FAI, 147.5 mg PbI2, and 260.6 mg PbBr2 in 1 mL of a 4:1 volume ratio mixed solvent of DMF and DMSO to prepare a stoichiometric ratio of CsI. 0.2 FA 0.8 PbI 1.6 Br 1.4 Except for the perovskite precursor solution, everything else was the same as in Example 1;

[0069] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0070] Example 3

[0071] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which triphenyl phosphate is replaced with phenyl phosphate, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0072] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0073] Example 4

[0074] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which triphenyl phosphate is replaced with diphenyl phosphate, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0075] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0076] Example 5

[0077] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which triphenyl phosphate is replaced with triethyl phosphate, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0078] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0079] Example 6

[0080] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which the concentration of triphenyl phosphate added to the perovskite precursor solution is 0.05 mg / mL, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0081] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0082] Example 7

[0083] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which the concentration of triphenyl phosphate added to the perovskite precursor solution is 1 mg / mL, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0084] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0085] Example 8

[0086] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which the concentration of triphenyl phosphate added to the perovskite precursor solution is 2 mg / mL, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0087] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0088] Example 9

[0089] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which the concentration of triphenyl phosphate added in the perovskite precursor solution is 0.02 mg / mL, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0090] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0091] Example 10

[0092] This embodiment provides a wide-bandgap perovskite solar cell. Except for step (3) of its preparation method, in which the concentration of triphenyl phosphate added in the perovskite precursor solution is 2.5 mg / mL, the wide-bandgap perovskite solar cell is the same as that in Example 1.

[0093] This embodiment also provides a perovskite-organic tandem solar cell, which is the same as in Embodiment 1 except that the perovskite active layer is adapted to this embodiment.

[0094] Comparative Example 1

[0095] This comparative example provides a wide-bandgap perovskite solar cell, which is the same as Example 1 except that triphenyl phosphate is not added to the perovskite precursor solution in step (3) of its preparation method.

[0096] This comparative example also provides a perovskite-organic tandem solar cell, which is identical to Example 1 except for the adaptive change of the perovskite active layer according to this embodiment.

[0097] The anion distribution diagram of the perovskite active layer described in Comparative Example 1 of this invention is as follows: Figure 1 As shown, the anion distribution diagram of the perovskite active layer described in Example 1 is as follows. Figure 2 As shown, the cation depth distribution diagrams of the perovskite active layers described in Comparative Example 1 and Example 1 are as follows: Figure 3 As shown by Figures 1-3It is known that triphenyl phosphate can regulate the competitive crystallization and compositional distribution of wide-bandgap perovskite Br / I; the bandgap and photoelectric conversion efficiency of the wide-bandgap perovskite solar cells described in Examples 1 and 2 are shown in the figure. Figure 4 As shown, the photoelectric conversion efficiency of the perovskite-organic tandem solar cell described in Example 2 is illustrated in the figure below. Figure 5 As shown by Figure 4 and Figure 5 It is evident that the present invention can significantly improve the photoelectric conversion efficiency of stacked devices.

[0098] The types and concentrations of organophosphate compounds added to the perovskite active layer in the wide-bandgap perovskite solar cells and perovskite-organic tandem solar cells of the above embodiments and comparative examples are shown in Table 1. The photoelectric conversion efficiency of the wide-bandgap perovskite solar cells of the above embodiments and comparative examples was tested using the following methods and conditions: a solar simulator (Enlitech, model SS-F5-3A, irradiance 100 mW·cm²) was used. -2 The efficiency of the perovskite-organic tandem solar cell was tested using a simulated AM 1.5G sunlight source and a Keithley 2400 source meter in a glove box (nitrogen atmosphere). The forward scan range was -0.2V to 1.3V, and the reverse scan range was 1.2V to -0.2V, with each step being 0.02V. The test method and conditions for the perovskite-organic tandem solar cell were as follows: an Enlitech solar simulator (model SS-F5-3A, irradiance 100mW·cm²) was used. -2 The device was tested in a glove box (nitrogen atmosphere) using a simulated AM 1.5G sunlight source (JV) coupled with a Keithley 2400 source meter. The forward scan range was -0.2V to 2.2V, and the reverse scan range was 2.2V to -0.2V, with each step being 0.02V. The efficiency after 1000 hours of continuous operation was also tested. The test method and conditions were as follows: First, the JV curve was recorded to verify the voltage at the maximum power point (MPP). Then, the operational stability of the unpackaged device under continuous white LED illumination at 1 solar intensity was tested at MPP. During the entire MPP tracking process, the illumination on the PSCs was continuous except for light source calibration. The test results are shown in Table 1.

[0099] Table 1

[0100]

[0101]

[0102] The following can be seen from Table 1:

[0103] (1) The optimized wide-bandgap perovskite solar cell of this invention achieves record-breaking photoelectric conversion efficiency: for perovskites with bandgap of 1.72 eV and 1.84 eV, the photoelectric conversion efficiency is 21.39% and 19.64%, respectively, with improvements in open-circuit voltage and fill factor. Furthermore, the uniform phase distribution alleviates lattice strain in the wide-bandgap perovskite solar cell device, ensuring a T1100 hourly operation time. 95 Lifetime. When a wide-bandgap perovskite front cell is stacked with an organic front cell, a monolithic perovskite-organic tandem solar cell was demonstrated to achieve an efficiency of 26.11% (certified efficiency 25.07%; area 0.102 cm²). 2 ).

[0104] (2) As can be seen from Examples 1-2 and Comparative Example 1, the present invention can effectively improve the photoelectric conversion efficiency of perovskite-organic tandem solar cells by adding organophosphate compounds; As can be seen from Examples 1 and Examples 3-5, the organophosphate compounds of the present invention are preferably triphenyl phosphates, which can not only construct six-membered hydrogen bonds, but also have strong π-π conjugation and steric hindrance effects, which can further improve the performance of perovskite-organic tandem solar cells; As can be seen from Examples 1 and Examples 6-10, the amount of organophosphate compounds added to the perovskite active layer will affect their effect, thereby affecting the performance of perovskite-organic tandem solar cells.

[0105] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A wide-bandgap perovskite solar cell, characterized in that, The wide-bandgap perovskite solar cell includes a conductive substrate, a hole transport layer, a perovskite active layer, and an electrode layer stacked sequentially. The perovskite active layer includes organophosphate compounds.

2. The wide-bandgap perovskite solar cell according to claim 1, characterized in that, The organophosphate compounds include any one or a combination of at least two of phenyl phosphate, diphenyl phosphate, triphenyl phosphate, diethyl phosphate, or triethyl phosphate, preferably triphenyl phosphate; Preferably, the concentration of the organophosphate compound in the perovskite precursor solution used to prepare the perovskite active layer is 0.05-2 mg / mL.

3. The wide-bandgap perovskite solar cell according to claim 1 or 2, characterized in that, The perovskite active layer has the general chemical formula Cs. x FA 1-x PbI y Br z Where x is 0.1-0.3, y is 1.5-2.1, z is 0.9-1.5, and y+z=3.

4. The wide-bandgap perovskite solar cell according to any one of claims 1-3, characterized in that, A passivation layer is also included between the perovskite active layer and the electron transport layer; Preferably, the passivation layer is made of PDAI.

5. The wide-bandgap perovskite solar cell according to any one of claims 1-4, characterized in that, The hole transport layer is made of Me-2PACz; Preferably, the material of the electron transport layer includes C. 60 ; Preferably, the electrode layer is made of Ag.

6. A method for preparing a wide-bandgap perovskite solar cell as described in any one of claims 1-5, characterized in that, The preparation method includes the following steps: A conductive substrate, a hole transport layer, a perovskite active layer, an electron transport layer, and an electrode layer are sequentially fabricated on the surface of a conductive substrate. The perovskite precursor solution used to prepare the perovskite active layer includes organophosphate compounds.

7. The preparation method according to claim 6, characterized in that, In the perovskite precursor solution, the concentration of the organophosphate compound is 0.05-2 mg / mL; Preferably, a passivation layer is prepared after the perovskite active layer is prepared and before the electron transport layer is prepared.

8. A perovskite-organic tandem solar cell, characterized in that, The perovskite-organic tandem solar cell is prepared by stacking the top cell and the bottom cell at both ends using a two-end stacking method. The top cell includes a wide-bandgap perovskite solar cell as described in any one of claims 1-5, and the bottom cell includes a narrow-bandgap organic cell.

9. The perovskite-organic tandem solar cell according to claim 8, characterized in that, The perovskite-organic tandem solar cell includes a conductive substrate, a hole transport layer, a perovskite active layer, an interconnect layer, a narrow bandgap organic active layer, an electron transport layer, and an electrode layer.

10. The perovskite-organic tandem solar cell according to claim 8 or 9, characterized in that, The material of the interconnect layer includes C. 60 SnO2, Au and MoO3; Preferably, the material of the narrow bandgap organic active layer includes PM6, BTP-eC9, and ICBA.

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