Perovskite solar cell and preparation method thereof and perovskite photovoltaic cell module

Abstract

This disclosure provides a perovskite solar cell, its fabrication method, and a perovskite photovoltaic cell module. A perovskite solar cell includes a substrate layer, a hole transport layer, a perovskite layer, and an electron transport layer stacked sequentially from the inside to the outside of the substrate layer, and also includes an interface modification layer stacked between the hole transport layer and the perovskite layer. In this application's perovskite solar cell, by adding a polymer material at the interface of the perovskite material, the electrical properties at the perovskite material interface are altered, interface defects are passivated, and non-radiative recombination at the interface is reduced. This improves the problem of severe open-circuit voltage loss in wide-bandgap perovskite materials, enhances the photoelectric performance of the perovskite solar cell, and gives the perovskite solar cell better stability.

Description

Technical Field

[0001] This disclosure relates to the field of solar cell technology, and in particular to a perovskite solar cell, a method for preparing the same, and a perovskite photovoltaic cell module. Background Technology

[0002] Currently, with rapid economic and social development, energy demand has become a common issue for human survival. The massive consumption of traditional fossil fuels and the resulting environmental problems have made green and renewable clean energy a focus of global attention, among which solar energy is the largest and most widely distributed green energy source.

[0003] Solar cells convert light energy into electrical energy; therefore, the effective development of solar cell devices is a crucial way to achieve more efficient utilization of solar energy. Among them, perovskite solar cells are one of the most promising emerging solar cells in the photovoltaic field in recent years. They possess advantages such as tunable bandgap, high light absorption coefficient, and simple fabrication, and are considered a highly promising next-generation photovoltaic technology. It is worth noting that tandem cells combining perovskite and silicon solar cells can utilize sunlight more efficiently, achieving higher photoelectric conversion efficiency.

[0004] In tandem solar cells with crystalline silicon, perovskite cells, acting as the top cell, require a bandgap of ~1.7 eV to meet the solar cell's sunlight absorption requirements. However, while widening the bandgap of perovskite cells to meet the tandem cell's requirements, this comes at the cost of reduced device efficiency, primarily due to excessive open-circuit voltage loss within the cell.

[0005] Researchers have made many attempts to address the problem of excessive open-circuit voltage loss in wide-bandgap perovskite materials. For example, introducing suitable additives into the perovskite film can reduce phase separation, improve film stability, and enhance device performance. Introducing passivation materials at the upper and lower interfaces of the perovskite film is also a common method to improve open-circuit voltage loss. Summary of the Invention

[0006] This disclosure provides a perovskite solar cell, a method for preparing the same, and a perovskite photovoltaic cell module, to at least solve one of the technical problems existing in the prior art.

[0007] According to a first aspect of this disclosure, a perovskite solar cell is provided, comprising a substrate layer, a hole transport layer, a perovskite layer, and an electron transport layer stacked sequentially from the inside to the outside on the substrate layer, and further comprising an interface modification layer, wherein the interface modification layer is stacked between the hole transport layer and the perovskite layer.

[0008] In one embodiment, the material of the interface modification layer comprises a polymer material.

[0009] In one feasible embodiment, the polymer material is one of polyvinylidene fluoride, polyhexafluoropropylene, and poly(vinylidene fluoride-co-hexafluoropropylene).

[0010] In one feasible embodiment, the thickness of the interface modification layer is 5 - 20 nm.

[0011] In one feasible embodiment, the interface modification layer can be prepared once or multiple times.

[0012] In one feasible embodiment, the band gap of the perovskite layer is above 1.65 eV.

[0013] In one feasible embodiment, the material of the hole transport layer is one or more of NiO x , MoO3, and Cu2O;

[0014] The material of the electron transport layer is one or more of fullerene, graphene, [6,6]-phenyl-C61-butyric acid methyl ester, SnO2, and BCP.

[0015] In one feasible embodiment, the material of the perovskite layer is an inorganic perovskite material, and the inorganic perovskite material is CsPbX3, where X is Cl, Br, or I, CsPb(X a Y 1-a )3, where X is Cl, Br, or I, Y is Cl, Br, or I, and 0 < a < 1;

[0016] Or, the material of the perovskite layer is an organic-inorganic perovskite material, and the organic-inorganic perovskite material is MAPbX3, where X is Cl or Br, MAPb(I 1-x Br x )3, 0.2 < x < 1, MA 1-x Cs x Pb(I 1-y Br y )3, 0.2 < x < 1, 0.2 < y < 1, FAPbX3, where X is Cl or Br, FAPb(I 1-x Br x )3, 0.2 < x < 1, FA 1-x Cs x Pb(I 1-y Br y )3, 0.15 < x < 1, 0.2 < y < 1, (FA y MA 1-y ) 1-x Cs x Pb(I 1-z Br z )3, 0.2 < x < 1, 0 < y < 1, 0.15 < z < 1; MA is methylammonium ion, and FA is formamidinium ion.

[0017] According to a second aspect of this disclosure, a method for fabricating the perovskite solar cell described above is provided, the method comprising:

[0018] A base layer is provided, and a hole transport layer is fabricated on the base layer;

[0019] An interface modification layer is prepared on the surface of the hole transport layer opposite to the substrate layer;

[0020] A perovskite layer is prepared on the surface of the interface modification layer that is opposite to the hole transport layer.

[0021] An electron transport layer is prepared on the surface of the perovskite layer opposite to the interface modification layer.

[0022] In one embodiment, preparing an interface modification layer on the surface of the hole transport layer away from the substrate layer includes: dissolving a polymer material in an organic solvent to obtain a solution with a concentration of 0.5–3 mg / mL; coating the solution onto the surface of the hole transport layer away from the substrate layer and annealing it to obtain the interface modification layer.

[0023] In one embodiment, the organic solvent is one or more of N,N-dimethylformamide, dimethylacetamide, DMSO / DBSO mixed solvent, DMF / DMSO mixed solvent, N-methylpyrrolidone, tetrahydrofuran, acetone, methyl ethyl ketone, xylene, toluene, ethyl acetate, butyl acetate, cyclohexanone, and methylcyclohexanone.

[0024] According to a third aspect of this disclosure, a perovskite photovoltaic cell module is provided, comprising the perovskite solar cell described above, or a perovskite solar cell prepared by the preparation method described above.

[0025] Compared with the prior art, the advantages of this application are as follows: 1) In the perovskite solar cell of this application, by adding polymer materials at the interface of the perovskite material, the electrical properties at the interface of the perovskite material are changed, interface defects are passivated, and non-radiative recombination at the interface is reduced, thereby improving the problem of severe open-circuit voltage loss of wide-bandgap perovskite materials, improving the photoelectric performance of perovskite solar cells, and making perovskite solar cells have better stability. 2) In the perovskite solar cell of this application, when the interface modification layer material is PVDF-HFP polymer material, the fluorine atoms in PVDF-HFP can form strong hydrogen bonds with the organic cations in the perovskite thin film layer and with Pb 2+ Coordination bonds are formed, providing effective interface passivation. Based on the interaction between PVDF-HFP and perovskite materials, the charge transport interface is optimized, thereby enabling perovskite solar cells to have higher photoelectric conversion efficiency and better stability.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0027] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which:

[0028] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0029] Figure 1 A schematic diagram of the structure of the perovskite solar cell disclosed herein is shown;

[0030] Figure 2 A schematic diagram of the structure of the perovskite solar cell of Embodiment 1 of this disclosure is shown;

[0031] Figure 3 A scanning electron microscope image of a cross-section of the perovskite solar cell of Embodiment 1 of this disclosure is shown;

[0032] Figure 4 The current density and voltage curves of perovskite solar cells prepared according to embodiments and comparative examples of this disclosure are shown.

[0033] Explanation of the reference numerals: 10 - conductive substrate layer, 20 - hole transport layer, 30 - interface modification layer, 40 - perovskite layer, 50 - electron transport layer, 60 - metallic conductive layer. Detailed Implementation

[0034] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0035] Currently, wide-bandgap perovskite materials are an important component of tandem solar cells, but their excessive open-circuit voltage loss hinders the improvement of the final efficiency of tandem solar cells. We have found that some polymer materials have a very positive effect on improving the quality of perovskite films. Thanks to the abundant functional groups in polymer materials, incorporating polymer additives into perovskite films or using them as intermediate layers at the perovskite upper / lower interface can form stable interactions with the perovskite, thereby improving the ionic properties of the bulk phase or interface and enhancing the performance of the solar cell device. Therefore, introducing suitable polymer materials into wide-bandgap perovskite materials to improve their photoelectric performance is highly feasible. Therefore, this application describes the application of a polymer material to a wide-bandgap perovskite material (bandgap E...). g The lower interface (>1.65eV) is improved to enhance its interface properties and reduce the open-circuit voltage loss of perovskite materials.

[0036] Based on this, according to an embodiment of the present disclosure, such as Figure 1 As shown, the present invention provides a wide-bandgap perovskite solar cell, which includes a conductive substrate layer 10, a hole transport layer 20, a perovskite layer 40, an electron transport layer 50, and a metal conductive layer 60, which are stacked sequentially from the inner layer to the outer layer (i.e. from the inside to the outside). It also includes an interface modification layer 30 stacked between the hole transport layer 20 and the perovskite layer 40.

[0037] In some embodiments, the interface modification layer 30 is made of a polymer material. Furthermore, the interface modification layer 30 can be prepared in one step or in multiple steps.

[0038] This application improves the severe open-circuit voltage loss problem of wide-bandgap perovskite materials by adding polymer materials to the interface of perovskite materials, thereby changing the electrical properties of the perovskite material interface, passivating interface defects, reducing non-radiative recombination at the interface, improving the photoelectric performance of perovskite solar cells, and making perovskite solar cells more stable.

[0039] In some embodiments, for example, the polymer material is one or a mixture of polyvinylidene fluoride, polyhexafluoropropylene, and poly(vinylidene fluoride-co-hexafluoropropylene). The poly(vinylidene fluoride-co-hexafluoropropylene) has the following structural formula: Its English abbreviation is PVDF-HFP.

[0040] When the interface modification layer material is a PVDF-HFP polymer, the fluorine atoms in PVDF-HFP can form strong hydrogen bonds with the organic cations in the perovskite film layer and with Pb. 2+Form a coordination bond to provide effective interface passivation. Based on the interaction between PVDF-HFP and perovskite materials, optimize the charge transport interface, thereby enabling the perovskite solar cell to have higher photoelectric conversion efficiency and better stability.

[0041] In some embodiments, for example, the thickness of the hole transport layer 20 is 10 - 20 nm, the thickness of the interface modification layer 30 is 5 - 20 nm, the thickness of the perovskite layer 40 is 480 - 500 nm, the thickness of the electron transport layer 50 is 20 - 50 nm, and the thickness of the metal conductive layer 60 is 50 - 100 nm.

[0042] In some embodiments, the bandgap of the perovskite layer is above 1.65 eV. When the bandgap of the perovskite layer is above 1.65 eV, the prepared perovskite solar cell can meet the requirement of absorbing sunlight for tandem cells.

[0043] In some embodiments, for example, the conductive base layer 10 is indium tin oxide transparent conductive film glass (ITO glass).

[0044] The material of the hole transport layer 20 is one or more of NiO x (nickel oxide), MoO3 (molybdenum oxide), Cu2O (cuprous oxide).

[0045] The material of the electron transport layer 50 is one or more of fullerene (C 60 ), graphene, [6,6]-phenyl-C61-butyric acid methyl ester (PC 61 BM), SnO2 (tin oxide), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0046] The material of the perovskite layer 40 is an inorganic perovskite material or an organic-inorganic perovskite material. Exemplarily, for example, the inorganic perovskite material is CsPbX3, X is Cl, Br or I, CsPb(X a Y 1-a )3, X is Cl, Br or I, Y is Cl, Br or I, 0 < a < 1;

[0047] The organic-inorganic perovskite material is MAPbX3, X is Cl or Br, MAPb(I 1-x Br x )3, 0.2 < x < 1, MA 1-x Cs x Pb(I 1-y Br y )3, 0.2 < x < 1, 0.2 < y < 1, FAPbX3, X is Cl or Br, FAPb(I 1-x Br x )3, 0.2 < x < 1, FA1-x Cs x Pb(I 1- y Br y )3, 0.15 < x < 1, 0.2 < y < 1, (FA y MA 1-y ) 1-x Cs x Pb(I 1-z Br z )3, 0.2 < x < 1, 0 < y < 1, 0.15 < z < 1; MA is methylammonium ion (CH3NH 3+ ) and FA is formamidinium ion (HC(NH2) 2+ ).

[0048] In a second aspect, according to an embodiment of the present disclosure, the present invention further provides a method for preparing a wide-bandgap perovskite solar cell, comprising:

[0049] Step (1): Provide a conductive substrate layer and prepare a hole transport layer on the conductive substrate layer;

[0050] Step (2): Prepare an interface modification layer on the surface of the hole transport layer facing away from the conductive substrate layer; the material of the interface modification layer includes a polymer material;

[0051] Step (3): Prepare a perovskite layer on the surface of the interface modification layer facing away from the hole transport layer;

[0052] Step (4): Prepare an electron transport layer on the surface of the perovskite layer facing away from the interface modification layer.

[0053] The principle of the method of this application is to dissolve the PVDF-HFP polymer material in an organic solvent, coat it on the surface of the hole transport layer, evaporate the organic solvent after annealing treatment, and finally form a polymer network (i.e., the interface modification layer) on the surface of the hole transport layer. After coating the perovskite solution, the fluorine atoms in PVDF-HFP can form strong hydrogen bonds with the organic cations in the perovskite thin film and form coordination bonds with Pb 2+ to provide effective interface passivation. Based on the interaction between PVDF-HFP and the perovskite material, the charge transport interface is optimized, thereby improving the overall device performance of the perovskite solar cell.

[0054] For example, preparing an interface modification layer on the surface of the hole transport layer facing away from the conductive substrate layer includes: dissolving the polymer material in an organic solvent to obtain a solution, and the concentration of the solution is 0.5 - 3 mg / mL;

[0055] Coating the solution on the surface of the hole transport layer facing away from the conductive substrate layer and annealing to obtain the interface modification layer.

[0056] The organic solvent is one or more of N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), DMSO / DBSO mixed solvent, DMF / DMSO mixed solvent, N-methylpyrrolidone (NMP), tetrahydrofuran (THF), acetone (Acetone), methyl ethyl ketone (MEK), xylene, toluene, ethyl acetate (EA), butyl acetate (BA), cyclohexanone, and methylcyclohexanone.

[0057] For example, the solution can be coated by spin coating, blade coating, slot coating or spraying.

[0058] For example, during annealing, the annealing temperature is 100-150℃ and the annealing time is 10-20 minutes.

[0059] Furthermore, the spin coating speed is 4000-6000 rpm, and the spin coating time is 20-40 s.

[0060] The preparation process of dissolving polymer materials in organic solvents to obtain solutions, the spin coating process, and the annealing process are all carried out in an inert atmosphere.

[0061] In some embodiments, we have also found that the interface modification layer 30 can also be disposed between the electron transport layer 50 and the perovskite layer 40, and the resulting perovskite solar cell can also improve its photoelectric performance and have better stability.

[0062] Specifically, a perovskite solar cell includes a conductive substrate layer 10, an electron transport layer 50, a perovskite layer 40, a hole transport layer 20, and a metal conductive layer 60, which are stacked sequentially from the inner layer to the outer layer. It also includes an interface modification layer 30 stacked between the electron transport layer 50 and the perovskite layer 40. The material of the interface modification layer 30 includes a polymer material.

[0063] This application improves the problem of severe open-circuit voltage loss in wide-bandgap perovskite materials by adding polymer materials to the interface of perovskite materials, thereby changing the electrical properties of the perovskite material interface, passivating interface defects, and reducing non-radiative recombination at the interface. It can also improve the photoelectric performance of perovskite solar cells and make perovskite solar cells more stable.

[0064] The fabrication method of this perovskite solar cell includes:

[0065] Step (1): Provide a conductive substrate layer 10; fabricate an electron transport layer 50 on the conductive substrate layer 10;

[0066] Step (2): An interface modification layer 30 is prepared on the surface of the electron transport layer 50 away from the conductive substrate layer 10; the material of the interface modification layer 30 includes a polymer material.

[0067] Step (3): Prepare a perovskite layer 40 on the surface of the interface modification layer 30 that is away from the electron transport layer 50;

[0068] Step (4): A hole transport layer 20 is prepared on the surface of the perovskite layer 40 away from the interface modification layer 30.

[0069] Step (5): Prepare a metal conductive layer 60 on the surface of the hole transport layer 20 away from the perovskite layer 40.

[0070] According to one embodiment of this disclosure, the present invention also provides a wide-bandgap perovskite photovoltaic cell module, comprising the perovskite solar cell described above, or a perovskite solar cell prepared by the above-described preparation method. Perovskite photovoltaic cell modules having perovskite solar cells with the above-described structure, and perovskite photovoltaic cell modules having perovskite solar cells prepared by the above-described method, both exhibit high photoelectric performance and good stability.

[0071] The present application will be further described in detail below with reference to specific embodiments:

[0072] Example 1

[0073] A wide-bandgap perovskite solar cell, such as Figure 2 As shown, the structure includes, from the innermost layer to the outermost layer, a conductive substrate layer 10, a hole transport layer 20, an interface modification layer 30, a perovskite layer 40, a first electron transport layer 51, a second electron transport layer 52, and a metallic conductive layer 60, stacked sequentially. The conductive substrate layer 10 is ITO conductive glass, the hole transport layer 20 is made of NiOx with a thickness of 10–20 nm, the interface modification layer 30 is made of poly(vinylidene fluoride-co-hexafluoropropylene) with a thickness of 5–20 nm, and the perovskite layer 40 is made of Cs. 0.2 FA 0.8 Pb(I 0.8 Br 0.2 3. The thickness of the perovskite layer is 480-500 nm. The material of the first electron transport layer 51 is methyl [6,6]-phenyl-C61-butyrate, and the thickness of the first electron transport layer is 20-30 nm. The material of the second electron transport layer 52 is BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), and the thickness of the second electron transport layer is 10-20 nm. The material of the metal conductive layer 60 is Ag, and the thickness of the metal conductive layer is 50-100 nm.

[0074] The fabrication of this perovskite solar cell includes the following steps:

[0075] Step (1), prepare hole transport layer 20:

[0076] NiO x Dissolved in ultrapure water, a spin-coating solution with a concentration of 20 mg / mL was obtained. 100 μL of the spin-coating solution was dropped onto a cleaned ITO substrate. The spin-coating speed was 6000 rpm for 30 s. After spin-coating, the substrate was placed on a 100℃ heating stage and annealed for 10–15 min to obtain NiO. x Thin film. (4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid (Me-4PACz) was dissolved in ethanol to obtain a Me-4PACz solution with a concentration of 0.5 mg / mL. 100 μL of the Me-4PACz solution was dropped onto a NiOx thin film, and spin-coated at 4000 rpm for 30 s. After spin-coating, the film was placed on a 100℃ heating stage and annealed for 10–15 min to prepare the hole transport layer 20.

[0077] Step (2), prepare interface modification layer 30:

[0078] The polymer material PVDF-HFP was dissolved in a mixed solution of DMF / DMSO (volume ratio 4:1) and heated and stirred at 55°C to obtain a solution with a concentration of 1 mg / mL. 100 μL of the solution was spin-coated onto the surface of the hole transport layer at a spin speed of 4000 rpm for 30 s. After spin-coating, the layer was annealed at 100°C for 10 min to obtain the interface modification layer.

[0079] Step (3), prepare perovskite layer 40:

[0080] PbI₂, FAI, FABr, and CsBr were weighed according to stoichiometric ratios and dissolved in a DMF / DMSO mixed solvent to obtain a 1.5 M perovskite precursor solution; the DMF:DMSO volume ratio (V:V) was 4:1. 80 μL of the perovskite precursor solution was spin-coated onto the surface of the interface modification layer. The spin-coating process consisted of two steps: the first step was spin-coating at 1000 rpm for 10 s, and the second step was spin-coating at 5000 rpm for 30 s. 120 μL of chlorobenzene was added dropwise immediately 10 s before the end of the second step. After spin-coating, the layer was annealed at 100 °C for 1 hour to obtain the perovskite layer.

[0081] Step (4), prepare electron transport layer 50:

[0082] PC 61BM was dissolved in chlorobenzene solvent to obtain a spin-coating solution with a concentration of 20 mg / mL; 60 μL of the spin-coating solution was spin-coated onto the surface of the perovskite layer at a spin speed of 2000 rpm for 30 s to obtain the first electron transport layer 51.

[0083] BCP was dissolved in isopropanol to obtain a spin-coating solution with a concentration of 0.5 mg / mL. 80 μL of the spin-coating solution was spin-coated onto the surface of the first electron transport layer at a spin speed of 5000 rpm for 30 s. After spin-coating, the second electron transport layer 52 was obtained.

[0084] Step (5), prepare the metal conductive layer 60:

[0085] An Ag electrode was prepared on the surface of the second electron transport layer by vacuum evaporation at a deposition rate of [missing information]. A metallic conductive layer is obtained, thus ultimately producing a wide-bandgap perovskite solar cell.

[0086] Example 2

[0087] This Example 2 is largely the same as Example 1, except that in step (2), the concentration of the solution required to prepare the interface modification layer is 0.5 mg / mL.

[0088] In Example 2, a wide-bandgap perovskite solar cell was finally prepared.

[0089] Example 3

[0090] This Example 3 is largely the same as Example 1, except that in step (2), the concentration of the solution required to prepare the interface modification layer is 3 mg / mL.

[0091] In Example 3, a wide-bandgap perovskite solar cell was finally prepared.

[0092] Comparative Example 1

[0093] The preparation of Comparative Example 1 is largely the same as that of Example 1, except that step (2) is not included, that is, the perovskite layer is directly prepared on the surface of the hole transport layer.

[0094] Comparative Example 1 ultimately yielded a wide-bandgap perovskite solar cell.

[0095] Comparative Example 2

[0096] The preparation of Comparative Example 2 is largely the same as that of Example 1, except that in step (2), the concentration of the solution required to prepare the interface modification layer is 5 mg / mL.

[0097] In Comparative Example 2, a wide-bandgap perovskite solar cell was finally prepared.

[0098] Characterization and Testing

[0099] 1) The cross-section of the perovskite solar cell prepared in Example 1 was tested by scanning electron microscopy, and the results are as follows: Figure 3 As shown.

[0100] Figure 3 The scanning electron microscope (SEM) image of the cross-section of the wide-bandgap perovskite solar cell fabricated in Example 1 is shown. Figure 3 As can be seen, by adding an interface modification layer made of polymer PVDF-HFP to the lower interface of the perovskite layer, the interface properties of the perovskite solar cell and the growth environment of the perovskite film can be improved, resulting in a more dense perovskite film layer.

[0101] 2) The photovoltaic performance parameters of the perovskite solar cells prepared in the above embodiments and comparative examples were tested, and the results are shown in Table 1 and... Figure 4 As shown.

[0102] Table 1. Photovoltaic performance parameters of perovskite solar cells

[0103] Examples / Comparative Examples <![CDATA[J SC (mA / cm 2 )]]> <![CDATA[V OC (V)]]> FF (%) PCE (%) Example 1 20.33 1.18 78.82 18.91 Example 2 20.20 1.21 80.01 19.49 Example 3 20.07 1.17 77.89 18.35 Comparative Example 1 19.71 1.15 75.95 17.25 Comparative Example 2 18.34 1.10 72.99 14.76

[0104] As can be seen from Table 1 above, the open-circuit voltage (V) of the wide-bandgap perovskite solar cells prepared in Examples 1-3 is... oc ), short-circuit current (J) sc The fill factor (FF) and power conversion efficiency (PCE) of the perovskite solar cell prepared in Comparative Example 2 are higher than those of Comparative Example 1 and Comparative Example 2. In Comparative Example 2, when the required solution concentration of the interface modification layer is 5 mg / mL, the open-circuit voltage (V) of the prepared perovskite solar cell is higher. oc ), short-circuit current (J) sc The fill factor (FF) and power conversion efficiency (PCE) actually decreased. Therefore, after PVDF-HFP polymer modification, the short-circuit current density, open-circuit voltage, and fill factor of the battery device all improved. This indicates that the F atoms in the polymer modification layer (interface modification layer) can improve the interface properties of the perovskite solar cell and the growth environment of the perovskite thin film, passivate harmful defects at the interface, and reduce non-radiative recombination. Thus, the photovoltaic parameters of the battery device improved after PVDF-HFP solution treatment.

[0105] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0106] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0107] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0108] The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. Furthermore, the described specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0109] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A perovskite solar cell, comprising a substrate layer, and a hole transport layer, a perovskite layer, and an electron transport layer sequentially stacked from the inside to the outside of the substrate layer, characterized in that: It also includes an interface modification layer, which is stacked between the hole transport layer and the perovskite layer.

2. The perovskite solar cell according to claim 1, characterized in that: The material of the interface modification layer includes a polymer material.

3. The perovskite solar cell according to claim 2, characterized in that: The polymer material is one of polyvinylidene fluoride, polyhexafluoropropylene, or poly(vinylidene fluoride-co-hexafluoropropylene).

4. The perovskite solar cell according to claim 1, characterized in that: The thickness of the interface modification layer is 5–20 nm.

5. The perovskite solar cell according to claim 4, characterized in that: The interface modification layer can be prepared in one step or in multiple steps.

6. The perovskite solar cell according to claim 1, characterized in that: The perovskite layer has a band gap of 1.65 eV or higher.

7. The perovskite solar cell according to claim 1, characterized in that: The hole transport layer is made of NiO. x One or more of the following: MoO3, Cu2O; The electron transport layer is made of one or more of the following materials: fullerene, graphene, methyl [6,6]-phenyl-C61-butyrate, SnO2, and BCP.

8. The perovskite solar cell according to claim 6, characterized in that: The perovskite layer is made of inorganic perovskite material, specifically CsPbX3, where X is Cl, Br, or I, or CsPb(X) a Y 1-a 3, X is Cl, Br or I, Y is Cl, Br or I, 0 <a<1; Alternatively, the material of the perovskite layer is an organic-inorganic perovskite material, and the organic-inorganic perovskite material is MAPbX3, where X is Cl or Br, MAPb(I 1-x Br x )3, 0.2 < x < 1, MA 1-x Cs x Pb(I 1-y Br y )3, 0.2 < x < 1, 0.2 < y < 1, FAPbX3, where X is Cl or Br, FAPb(I 1-x Br x )3, 0.2 < x < 1, FA 1-x Cs x Pb(I 1-y Br y )3, 0.15 < x < 1, 0.2 < y < 1, (FA y MA 1-y ) 1-x Cs x Pb(I 1-z Br z )3, 0.2 < x < 1, 0 < y < 1, 0.15 < z < 1; MA is methylammonium ion, and FA is formamidinium ion.

9. A method for preparing a perovskite solar cell according to any one of claims 1-8, characterized in that: The method includes: A base layer is provided, and a hole transport layer is fabricated on the base layer; An interface modification layer is prepared on the surface of the hole transport layer opposite to the substrate layer; A perovskite layer is prepared on the surface of the interface modification layer that is opposite to the hole transport layer. An electron transport layer is prepared on the surface of the perovskite layer opposite to the interface modification layer.

10. The preparation method according to claim 9, characterized in that: Preparing an interface modification layer on the surface of the hole transport layer away from the substrate layer includes: dissolving a polymer material in an organic solvent to obtain a solution with a concentration of 0.5–3 mg / mL; coating the solution onto the surface of the hole transport layer away from the substrate layer and annealing it to obtain the interface modification layer.

11. The preparation method according to claim 10, characterized in that: The organic solvent is one or more of N,N-dimethylformamide, dimethylacetamide, DMSO / DBSO mixed solvent, DMF / DMSO mixed solvent, N-methylpyrrolidone, tetrahydrofuran, acetone, methyl ethyl ketone, xylene, toluene, ethyl acetate, butyl acetate, cyclohexanone, and methylcyclohexanone.

12. A perovskite photovoltaic cell module, characterized in that: This includes the perovskite solar cell according to any one of claims 1-8, or the perovskite solar cell prepared by the preparation method according to any one of claims 9-11.

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