Flexible perovskite cell, preparation method thereof and photovoltaic module

Abstract

The application provides a flexible perovskite battery and a preparation method and a photovoltaic module thereof, wherein an interface insertion layer is arranged between a flexible conductive substrate and a hole transport layer of the flexible perovskite battery, and the components of the interface insertion layer include metal oxide nanocrystal materials with a particle size range of 25nm-150nm. In the application, by introducing the interface insertion layer between the flexible conductive substrate and the hole transport layer of the flexible perovskite battery, the size effect and the surface chemical properties of the metal oxide nanocrystal are utilized to effectively improve the interface wettability, induce high-quality crystallization of perovskite, inhibit interface recombination through weak interaction, and enhance light absorption through light scattering, so that the film forming quality, the carrier transport efficiency and the light utilization of the flexible perovskite battery are synergistically improved; therefore, the flexible perovskite battery exhibits excellent photoelectric performance.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic device technology, and relates to a flexible perovskite cell, and more particularly to a flexible perovskite cell, its preparation method and photovoltaic module. Background Technology

[0002] With the development of wearable devices, building-integrated photovoltaics (BIPV), and portable energy systems, flexible perovskite solar cells have become a core direction of next-generation photovoltaic technology due to their high power-to-weight ratio, bendability, and low-cost solution processing advantages. However, flexible devices face severe interface compatibility issues in the process of industrialization.

[0003] However, the low surface energy and poor temperature resistance (<150℃) of flexible conductive substrates (such as PET / ITO) pose significant challenges to interfacial compatibility. The low surface energy leads to poor film quality in hole transport layers (such as PTAA), easily forming discontinuous films with both isolated island-like aggregates and micron-sized pores. This, in turn, induces dewetting and abnormal crystallization of the perovskite precursor, resulting in direct contact between the electrode and the perovskite, a surge in interfacial recombination, and poor device performance. On the other hand, the high temperatures (>200℃) required for high-quality fabrication of hole transport layers (such as sputtered NiO) exceed the tolerance limits of flexible conductive substrates.

[0004] To address the issues of poor hole transport layer coverage and low crystal quality of the perovskite layer, several technical solutions have been developed in the prior art. However, these solutions have not effectively solved the problems of poor hole transport layer coverage and low crystal quality of the perovskite layer in flexible perovskite solar cells, and the photoelectric performance of flexible perovskite solar cells cannot meet the needs of practical applications.

[0005] For example, CN117794333A discloses an optimized crystallization method for the hole transport layer of a flexible, high-efficiency, large-area perovskite solar cell. A hole transport layer, interface modification layer, metal halide perovskite layer, electron transport layer, hole blocking layer, and electrode layer are prepared on indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) transparent conductive glass using a blade coating method. NiO is selected as the electrode material. x NiO is dissolved in ultrapure water and used as an interface modification layer. x Dissolves in ultrapure water and is used to inhibit crystallization in large-area perovskite layers.

[0006] For example, CN119451513A discloses a perovskite solar cell and its fabrication method, as well as a photovoltaic module. This document aims to address the problem of uneven perovskite layer coverage in the hole transport layer affecting cell performance. To this end, the fabrication method of the perovskite solar cell in this document includes fabricating a hole transport layer on a substrate, fabricating an interface modification layer on the hole transport layer, fabricating a perovskite layer on the interface modification layer, and sequentially fabricating an electron transport layer and electrodes on the perovskite layer to obtain a perovskite solar cell.

[0007] In summary, existing flexible perovskite solar cells suffer from several drawbacks. The low surface energy of the flexible conductive substrate leads to uneven coverage of the hole transport layer, resulting in a discontinuous film. This, in turn, causes poor coverage of the hole transport layer and low crystallinity of the perovskite layer, ultimately preventing the photoelectric performance of the flexible perovskite solar cells from meeting the demands of practical applications. Therefore, developing a novel flexible perovskite solar cell, its fabrication method, and photovoltaic modules is crucial. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a flexible perovskite solar cell, its fabrication method, and a photovoltaic module. In this invention, an interface insertion layer is introduced between the flexible conductive substrate and the hole transport layer of the flexible perovskite solar cell. Utilizing the size effect and surface chemical properties of metal oxide nanocrystals, the interface wettability is effectively improved, and high-quality crystallization of the perovskite is induced. Furthermore, weak interactions suppress interfacial recombination, and light absorption is enhanced through light scattering. These factors synergistically improve the film quality, carrier transport efficiency, and light utilization of the flexible perovskite solar cell. Therefore, the flexible perovskite solar cell exhibits excellent photoelectric performance.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a flexible perovskite solar cell, wherein an interface insertion layer is disposed between the flexible conductive substrate and the hole transport layer of the flexible perovskite solar cell, and the component of the interface insertion layer includes metal oxide nanocrystals with a particle size range of 25 nm to 150 nm.

[0011] In this invention, the particle size range of the metal oxide nanocrystalline material is 25nm~150nm. For example, the particle size range can be 25nm~30nm, 25nm~40nm, 30nm~40nm, 30nm~50nm, 30nm~70nm, 30nm~100nm, 30nm~150nm, 50nm~80nm, 50nm~100nm, 50nm~150nm, 80nm~100nm, 80nm~150nm, 100nm~120nm, 100nm~150nm, or 120nm~150nm, but it is not limited to the listed numerical range. Other unlisted numerical ranges within this range are also applicable.

[0012] In the flexible perovskite solar cell provided by this invention, an interface insertion layer is introduced between the flexible conductive substrate and the hole transport layer. On the one hand, the interface insertion layer improves the wettability of the hole transport layer, enhances the coverage and film quality of the hole transport layer and the perovskite layer, thereby improving the open-circuit voltage and fill factor of the flexible perovskite solar cell. On the other hand, the hydroxyl groups (-OH) on the surface of the metal oxide nanocrystalline material can form weak interactions (such as hydrogen bonds and van der Waals forces) with sulfur atoms or benzene rings in the hole transport layer, effectively reducing non-radiative recombination at the interface and improving carrier transport efficiency, thereby further improving the open-circuit voltage and fill factor of the flexible perovskite solar cell. Furthermore, the metal oxide nanocrystalline material has anti-reflection properties and light scattering effects, which is beneficial to improving the absorption of light by the perovskite layer, thereby increasing the short-circuit current of the flexible perovskite solar cell.

[0013] In the flexible perovskite solar cell provided by this invention, the particle size range of the metal oxide nanocrystal material in the interfacial insertion layer is 25nm~150nm. The particle size of the metal oxide nanocrystal material is within this range, which can not only solve the problems of poor wettability and uneven coverage of the hole transport layer on the flexible electrode with low surface energy, but also overcome the dewetting phenomenon of the perovskite precursor solution on the surface of the hole transport layer, induce the preferential growth of perovskite crystals, thereby achieving effective suppression of interfacial recombination and simultaneous improvement of carrier extraction efficiency.

[0014] In summary, this invention introduces an interface insertion layer between the flexible conductive substrate and the hole transport layer of a flexible perovskite solar cell. By utilizing the size effect and surface chemical properties of metal oxide nanocrystals, the interfacial wettability is effectively improved, and high-quality crystallization of the perovskite is induced. Furthermore, interfacial recombination is suppressed through weak interactions, and light absorption is enhanced by light scattering. These factors synergistically improve the film quality, carrier transport efficiency, and light utilization of the flexible perovskite solar cell. Therefore, the flexible perovskite solar cell exhibits excellent photoelectric performance.

[0015] Preferably, the particle size range of the metal oxide nanocrystalline material is 60nm~140nm. For example, the particle size range can be 60nm~80nm, 60nm~100nm, 60nm~120nm, 60nm~140nm, 80nm~100nm, 80nm~120nm, 80nm~100nm, 100nm~120nm, or 100nm~140nm, but it is not limited to the listed numerical ranges. Other unlisted numerical ranges within this range are also applicable.

[0016] Preferably, the metal oxide nanocrystalline material comprises metal oxide nanocrystals, wherein the components of the metal oxide nanocrystals include any one or a combination of at least two of indium tin oxide, indium zinc oxide, indium tungsten oxide, fluorine-doped tin oxide or aluminum-doped zinc oxide, aluminum oxide or silicon oxide. Typical but non-limiting combinations include combinations of indium tin oxide and indium zinc oxide, combinations of fluorine-doped tin oxide and aluminum-doped zinc oxide, combinations of aluminum oxide and silicon oxide, combinations of indium tungsten oxide and aluminum-doped zinc oxide, or combinations of indium tin oxide, indium zinc oxide and indium tungsten oxide.

[0017] Preferably, the interface insertion layer has a transmittance of ≥80% in the 400nm~800nm ​​wavelength band and a thickness of 65nm~95nm.

[0018] In this invention, the transmittance of the interface insertion layer in the 400nm~800nm ​​wavelength band is ≥80%, for example, it can be 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98% or 100%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] In this invention, the thickness of the interface insertion layer is 65nm~95nm, for example, it can be 65nm, 68nm, 70nm, 72nm, 75nm, 78nm, 80nm, 82nm, 85nm, 88nm, 90nm, 92nm or 95nm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the flexible conductive substrate includes a polymer flexible substrate and a substrate electrode disposed on the polymer flexible substrate;

[0021] or,

[0022] The conductive substrate includes a flexible conductive substrate comprising a metal foil, and a substrate electrode disposed on the metal foil.

[0023] Preferably, the polymer flexible substrate is made of any one or a combination of at least two of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), or polydimethylsiloxane (PDMS). Typical but non-limiting combinations include combinations of PET and PEN, PI and PDMS, PET and PI, PEN and PDMS, or PET, PEN and PI.

[0024] Preferably, the metal foil includes any one or a combination of at least two of copper foil, silver foil, gold foil, aluminum foil, titanium foil, or stainless steel foil. Typical but non-limiting combinations include combinations of copper foil and silver foil, combinations of gold foil and aluminum foil, combinations of titanium foil and stainless steel foil, combinations of copper foil, aluminum foil, and stainless steel foil, or combinations of silver foil, gold foil, and titanium foil.

[0025] Preferably, the substrate electrode is made of any one or a combination of at least two of indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), fluorine-doped tin oxide (FTO), or aluminum-doped zinc oxide (AZO). Typical but non-limiting combinations include combinations of ITO and IZO, IWO and FTO, AZO and ITO, IZO, IWO and FTO, or ITO, AZO and IWO.

[0026] Preferably, the flexible conductive substrate has a thickness of 10 μm to 500 μm and a planar dimension of (50~500) × (100~600) mm. 2 Typical but non-limiting size combinations include 50×100mm. 2 100×200mm 2 200×300mm 2 300×400mm 2 400×500mm 2 Or 500×600mm 2 However, this is not limited to the listed size combinations; other unlisted size combinations within this size range also apply.

[0027] Preferably, the hole transport layer comprises a hole transport material, which includes one or more of PEDOT:PSS, Spiro OMeTAD, TPD, PTAA, P3HT, PCPDTBT, or VNPB. Typical but non-limiting combinations include a combination of PEDOT:PSS and Spiro OMeTAD, a combination of TPD and PTAA, a combination of P3HT and PCPDTBT, a combination of VNPB and PTAA, or a combination of PEDOT:PSS, Spiro OMeTAD, and PTAA.

[0028] Preferably, the thickness of the hole transport layer is 10nm to 100nm, for example, it can be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm or 100nm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0029] Preferably, the flexible perovskite solar cell further includes a perovskite layer, an electron transport layer, and a top electrode, which are sequentially stacked along a direction away from the hole transport layer.

[0030] Preferably, the perovskite layer comprises an ABX3 structure compound, wherein A is methylammonium ion, formamidinium ion, butylammonium ion, or Cs. + K + Or Na + B is any combination of one or at least two of the following, where B is Pb. 2+ Sn 2+ 、Ge 2+ Mn 2+ or Cu 2+ Any combination of one or at least two of them, X is Cl - ,Br - Or I - Any one or at least two of them.

[0031] In this invention, A represents methylammonium ion, formamidinium ion, butammonium ion, or Cs. + K + Or Na + Any combination of one or at least two of the following, typically but not limiting combinations include the combination of methylammonium ion and formamidinium ion, and butylammonium ion and Cs + The combination, K + with Na + The combination of CH3NH3 + NH2CH=NH2 + With Cs + Combinations, or C4H9NH3 + K + with Na + The combination of .

[0032] In this invention, B is Pb. 2+ Sn 2+ 、Ge 2+ Mn 2+ Cu 2+ Any one or at least two of the following, typical but non-limiting combinations include Pb 2+With Sn 2+ The combination, Ge 2+ With Mn 2+ Combination of Cu 2+ With Pb 2+ The combination of Sn 2+ 、Ge 2+ With Mn 2 + The combination of, or Pb 2+ Sn 2+ Cu 2+ The combination of .

[0033] In this invention, X is Cl - ,Br - Or I - Any one or at least two of the above, typical but non-limiting combinations include Cl - With Br - The combination, Br - with I - The combination, Cl - with I - Combinations, or Cl - ,Br - with I - The combination of .

[0034] Preferably, the thickness of the perovskite layer is 100nm to 1000nm, for example, it can be 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm or 1000nm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0035] Preferably, the electron transport layer comprises n-type organic semiconductor materials or n-type inorganic semiconductor materials.

[0036] Preferably, the electron transport layer comprises titanium dioxide (TiO2), tin oxide (SnO2), zinc oxide (ZnO), and fullerene (C). 60 ), graphene or fullerene derivatives [6,6]-phenyl-C 61 Any one or at least two of methyl butyrate (PCBM), typical but not limiting combinations include combinations of titanium oxide and tin oxide, combinations of zinc oxide and fullerene, combinations of graphene and PCBM, combinations of tin oxide, zinc oxide and fullerene, or combinations of titanium oxide, PCBM and graphene.

[0037] Preferably, the components of the electron transport layer include any one or a combination of at least two of single-crystal materials, polycrystalline materials, and amorphous materials. Typical but non-limiting combinations include combinations of single-crystal materials and polycrystalline materials, combinations of polycrystalline materials and amorphous materials, combinations of single-crystal materials, polycrystalline materials and amorphous materials, or combinations of single-crystal materials and amorphous materials.

[0038] Preferably, the electron transport layer comprises nanocrystalline particles.

[0039] Preferably, the thickness of the electron transport layer is 10nm to 100nm, for example, it can be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm or 100nm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0040] In a second aspect, the present invention provides a method for preparing the flexible perovskite solar cell described in the first aspect, the method comprising:

[0041] An interface insertion layer is prepared on the surface of a flexible conductive substrate by a solution method, and then a hole transport layer is prepared on the surface of the obtained interface insertion layer to obtain a flexible perovskite solar cell.

[0042] The components of the interface insertion layer include metal oxide nanocrystals with a particle size range of 25 nm to 150 nm.

[0043] Preferably, the solution method includes:

[0044] After coating a dispersion of metal oxide nanocrystalline material onto the surface of a flexible conductive substrate, a heat treatment is performed to obtain an interface insertion layer.

[0045] Preferably, the mass concentration of the metal oxide nanocrystal material in the dispersion is 0.1 wt%-10 wt%.

[0046] The heat treatment temperature is 80℃~150℃, and the time is 1min~30min.

[0047] In this invention, the mass concentration of the metal oxide nanocrystal material in the dispersion of the metal oxide nanocrystal material is 0.1wt%-10wt%, for example, it can be 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt% or 10wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] In this invention, the heat treatment temperature is 80℃~150℃, for example, it can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃ or 150℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0049] In this invention, the heat treatment time is 1 min to 30 min, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min or 30 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0050] Preferably, the solvent in the dispersion of the metal oxide nanocrystalline material includes any one or a combination of at least two of ethanol, isopropanol, butanol, ethyl acetate, acetone, toluene, or chlorobenzene. Typical but non-limiting combinations include combinations of ethanol and isopropanol, butanol and ethyl acetate, acetone and toluene, chlorobenzene and ethanol, or isopropanol, ethyl acetate, and acetone.

[0051] Preferably, the method for preparing the hole transport layer includes:

[0052] After applying a slurry of hole transport material to the surface of the interface insertion layer by any one or a combination of at least two of spin coating, doctor blade coating, slot coating, or roll-to-roll coating, the layer is annealed to obtain the hole transport layer.

[0053] In this invention, a slurry of hole transport material is applied to the surface of the interface insertion layer by any one or at least a combination of two of the following methods: spin coating, doctor blade coating, slot coating, or roll-to-roll coating. Typical but non-limiting combinations include a combination of spin coating and doctor blade coating, a combination of slot coating and roll-to-roll coating, a combination of doctor blade coating and slot coating, or a combination of spin coating, doctor blade coating, and roll-to-roll coating.

[0054] Preferably, the preparation method further includes the sequential preparation of a perovskite layer, an electron transport layer, and a top electrode after the preparation of the hole transport layer.

[0055] Preferably, the method for preparing the perovskite layer includes:

[0056] After applying a slurry of perovskite material to the surface of the hole transport layer by any one or a combination of at least two of the following methods: transfer coating, blade coating, slot coating, or roll-to-roll coating, the perovskite layer is obtained by annealing.

[0057] In this invention, a slurry of perovskite material is applied to the surface of the hole transport layer by any one or at least a combination of two of the following methods: spin coating, blade coating, slot coating, or roll-to-roll coating. Typical but non-limiting combinations include a combination of spin coating and blade coating, a combination of slot coating and roll-to-roll coating, a combination of blade coating and slot coating, or a combination of spin coating, blade coating, and roll-to-roll coating.

[0058] Preferably, the method for preparing the electron transport layer includes any one or a combination of at least two of the following: magnetron sputtering, electron beam evaporation, molecular beam epitaxy, vapor phase or liquid phase chemical deposition, atomic layer deposition, hydrothermal method or sol-gel method. Typical but non-limiting combinations include the combination of magnetron sputtering and electron beam evaporation, the combination of molecular beam epitaxy and atomic layer deposition, the combination of hydrothermal method and sol-gel method, or the combination of vapor phase chemical deposition, liquid phase chemical deposition and atomic layer deposition.

[0059] Thirdly, the present invention provides a photovoltaic module comprising at least two flexible perovskite cells as described in the first aspect, or flexible perovskite cells prepared by the preparation method described in the second aspect.

[0060] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] (1) In the flexible perovskite solar cell provided by the present invention, by introducing an interface insertion layer between the flexible conductive substrate and the hole transport layer, on the one hand, the interface insertion layer improves the wettability of the hole transport layer, and improves the coverage and film quality of the hole transport layer and the perovskite layer, thereby improving the open-circuit voltage and fill factor of the flexible perovskite solar cell; on the other hand, the hydroxyl groups (-OH) on the surface of the metal oxide nanocrystal material can form weak interactions (such as hydrogen bonds and van der Waals forces) with the sulfur atoms or benzene rings in the hole transport layer, effectively reducing non-radiative recombination between interfaces and improving the carrier transport efficiency, thereby further improving the open-circuit voltage and fill factor of the flexible perovskite solar cell; on the other hand, the metal oxide nanocrystal material has anti-reflection properties and light scattering effect, which is beneficial to improving the absorption of light by the perovskite layer, thereby improving the short-circuit current of the flexible perovskite solar cell;

[0063] (2) In the flexible perovskite battery provided by the present invention, the particle size range of the metal oxide nanocrystal material in the interface insertion layer is 25nm~150nm. The particle size of the metal oxide nanocrystal material is within this range, which can not only solve the problem of poor wettability and uneven coverage of the hole transport layer on the flexible electrode with low surface energy, but also overcome the dewetting phenomenon of the perovskite precursor solution on the surface of the hole transport layer, induce the preferential growth of perovskite crystals, thereby achieving effective suppression of interface recombination and simultaneous improvement of carrier extraction efficiency.

[0064] (3) In this invention, by introducing an interface insertion layer between the flexible conductive substrate and the hole transport layer of the flexible perovskite solar cell, the size effect and surface chemical properties of metal oxide nanocrystals are utilized to effectively improve the interface wettability and induce high-quality crystallization of perovskite. Furthermore, weak interactions suppress interface recombination and light absorption are enhanced by light scattering, thereby synergistically improving the film quality, carrier transport efficiency and light utilization of the flexible perovskite solar cell. Therefore, the flexible perovskite solar cell exhibits excellent photoelectric performance. Attached Figure Description

[0065] Figure 1 These are schematic diagrams of the flexible perovskite solar cells provided in Examples 1-10.

[0066] Figure 2 These are flowcharts illustrating the fabrication process of photovoltaic modules comprising at least two flexible perovskite cells, as provided in Examples 1-10.

[0067] Figure 3 This is a schematic diagram of the flexible perovskite solar cell provided in Comparative Example 1.

[0068] Figure 4 This is a flowchart of the fabrication process of a photovoltaic module containing at least two flexible perovskite cells, as provided in Comparative Example 1.

[0069] Figure 5 These are the current-voltage characteristic curves of the photovoltaic modules provided in Example 1 and Comparative Example 1 under forward and reverse scanning conditions. Detailed Implementation

[0070] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0071] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0072] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0073] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0074] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0075] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0076] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0077] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0078] Example 1

[0079] This embodiment provides a method such as Figure 1 The flexible perovskite solar cell shown includes a flexible conductive substrate, an interface insertion layer with a thickness of 80 nm, a hole transport layer with a thickness of 50 nm, a perovskite layer with a thickness of 300 nm, an electron transport layer with a thickness of 45 nm, and a top electrode with a thickness of 100 nm, which are stacked sequentially.

[0080] The flexible conductive substrate has a thickness of 125 μm and a planar dimension of 300 × 400 mm. 2The flexible conductive substrate includes a polymer flexible substrate (made of polyethylene terephthalate (PET)) and a substrate electrode (indium tin oxide (ITO)) disposed on the polymer flexible substrate.

[0081] The interface insertion layer comprises metal oxide (indium tin oxide) nanocrystalline materials with a particle size range of 90nm to 110nm; the interface insertion layer has a transmittance of ≥80% in the 400nm to 800nm ​​wavelength band.

[0082] The hole transport layer comprises hole transport material (PTAA).

[0083] The perovskite layer is composed of Cs. 0.05 FA 0.95 PbI3;

[0084] The electron transport layer is composed of stacked C layers with a thickness of 25 nm. 60 It consists of a layer and a SnO2 layer with a thickness of 20 nm;

[0085] The top electrode is a copper electrode.

[0086] This embodiment also provides a photovoltaic module comprising 42 of the aforementioned flexible perovskite solar cells, such as... Figure 2 As shown, the method for manufacturing photovoltaic modules is as follows:

[0087] (1) Select a size of 300×400mm 2 PET / ITO was used as a flexible conductive substrate; the main agent of polydimethylsiloxane (PDMS) and the curing agent were mixed evenly at a mass ratio of 10:1, and this mixture was used as an adhesive layer to bond and fix the PET / ITO substrate onto a white glass carrier; then, the bonded substrate assembly was heated at 100°C for 30 minutes to cure the PDMS and complete the rigid support treatment of the flexible substrate.

[0088] (2) Using laser etching technology, P1 channels were etched on the ITO conductive layer to divide it into 42 sub-cell units. After etching, the flexible conductive substrate was placed in an ultraviolet ozone cleaner for 15 minutes to remove organic residues on the surface and improve surface wettability, in preparation for the subsequent preparation of functional layers.

[0089] (3) In an air environment, a slit coating process is used to control the height of the slit cutter head from the surface of the flexible conductive substrate to be 80 μm, the cutting head moving speed to be 20 mm / s, and the total liquid output to be 500 μL. After coating the surface of the flexible conductive substrate with a dispersion of metal oxide (indium tin oxide) nanocrystalline material with a mass concentration of 1 wt% (solvent is isopropanol), the substrate is heat-treated at 100 °C for 10 min to obtain the interface insertion layer.

[0090] (4) First, prepare a PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]) chlorobenzene solution with a concentration of 1 mg / mL and stir it at 25°C for more than 30 minutes for later use; then, deposit a hole transport layer on the interface insertion layer in an air environment using a slit coating process. The specific process parameters are: slit tip height of 80 μm, coating speed of 20 mm / s, and total liquid supply of 500 μL; after coating, anneal at 100°C for 10 minutes to obtain the hole transport layer.

[0091] (5) Prepare a 0.7 mol / L concentration of component Cs 0.05 FA 0.95 A perovskite precursor solution of PbI3 was prepared, wherein the solvent of the perovskite precursor solution consisted of N,N-dimethylformamide, 2-methoxyethanol, dimethyl sulfoxide, and N-methylpyrrolidone in a volume ratio of 18:18:1:1. In an air environment, a perovskite layer was deposited on the hole transport layer using a slit coating process. The specific process parameters were: slit tip height of 80 μm, coating speed of 24 mm / s, and total liquid supply of 650 μL. After coating, the perovskite layer was annealed at 100 °C for 30 minutes.

[0092] (6) First, a fullerene (C) layer with a thickness of 25 nm was deposited on the surface of the perovskite layer using thermal evaporation technology. 60 ) layer; subsequently, atomic layer deposition (ALD) technology was used on C 60 A dense tin dioxide (SnO2) layer with a thickness of 20 nm is deposited on the surface of the layer to obtain the electron transport layer (made of C). 60 (Composed of a layer and a SnO2 layer).

[0093] (7) Perform P2 laser scribing on the semi-finished device after completing the above steps, and make the P2 channel penetrate the electron transport layer, perovskite layer, hole transport layer and interface insertion layer, in order to separate the interface insertion layer (inclusive) to the electron transport layer (inclusive) and all functional layers in between.

[0094] (8) A copper thin film with a thickness of 100 nm was deposited on the surface of the electron transport layer using thermal evaporation technology as the top electrode of the flexible perovskite solar cell.

[0095] (9) The P3 channel is processed by laser scribing process, and the back electrode is cut and separated to complete the independence and series connection of each sub-cell unit, thereby obtaining a photovoltaic module containing 42 flexible perovskite cells.

[0096] Example 2

[0097] This embodiment provides a flexible perovskite solar cell, which includes a flexible conductive substrate, an interface insertion layer with a thickness of 65 nm, a hole transport layer with a thickness of 50 nm, a perovskite layer with a thickness of 300 nm, an electron transport layer with a thickness of 45 nm, and a top electrode with a thickness of 100 nm, which are stacked sequentially.

[0098] The flexible conductive substrate has a thickness of 125 μm and a planar dimension of 300 × 400 mm. 2 The flexible conductive substrate includes a polymer flexible substrate (made of polyethylene terephthalate (PET)) and a substrate electrode (indium tin oxide (ITO)) disposed on the polymer flexible substrate.

[0099] The interface insertion layer comprises metal oxide (indium zinc oxide) nanocrystalline materials with a particle size range of 60nm to 90nm; the transmittance of the interface insertion layer in the 400nm to 800nm ​​wavelength band is ≥80%.

[0100] The hole transport layer comprises a hole transport material PTAA;

[0101] The perovskite layer is composed of Cs. 0.05 FA 0.95 PbI3;

[0102] The electron transport layer is composed of stacked C layers with a thickness of 25 nm. 60 It consists of a layer and a SnO2 layer with a thickness of 20 nm;

[0103] The top electrode is a copper electrode.

[0104] This embodiment also provides a photovoltaic module comprising 42 of the aforementioned flexible perovskite solar cells. The method for fabricating the photovoltaic module is as follows:

[0105] (1) Select a size of 300×400mm 2 PET / ITO was used as a flexible conductive substrate; the main agent of polydimethylsiloxane (PDMS) and the curing agent were mixed evenly at a mass ratio of 10:1, and this mixture was used as an adhesive layer to bond and fix the PET / ITO substrate onto a white glass carrier; then, the bonded substrate assembly was heated at 100°C for 30 minutes to cure the PDMS and complete the rigid support treatment of the flexible substrate.

[0106] (2) Using laser etching technology, P1 channels were etched on the ITO conductive layer to divide it into 42 sub-cell units. After etching, the flexible conductive substrate was placed in an ultraviolet ozone cleaner for 15 minutes to remove organic residues on the surface and improve surface wettability, in preparation for the subsequent preparation of functional layers.

[0107] (3) In an air environment, a slit coating process is used to control the height of the slit cutter head from the surface of the flexible conductive substrate to be 80 μm, the cutting head moving speed to be 20 mm / s, and the total liquid output to be 500 μL. After coating the surface of the flexible conductive substrate with a dispersion of metal oxide (indium zinc oxide) nanocrystalline material with a mass concentration of 0.1 wt% (solvent including ethanol), the substrate is heat-treated at 80 °C for 30 min to obtain an interface insertion layer.

[0108] (4) First, prepare a PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]) chlorobenzene solution with a concentration of 1 mg / mL and stir it at 25°C for more than 30 minutes for later use; then, deposit a hole transport layer on the interface insertion layer in an air environment using a slit coating process. The specific process parameters are: slit tip height 80 μm, coating speed 20 mm / s, and total liquid supply 500 μL; after coating, anneal at 100°C for 10 minutes to obtain the hole transport layer.

[0109] (5) Prepare a 0.7 mol / L concentration of component Cs 0.05 FA 0.95 A perovskite precursor solution of PbI3 was prepared, wherein the solvent of the perovskite precursor solution consisted of N,N-dimethylformamide, 2-methoxyethanol, dimethyl sulfoxide, and N-methylpyrrolidone in a volume ratio of 18:18:1:1. In an air environment, a perovskite layer was deposited on the hole transport layer using a slit coating process. The specific process parameters were: slit tip height of 80 μm, coating speed of 24 mm / s, and total liquid supply of 650 μL. After coating, the perovskite layer was annealed at 100 °C for 30 minutes.

[0110] (6) First, a fullerene (C) layer with a thickness of 25 nm was deposited on the surface of the perovskite layer using thermal evaporation technology. 60 ) layer; subsequently, atomic layer deposition (ALD) technology was used on C 60 A dense tin dioxide (SnO2) layer with a thickness of 20 nm is deposited on the surface of the layer to obtain the electron transport layer (made of C). 60 (Composed of a layer and a SnO2 layer).

[0111] (7) Perform P2 laser scribing on the semi-finished device after completing the above steps, and make the P2 channel penetrate the electron transport layer, perovskite layer, hole transport layer and interface insertion layer, in order to separate the interface insertion layer (inclusive) to the electron transport layer (inclusive) and all functional layers in between.

[0112] (8) A copper thin film with a thickness of 100 nm was deposited on the surface of the electron transport layer using thermal evaporation technology as the top electrode of the flexible perovskite solar cell.

[0113] (9) The P3 channel is processed by laser scribing process, and the back electrode is cut and separated to complete the independence and series connection of each sub-cell unit, thereby obtaining a photovoltaic module containing 42 flexible perovskite cells.

[0114] Example 3

[0115] This embodiment provides a flexible perovskite solar cell, which includes a flexible conductive substrate, an interface insertion layer with a thickness of 95 nm, a hole transport layer with a thickness of 50 nm, a perovskite layer with a thickness of 300 nm, an electron transport layer with a thickness of 45 nm, and a top electrode with a thickness of 100 nm, which are stacked sequentially.

[0116] The flexible conductive substrate has a thickness of 125 μm and a planar dimension of 300 × 400 mm. 2 The flexible conductive substrate includes a polymer flexible substrate (made of polyethylene terephthalate (PET)) and a substrate electrode (indium tin oxide (ITO)) disposed on the polymer flexible substrate.

[0117] The interface insertion layer comprises metal oxide (alumina) nanocrystalline materials with a particle size range of 100nm to 140nm; the transmittance of the interface insertion layer in the 400nm to 800nm ​​wavelength band is ≥80%.

[0118] The hole transport layer comprises hole transport material (PTAA).

[0119] The perovskite layer is composed of Cs. 0.05 FA 0.95 PbI3;

[0120] The electron transport layer is composed of stacked C layers with a thickness of 25 nm. 60 It consists of a layer and a SnO2 layer with a thickness of 20 nm;

[0121] The top electrode is a copper electrode.

[0122] This embodiment also provides a photovoltaic module comprising 42 of the aforementioned flexible perovskite solar cells. The method for fabricating the photovoltaic module is as follows:

[0123] (1) Select a size of 300×400mm 2 PET / ITO was used as a flexible conductive substrate; the main agent of polydimethylsiloxane (PDMS) and the curing agent were mixed evenly at a mass ratio of 10:1, and this mixture was used as an adhesive layer to bond and fix the PET / ITO substrate onto a white glass carrier; then, the bonded substrate assembly was heated at 100°C for 30 minutes to cure the PDMS and complete the rigid support treatment of the flexible substrate.

[0124] (2) Using laser etching technology, P1 channels were etched on the ITO conductive layer to divide it into 42 sub-cell units. After etching, the flexible conductive substrate was placed in an ultraviolet ozone cleaner for 15 minutes to remove organic residues on the surface and improve surface wettability, in preparation for the subsequent preparation of functional layers.

[0125] (3) In an air environment, a slit coating process is used to control the height of the slit cutter head from the surface of the flexible conductive substrate to be 80 μm, the cutting head moving speed to be 20 mm / s, and the total liquid output to be 500 μL. After coating the surface of the flexible conductive substrate with a dispersion of metal oxide (alumina) nanocrystalline material with a mass concentration of 10 wt% (solvent is isopropanol), the substrate is heat-treated at 150 °C for 1 min to obtain the interface insertion layer.

[0126] (4) First, prepare a PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]) chlorobenzene solution with a concentration of 1 mg / mL and stir it at 25°C for more than 30 minutes for later use; then, deposit a hole transport layer on the interface insertion layer in an air environment using a slit coating process. The specific process parameters are: slit tip height of 80 μm, coating speed of 20 mm / s, and total liquid supply of 500 μL; after coating, anneal at 100°C for 10 minutes to obtain the hole transport layer.

[0127] (5) Prepare a 0.7 mol / L concentration of component Cs 0.05 FA 0.95 A perovskite precursor solution of PbI3 was prepared, wherein the solvent of the perovskite precursor solution consisted of N,N-dimethylformamide, 2-methoxyethanol, dimethyl sulfoxide, and N-methylpyrrolidone in a volume ratio of 18:18:1:1. In an air environment, a perovskite layer was deposited on the hole transport layer using a slit coating process. The specific process parameters were: slit tip height of 80 μm, coating speed of 24 mm / s, and total liquid supply of 650 μL. After coating, the perovskite layer was annealed at 100 °C for 30 minutes.

[0128] (6) First, a fullerene (C) layer with a thickness of 25 nm was deposited on the surface of the perovskite layer using thermal evaporation technology. 60 ) layer; subsequently, atomic layer deposition (ALD) technology was used on C 60 A dense tin dioxide (SnO2) layer with a thickness of 20 nm is deposited on the surface of the layer to obtain the electron transport layer (made of C). 60 (Composed of a layer and a SnO2 layer).

[0129] (7) Perform P2 laser scribing on the semi-finished device after completing the above steps, and make the P2 channel penetrate the electron transport layer, perovskite layer, hole transport layer and interface insertion layer, in order to separate the interface insertion layer (inclusive) to the electron transport layer (inclusive) and all functional layers in between.

[0130] (8) A copper thin film with a thickness of 100 nm was deposited on the surface of the electron transport layer using thermal evaporation technology as the top electrode of the flexible perovskite solar cell.

[0131] (9) The P3 channel is processed by laser scribing process, and the back electrode is cut and separated to complete the independence and series connection of each sub-cell unit, thereby obtaining a photovoltaic module containing 42 flexible perovskite cells.

[0132] Example 4

[0133] This embodiment provides a flexible perovskite solar cell, which is the same as that in Example 1 except that the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 25nm~50nm.

[0134] This embodiment also provides a photovoltaic module comprising 42 flexible perovskite solar cells as described in this embodiment. Except for step (3) of the photovoltaic module preparation method, in which the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 25nm~50nm, the rest are the same as in Example 1.

[0135] Example 5

[0136] This embodiment provides a flexible perovskite solar cell, which is the same as that in Example 1, except that the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 140nm~150nm.

[0137] This embodiment also provides a photovoltaic module comprising 42 flexible perovskite solar cells as described in this embodiment. Except for step (3) of the photovoltaic module preparation method, in which the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 140nm~150nm, the rest are the same as in Example 1.

[0138] Example 6

[0139] This embodiment provides a flexible perovskite solar cell, except that the thickness of the interface insertion layer is 50 nm.

[0140] This embodiment also provides a photovoltaic module containing 42 flexible perovskite cells as described in this embodiment. Except for reducing the total liquid output of the slit coating process in step (3) of the photovoltaic module preparation method, the rest is the same as in embodiment 1.

[0141] Example 7

[0142] This embodiment provides a flexible perovskite solar cell, except that the thickness of the interface insertion layer is 110 nm.

[0143] This embodiment also provides a photovoltaic module comprising 42 flexible perovskite solar cells as described in this embodiment. Except for increasing the total liquid output of the slit coating process in step (3) of the photovoltaic module preparation method, the rest is the same as in Embodiment 1.

[0144] Example 8

[0145] This embodiment provides a photovoltaic module containing 42 flexible perovskite cells. Except for step (3) of the photovoltaic module preparation method, in which the mass concentration of the dispersion of metal oxide nanocrystal material is 0.02wt% and the total liquid output of the slit coating process is increased so that the thickness of the interface insertion layer remains unchanged, the rest is the same as in embodiment 1.

[0146] Example 9

[0147] This embodiment provides a photovoltaic module containing 42 flexible perovskite cells. Except for step (3) of the photovoltaic module preparation method, in which the mass concentration of the dispersion of metal oxide nanocrystal material is 15wt% and the total liquid output of the slit coating process is reduced so that the thickness of the interface insertion layer remains unchanged, the rest is the same as in Example 1.

[0148] Example 10

[0149] This embodiment provides a photovoltaic module containing 42 flexible perovskite cells. Except for step (3) of the photovoltaic module preparation method, in which heat treatment is performed at 200°C, the rest is the same as in embodiment 1.

[0150] Comparative Example 1

[0151] This comparative example provides a way to... Figure 3 The flexible perovskite solar cell shown is identical to that in Example 1, except that the interface insertion layer is omitted.

[0152] This comparative example also provides a photovoltaic module comprising 42 flexible perovskite cells as described in this embodiment, such as... Figure 4 As shown, except for step (3) of the photovoltaic module preparation method, the rest are the same as in Example 1.

[0153] Comparative Example 2

[0154] This comparative example provides a flexible perovskite solar cell, which is the same as Example 1 except that the particle size of the metal oxide (indium tin oxide) nanocrystalline material is in the range of 2nm to 20nm.

[0155] This comparative example also provides a photovoltaic module comprising 42 flexible perovskite cells as described in this embodiment. Except for step (3) of the photovoltaic module preparation method, in which the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 2nm~20nm, all other steps are the same as in Example 1.

[0156] Comparative Example 3

[0157] This comparative example provides a flexible perovskite solar cell, which is the same as Example 1 except that the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 180~200nm.

[0158] This comparative example also provides a photovoltaic module comprising 42 flexible perovskite cells as described in this embodiment. Except for step (3) of the photovoltaic module preparation method, in which the particle size range of the metal oxide (indium tin oxide) nanocrystalline material is 180~200nm, the rest are the same as in Example 1.

[0159] The photovoltaic modules provided in the above embodiments and comparative examples were tested using the following method: under standard test conditions (AM1.5G spectrum, 1000W / m²). 2 Under irradiance (cell temperature 25℃), the current-voltage characteristic curves of the photovoltaic modules were measured using a solar simulator and IV test system. The open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF), and power conversion efficiency (PCE) of the photovoltaic modules under forward scanning are shown in Table 1. The same parameters are also shown in Table 2. The current-voltage characteristic curves of the photovoltaic modules provided in Example 1 and Comparative Example 1 under both forward and reverse scanning are shown in Table 2. Figure 5 As shown.

[0160] Table 1

[0161]

[0162] Table 2

[0163]

[0164] From Table 1, we can obtain:

[0165] (1) The photovoltaic modules provided in Examples 1 to 3 exhibit higher open-circuit voltage, higher short-circuit current, higher fill factor and higher conversion efficiency.

[0166] (2) By comparing Example 1 with Examples 4 and 5, it can be seen that when the particle size range of the metal oxide nanocrystal material is preferably 60nm~140nm, the photovoltaic module exhibits better performance. This is because the nanocrystals in this particle size range can construct suitable micro-nano-level interface roughness. On the one hand, the capillary force generated can maximize the wettability and film quality of the hole transport layer and effectively induce the orientation growth of perovskite crystals. On the other hand, this size can enhance the light scattering effect without causing interface short circuit or flatness deterioration, thereby maximizing light capture while ensuring efficient charge collection and balancing optical gain and electrical loss.

[0167] (3) By comparing Example 1 with Examples 6 and 7, it can be seen that when the thickness of the interface insertion layer is 65nm~95nm, the photovoltaic module exhibits better performance. This is because this thickness range achieves the best balance between conductivity and optical performance, ensuring the complete interface modification effect while avoiding the decrease in fill factor due to excessive resistance.

[0168] (4) By comparing Example 1 with Examples 8 and 9, it can be seen that in the preparation method of the flexible perovskite battery in this invention, when the mass concentration of metal oxide nanocrystal material in the dispersion of metal oxide nanocrystal material is 0.1wt%-10wt%, the photovoltaic module exhibits better performance; if the mass concentration is too low, it is easy to cause discontinuous film formation or insufficient thickness, making it difficult to play the role of interface modification; if the mass concentration is too high, it is easy to cause nanocrystal agglomeration, resulting in excessive surface roughness of the film or even the generation of pore defects, increasing the interface resistance; when the mass concentration of metal oxide nanocrystal material is within this concentration range, it ensures that a uniform and dense interface insertion layer can be prepared, which is beneficial to improving the flatness of the subsequent functional layer;

[0169] (5) By comparing Example 1 with Examples 10 and 11, it can be seen that in the preparation method of the flexible perovskite cell in the present invention, when the heat treatment temperature is 80℃~150℃, the photovoltaic module exhibits better performance. This is because when the heat treatment temperature is in this range, it can ensure the full evaporation of the solvent, eliminate the obstacle of organic residue to the transport of charge carriers, and promote the physical contact between metal oxide nanocrystal materials, thereby enhancing the adhesion and conductivity of the thin film. At the same time, this temperature range also avoids the deformation of the flexible conductive substrate caused by overheating, thereby ensuring the mechanical stability and photoelectric performance of the photovoltaic module.

[0170] (6) As can be seen from the comparison between Example 1 and Comparative Example 1, in the flexible perovskite solar cell provided by the present invention, by introducing an interface insertion layer between the flexible conductive substrate and the hole transport layer, on the one hand, the interface insertion layer improves the wettability of the hole transport layer, and improves the coverage and film quality of the hole transport layer and the perovskite layer, thereby improving the open-circuit voltage and fill factor of the flexible perovskite solar cell; on the other hand, the hydroxyl groups (-OH) on the surface of the metal oxide nanocrystal material can form weak interactions (such as hydrogen bonds and van der Waals forces) with the sulfur atoms or benzene rings in the hole transport layer, effectively reducing non-radiative recombination between interfaces and improving the carrier transport efficiency, thereby further improving the open-circuit voltage and fill factor of the flexible perovskite solar cell; on the other hand, the metal oxide nanocrystal material has anti-reflection properties and light scattering effect, which is beneficial to improving the absorption of light by the perovskite layer, thereby improving the short-circuit current of the flexible perovskite solar cell;

[0171] (7) By comparing Example 1 with Comparative Examples 2 and 3, it can be seen that when the particle size range of the metal oxide nanocrystal material in the interface insertion layer is 2nm~20nm, it can only solve part of the interface energy level matching problem, and cannot effectively regulate the hole transport layer film quality and induce the preferential growth of perovskite crystals.

[0172] However, when the particle size of the metal oxide nanocrystal material in the interfacial insertion layer is in the range of 25 nm to 150 nm, the particle size of the metal oxide nanocrystal material is within this range. This not only solves the problem of poor wettability and uneven coverage of the hole transport layer on the flexible electrode with low surface energy, but also overcomes the dewetting phenomenon of the perovskite precursor solution on the surface of the hole transport layer, and induces the preferential growth of perovskite crystals, thereby achieving effective suppression of interfacial recombination and simultaneous improvement of carrier extraction efficiency.

[0173] (8) As can be seen from the comparison between Example 1 and Comparative Examples 1 to 3, in this invention, by introducing an interface insertion layer between the flexible conductive substrate and the hole transport layer of the flexible perovskite solar cell, the size effect and surface chemical properties of metal oxide nanocrystals are utilized to effectively improve the interface wettability and induce high-quality crystallization of perovskite. Furthermore, weak interactions suppress interface recombination, and light absorption is enhanced by light scattering. This synergistically improves the film quality, carrier transport efficiency, and light utilization of the flexible perovskite solar cell. Therefore, the flexible perovskite solar cell exhibits excellent photoelectric performance.

[0174] The applicant declares that 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 flexible perovskite solar cell, characterized in that, An interface insertion layer is provided between the flexible conductive substrate and the hole transport layer of the flexible perovskite solar cell. The component of the interface insertion layer includes metal oxide nanocrystals with a particle size range of 60 nm to 140 nm. The interface insertion layer has a transmittance of ≥80% in the 400nm~800nm ​​wavelength band and a thickness of 65nm~95nm; The hole transport layer comprises a hole transport material, which includes one or more of PEDOT:PSS, SpiroOMeTAD, TPD, PTAA, P3HT, PCPDTBT, or VNPB. The surface of the metal oxide nanocrystalline material has hydroxyl groups, and the hole transport layer contains sulfur atoms or benzene rings. The hydroxyl groups on the surface of the metal oxide nanocrystalline material form a weak interaction with the sulfur atoms or benzene rings in the hole transport layer.

2. The flexible perovskite solar cell according to claim 1, characterized in that, The composition of the metal oxide nanocrystalline material includes any one or a combination of at least two of indium tin oxide, indium zinc oxide, indium tungsten oxide, fluorine-doped tin oxide or aluminum-doped zinc oxide, aluminum oxide or silicon oxide.

3. The flexible perovskite solar cell according to claim 1 or 2, characterized in that, The flexible conductive substrate includes a polymer flexible substrate and a substrate electrode disposed on the polymer flexible substrate; or, The flexible conductive substrate includes a metal foil and a substrate electrode disposed on the metal foil; The flexible perovskite solar cell further includes a perovskite layer, an electron transport layer, and a top electrode, which are sequentially stacked along a direction away from the hole transport layer.

4. A method for preparing a flexible perovskite solar cell according to any one of claims 1 to 3, characterized in that, The preparation method includes: An interface insertion layer is prepared on the surface of a flexible conductive substrate by a solution method, and then a hole transport layer is prepared on the surface of the obtained interface insertion layer to obtain a flexible perovskite solar cell. The components of the interface insertion layer include metal oxide nanocrystals with a particle size range of 25 nm to 150 nm.

5. The preparation method according to claim 4, characterized in that, The solution method includes: After coating a dispersion of metal oxide nanocrystalline material onto the surface of a flexible conductive substrate, a heat treatment is performed to obtain an interface insertion layer.

6. The preparation method according to claim 5, characterized in that, The mass concentration of the metal oxide nanocrystal material in the dispersion is 0.1 wt% to 10 wt%. The heat treatment temperature is 80℃~150℃, and the time is 1min~30min.

7. The preparation method according to any one of claims 4 to 6, characterized in that, The method for preparing the hole transport layer includes: After applying the slurry of the hole transport material to the surface of the interface insertion layer by any one or at least a combination of two of the following methods: spin coating, doctor blade coating, slot coating, or roll-to-roll coating, the layer is annealed to obtain the hole transport layer. And / or, the preparation method further includes the sequential preparation of a perovskite layer, an electron transport layer, and a top electrode after the preparation of the hole transport layer.

8. A photovoltaic module, characterized in that, The photovoltaic module comprises at least two flexible perovskite cells as described in any one of claims 1 to 3, or flexible perovskite cells prepared by the preparation method described in any one of claims 4 to 7.

Images