Solar cell and preparation method, and electric device and power generation device

Abstract

Disclosed in the present application are a solar cell and a preparation method, and an electric device and a power generation device. The solar cell comprises a solar cell body and a protective layer, wherein the protective layer is arranged on at least one side of the solar cell body, and comprises at least one stress compensation layer; a neutral surface of the solar cell is located on a functional layer; alternatively, the neutral surface of the solar cell is located in a substrate, and the distance between the surface of the functional layer close to the substrate and the neutral surface is less than or equal to 10 μm; alternatively, the neutral surface of the solar cell is located in the protective layer, and the distance between the surface of the functional layer close to the protective layer and the neutral surface is less than or equal to 10 μm. The embodiments of the present application take into account the interaction between the structures of the layers of the solar cell; and by means of providing the protective layer, the formed protective layer matches the solar cell body, such that the neutral surface of the solar cell is close to or is located on the functional layer prone to failure, thereby reducing the risk of failure of the functional layer and improving the bending resistance of the solar cell.

Description

Solar cell and preparation method, electrical equipment and power generation equipment

[0001] This disclosure claims priority to Chinese patent application No. 2024100215257, filed on January 5, 2024, entitled “Solar Cells, Preparation Methods, and Electrical Equipment,” which is incorporated herein by reference in its entirety. Technical Field

[0002] The present invention relates to the technical field of photovoltaic devices, and in particular to a solar cell and a preparation method thereof, an electrical device and a power generation device. Background Art

[0003] This section merely provides background information related to the present application and is not necessarily prior art.

[0004] Solar cells, which directly convert light energy into electricity through the photovoltaic effect, are one of the most widely used new energy power batteries. Currently, some solar cells use flexible substrates, promising integration with flexible electronic devices and playing a significant role in portable electronics, flexible display devices, and wearable electronic devices. However, electronic devices, including flexible solar cells, are susceptible to damage to their functional layers when subjected to external forces such as bending, which can affect the performance of the solar cell. Summary of the Invention

[0005] In view of the technical problems existing in the background technology, the present application provides a solar cell and a preparation method, an electrical device and a power generation device, aiming to improve the bending resistance of the solar cell.

[0006] In order to achieve the above objectives, the first aspect of the present application provides a solar cell, comprising:

[0007] The solar cell body comprises a substrate and a functional layer arranged in a stacked manner; the functional layer comprises a plurality of film layers arranged in a stacked manner;

[0008] A protective layer is provided on at least one side of the solar cell body along a stacking direction of the substrate and the functional layer, the protective layer comprising at least one stress compensation layer;

[0009] The neutral plane of the solar cell is located in the functional layer; or the neutral plane of the solar cell is located in the substrate, and the distance between the surface of the functional layer close to the substrate and the neutral plane is less than or equal to 10 μm; or the neutral plane of the solar cell is located in the protective layer, and the distance between the surface of the functional layer close to the protective layer and the neutral plane is less than or equal to 10 μm.

[0010] The embodiments of the present application take into account the interaction between the various layers of the solar cell structure. By setting a protective layer, the formed protective layer is matched with the solar cell body, so that the neutral plane of the solar cell is close to or located on the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer and improving the bending resistance of the solar cell.

[0011] In any embodiment of the present application, the protective layer includes a stress compensation body and a first bending portion, the first bending portion is formed by extending at least one stress compensation layer in the stress compensation body, the solar cell body includes a first surface and a side surface surrounding the first surface, the first surface is one of the light-receiving surface and the backlight surface of the solar cell body, the stress compensation body is arranged on the first surface, and the first bending portion is arranged on the side surface.

[0012] The embodiment of the present application can reduce the curling of the edge of the stress compensation body by providing the first bent portion, and can also improve the protection of the side surface of the solar cell body.

[0013] In any embodiment of the present application, the protective layer also includes a second bending portion, which is formed by extending at least one stress compensation layer in the first bending portion. The solar cell body also includes a second surface arranged opposite to the first surface, and the second surface is the other of the light-receiving surface and the backlight surface of the solar cell body, and the second bending portion is arranged on the second surface.

[0014] The embodiment of the present application further improves the protection of the second surface of the solar cell body by setting the second bending portion, and the solution of setting the second bending portion on the entire second surface is beneficial to blocking the entire solar cell body from the external environment, thereby improving the service life.

[0015] In any embodiment of the present application, the second surface has a first area and a second area, the second bending portion is arranged in the second area of ​​the second surface, and the solar cell further includes another protective layer, and the other protective layer is arranged in the first area.

[0016] The embodiment of the present application, through the provision of two differentiated protective layers, is conducive to the flexible selection of matching protective layer materials according to preset parameters, and is further conducive to making the neutral plane of the solar cell close to or located on the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer, and further improving the bending resistance of the solar cell and increasing the service life of the solar cell.

[0017] In any embodiment of the present application, protective layers are provided on both sides of the solar cell body, the protective layers include a stress compensation body and a joint portion, the joint portion is formed by extending at least one stress compensation layer in the stress compensation body, and a water-oxygen barrier glue is provided between the two joint portions.

[0018] The embodiments of the present application provide protective layers on both sides of the solar cell body, which facilitates the flexible selection of matching protective layer materials according to preset parameters, and further facilitates the neutral plane of the solar cell to be close to or located on the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer. At the same time, by providing a joint and directly providing water-oxygen barrier glue at the two joints, the ability of the solar cell to resist the intrusion of moisture and / or oxygen from the external environment is further enhanced.

[0019] In any embodiment of the present application, there is a gap between the water and oxygen barrier adhesive and the solar cell body.

[0020] In the embodiment of the present application, the gap provides space for deformation of the solar cell during the bending process, thereby further improving the bending resistance of the solar cell.

[0021] In any embodiment of the present application, the width of the gap is 0.1 cm to 1 cm.

[0022] In the embodiment of the present application, within the above-mentioned width range, a suitable space is provided for the deformation of the solar cell during the bending process, thereby improving the bending resistance of the solar cell.

[0023] In any embodiment of the present application, the film layer includes a substrate and a functional layer disposed on the substrate, and the neutral plane is located in the functional layer.

[0024] In any embodiment of the present application, the solar cell includes at least two stress compensation layers, one of which is a viscoelastic layer and the other is an encapsulation layer, and the viscoelastic layer is located between the solar cell body and the encapsulation layer.

[0025] In the embodiments of the present application, the position adjustment of the neutral plane is more easily achieved by disposing the viscoelastic layer and the packaging layer.

[0026] In any embodiment of the present application, the solar cell includes at least four stress compensation layers, which are a first viscoelastic layer, a high elastic layer, a second viscoelastic layer, and an encapsulation layer arranged in sequence, and the first viscoelastic layer away from the encapsulation layer is adhered to the solar cell body.

[0027] Through the above-mentioned configuration, the embodiments of the present application can enable the adjacent substrate or film layer or stress compensation layer to reduce the stress and deformation it experiences by squeezing the high-elastic layer, thereby further improving the bending resistance of the solar cell.

[0028] In any embodiment of the present application, the Young's modulus of the high elastic layer is 500 MPa to 5000 MPa.

[0029] In the embodiment of the present application, within the range of the Young's modulus, the adjacent substrate or film layer or stress compensation layer can reduce the stress and deformation thereof by squeezing the high elastic layer.

[0030] In any embodiment of the present application, the thickness of the high elastic layer is 5 μm to 200 μm.

[0031] In the embodiment of the present application, within the above thickness range, without significantly increasing the overall thickness of the solar cell, the adjacent substrate or film layer or stress compensation layer can reduce its own stress and deformation by squeezing the high elastic layer.

[0032] In any embodiment of the present application, the high elastic layer includes at least one of silicone and polyurethane elastomer.

[0033] In the embodiment of the present application, by providing a specific material, the high elastic layer using the above material can more easily achieve the transfer of the neutral plane from the substrate to the functional layer.

[0034] In any embodiment of the present application, at room temperature, the Young's modulus of the first viscoelastic layer is 10 kPa to 80 kPa, the creep amount is greater than or equal to 150%, and the creep recovery rate is greater than or equal to 90%; and / or the Young's modulus of the second viscoelastic layer is 10 kPa to 80 kPa, the creep amount is greater than or equal to 150%, and the creep recovery rate is greater than or equal to 90%.

[0035] In the embodiments of the present application, within the above-mentioned ranges of Young's modulus, creep amount and creep recovery rate, lamination with an adjacent substrate or film layer or stress compensation layer can be achieved, making it easier to adjust the position of the neutral plane.

[0036] In any embodiment of the present application, the thickness of the first viscoelastic layer is 5 μm to 15 μm; and / or the thickness of the second viscoelastic layer is 5 μm to 15 μm.

[0037] In the embodiments of the present application, within the above-mentioned thickness range, without significantly increasing the overall thickness of the solar cell, lamination with the adjacent substrate or film layer or stress compensation layer can be achieved, making it easier to adjust the position of the neutral plane.

[0038] In any embodiment of the present application, the first viscoelastic layer includes at least one of polyurethane, rubber and polyacrylate pressure-sensitive adhesives; and / or the second viscoelastic layer includes at least one of polyurethane and polyacrylate.

[0039] In the embodiments of the present application, the specific materials provided enable the viscoelastic layer made of the above materials to be laminated with the adjacent substrate or film layer or stress compensation layer, making it easier to adjust the position of the neutral plane.

[0040] In any embodiment of the present application, the encapsulation layer includes at least one of polymethyl methacrylate (PET), polyethylene naphthalate (PEN) and polycarbonate (PC).

[0041] In the embodiments of the present application, specific materials are provided so that the encapsulation layer using the above materials can block the influence of the ambient atmosphere on the solar cell body.

[0042] In any embodiment of the present application, the functional layer satisfies at least any one of the conditions (1) to (3):

[0043] (1) The functional layer includes a perovskite layer and a carrier transport layer. The carrier transport layer is located on one side of the perovskite layer and is used to transport carriers.

[0044] (2) The functional layer includes a first electrode layer, a first carrier transport layer, a perovskite layer, a second carrier transport layer, and a second electrode layer stacked in sequence; the first electrode layer is disposed on a substrate and is a transparent conductive oxide thin film; the first carrier transport layer is a hole transport layer, and the second carrier transport layer is an electron transport layer, or the first carrier transport layer is an electron transport layer, and the second carrier transport layer is a hole transport layer;

[0045] (3) The functional layer includes a functional layer of a full perovskite stacked solar cell.

[0046] In a second aspect, an embodiment of the present application provides a method for preparing a solar cell, comprising:

[0047] A solar cell body is provided, wherein the solar cell body comprises a substrate and a functional layer arranged in a stacked manner; the functional layer comprises a plurality of film layers arranged in a stacked manner;

[0048] Disposing a protective layer on at least one side of the solar cell body along the stacking direction of the substrate and the functional layer, the protective layer comprising at least one stress compensation layer;

[0049] The neutral plane of the solar cell is located in the functional layer; or the neutral plane of the solar cell is located in the substrate, and the distance between the surface of the functional layer close to the substrate and the neutral plane is less than or equal to 10 μm; or the neutral plane of the solar cell is located in the protective layer, and the distance between the surface of the functional layer close to the protective layer and the neutral plane is less than or equal to 10 μm.

[0050] The embodiments of the present application take into account the interaction between the various layers of the solar cell structure, so that the formed protective layer matches the solar cell body, and the neutral plane of the solar cell is close to or located on the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer and improving the bending resistance of the solar cell.

[0051] In any embodiment of the present application, the step of providing a protective layer on at least one side of the solar cell body includes:

[0052] Disposing a protective layer on at least one side of the solar cell body according to preset parameters, the protective layer including at least one stress compensation layer, the preset parameters including the thickness of each stress compensation layer and the Young's modulus of the stress compensation material used to form the stress compensation layer;

[0053] The method for determining the preset parameters includes:

[0054] The preset parameters are determined based on the property parameters of the solar cell body and the position parameters of the neutral plane. The property parameters include the thickness of the substrate and the Young's modulus of the substrate material used to form the substrate, as well as the thickness of each film layer and the Young's modulus of the film layer material used to form the film layer. The position parameters include the distance from the neutral plane to the side of the stress compensation layer away from the neutral plane.

[0055] The embodiments of the present application determine the preset parameters of the protective layer through the property parameters of the solar cell body and the position parameters of the neutral plane, so that the formed protective layer matches the solar cell body, and the neutral plane of the solar cell formed by the protective layer and the solar cell body is close to or located on the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer and further improving the bending resistance of the solar cell.

[0056] In any embodiment of the present application, the preset parameters also include the Poisson's ratio of the stress compensation material used to form the stress compensation layer, and the property parameters also include the Poisson's ratio of the base material used to form the base, and the Poisson's ratio of the film material used to form each film layer.

[0057] The embodiments of the present application take into account the influence of the lateral deformation of each layer structure on the position parameters of the neutral plane, thereby improving the accuracy of the position adjustment of the neutral plane.

[0058] In any embodiment of the present application, the protective layer includes a stress compensation body and a first bent portion; the first bent portion is formed by extending the stress compensation body; the solar cell body includes a first surface and a side surface surrounding the first surface; the first surface is one of a light-receiving surface and a backlight surface of the solar cell body; and the step of providing the protective layer on at least one side of the solar cell body according to preset parameters includes:

[0059] According to preset parameters, the stress compensation body is arranged on the first surface;

[0060] bend the first bent portion to the side; or

[0061] According to preset parameters, the first bending portion is arranged on the side;

[0062] The stress-compensating body is bent toward the first surface.

[0063] In the embodiment of the present application, a protective layer is set on the first surface and side of the solar cell body according to preset parameters, which not only improves the bending resistance of the solar cell, but also increases the degree of protection for the side of the solar cell, further extending the service life of the solar cell.

[0064] In any embodiment of the present application, the protective layer further includes a second bent portion, the second bent portion is formed by extending the first bent portion, and the solar cell body further includes a second surface arranged opposite to the first surface, the second surface being the other of the light-receiving surface and the backlight surface of the solar cell body, wherein,

[0065] After the step of bending the first bent portion to the side, the method further includes: bending the second bent portion to the second surface; or

[0066] After the step of arranging the first bent portion on the side, the method further includes: bending the second bent portion to the second surface; or

[0067] The step of arranging the first bending portion on the side surface is as follows: arranging the second bending portion on the second surface, and bending the first bending portion to the side surface.

[0068] In the embodiments of the present application, a protective layer is set on the first surface, side surface and second surface of the solar cell body according to preset parameters, which not only improves the bending resistance of the solar cell, but also further improves the degree of protection of the second surface of the solar cell, thereby extending the service life of the solar cell.

[0069] In any embodiment of the present application, a protective layer is provided on both sides of the solar cell body, the protective layer includes a stress compensation body and a joint portion, the joint portion is formed by extending at least one stress compensation layer in the stress compensation body, the preset parameters include a first sub-preset parameter and a second sub-preset parameter, and the step of providing the protective layer on at least one side of the solar cell body according to the preset parameters includes:

[0070] Disposing one of the protective layers on one side of the solar cell body according to the first sub-preset parameter;

[0071] Disposing another protective layer on the other side of the solar cell body according to the second sub-preset parameter; and

[0072] A water-oxygen barrier adhesive is provided between the two joint portions, wherein the first sub-preset parameter and the second sub-preset parameter are different.

[0073] The embodiments of the present application respectively set protective layers on both sides of the solar cell body according to different preset parameters, so that the parameters of the protective layers on both sides of the solar cell body are differentiated, so that the neutral plane of the solar cell is close to or located at the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer, and further improving the bending resistance of the solar cell and increasing the service life of the solar cell.

[0074] In any embodiment of the present application, in the step of determining the preset parameters based on the property parameters of the solar cell body and the position parameters of the neutral plane, the distance of the neutral plane from the side of the protective layer away from the neutral plane, the thickness of the stress compensation layer, the Young's modulus of the stress compensation material used to form the stress compensation layer, the thickness of the substrate and the Young's modulus of the substrate material used to form the substrate, the thickness of the plurality of film layers and the Young's modulus of the film layer materials used to form the plurality of film layers satisfy the following:

[0075] Wherein, h refers to the distance between the neutral plane and the side of the protective layer away from the neutral plane, i refers to the i-th layer, n refers to the number of layers in the entire device structure, t is the thickness of each layer, E is the Young's modulus of the material of each layer, j represents a variable, and j=1 means that the value starts from j at 1.

[0076] The embodiments of the present application provide a specific method for determining the preset parameters of the protective layer, and the above method is used to match the formed protective layer with the main body of the solar cell. The neutral plane of the solar cell formed by the protective layer and the main body of the solar cell is close to or located on the functional layer that is prone to failure, thereby reducing the failure risk of the functional layer, thereby improving the bending resistance of the solar cell and increasing the service life of the solar cell. It is understandable that the embodiments of the present application provide a specific method for determining the preset parameters of the protective layer, and other methods for determining the preset parameters of the protective layer can also be used.

[0077] In any embodiment of the present application, in the step of determining the preset parameters according to the property parameters of the solar cell body and the position parameters of the neutral plane,

[0078] The preset parameters also include the Poisson's ratio of the stress compensation material used to form the stress compensation layer, and the property parameters also include the Poisson's ratio of the base material used to form the base, and the Poisson's ratio of the film material used to form each film layer;

[0079] The distance of the neutral plane from the side of the protective layer away from the neutral plane, the thickness of the stress compensation layer, the Young's modulus of the stress compensation material used to form the stress compensation layer, the Poisson's ratio of the stress compensation material used to form the stress compensation layer, the thickness of the substrate, the Young's modulus of the base material used to form the substrate, the Poisson's ratio of the base material used to form the substrate, the thickness of the plurality of film layers, the Young's modulus of the film layer material used to form each film layer, and the Poisson's ratio of the film layer material used to form each film layer satisfy the following requirements:

[0080] Wherein, h refers to the distance between the neutral plane and the side of the protective layer away from the neutral plane, i refers to the i-th layer, n refers to the number of layers in the entire device structure, t is the thickness of each layer, E is the Young's modulus of the material of each layer, j represents a variable, j=1 means starting from j at 1, and ν refers to the Poisson's ratio.

[0081] A third aspect of the present application provides an electrical device, comprising a solar cell prepared by any preparation method provided in the first aspect or any solar cell provided in the second aspect.

[0082] A fourth aspect of the present application provides a power generation device, comprising a solar cell prepared by any preparation method provided in the first aspect or any solar cell provided in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0084] FIG1 is a schematic diagram of a first structure of a solar cell provided in an embodiment of the present application;

[0085] FIG2 is a schematic diagram of a second structure of a solar cell provided in an embodiment of the present application;

[0086] FIG3 is a schematic diagram of a third structure of a solar cell provided in an embodiment of the present application;

[0087] FIG4 is a schematic diagram of a fourth structure of a solar cell provided in an embodiment of the present application;

[0088] FIG5 is a fifth structural diagram of a solar cell provided in an embodiment of the present application;

[0089] FIG6 is a schematic diagram of a sixth structure of a solar cell provided in an embodiment of the present application;

[0090] FIG7 is a seventh structural diagram of a solar cell provided in an embodiment of the present application;

[0091] FIG8 is a schematic diagram of an eighth structure of a solar cell provided in an embodiment of the present application;

[0092] FIG9 is a ninth structural diagram of a solar cell provided in an embodiment of the present application;

[0093] FIG10 is a schematic diagram of the tenth structure of a solar cell provided in an embodiment of the present application;

[0094] FIG11 is a schematic structural diagram of an electrical device provided in an embodiment of the present application;

[0095] FIG12 is a schematic structural diagram of a power generation device provided in an embodiment of the present application;

[0096] FIG13 is a photograph of a solar cell provided in a comparative example before and after a bending experiment, wherein the left picture is before the bending experiment, and the right picture is after the bending experiment.

[0097] Explanation of the accompanying drawings: 100-solar cell, 10-solar cell body, 20-protective layer, 11-substrate, 12-functional layer, 121-film layer, 21-stress compensation layer, S-neutral plane, 101-first surface, 102-side surface, 201-stress compensation body, 202-first bending portion, 203-second bending portion, 103-second surface, A1-first area, A2-second area, 204-joining portion, 30-water and oxygen barrier adhesive, 211-viscoelastic layer, 212-packaging layer, 213-high elastic layer, 2111-first viscoelastic layer, 2112-second viscoelastic layer, 2113-third viscoelastic layer, 2121-first packaging layer, 2122-second packaging layer, 1000-electrical equipment, 2000-power generation equipment. DETAILED DESCRIPTION

[0098] The present application will be further described below in conjunction with specific embodiments. It should be understood that these specific embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0099] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0100] In the description herein, unless otherwise indicated, the term "or" is inclusive. That is, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0101] In the description of this article, it should be noted that, unless otherwise specified, “above” and “below” include the number itself, and “several” in “one or several” means two or more.

[0102] Unless otherwise specified, the terms used in this application have the commonly understood meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values ​​of the various parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this application).

[0103] In recent years, perovskite materials have been widely used in solar cells due to their advantages of low carrier recombination probability, high carrier mobility, and long carrier diffusion length. Perovskite materials are attached to a substrate structure by coating or spin coating to form a perovskite layer. Before the perovskite layer material is formed, several functional film layers can be pre-formed on the substrate structure. An electrode layer can be pre-formed on the substrate structure; an electrode layer and a carrier transport layer can also be pre-formed on the substrate structure in sequence, where the carrier transport layer is an electron-hole layer or a hole-transport layer; an electrode layer, a carrier transport layer, and a passivation layer can also be pre-formed on the substrate structure in sequence, where the carrier transport layer is an electron-hole layer or a hole-transport layer. The particles of the material in the perovskite layer generally do not have strong interactions with each other. When perovskite solar cells, including those on flexible substrates, are bent, their perovskite layers are stretched or compressed by the bending force. After repeated bending, the perovskite layer is prone to creases, cracks, and even fissures, which can affect the device performance of the perovskite solar cell and even lead to device damage. Therefore, improving the bending resistance of solar cells is of great significance.

[0104] Prior art methods typically improve the bending resistance of solar cells by directly improving film properties or adding protective films. However, these approaches ignore the impact of interactions between film structures on the bending resistance of solar cells, resulting in poor improvements or even counterproductive effects.

[0105] Taking flexible perovskite solar cells as an example, the thickness of a conventional flexible substrate is about 50μm to 200μm, while the total thickness of the other film layer structures attached to the flexible substrate is about 1μm. Therefore, in a complete flexible perovskite solar cell, its neutral plane is located on the flexible substrate (at a position of about 1 / 2 of the total film thickness). The film layers away from the neutral plane are subjected to greater stress during the bending process and are prone to greater strain, which will bring greater failure risks to the film layers or the interfaces of the film layers. By directly improving the performance of the film layer to improve the bending resistance of the solar cell, since the structure of the film layers of the device has not changed significantly, the position of the neutral plane has not changed significantly, the stress on the film layers on the flexible substrate will not be significantly reduced, and the bending resistance of the flexible perovskite solar cell will not be significantly improved. By adding a protective film layer, although the film structure of the device has changed, the existing setting idea is still to improve the bending resistance of the entire device by improving the material properties of the protective layer. The protective layer is designed and prepared in isolation, ignoring the influence of the interaction between the various film layer structures on the bending resistance of the solar cell. It is easy to cause the functional film layers of the flexible perovskite solar cell with the newly added protective film layer to still be in a stress-intensive area, and the bending resistance of the flexible perovskite solar cell will not be significantly improved, or even have the opposite effect.

[0106] In order to solve the above technical problems, an embodiment of the present application provides a method for preparing a solar cell, wherein the preset parameters of the protective layer are determined by the property parameters of the solar cell body and the position parameters of the neutral plane, and a protective layer is set on at least one side of the solar cell body according to the determined preset parameters of the protective layer to improve the bending resistance of the solar cell.

[0107] The technical solutions described in the embodiments of this application are applicable to solar cells and their preparation methods, electrical equipment, and power generation equipment. The solar cells disclosed in this application can be used in the field of solar power stations and lighting, and this application does not limit them.

[0108] Please refer to FIG1 , which is a schematic structural diagram of a solar cell provided in an embodiment of the present application.

[0109] 1 , an embodiment of the present application provides a solar cell 100. The solar cell 100 includes a solar cell body 10 and a protective layer 20. The solar cell body 10 includes a stacked substrate 11 and a functional layer 12. The functional layer 12 includes a plurality of stacked film layers 121. The protective layer 20 is provided on at least one side of the solar cell body 10 along the stacking direction of the substrate 11 and the functional layer 12, and the protective layer 20 includes at least one stress compensation layer 21. The neutral plane S of the solar cell 100 is located in the functional layer 12. Or the neutral plane S of the solar cell 100 is located in the substrate 11, and the distance between the surface of the functional layer 12 close to the substrate 11 and the neutral plane S is less than or equal to 10 μm. Or the neutral plane S of the solar cell 100 is located in the protective layer 20, and the distance between the surface of the functional layer 12 close to the protective layer 20 and the neutral plane S is less than or equal to 10 μm.

[0110] Solar cell 100 refers to a device that directly converts light energy into electrical energy through the photovoltaic effect. Generally speaking, solar cell 100 includes first-generation solar cells represented by crystalline silicon solar cells, second-generation solar cells represented by thin-film solar cells made of direct bandgap semiconductors such as copper indium gallium selenide (CIGS), gallium arsenide (GaAs), and cadmium telluride (CdTe), and third-generation solar cells represented by dye-sensitized solar cells (DSSCs), organic photovoltaic cells (OPVs), and perovskite solar cells (PSCs).

[0111] The solar cell body 10 refers to the main structure forming the solar cell 100 .

[0112] The substrate 11 is used to support the functional layer 12. In some embodiments, the substrate 11 is made of a flexible material to improve the flexibility of the solar cell 100, so that the flexible solar cell 100 can be integrated with flexible electronic devices, and play an important role in the fields of portable electronic products, flexible display devices, and wearable electronic devices. In some embodiments, the substrate 11 has a certain light transmittance, which allows external light to pass through the substrate 11 to reach the functional layer 12. In some embodiments, the material of the substrate 11 can be, for example (but not limited to) an organic polymer material, and further, it can be a mixture of one or more of the following materials in different proportions: including but not limited to polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), etc.

[0113] The functional layer 12 is the main structure that realizes the photovoltaic effect of the solar cell 100. It includes several film layers 121, each of which performs a portion of the photovoltaic effect. When a flexible solar cell 100 is bent, the functional layer 12 is stretched or compressed by the bending. Repeated bending can easily cause creases, cracks, or even fissures in the functional layer 12, potentially leading to failure of the solar cell 100.

[0114] Taking a single-cell perovskite solar cell as an example, the plurality of film layers 121 include at least a first electrode layer, a perovskite layer, and a second electrode layer, wherein at least one of the first electrode layer and the second electrode layer is a transparent electrode, so that incident photons can pass through the transparent electrode and be absorbed by the perovskite layer. In some embodiments, one of the first electrode layer and the second electrode layer is a transparent electrode layer, and the other is a metal electrode layer. The metal electrode layer is provided to reduce the resistivity of the solar cell 100 and improve the cell efficiency of the solar cell 100. In some embodiments, the plurality of film layers 121 further include at least one carrier transport layer, which is provided between the first electrode layer and the perovskite layer or between the perovskite layer and the second electrode layer to improve the photoelectric conversion efficiency of the solar cell 100. In some embodiments, the plurality of film layers 121 include two carrier transport layers, namely an electron transport layer and a hole transport layer, one provided between the first electrode layer and the perovskite layer, and the other provided between the perovskite layer and the second electrode layer, to further improve the photoelectric conversion efficiency of the solar cell 100. In some embodiments, the plurality of film layers 121 include a transparent electrode layer, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode layer stacked in sequence. It should be noted that the single-cell perovskite solar cell provided above can be used alone or in devices such as a perovskite-perovskite tandem cell, a perovskite-crystalline silicon tandem cell, or a perovskite-heterojunction tandem cell, and this application does not limit this.

[0115] The protective layer 20 is used to protect the solar cell body 10 and can improve the bending resistance of the solar cell 100 while protecting the solar cell body 10. In some embodiments, the material forming the protective layer 20 can be a water and oxygen barrier material. In addition to the aforementioned functions, it can also reduce the impact of the external environment on the solar cell body 10.

[0116] The protective layer 20 can be arranged only on one side of the solar cell body 10 (as shown in FIG1 ), or on two opposite sides of the solar cell body 10 (as shown in FIG5 ), or can cover the entire solar cell body 10 (as shown in FIG3 ), or can have other common settings in the art, which will not be described in detail in this application.

[0117] The stress-compensating layer 21 is a single-layer substructure of the protective layer 20, disposed on at least one side of the solar cell body 10. The addition of the stress-compensating layer 21 shifts the position of the neutral plane S to be located near or within the functional layer 12. This reduces the bending forces acting on the functional layer 12 when the solar cell body 10 is bent. The Young's modulus of the film material forming the film layer 121 has a well-known meaning in the art and can be measured using equipment and methods known in the art. For example, the Young's modulus of the material can be measured using a pulse excitation method.

[0118] The neutral plane S refers to the surface of a physical structure that is neither tensile nor compressive. Since it is stress-free, its shape depends solely on the material properties and the cross-sectional shape. In most cases, it is a plane perpendicular to the principal axes. The plane section assumption states that the position of the neutral plane S on a cross section is constant; that is, regardless of where the section is bent, the position of the neutral plane S remains the same. This assumption is a fundamental engineering assumption that provides a simple and practical method for calculating bending deformation in material mechanics. This assumption is valid for most engineering materials and common bending shapes.

[0119] For the solution in which the neutral plane S is located in the functional layer 12 or the neutral plane S is located in the substrate 11, and the distance between the surface of the functional layer 12 close to the substrate 11 and the neutral plane S is less than or equal to the threshold, the stress on the functional layer 12 during the bending process of the solar cell 100 is small, and it is not easy to fail during the bending process, and the bending resistance of the solar cell 100 can be effectively improved.

[0120] The embodiments of the present application take into account the interaction between the various layers of the solar cell 100. By setting the protective layer 20, the formed protective layer 20 is matched with the solar cell body 10, so that the neutral plane S of the solar cell 100 is close to or located on the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12 and improving the bending resistance of the solar cell 100.

[0121] It should be noted that the solar cell body 10 includes a plurality of battery modules arranged in an array, each battery module includes a plurality of battery cells, and the protective layer 20 may cover the solar cell body 10 as a whole, or may be arranged in a one-to-one correspondence with the battery modules.

[0122] Please refer to FIG. 2 , which is a second structural diagram of a solar cell provided in an embodiment of the present application.

[0123] Referring to FIG. 2 , the solar cell 100 provided in the embodiment of the present application differs from the solar cell 100 provided in the embodiment shown in FIG. 1 in that: in the solar cell 100 provided in the embodiment of the present application, the solar cell body 10 includes a first surface 101 and a side surface 102 surrounding the first surface 101. The first surface 101 is either a light-receiving surface or a light-removing surface of the solar cell body 10. The protective layer 20 includes a stress-compensating body 201 and a first bent portion 202. The first bent portion 202 is formed by extending from at least one stress-compensating layer 21 in the stress-compensating body 201. The stress-compensating body 201 is disposed on the first surface 101, and the first bent portion 202 is disposed on the side surface 102.

[0124] In some embodiments, the first surface 101 is the backlight surface of the solar cell body 10, and the stress compensation body 201 is disposed on the first surface 101 of the solar cell body 10. In some embodiments, the stress compensation body 201 is adhesive and can be attached to the first surface 101 by gluing, or by other methods such as heat pressing, depending on the specific needs. In other embodiments, the first surface 101 can also be the light-receiving surface of the solar cell body 10.

[0125] In some embodiments, the thickness of the first bent portion 202 may be the same as the thickness of the stress-compensating body 201 to simplify the manufacturing process.

[0126] In some embodiments, the thickness of the first bent portion 202 may be different from that of the stress-compensating body 201. That is, the first bent portion 202 may be formed by extending a portion of the stress-compensating layer 21 in the stress-compensating body 201 to reduce the thickness of the side surface 102 of the solar cell 100. Alternatively, the first bent portion 202 may be formed by adding other layers, such as a thermal conductive layer or a hydrophobic layer, to the extended region of the stress-compensating body 201 to provide other functions, such as thermal conductivity or hydrophobicity, to the side surface 102 of the solar cell 100. In some embodiments, the first bent portion 202 bends to the side surface 102 and may cover the entire side surface 102 or a portion of the side surface 102.

[0127] The stress-compensating body 201 is used to implement the primary function of the stress-compensating layer 21. Specifically, it is used to reduce the bending force exerted on the functional layer 12 when the solar cell body 10 is bent. The first bent portion 202 is used to further protect the side surface 102 of the solar cell body 10. The first bent portion 202 can be provided on all or part of the side surface 102. The embodiments of the present application provide a solution in which the first bent portion 202 is provided on all side surfaces 102.

[0128] In the embodiment of the present application, the first bending portion 202 is provided to reduce the curling of the edge of the stress compensation body 201 and improve the protection of the side surface 102 of the solar cell body 10 .

[0129] Please refer to FIG3 , which is a third structural diagram of a solar cell provided in an embodiment of the present application.

[0130] Referring to FIG3 , the solar cell 100 provided in the embodiment of the present application differs from the solar cell 100 provided in the embodiment of FIG2 in that the protective layer 20 of the solar cell 100 provided in the embodiment of the present application further includes a second bent portion 203, which is formed by extending at least one stress compensation layer 21 in the first bent portion 202. The solar cell body 10 further includes a second surface 103 disposed opposite the first surface 101. The second surface 103 is the other of the light-receiving and light-repelling surfaces of the solar cell body 10. The second bent portion 203 is disposed on the second surface 103.

[0131] The second bent portion 203 is used to further enhance the protection of the solar cell body 10 and to mate with the stress-compensating body 201, thereby further enhancing the bending resistance of the solar cell 100. The second bent portion 203 may be disposed on the entire second surface 103 or on a portion of the second surface 103. The embodiments of the present application provide a solution in which the second bent portion 203 is disposed on the entire second surface 103.

[0132] It should be noted that the stress compensation body 201, the first bending portion 202 and the second bending portion 203 can be made of the same material to simplify the manufacturing process; different materials can also be used. The stress compensation body 201, the first bending portion 202 and the second bending portion 203 are preset to different materials according to the size of the solar cell body 10. When it is bent, the protective layer 20 is set on each surface of the solar cell body 10 along the preset bending scheme, which is convenient for customizing materials according to needs.

[0133] The embodiment of the present application further improves the protection of the second surface 103 of the solar cell body 10 by setting the second bending portion 203, and the solution of setting the second bending portion 203 on the entire second surface 103 is beneficial to blocking the entire solar cell body 10 from the external environment, thereby improving the service life.

[0134] In addition, the second bending portion 203 can only cover a partial area of ​​the second surface 103, that is, the covered area is the edge position of the second surface 103, so as to improve the situation where the edge of the first bending portion 202 curls when there is only the first bending portion 202, thereby increasing the overall reliability of the protective layer 20.

[0135] Please refer to FIG4 , which is a fourth structural diagram of a solar cell provided in an embodiment of the present application.

[0136] Referring to FIG4 , the solar cell 100 provided in the embodiment of the present application differs from the solar cell 100 provided in the embodiment shown in FIG3 in that the second surface 103 of the solar cell 100 provided in the embodiment of the present application has a first area A1 and a second area A2. The second bent portion 203 is disposed in the second area A2 of the second surface 103. The solar cell 100 further includes another protective layer 20 disposed in the first area A1.

[0137] The embodiment of the present application provides a solution in which the second bent portion 203 is provided on a portion of the second surface 103. The two protective layers 20 of the solar cell 100 can be made of the same material or different materials, and have the same or different thicknesses, which are specifically set according to preset parameters.

[0138] The embodiment of the present application, through the provision of two differentiated protective layers 20, is conducive to the flexible selection of matching materials of the protective layer 20 according to preset parameters, and is further conducive to making the neutral plane S of the solar cell 100 close to or located on the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12, and further improving the bending resistance of the solar cell 100 and increasing the service life of the solar cell 100.

[0139] Please refer to FIG5 , which is a fifth structural diagram of a solar cell provided in an embodiment of the present application.

[0140] Referring to FIG5 , the solar cell 100 provided in the embodiment of the present application differs from the solar cell 100 provided in the embodiment shown in FIG1 in that a protective layer 20 is provided on both sides of the solar cell body 10 of the solar cell 100 provided in the embodiment of the present application. The protective layer 20 includes a stress compensation body 201 and a bonding portion 204. The bonding portion 204 is formed by extending from at least one stress compensation layer 21 in the stress compensation body 201, and a water-oxygen barrier adhesive 30 is provided between the two bonding portions 204.

[0141] The water-oxygen barrier adhesive 30 is an adhesive structure capable of preventing moisture and / or oxygen from the external environment from invading the solar cell body 10. In some embodiments, a bonding portion 204 is provided on the side 102 of the solar cell body 10, with one end bonding to the bonding portion 204 of one protective layer 20 and the other end bonding to the bonding portion 204 of another protective layer 20. In some embodiments, the water-oxygen barrier adhesive 30 is provided on all side surfaces 102 of the solar cell body 10. Combined with the provision of the protective layer 20, this prevents the solar cell body 10 from communicating with moisture and oxygen from the external environment, thereby improving the protection of the solar cell body 10.

[0142] The materials of the protective layers 20 on both sides of the solar cell body 10 can be the same or different, and their thicknesses can be the same or different, which are specifically set according to preset parameters.

[0143] The embodiment of the present application provides a protective layer 20 on both sides of the solar cell body 10, which facilitates the flexible selection of a matching material for the protective layer 20 according to preset parameters, and further facilitates making the neutral plane S of the solar cell 100 close to or located on the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12. At the same time, by providing a joint 204 and directly providing a water-oxygen barrier adhesive 30 on the two joints 204, the ability of the solar cell 100 to resist the intrusion of moisture and / or oxygen from the external environment is further enhanced.

[0144] Please refer to FIG. 6 , which is a schematic diagram of a sixth structure of a solar cell provided in an embodiment of the present application.

[0145] 6 , the difference between the solar cell 100 provided in the embodiment of the present application and the solar cell 100 provided in the embodiment shown in FIG5 is that a gap exists between the water-oxygen barrier adhesive 30 and the solar cell body 10 of the solar cell 100 provided in the embodiment of the present application.

[0146] In the embodiment of the present application, the gap provides space for deformation of the solar cell 100 during the bending process, thereby further improving the bending resistance of the solar cell 100.

[0147] In any embodiment of the present application, the width of the gap is 0.1 cm to 1 cm.

[0148] In some embodiments, the width of the gap may be 0.1 cm, 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1 cm, or a range consisting of any two of the above values. For example, the gap may be 0.1 cm to 0.4 cm, 0.3 cm to 0.7 cm, 0.6 cm to 0.8 cm, 0.7 cm to 1 cm, or the like.

[0149] In the embodiment of the present application, within the above-mentioned width range, a suitable space is provided for deformation of the solar cell 100 during the bending process, thereby improving the bending resistance of the solar cell 100 .

[0150] Please refer to FIG. 7 , which is a seventh structural diagram of a solar cell provided in an embodiment of the present application.

[0151] Referring to Figure 7, the difference between the solar cell 100 provided in the embodiment of the present application and the solar cell 100 provided in the embodiment shown in Figure 1 is that the solar cell 100 provided in the embodiment of the present application includes at least two stress compensation layers 21, one of which is a viscoelastic layer 211 and the other is an encapsulation layer 212, and the viscoelastic layer 211 is located between the solar cell body 10 and the encapsulation layer 212.

[0152] The viscoelastic layer 211 is a layer structure with both viscosity and elasticity, used to adhere to the solar cell body 10 and facilitate adhesion of the encapsulation layer 212 to the solar cell body 10 through the viscoelastic layer 211. The viscoelastic layer 211 facilitates adjustment of the neutral plane S. Generally speaking, the Young's modulus of the viscoelastic layer 211 is between 10 kPa and 80 kPa, making it more flexible and enabling greater adjustment of the neutral plane position with a thinner thickness. The encapsulation layer 212 has barrier properties, shielding the solar cell body 10 from the effects of ambient atmosphere. In some embodiments, the Young's modulus of the encapsulation layer 212 is between 1000 MPa and 8000 MPa, with a Poisson's ratio of 0 to 0.5. It is understood that the viscoelastic layer 211, due to its viscosity and flexibility, is more easily compatible with the other stress-compensating layers 21, enabling better adjustment of the neutral plane S within the solar cell 10 and enhancing protection for the solar cell body 10.

[0153] In the embodiment of the present application, the position adjustment of the neutral plane S is more easily achieved by disposing the viscoelastic layer 211 and the encapsulation layer 212 .

[0154] Please refer to FIG8 , which is an eighth structural diagram of a solar cell provided in an embodiment of the present application.

[0155] Referring to FIG8 , the solar cell 100 provided in the embodiment of the present application differs from the solar cell 100 provided in the embodiment of FIG7 in that the protective layer 20 of the solar cell 100 provided in the embodiment of the present application includes a stress-compensating body 201, a first bent portion 202, and a second bent portion 203. The stress-compensating body 201 is disposed on the entire first surface 101. In this embodiment, the stress-compensating body 201 is formed by at least two stress-compensating layers 21, one of which is a viscoelastic layer 211 and the other is an encapsulation layer 212. The first bent portion 202 is formed by extending the encapsulation layer 212 that forms the stress-compensating body 201 and is disposed on the entire side surface 102. The second bent portion 203 is formed by extending the encapsulation layer 212 that forms the first bent portion 202 and is disposed on the entire second surface 103.

[0156] In the embodiment of the present application, the position adjustment of the neutral plane S is more easily achieved by disposing the viscoelastic layer 211 and the encapsulation layer 212 .

[0157] Please refer to FIG. 9 , which is a ninth structural diagram of a solar cell provided in an embodiment of the present application.

[0158] 9 , the difference between the solar cell 100 provided in the embodiment of the present application and the solar cell 100 provided in the embodiment shown in FIG1 is that the solar cell 100 includes at least four stress compensation layers 21 , which are sequentially arranged as a first viscoelastic layer 2111 , a high elastic layer 213 , a second viscoelastic layer 2112 , and an encapsulation layer 212 , and the first viscoelastic layer 2111 is adhered to the solar cell body 10 .

[0159] The highly elastic layer 213 is used to reduce the overall thickness of the solar cell 100 and can reduce the stress and deformation experienced by the adjacent substrate 11, film layer 121, or stress-compensating layer 21 by squeezing the highly elastic layer 213. In some embodiments, the highly elastic layer 213 is a film layer having a larger Young's modulus than the first viscoelastic layer 2111 and the second viscoelastic layer 2112, thereby facilitating the transfer of the neutral plane S from the substrate 11 to the functional layer 12. The viscoelastic layers 211 are provided on opposite sides of the highly elastic layer 213 to achieve adhesion between the highly elastic layer 213 and the solar cell body 10, as well as between the highly elastic layer 213 and the encapsulation layer 212.

[0160] Through the above-mentioned configuration, the embodiment of the present application can reduce the stress and deformation of the adjacent substrate 11 or film layer 121 or stress compensation layer 21 by squeezing the high elastic layer 213, thereby further improving the bending resistance of the solar cell 100.

[0161] Please refer to FIG. 10 , which is a tenth structural diagram of a solar cell provided in an embodiment of the present application.

[0162] 10 , the solar cell 100 provided in the embodiment of the present application differs from the solar cell 100 provided in the embodiment shown in FIG1 in that the solar cell 100 includes at least six stress-compensating layers 21. The four stress-compensating layers 21 are sequentially arranged: a first viscoelastic layer 2111, a high elastic layer 213, a second viscoelastic layer 2112, and a first encapsulation layer 2121. These layers are disposed on one side of the solar cell body 10, with the first viscoelastic layer 2111 being bonded to the solar cell body 10.

[0163] Two other stress compensation layers 21 are stacked in sequence on the other side of the solar cell body 10 to form another protective layer 20. The two stress compensation layers 21 are a third viscoelastic layer 2113 and a second encapsulation layer 2122. The third viscoelastic layer 2113 is adhered to the solar cell body 10.

[0164] In the embodiment of the present application, the protective layer 20 is provided on both sides of the solar cell body 10 , thereby further improving the bending resistance of the solar cell 100 .

[0165] In any embodiment of the present application, the Young's modulus of the high elastic layer 213 is 500 MPa to 5000 MPa.

[0166] In some embodiments, the Young's modulus of the highly elastic layer 213 is 500 MPa, 800 MPa, 1000 MPa, 1200 MPa, 1500 MPa, 1800 MPa, 2000 MPa, 2200 MPa, 2500 MPa, 2800 MPa, 3000 MPa, 3200 MPa, 3500 MPa, 4000 MPa, 4200 MPa, 4500 MPa, 4800 MPa, 5000 MPa, or the like, or a range consisting of any two of the above values. For example, the Young's modulus can be 500 MPa to 1500 MPa, 1200 MPa to 2500 MPa, 2200 MPa to 3500 MPa, or 3000 MPa to 5000 MPa.

[0167] In the embodiment of the present application, within the range of the Young's modulus, the adjacent substrate 11 or film layer 121 or stress compensation layer 21 can reduce the stress and deformation thereof by squeezing the high elastic layer 213 .

[0168] In any embodiment of the present application, the thickness of the high elastic layer 213 is 5 μm to 200 μm.

[0169] In some embodiments, the thickness of the highly elastic layer 213 is 5 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, or a range consisting of any two of the above values. For example, the thickness can be 5 μm to 50 μm, 40 μm to 100 μm, 80 μm to 150 μm, 140 μm to 200 μm, or the like.

[0170] In the embodiment of the present application, within the above thickness range, without significantly increasing the overall thickness of the solar cell 100, the adjacent substrate 11 or film layer 121 or stress compensation layer 21 can reduce its own stress and deformation by squeezing the high elastic layer 213.

[0171] In any embodiment of the present application, the high elastic layer 213 includes at least one of silicone and polyurethane elastomer.

[0172] In some embodiments, the silicone comprises polydimethylsiloxane.

[0173] In the embodiment of the present application, by providing a specific material, the high elastic layer 213 made of the above material can more easily achieve the transfer of the neutral plane S from the substrate 11 to the functional layer 12 .

[0174] In any embodiment of the present application, at room temperature, the Young's modulus of the first viscoelastic layer 2111 is 10 kPa to 80 kPa, the creep amount is greater than or equal to 150%, and the creep recovery rate is greater than or equal to 90%. In any embodiment of the present application, at room temperature, the Young's modulus of the second viscoelastic layer 2112 is 10 kPa to 80 kPa, the creep amount is greater than or equal to 150%, and the creep recovery rate is greater than or equal to 90%.

[0175] Normal temperature, also called general temperature or room temperature, is generally defined as 25°C. In Chinese engineering, normal temperature is measured as 20°C, which is the temperature in spring and autumn in most parts of the country, such as the circulating water temperature (natural water temperature). The Young's modulus, creep amount, and creep recovery rate of the first viscoelastic layer 2111 and the second viscoelastic layer 2112 have meanings well known in the art and can be tested using equipment and methods known in the art. In some embodiments, all three parameters can be tested using a rheometer.

[0176] The Young's modulus is measured using a rheometer using the rheometer's dynamic test mode, which measures the dynamic response of a sample by oscillating it. In a dynamic test, the sample is placed on a vibrating plate or string that vibrates at a constant frequency and amplitude. The sample's response is measured by measuring the displacement and force on the plate or string.

[0177] The creep amount and creep recovery rate are tested using a rheometer using the creep test mode of the rheometer. This method studies the creep behavior of a sample by measuring its response to constant stress or strain over time. In a creep test, the sample is placed in a fixed-shape sample chamber, and the stress or strain in the sample chamber is applied to the sample.

[0178] In some embodiments, at room temperature, the Young's modulus of the first viscoelastic layer 2111 may be 10 kPa, 15 kPa, 20 kPa, 25 kPa, 30 kPa, 35 kPa, 40 kPa, 45 kPa, 50 kPa, 55 kPa, 60 kPa, 65 kPa, 70 kPa, 75 kPa, 80 kPa, or a range consisting of any two of the above values. For example, the Young's modulus may be 10 kPa to 40 kPa, 20 kPa to 50 kPa, 30 kPa to 60 kPa, 40 kPa to 70 kPa, or the like. At room temperature, the creep amount of the viscoelastic layer 211 can be 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200%, 205%, 210%, 215%, 220%, or any range consisting of any two of the aforementioned values. For example, the creep amount can be 150% to 180%, 160% to 190%, 170% to 200%, 180% to 210%, or any range consisting of any two of the aforementioned values. At room temperature, the creep recovery rate of the viscoelastic layer 211 can be 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, or any range consisting of any two of the aforementioned values. For example, it may be 90% to 130%, 100% to 140%, 110% to 150%, 120% to 160%, etc.

[0179] In some embodiments, at room temperature, the Young's modulus of the second viscoelastic layer 2112 may be 10 kPa, 15 kPa, 20 kPa, 25 kPa, 30 kPa, 35 kPa, 40 kPa, 45 kPa, 50 kPa, 55 kPa, 60 kPa, 65 kPa, 70 kPa, 75 kPa, 80 kPa, or a range consisting of any two of the above values. For example, the Young's modulus may be 10 kPa to 40 kPa, 20 kPa to 50 kPa, 30 kPa to 60 kPa, 40 kPa to 70 kPa, or the like. At room temperature, the creep amount of the viscoelastic layer 211 can be 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200%, 205%, 210%, 215%, 220%, or any range consisting of any two of the aforementioned values. For example, the creep amount can be 150% to 180%, 160% to 190%, 170% to 200%, 180% to 210%, or any range consisting of any two of the aforementioned values. At room temperature, the creep recovery rate of the viscoelastic layer 211 can be 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, or any range consisting of any two of the aforementioned values. For example, it may be 90% to 130%, 100% to 140%, 110% to 150%, 120% to 160%, etc.

[0180] In the embodiment of the present application, within the range of the above-mentioned Young's modulus, creep amount and creep recovery rate, it is possible to achieve adhesion with the adjacent substrate 11 or film layer 121 or stress compensation layer 21, making it easier to adjust the position of the neutral plane S.

[0181] In any embodiment of the present application, the thickness of the first viscoelastic layer 2111 is 5 μm to 15 μm. In any embodiment of the present application, the thickness of the second viscoelastic layer 2112 is 5 μm to 15 μm.

[0182] In some embodiments, the thickness of the first viscoelastic layer 2111 may be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, or the like, or a range consisting of any two of the above values. For example, the thickness may be 5 μm to 12 μm, 6 μm to 13 μm, 7 μm to 14 μm, 8 μm to 15 μm, or the like. In some embodiments, the thickness of the second viscoelastic layer 2112 may be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, or the like, or a range consisting of any two of the above values. For example, the thickness may be 5 μm to 12 μm, 6 μm to 13 μm, 7 μm to 14 μm, 8 μm to 15 μm, or the like.

[0183] In the embodiments of the present application, within the above-mentioned thickness range, without significantly increasing the overall thickness of the solar cell 100, bonding with the adjacent substrate 11 or film layer 121 or stress compensation layer 21 can be achieved, making it easier to adjust the position of the neutral plane S.

[0184] In any embodiment of the present application, the first viscoelastic layer 2111 includes at least one of polyurethane and polyacrylate. In any embodiment of the present application, the second viscoelastic layer 2112 includes at least one of polyurethane and polyacrylate.

[0185] In the embodiment of the present application, the specific material provided enables the viscoelastic layer 211 made of the above material to be laminated with the adjacent substrate 11 or film layer 121 or stress compensation layer 21, making it easier to adjust the position of the neutral plane S.

[0186] In any embodiment of the present application, the encapsulation layer 212 includes at least one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polycarbonate (PC).

[0187] In the embodiment of the present application, the specific material provided enables the encapsulation layer 212 made of the above material to block the influence of the ambient atmosphere on the solar cell body 10 .

[0188] In any embodiment of the present application, the functional layer 12 satisfies at least any one of the conditions (1) to (3):

[0189] (1) The functional layer 12 includes a perovskite layer and a carrier transport layer. The carrier transport layer is located on one side of the perovskite layer and is used to transport carriers. In some embodiments, a passivation layer is provided between the perovskite layer and the carrier transport layer.

[0190] (2) The functional layer 12 includes a first electrode layer, a first carrier transport layer, a perovskite layer, a second carrier transport layer, and a second electrode layer stacked in sequence. The first electrode layer is disposed on the substrate and is a transparent conductive oxide thin film. The first carrier transport layer is a hole transport layer, and the second carrier transport layer is an electron transport layer, or the first carrier transport layer is an electron transport layer, and the second carrier transport layer is a hole transport layer.

[0191] (3) The functional layer 12 includes a full perovskite tandem solar cell functional layer.

[0192] The perovskite layer absorbs photon energy from sunlight, generating electron-hole pairs. Under the action of a built-in electric field, these electron-hole pairs separate into free electrons and holes. The holes and electrons are collected by two different electrodes, which are connected to form a circuit to generate a photocurrent. The carrier transport layer transports electrons or holes generated by the perovskite layer when excited by photons. The hole transport layer collects and transports holes, achieving effective electron-hole separation. The electron transport layer, also known as the electron collection layer, transports electrons and blocks electron-hole recombination. The passivation layer passivates defects in the perovskite layer. An all-perovskite tandem solar cell is a solar cell that stacks two perovskite absorber layers with different band gaps. This type of tandem solar cell can effectively broaden the cell's absorption spectrum and reduce thermal relaxation losses. The functional layer of an all-perovskite tandem solar cell is the main structure that enables the photovoltaic effect of the all-perovskite tandem solar cell.

[0193] The solution of adjusting the position of the neutral plane S of the solar cell 100 to improve the bending resistance of the solar cell 100 in the embodiment of the present application can be applied to various different types of solar cells 100 .

[0194] In order to achieve the above-mentioned object, the second aspect of the present application provides a method for preparing a solar cell, comprising:

[0195] S1: Provide a solar cell body 10, which includes a stacked substrate 11 and a functional layer 12. The functional layer 12 includes a plurality of stacked film layers 121.

[0196] S2 : disposing a protective layer 20 on at least one side of the solar cell body 10 along the stacking direction of the substrate 11 and the functional layer 12 . The protective layer 20 includes at least one stress compensation layer 21 .

[0197] The neutral plane S of the solar cell 100 is located in the functional layer 12. Alternatively, the neutral plane S of the solar cell 100 is located within the substrate 11, and the distance between the surface of the functional layer 12 near the substrate 11 and the neutral plane S is less than or equal to 10 μm. Alternatively, the neutral plane S of the solar cell 100 is located within the protective layer 20, and the distance between the surface of the functional layer 12 near the protective layer 20 and the neutral plane S is less than or equal to 10 μm.

[0198] The embodiments of the present application take into account the interaction between the various layers of the solar cell 100 structure, so that the formed protective layer 20 matches the solar cell body 10, and the neutral plane S of the solar cell 100 is close to or located on the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12 and improving the bending resistance of the solar cell 100.

[0199] In any embodiment of the present application, the step S2 of “providing a protective layer 20 on at least one side of the solar cell body 10 ” includes:

[0200] A protective layer 20 is provided on at least one side of the solar cell body 10 according to preset parameters. The protective layer 20 includes at least one stress compensation layer 21 . The preset parameters include the thickness of each stress compensation layer 21 and the Young's modulus of the stress compensation material used to form the stress compensation layer 21 .

[0201] The method for determining the preset parameters includes:

[0202] The preset parameters are determined based on the property parameters of the solar cell body 10 and the position parameters of the neutral plane S. The property parameters include the thickness of the substrate 11 and the Young's modulus of the substrate material used to form the substrate 11, as well as the thickness of each film layer 121 and the Young's modulus of the film layer material used to form the film layer 121. The position parameters include the distance between the neutral plane S and the side of the stress compensation layer 21 away from the neutral plane S.

[0203] The preset parameters refer to pre-determined parameters for preparing the protective layer 20 .

[0204] In the embodiment of the present application, the preset parameters of the protective layer 20 are determined by the property parameters of the solar cell body 10 and the position parameters of the neutral plane S, so that the formed protective layer 20 matches the solar cell body 10, and the neutral plane S of the solar cell 100 formed by the protective layer 20 and the solar cell body 10 is close to or located on the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12 and further improving the bending resistance of the solar cell 100.

[0205] In any embodiment of the present application, the preset parameters also include the Poisson's ratio of the stress compensation material used to form the stress compensation layer 21, and the property parameters also include the Poisson's ratio of the substrate material used to form the substrate 11, and the Poisson's ratio of the film layer material used to form each film layer 121.

[0206] The Poisson's ratio of the stress-compensating material forming the stress-compensating layer 21 has a well-known meaning in the art and can be tested using equipment and methods known in the art. For example, the Poisson's ratio of the material can be tested using optical interferometry. The embodiments of the present application consider the effect of the lateral deformation of each layer structure on the position parameters of the neutral plane S, thereby improving the accuracy of the position adjustment of the neutral plane S.

[0207] In some embodiments, in S2, the step of providing a protective layer 20 on at least one side of the solar cell body 10 according to preset parameters includes:

[0208] S211 : Disposing the stress compensation body 201 on the first surface 101 according to preset parameters.

[0209] S212 : Bend the first bent portion 202 to the side surface 102 .

[0210] In some embodiments, the stress compensation body 201 may be disposed on the first surface 101 before the first bent portion 202 is bent toward the side surface 102. Alternatively, the protective layer 20 may be pre-bent so that a portion of the protective layer 20 forms the stress compensation body 201 and another portion forms the first bent portion 202. The pre-bent protective layer 20 is then disposed on the first surface 101 and side surface 102 of the solar cell body 10.

[0211] It should be noted that the preset parameters of the stress compensation body 201 will affect the change of the position parameters of the neutral plane S of the solar cell 100 ; while the preset parameters of the first bent portion 202 will not affect the change of the position parameters of the neutral plane S of the solar cell 100 .

[0212] In some embodiments, in S2, the step of providing a protective layer 20 on at least one side of the solar cell body 10 according to preset parameters includes:

[0213] S221 : Disposing the first bending portion 202 on the side surface 102 according to preset parameters.

[0214] In some embodiments, the first bending portion 202 is sticky and can be set on the side 102 by gluing, or by other methods such as hot pressing, etc., according to specific needs.

[0215] S222 : Bend the stress compensation body 201 toward the first surface 101 .

[0216] In some embodiments, the first bending portion 202 can be first set on the side 102, and then the stress compensation body 201 can be bent to the first surface 101; the protective layer 20 can also be bent in advance so that a part of the protective layer 20 is the stress compensation body 201, and the other part is bent into the first bending portion 202, and then the pre-bent protective layer 20 is set on the first surface 101 and the side 102 of the solar cell body 10.

[0217] In an embodiment of the present application, the protective layer 20 is arranged on the first surface 101 and the side 102 of the solar cell body 10 according to preset parameters, which not only improves the bending resistance of the solar cell 100, but also improves the degree of protection of the side 102 of the solar cell 100, further extending the service life of the solar cell 100.

[0218] In any embodiment of the present application, the protective layer 20 also includes a second bending portion 203, which is formed by extending the first bending portion 202. The solar cell body 10 also includes a second surface 103 arranged opposite to the first surface 101. The second surface 103 is the other of the light-receiving surface and the backlight surface of the solar cell body 10.

[0219] In some embodiments, after the step of bending the first bending portion 202 to the side surface 102 in S212 , the method further includes: bending the second bending portion 203 to the second surface 103 .

[0220] In some embodiments, after the step S221 of disposing the first bending portion 202 on the side surface 102 , the step further includes: bending the second bending portion 203 to the second surface 103 .

[0221] In some embodiments, the step of disposing the first bending portion 202 on the side surface 102 in S221 is: disposing the second bending portion 203 on the second surface 103 , and bending the first bending portion 202 to the side surface 102 .

[0222] The protective layer 20 can be disposed on the solar cell body 10 in a variety of ways, which are not limited in this application. Any method is sufficient as long as the protective layer 20 is disposed on the surface of the solar cell body 10. Specifically, in some embodiments, the protective layer 20 includes a stress compensation body 201, a first bend 202, and a second bend 203 connected in sequence. When the protective layer 20 is disposed on the solar cell body 10, it can be disposed on the solar cell body 10 in the order of the stress compensation body 201, the first bend 202, and the second bend 203; it can also be disposed on the solar cell body 10 in the order of the first bend 202, the second bend 203, and the stress compensation body 201; it can also be disposed on the solar cell body 10 in the order of the second bend 203, the first bend 202, and the stress compensation body 201.

[0223] In some embodiments, the first surface 101 is the backlight surface of the solar cell body 10, and the second surface 103 is the light-receiving surface of the solar cell body 10. In other embodiments, the first surface 101 may also be the light-receiving surface of the solar cell body 10, and the second surface 103 may be the backlight surface of the solar cell body 10. The stress-compensating body 201 is disposed on the first surface 101, and the second bent portion 203 is disposed on the second surface 103. The thickness of the second bent portion 203 is less than the thickness of the stress-compensating body 201, or the thickness of the second bent portion 203 is equal to the thickness of the stress-compensating body 201, and the Young's modulus of the second bent portion 203 is greater than the Young's modulus of the stress-compensating body 201. Or the thickness of the second bending portion 203 is smaller than the thickness of the stress compensation body 201 and the Young's modulus of the second bending portion 203 is greater than the Young's modulus of the stress compensation body 201, which can make the neutral plane S of the solar cell 100 formed by the protective layer 20 and the solar cell body 10 closer to or located on the functional layer 12 that is prone to failure, further improving the bending resistance of the solar cell 100.

[0224] In an embodiment of the present application, the protective layer 20 is arranged on the first surface 101, the side surface 102 and the second surface 103 of the solar cell body 10 according to preset parameters, which not only improves the bending resistance of the solar cell 100, but also further improves the degree of protection of the second surface 103 of the solar cell 100, thereby extending the service life of the solar cell 100.

[0225] In addition, the second bending portion 203 can only cover a partial area of ​​the second surface 103, that is, the covered area is the edge position of the second surface 103, so as to improve the situation where the edge of the first bending portion 202 curls when there is only the first bending portion 202, thereby increasing the overall reliability of the protective layer 20.

[0226] In any embodiment of the present application, a protective layer 20 is provided on both sides of the solar cell body 10. The protective layer 20 includes a stress compensation body 201 and a junction 204. The junction 204 is formed by extending at least one stress compensation layer 21 in the stress compensation body 201. The preset parameters include a first sub-preset parameter and a second sub-preset parameter.

[0227] In some embodiments, the joint portion 204 is used to join other film layers 121. In some embodiments, the joint portion 204 may be formed by extending only one stress-compensating layer 21, or may be formed by extending multiple stress-compensating layers 21. In some embodiments, the extension direction of the joint portion 204 is the same as the extension direction of the stress-compensating layer 21.

[0228] In S2, the step of providing a protective layer 20 on at least one side of the solar cell body 10 according to preset parameters includes:

[0229] S231 : Disposing one of the protection layers 20 on one side of the solar cell body 10 according to the first sub-preset parameter.

[0230] S232 : Disposing another protective layer 20 on the other side of the solar cell body 10 according to the second sub-preset parameter.

[0231] S233: Disposing a water and oxygen barrier adhesive 30 between the two joint portions 204 , wherein the first sub-preset parameter and the second sub-preset parameter are different.

[0232] In some embodiments, the design of the protective layer 20 on opposite sides of the solar cell body 10 is differentiated by the difference between the first sub-preset parameter and the second sub-preset parameter, thereby causing the neutral plane S to move closer to or into the functional layer 12 from its initial position, thereby improving the bending resistance of the solar cell 100 and extending the service life of the solar cell 100. For example, a protective layer A is provided on the light-receiving surface of the solar cell body 10 according to the first sub-preset parameter, and a protective layer B is provided on the backlight surface of the solar cell body 10 according to the second sub-preset parameter. The thickness of the stress-compensating body 201 of the protective layer A is smaller than the thickness of the stress-compensating body 201 of the protective layer B, and / or the Young's modulus of the stress-compensating body 201 of the protective layer A is greater than the Young's modulus of the stress-compensating body 201 of the protective layer B.

[0233] In the embodiment of the present application, a protective layer 20 is provided on both sides of the solar cell body 10 according to different preset parameters, so that the parameters of the protective layer 20 on both sides of the solar cell body 10 are differentiated, so that the neutral plane S of the solar cell 100 is close to or located at the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12, thereby improving the bending resistance of the solar cell 100 and increasing the service life of the solar cell 100.

[0234] In any embodiment of the present application, in the method for determining the preset parameters in S2, in the step of determining the preset parameters based on the property parameters of the solar cell body 10 and the position parameters of the neutral plane S, the distance of the neutral plane S from the side of the protective layer 20 away from the neutral plane S, the thickness of the stress compensation layer 21, the Young's modulus of the stress compensation material used to form the stress compensation layer 21, the thickness of the substrate 11 and the Young's modulus of the substrate material used to form the substrate 11, the thickness of the plurality of film layers 121 and the Young's modulus of the film layer material used to form the plurality of film layers 121 satisfy the following:

[0235] Wherein, h refers to the distance between the neutral plane S and the side of the protective layer 20 away from the neutral plane S, i refers to the i-th layer, n refers to the number of layers in the entire device structure, t is the thickness of each layer, E is the Young's modulus of the material of each layer, j represents a variable, and j=1 means that the value starts from j at 1.

[0236] The embodiments of the present application provide a specific method for determining the preset parameters of the protective layer 20. By using the above method, the formed protective layer 20 is matched with the solar cell body 10. The neutral plane S of the solar cell 100 formed by the protective layer 20 and the solar cell body 10 is close to or located on the functional layer 12 that is prone to failure, thereby reducing the failure risk of the functional layer 12, thereby improving the bending resistance of the solar cell 100 and increasing the service life of the solar cell 100. It is understood that the embodiments of the present application provide a specific method for determining the preset parameters of the protective layer 20, and other methods for determining the preset parameters of the protective layer 20 can also be used.

[0237] In any embodiment of the present application, in the step of determining the preset parameters based on the property parameters of the solar cell body 10 and the position parameters of the neutral plane S, the preset parameters also include the Poisson's ratio of the stress compensation material used to form the stress compensation layer 21, and the property parameters also include the Poisson's ratio of the base material used to form the base 11, and the Poisson's ratio of the film layer material used to form each film layer 121.

[0238] The distance between the neutral plane S and the side of the protective layer 20 away from the neutral plane S, the thickness of the stress compensation layer 21, the Young's modulus of the stress compensation material used to form the stress compensation layer 21, the Poisson's ratio of the stress compensation material used to form the stress compensation layer 21, the thickness of the substrate 11, the Young's modulus of the base material used to form the substrate 11, the Poisson's ratio of the base material used to form the substrate 11, the thickness of the plurality of film layers 121, the Young's modulus of the film layer material used to form each film layer 121, and the Poisson's ratio of the film layer material used to form each film layer 121 satisfy the following conditions:

[0239] Among them, h refers to the distance between the neutral plane S and the side of the protective layer 20 away from the neutral plane S, i refers to the i-th layer, n refers to the number of layers in the entire device structure, t is the thickness of each layer, E is the Young's modulus of the material of each layer, j represents a variable, j=1 means that the value starts from j at 1, and ν refers to the Poisson's ratio.

[0240] The embodiments of the present application provide a specific method for determining the preset parameters of the protective layer 20 by considering the effect of the lateral deformation of each layer structure on the position parameters of the neutral plane S. This method allows the formed protective layer 20 to match the solar cell body 10. The neutral plane S of the solar cell 100 formed by the protective layer 20 and the solar cell body 10 is close to or located on the functional layer 12, which is prone to failure. This reduces the risk of failure of the functional layer 12, thereby improving the bending resistance of the solar cell 100 and increasing the service life of the solar cell 100.

[0241] The application of the above formula is described by taking an example where a protective layer 20 is provided on the backlight side of the solar cell body 10 according to preset parameters, and the protective layer 20 includes a stress compensation layer 21:

[0242] First, the solar cell body 10 includes a second electrode layer, a hole transport layer, a perovskite layer, an electron transport layer, a first electrode layer and a substrate 11 stacked in sequence, and a protective layer 20 is arranged on the side of the second electrode layer away from the substrate. The protective layer 20 only includes a stress compensation layer 21.

[0243] The thickness of the stress compensation layer 21 is t1, the Young's modulus of the stress compensation material forming the stress compensation layer 21 is E1, and the Poisson's ratio is ν1. The above three parameters are all unknown quantities.

[0244] The thickness of the second electrode layer is t2, and the Young's modulus of the film material forming the second electrode layer is E2, and the Poisson's ratio is ν2; the thickness of the hole transport layer is t3, and the Young's modulus of the film material forming the hole transport layer is E3, and the Poisson's ratio is ν3; the thickness of the perovskite layer is t4, and the Young's modulus of the film material forming the perovskite layer is E4, and the Poisson's ratio is ν4; the thickness of the electron transport layer is t5, and the Young's modulus of the film material forming the electron transport layer is E5, and the Poisson's ratio is ν5; the thickness of the first electrode layer is t6, and the Young's modulus of the film material forming the first electrode layer is E6, and the Poisson's ratio is ν6; the thickness of the substrate 11 is t7, and the Young's modulus of the film material forming the substrate 11 is E7, and the Poisson's ratio is ν7; the above parameters are all known quantities.

[0245] The neutral plane S is to be disposed in the functional layer 12 , and a distance h between the neutral plane S and the side of the stress compensation layer 21 away from the substrate is in the range of t1 to t1+t2+t3+t4+t5+t6.

[0246] One method is to first determine the thickness t1 of the stress-compensating layer 21, substitute the thickness t1 of the stress-compensating layer 21 and the parameters of the substrate 11 and the film layers 121 of the solar cell body 10 into the above formula to obtain a range of values ​​for the Young's modulus E1 and the Poisson's ratio ν1 of the stress-compensating material forming the stress-compensating layer 21, and then screen a suitable stress-compensating material for forming the stress-compensating layer 21 based on the range of values ​​for the Young's modulus E1 and the Poisson's ratio ν1 of the stress-compensating material forming the stress-compensating layer 21. Based on the above process, the preset parameters of the stress-compensating layer 21 (including the thickness t1 of the stress-compensating layer 21, the Young's modulus E1, and the Poisson's ratio ν1 of the stress-compensating material forming the stress-compensating layer 21) are obtained.

[0247] Another method is to first determine the Young's modulus E1 and Poisson's ratio ν1 of the stress-compensating material forming the stress-compensating layer 21, then substitute these Young's modulus E1 and Poisson's ratio ν1 of the stress-compensating material forming the stress-compensating layer 21, as well as the parameters of the substrate 11 and each film layer 121 of the solar cell body 10, into the above formula to obtain a range of values ​​for the thickness t1 of the stress-compensating layer 21. Based on the above process, the preset parameters of the stress-compensating layer 21 (including the thickness t1 of the stress-compensating layer 21, the Young's modulus E1 and the Poisson's ratio ν1 of the stress-compensating material forming the stress-compensating layer 21) are obtained.

[0248] Please refer to FIG11 , which is a schematic structural diagram of an electrical device provided in an embodiment of the present application.

[0249] 11 , the third aspect of the present application provides an electrical device 1000 , comprising a solar cell 100 prepared by any preparation method provided in the first aspect or any solar cell 100 provided in the second aspect.

[0250] In the embodiments of the present application, a solar cell 100 serves as a power source for an electrical device 1000, enabling normal operation of the electrical device 1000. Electrical device 1000 employing the solar cell 100 provided herein has at least the same advantages as the solar cell 100, and can improve battery performance of the electrical device 1000. For example, the electrical device 1000 may include a lighting device, a display device, or a new energy vehicle.

[0251] Please refer to FIG12 , which is a schematic structural diagram of a power generation device provided in an embodiment of the present application.

[0252] 12 , the fourth aspect of the present application provides a power generation device 2000 , comprising a solar cell 100 prepared by any preparation method provided in the first aspect or any solar cell 100 provided in the second aspect.

[0253] In the embodiments of the present application, a solar cell 100 serves as the energy source for a power generation device 2000, enabling the power generation device 2000 to output electrical energy. Power generation device 2000 utilizes the solar cell 100 provided in the present application and has at least the same advantages as solar cell 100, thereby improving the power generation performance of power generation device 2000. For example, power generation device 2000 can be used in fields such as building power generation, wearable device power generation, smartphone power generation, and vehicle battery power generation.

[0254] The beneficial effects of the present application are further illustrated below with reference to the examples.

[0255] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0256] Example 1

[0257] The preparation of solar cell 100, the structural diagram is shown in FIG7 :

[0258] 1. Provide a solar cell body 10 , and determine the initial position parameters of the neutral plane S according to the property parameters of the solar cell body 10 .

[0259] The solar cell body 10 of this embodiment includes a substrate 11 and a plurality of film layers 121 stacked in sequence, wherein the plurality of film layers 121 are respectively a first electrode layer, an electron transport layer, a perovskite layer, a hole transport layer and a second electrode layer.

[0260] The property parameters of the substrate 11 and each film layer 121 are shown in Table 1. In this embodiment, the lateral deformation of the substrate 11 and each film layer 121 is not considered, that is, the Poisson's ratio of the substrate 11 and each film layer 121 in this embodiment is 0.

[0261] Table 1 Attribute parameters of each film layer of the solar cell body

[0262] Note: This embodiment does not consider lateral deformation of the material, and the Poisson's ratio is zero. PET is polyethylene terephthalate; ITO is indium tin oxide; the molecular formula of the perovskite is FAPbI3; C60 is fullerene C60; BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; and Cu is copper.

[0263] Substituting the parameters of the substrate 11 and each film layer 121 into the above formula (1), the initial position parameter of the neutral plane S is calculated to be 5*10 4 nm, that is, close to 1 / 2 of the thickness of the substrate 11.

[0264] Second, the position of the neutral plane S is adjusted and the structure of the solar cell 100 is designed. Here, the design is based on the structure shown in Figure 7. The solar cell 100 includes two stress compensation layers 21, one of which is a viscoelastic layer 211 and the other is an encapsulation layer 212. The encapsulation layer 212 and the viscoelastic layer 211 are sequentially arranged on one side of the solar cell body 10. Specifically, the viscoelastic layer 211 is arranged on the side of the functional layer 12 away from the substrate 11, and the encapsulation layer 212 is arranged on the side of the viscoelastic layer 211 away from the substrate 11. The material of the encapsulation layer 212 is preset to be PET, with a Young's modulus of 3×10 6 The viscoelastic layer 211 is made of polyacrylate, has a thickness of 10 μm, and a Young's modulus of 50 kPa. This embodiment does not consider the lateral deformation of the protective layer 20, that is, the Poisson's ratio of each layer of material forming the protective layer 20 in this embodiment is 0.

[0265] Substituting the above parameters into the above formula (1), it is calculated that when the thickness of the encapsulation layer 212 is 120 μm, the neutral plane S is located on the functional layer 12 .

[0266] At the same time, when the thickness of the encapsulation layer 212 is within the range of 97 μm to 141 μm, the neutral plane S can be preferably adjusted to be close to or located on the functional layer 12. Specifically, when the thickness of the encapsulation layer 212 is 97 μm, the neutral plane S is located 10 μm below the functional layer 12, and when the thickness of the encapsulation layer 212 is 141 μm, the neutral plane S is located 10 μm above the functional layer 12.

[0267] Example 2

[0268] This embodiment differs from Example 1 in that it is designed according to the structure shown in Figure 8 . The protective layer 20 includes a stress-compensating body 201, a first bend 202, and a second bend 203. The stress-compensating body 201 is disposed across the entire first surface 101, which serves as the backlight side of the solar cell body 10. The stress-compensating body 201 of this embodiment is formed from at least two stress-compensating layers 21: a viscoelastic layer 211 and an encapsulation layer 212. The viscoelastic layer 211 is disposed on the side of the functional layer 12 away from the substrate 11. The first bend 202 is formed by extending the encapsulation layer 212 that forms the stress-compensating body 201 and is disposed across the entire side surface 102. The second bend 203 is formed by extending the encapsulation layer 212 that forms the first bend 202 and is disposed across the entire second surface 103.

[0269] The material of the packaging layer 212 is PET, and the Young's modulus is 3×10 6The material of the preset viscoelastic layer 211 is polyacrylate, with a thickness of 10 μm and a Young's modulus of 50 kPa. The material of the preset first bending portion 202 is PET, with a Young's modulus of 1×10 6 GPa. The material of the second bending portion 203 is PET, and the Young's modulus is 2×10 6 GPa, thickness is 25 μm. Substituting the above parameters into the above formula (1), it is calculated that when the thickness range of the encapsulation layer 212 is 90 μm, the neutral plane S is located on the functional layer 12.

[0270] Example 3

[0271] This embodiment differs from Example 1 in that it is designed according to the structure shown in FIG10 . Protective layers 20 are provided on both sides of the solar cell body 10. The solar cell 100 includes at least six stress-compensating layers 21. The four stress-compensating layers 21 are sequentially arranged: a first viscoelastic layer 2111, a high-elastic layer 213, a second viscoelastic layer 2112, and a first encapsulation layer 2121. These layers are disposed on one side of the solar cell body 10, specifically on the side of the functional layer 12 facing away from the substrate 11. The first viscoelastic layer 2111 is bonded to the solar cell body 10. The other two stress-compensating layers 21 are sequentially arranged: a third viscoelastic layer 2113 and a second encapsulation layer 2122. These layers are disposed on the other side of the solar cell body 10, with the third viscoelastic layer 2113 being bonded to the solar cell body 10.

[0272] The materials of the first encapsulation layer 2121 and the second encapsulation layer 2122 are both PET. The thickness of the first encapsulation layer 2121 is 25 μm, and the Young's modulus is 3×10 6 GPa. The thickness of the second encapsulation layer 2122 is 50 μm, and the Young's modulus is 2×10 6 GPa. Then, the material of the first viscoelastic layer 2111, the second viscoelastic layer 2112 and the third viscoelastic layer 2113 is preset to be polyacrylate, with a thickness of 10 μm and a Young's modulus of 50 kPa. The material of the high elastic layer 213 is preset to be polyurethane, with a Young's modulus of 1×10 6 Gpa.

[0273] Substituting the above parameters into the above formula (1), the thickness of the high elastic layer 213 is calculated to be 96 μm, thereby ensuring that the neutral plane S is located on the functional layer 12 .

[0274] Example 4

[0275] This embodiment differs from Example 1 in that the encapsulation layer 212 is initially configured to have a thickness of 80 μm and be made of PET. The viscoelastic layer 211 is configured to be made of polyacrylate, have a thickness of 10 μm, and a Young's modulus of 50 kPa. The position parameter of the neutral plane S, i.e., the distance between the neutral plane S and the side of the protective layer 20 away from the neutral plane S, is configured to be 91 μm.

[0276] Substituting the above parameters into the above formula (1), the Young's modulus parameter of the encapsulation layer 212 is calculated to be 1.25×10 6 GPa, thereby ensuring that the neutral plane S is located on the functional layer 12.

[0277] Example 5

[0278] The difference between this embodiment and embodiment 1 is that the material of the encapsulation layer 212 is PET, and the Young's modulus is 1×10 6 Substituting the above parameters into the above formula (1), it is calculated that the thickness of the encapsulation layer 212 is 72 μm, and the neutral plane S is located on the functional layer 12 .

[0279] At the same time, when the thickness of the encapsulation layer 212 is within the range of 56 μm to 88 μm, the neutral plane S can be preferably adjusted to be close to or located on the functional layer 12. Specifically, when the thickness of the encapsulation layer 212 is 56 μm, the neutral plane S is located 10 μm below the functional layer 12, and when the thickness of the encapsulation layer 212 is 88 μm, the neutral plane S is located 10 μm above the functional layer 12.

[0280] Comparative Example

[0281] The difference between this comparative example and Example 1 is that the protective layer 20 is not provided in this comparative example.

[0282] Bending performance test method:

[0283] By adjusting the sensor position, the bending radius was set to 10mm. The sample was secured to the clamping table using clamping pressure. The bending frequency was set to 3 bending cycles per second and the number of bends was set to 10,000. The bending operation mode used a single-sided slide. The bending resistance of the cell was evaluated by measuring the change in photoelectric conversion efficiency before and after bending.

[0284] Photoelectric conversion efficiency test method:

[0285] By changing the bias voltage point and measuring the current at the same time, the IV characteristics of the sample under test can be obtained.

[0286] 1) Place the test fixture containing the sample cell on the sample holder so that it is located in the measurement plane and ensure that the sample cell is located at the center of the solar simulator's output light spot (or the photovoltaic cell normal is parallel to the center line of the solar simulator's light source output light beam).

[0287] 2) Using Guangyan's solar simulator, which complies with the national standard IEC61215 for testing, and using crystalline silicon solar cells to calibrate the light intensity to reach the intensity of the sun, at 1000W / m 2 Under the conditions of irradiance, a mask is installed on the sample battery to be tested, and the temperature of the sample battery is controlled by a temperature monitoring device so that the temperature of the sample to be tested is maintained at (30±5℃) during the measurement process.

[0288] 3) Set the scanning direction, voltage range, scanning interval voltage and scanning interval time, etc. The scanning interval should not be greater than 0.02V, and the interval between two adjacent points should not be less than 0.3s. Measure the forward and reverse current-voltage characteristics of the sample battery under test, and record the open circuit voltage V OC , short-circuit current J SC .

[0289] Calculation formula: Fill factor FF = J m *V m / V OC *J SC , Jm is the maximum light output current, Vm is the maximum light output voltage; energy conversion efficiency PCE=V OC *J SC *FF / P in .P in is the incident light intensity, which is equal to 10 3 W / m 2 .

[0290] Table 2 Test results of bending performance of solar cells in the examples and comparative examples of the present application

[0291] Note: In the bending performance test of this application, the bending radius is set to 10mm.

[0292] As can be seen from Table 2, when the embodiment of the present invention adjusts the position of the neutral plane S to the functional layer 12 or close to the functional layer 12 by adding a protective layer 20, more than 90% of the initial photoelectric conversion efficiency can be retained after bending 10,000 times. However, when the neutral plane s is not adjusted (Comparative Example 1), the solar cell will be seriously damaged, and the retention rate of its initial photoelectric conversion efficiency after bending 10,000 times is only less than 10%. Figure 13 is a photo of the solar cell 100 provided in Comparative Example 1 before and after the bending test. The left picture is before the bending test, and the right picture is after the bending test. It can be seen that the surface of the solar cell 100 is obviously damaged after the bending test.

[0293] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0294] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0295] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. Solar cell, wherein, Comprising: A solar cell body, including a substrate and a functional layer arranged in a stacked manner; the functional layer includes a plurality of film layers arranged in a stacked manner; A protective layer, arranged on at least one side of the solar cell body along the stacking direction of the substrate and the functional layer, the protective layer includes at least one stress compensation layer; Wherein, the neutral plane of the solar cell is located in the functional layer; or, the neutral plane of the solar cell is located in the substrate, and the distance between the surface of the functional layer close to the substrate and the neutral plane is less than or equal to 10 μm; or, the neutral plane of the solar cell is located in the protective layer, and the distance between the surface of the functional layer close to the protective layer and the neutral plane is less than or equal to 10 μm.

2. The solar cell according to claim 1, wherein, The protective layer includes a stress compensation body and a first bending portion, the first bending portion is at least formed by extending at least one stress compensation layer in the stress compensation body, the solar cell body includes a first surface and a side surface surrounding the first surface, the first surface is one of the light-receiving surface and the backlight surface of the solar cell body, the stress compensation body is arranged on the first surface, and the first bending portion is arranged on the side surface.

3. The solar cell according to claim 2, wherein, The protective layer further includes a second bending portion, the second bending portion is at least formed by extending at least one stress compensation layer in the first bending portion, the solar cell body further includes a second surface opposite to the first surface, the second surface is the other of the light-receiving surface and the backlight surface of the solar cell body, and the second bending portion is arranged on the second surface.

4. The solar cell according to claim 3, wherein, The second surface has a first region and a second region, the second bending portion is arranged in the second region of the second surface, and the solar cell further includes another protective layer, and the another protective layer is arranged in the first region.

5. The solar cell according to claim 1, wherein Protective layers are arranged on both sides of the solar cell body, the protective layer includes a stress compensation body and a joint portion, the joint portion is formed by extending at least one stress compensation layer in the stress compensation body, and a water and oxygen barrier adhesive is arranged between the two joint portions.

6. The solar cell according to claim 5, wherein, There is a gap between the water and oxygen barrier adhesive and the solar cell body.

7. The solar cell according to claim 6, wherein, The width of the gap is 0.1 cm to 1 cm.

8. The solar cell according to any one of claims 1 to 7, wherein, The solar cell includes at least two stress compensation layers, one of which is a viscoelastic layer and the other is a packaging layer, and the viscoelastic layer is located between the solar cell body and the packaging layer.

9. The solar cell according to any one of claims 1 to 7, wherein, The solar cell includes at least four stress compensation layers, and the four stress compensation layers are a first viscoelastic layer, a high-elasticity layer, a second viscoelastic layer, and a packaging layer arranged in sequence, and the first viscoelastic layer far from the packaging layer is attached to the solar cell body.

10. The solar cell according to claim 9, wherein, The Young's modulus of the high-elasticity layer is 500 MPa to 5000 MPa.

11. The solar cell according to claim 9 or 10, wherein, The thickness of the high-elasticity layer is 5 μm to 200 μm.

12. The solar cell according to any one of claims 9 to 11, wherein, The high-elasticity layer includes at least one of silica gel and polyurethane elastomer.

13. The solar cell according to any one of claims 8 to 12, wherein, At room temperature, the Young's modulus of the first viscoelastic layer is 10 kPa to 80 kPa, the creep strain is greater than or equal to 150%, and the creep recovery rate is greater than or equal to 90%; and / or, the Young's modulus of the second viscoelastic layer is 10 kPa to 80 kPa, the creep strain is greater than or equal to 150%, and the creep recovery rate is greater than or equal to 90%.

14. The solar cell according to any one of claims 8 to 13, wherein, The thickness of the first viscoelastic layer is 5 μm to 15 μm; and / or, the thickness of the second viscoelastic layer is 5 μm to 15 μm.

15. The solar cell according to any one of claims 8 to 14, wherein, The first viscoelastic layer includes at least one of polyurethane and polyacrylate; and / or, the second viscoelastic layer includes at least one of polyurethane and polyacrylate.

16. The solar cell according to any one of claims 8 to 15, wherein, The encapsulation layer includes at least one of polyethylene terephthalate, polyethylene naphthalate, and polycarbonate.

17. The solar cell according to any one of claims 1 to 16, wherein, The functional layer includes a perovskite layer and a charge transport layer, and the charge transport layer is located on one side of the perovskite layer and is used for transporting charges.

18. The solar cell according to any one of claims 1 to 17, wherein, The functional layer includes a first electrode layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a second electrode layer stacked in sequence; the first electrode layer is provided on a substrate and is a transparent conductive oxide thin film; the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, or the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer.

19. The solar cell according to any one of claims 1 to 18, wherein, The functional layer includes a perovskite tandem solar cell functional layer.

20. A method for preparing a solar cell, wherein, Comprising: Providing a solar cell body, the solar cell body including a substrate and a functional layer stacked; the functional layer includes a plurality of film layers stacked; A protective layer is provided on at least one side of the solar cell body along the stacking direction of the substrate and the functional layer, and the protective layer includes at least one stress compensation layer; Wherein, the neutral plane of the solar cell is located in the functional layer; or, the neutral plane of the solar cell is located in the substrate, and the distance between the surface of the functional layer close to the substrate and the neutral plane is less than or equal to 10 μm; or, the neutral plane of the solar cell is located in the protective layer, and the distance between the surface of the functional layer close to the protective layer and the neutral plane is less than or equal to 10 μm.

21. The method for preparing a solar cell according to claim 20, wherein, The step of providing a protective layer on at least one side of the solar cell body includes: Providing a protective layer on at least one side of the solar cell body according to preset parameters, the protective layer including at least one stress compensation layer, and the preset parameters including the thickness of each stress compensation layer and the Young's modulus of the stress compensation material used to form the stress compensation layer; Wherein, the method for determining the preset parameters includes: Determining the preset parameters according to the property parameters of the solar cell body and the position parameters of the neutral plane, the property parameters including the thickness of the substrate and the Young's modulus of the substrate material used to form the substrate, and the thickness of each film layer and the Young's modulus of the film layer material used to form the film layer, and the position parameters including the distance between the neutral plane and the side of the stress compensation layer away from the neutral plane.

22. The method for preparing a solar cell according to claim 21, wherein, The preset parameters further include the Poisson's ratio of the stress compensation material for forming the stress compensation layer, the property parameters further include the Poisson's ratio of the substrate material for forming the substrate, and the Poisson's ratio of the film layer material for forming each of the film layers.

23. The manufacturing method of the solar cell according to any one of claims 20 to 22, wherein, The protective layer includes a stress compensation body and a first bent portion; the first bent portion is formed by extending from the stress compensation layer in at least part of the stress compensation body, the solar cell body includes a first surface and a side surface surrounding the first surface, and the first surface is one of the light-receiving surface and the backlight surface of the solar cell body; the step of disposing the protective layer on at least one side of the solar cell body according to the preset parameters includes: Disposing the stress compensation body on the first surface according to the preset parameters; Bending the first bent portion to the side surface; or Disposing the first bent portion on the side surface according to the preset parameters; Bending the stress compensation body to the first surface.

24. The manufacturing method of the solar cell according to claim 23, wherein, The protective layer further includes a second bent portion, the second bent portion is formed by extending from the stress compensation layer in at least part of the first bent portion, the solar cell body further includes a second surface disposed opposite to the first surface, and the second surface is the other of the light-receiving surface and the backlight surface of the solar cell body, wherein, After the step of bending the first bent portion to the side surface, it further includes: bending the second bent portion to the second surface; or After the step of disposing the first bent portion on the side surface, it further includes: bending the second bent portion to the second surface; or The step of disposing the first bent portion on the side surface is: disposing the second bent portion on the second surface and bending the first bent portion to the side surface.

25. The manufacturing method of a solar cell according to any one of claims 20 to 22, wherein, Protective layers are disposed on both sides of the solar cell body, the protective layer includes a stress compensation body and a joint portion, the joint portion is formed by extending from at least one of the stress compensation layers in the stress compensation body, the preset parameters include a first sub-preset parameter and a second sub-preset parameter, and the step of disposing the protective layer on at least one side of the solar cell body according to the preset parameters includes: Disposing one of the protective layers on one side of the solar cell body according to the first sub-preset parameter; Disposing the other of the protective layers on the other side of the solar cell body according to the second sub-preset parameter; and Disposing a water and oxygen barrier adhesive between the two joint portions, wherein the first sub-preset parameter and the second sub-preset parameter are different.

26. The method for preparing a solar cell according to any one of claims 20 to 25, wherein, In the step of determining the preset parameters according to the attribute parameters of the solar cell body and the position parameters of the neutral plane, the distance from the neutral plane to the side of the protective layer away from the neutral plane, the thickness of the stress compensation layer, the Young's modulus of the stress compensation material for forming the stress compensation layer, the thickness of the substrate and the Young's modulus of the substrate material for forming the substrate, the thicknesses of the plurality of film layers and the Young's modulus of the film layer materials for forming the plurality of film layers satisfy: Wherein, h refers to the distance from the neutral plane to the side of the protective layer away from the neutral plane, i refers to the i-th layer, n refers to the number of layers in the entire device structure, t is the thickness of each layer, E is the Young's modulus of each layer material, j represents a variable, and j = 1 means starting from j = 1.

27. The manufacturing method of a solar cell according to claim 26, wherein, In the step of determining the preset parameters according to the property parameters of the solar cell body and the position parameters of the neutral plane, The preset parameters further include the Poisson ratio of the stress compensation material for forming the stress compensation layer, and the property parameters further include the Poisson ratio of the substrate material for forming the substrate and the Poisson ratio of the film layer materials for forming each of the film layers; The distance between the neutral plane and the side of the protective layer away from the neutral plane, the thickness of the stress compensation layer, the Young's modulus of the stress compensation material for forming the stress compensation layer, the Poisson's ratio of the stress compensation material for forming the stress compensation layer, the thickness of the substrate, the Young's modulus of the substrate material for forming the substrate, the Poisson's ratio of the substrate material for forming the substrate, the thicknesses of several of the film layers, the Young's modulus of the film layer material for forming each of the film layers, and the Poisson's ratio of the film layer material for forming each of the film layers satisfy: Wherein, h refers to the distance from the neutral plane to the side of the protective layer away from the neutral plane, i refers to the i-th layer, n refers to the number of layers in the entire device structure, t is the thickness of each layer, E is the Young's modulus of the material of each layer, j represents a variable, j = 1 indicates that j starts taking values from 1, and ν refers to the Poisson ratio.

28. An electrical device, wherein, It includes the solar cell according to any one of claims 1 to 19 or the solar cell formed by the preparation method according to any one of claims 20 to 27.

29. A power generation device, wherein, It includes the solar cell according to any one of claims 1 to 19 or the solar cell formed by the preparation method according to any one of claims 20 to 27.

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