Solar cell, preparation method and electric equipment

Abstract

The invention discloses a solar cell, a preparation method and electric equipment. The solar cell comprises a solar cell main body and a protective layer, the protective layer is arranged on at least one side of the solar cell main body and comprises at least one stress compensation layer; wherein the neutral surface of the solar cell is positioned on the functional layer; or, the neutral surface of the solar cell is located in the substrate, and the distance between the surface, close to the substrate, of the functional layer and the neutral surface is smaller than or equal to 10 microns; or the neutral surface of the solar cell is located in the protective layer, and the distance between the surface, close to the protective layer, of the functional layer and the neutral surface is smaller than or equal to 10 microns. According to the embodiment of the invention, the interaction between the structures of all layers of the solar cell is considered, and the protection layer is arranged, so that the formed protection layer is matched with the solar cell main body, the neutral surface of the solar cell is close to or located on the functional layer which is liable to fail, the failure risk of the functional layer is reduced, and the reliability of the solar cell is improved. And the bending resistance of the solar cell is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic devices, and particularly to a solar cell, a preparation method thereof, and an electrical device. Background Art

[0002] The information provided in this part is only background information related to the present application, and it is not necessarily prior art.

[0003] A solar cell directly converts light energy into electrical energy through the photovoltaic effect and is one of the new energy power batteries widely used at present. At present, the substrates of some solar cells adopt flexible materials and are expected to be integrated with flexible electronic devices, playing an important role in fields such as portable electronic products, flexible display devices, and wearable electronic devices. However, when an electronic device including a flexible solar cell is subjected to external forces such as bending, the functional layer is prone to damage, thus affecting the device performance of the solar cell. Summary of the Invention

[0004] In view of the technical problems in the background art, the present application provides a solar cell, a preparation method thereof, and an electrical device, aiming to improve the bending resistance of the solar cell.

[0005] To achieve the above object, a first aspect of the present application provides a solar cell, including:

[0006] A solar cell main body including a substrate and a functional layer stacked; the functional layer includes a plurality of film layers stacked;

[0007] A protective layer disposed on at least one side of the solar cell main body along the stacking direction of the substrate and the functional layer, the protective layer including at least one stress compensation layer;

[0008] 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.

[0009] The embodiments of the present application consider the interaction between the structures of each layer of the solar cell. Through the setting of the protective layer, the formed protective layer matches the solar cell main body, so that the neutral plane of the solar cell is close to or located on the easily failed functional layer, reducing the failure risk of the functional layer and improving the bending resistance of the solar cell.

[0010] 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 disposed on the first surface, and the first bending portion is disposed on the side surface.

[0011] In the embodiment of the present application, through the setting of the first bending portion, on the one hand, the situation of curling at the edge of the stress compensation body can be reduced, and on the other hand, the protection effect on the side surface of the solar cell body can be improved.

[0012] In any embodiment of the present application, the protective layer further includes a second bending portion. The second bending portion is formed by extending at least one stress compensation layer in the first bending portion. The solar cell body further includes a second surface disposed opposite to the first surface. The second surface is the other one of the light-receiving surface and the backlight surface of the solar cell body. The second bending portion is disposed on the second surface.

[0013] In the embodiment of the present application, through the setting of the second bending portion, the protection effect on the second surface of the solar cell body is further improved, and the scheme of disposing the second bending portion on the entire second surface is beneficial to isolating the solar cell body as a whole from the external environment and improving the service life.

[0014] In any embodiment of the present application, the second surface has a first region and a second region. The second bending portion is disposed in the second region of the second surface. The solar cell further includes another protective layer, and the protective layer is disposed in the first region.

[0015] In the embodiment of the present application, through the setting of two different protective layers, it is beneficial to flexibly select the material of the matching protective layer according to preset parameters, which is further beneficial to making the neutral plane of the solar cell close to or located on the easily failed functional layer, thereby reducing the failure risk of the functional layer, and further improving the bending resistance performance of the solar cell and increasing the service life of the solar cell.

[0016] In any embodiment of the present application, 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 at least one stress compensation layer in the stress compensation body. A water and oxygen barrier adhesive is disposed between the two joint portions.

[0017] Embodiments of the present application are conducive to flexibly selecting the material of the protective layer that matches according to preset parameters by providing protective layers on both sides of the solar cell body, which further facilitates the neutral plane of the solar cell to be close to or located on the functional layer prone to failure, thereby reducing the failure risk of the functional layer. At the same time, by providing a joint part and directly arranging a water and oxygen barrier adhesive between the two joint parts, the ability of the solar cell to resist the intrusion of moisture and / or oxygen in the external environment is further improved.

[0018] In any embodiment of the present application, there is a gap between the water and oxygen barrier adhesive and the solar cell body.

[0019] Embodiments of the present application provide space for the deformation generated during the bending process of the solar cell through the gap, further improving the bending resistance performance of the solar cell.

[0020] In any embodiment of the present application, the width of the gap is 0.1 cm to 1 cm.

[0021] In the embodiments of the present application, within the above width range, a suitable space is provided for the deformation generated during the bending process of the solar cell, improving the bending resistance performance of the solar cell.

[0022] In any embodiment of the present application, the film layer includes a substrate and a functional layer provided on the substrate, and the neutral plane is located in the functional layer.

[0023] 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 a packaging layer, and the viscoelastic layer is located between the solar cell body and the packaging layer.

[0024] Embodiments of the present application are easier to adjust the position of the neutral plane through the arrangement of the viscoelastic layer and the packaging layer.

[0025] In any embodiment of the present application, the solar cell includes at least four stress compensation layers, and the four stress compensation layers are a viscoelastic layer, a high-elastic layer, a viscoelastic layer, and a packaging layer arranged in sequence. The viscoelastic layer far from the packaging layer is attached to the solar cell body.

[0026] Embodiments of the present application can enable adjacent substrates or film layers or stress compensation layers to slow down the stress and deformation they receive by squeezing the high-elastic layer through the above arrangement, further improving the bending resistance performance of the solar cell.

[0027] In any embodiment of the present application, the Young's modulus of the high-elastic layer is 500 MPa to 5000 MPa.

[0028] In the embodiments of the present application, within the above range of Young's modulus, adjacent substrates or film layers or stress compensation layers can slow down the stress and deformation they receive by squeezing the high-elastic layer.

[0029] In any embodiment of the present application, the thickness of the high-elasticity layer is 5 μm to 200 μm.

[0030] In the embodiments of the present application, within the above thickness range, without significantly increasing the overall thickness of the solar cell, adjacent substrates, film layers, or stress compensation layers can slow down the stress and deformation they receive by squeezing the high-elasticity layer.

[0031] In any embodiment of the present application, the high-elasticity layer includes at least one of silica gel and polyurethane elastomer.

[0032] In the embodiments of the present application, by providing the specific materials, the high-elasticity layer made of the above materials can more easily achieve the transfer of the neutral plane from the substrate to the functional layer.

[0033] In any embodiment of the present application, at room temperature, the Young's modulus of the 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%.

[0034] In the embodiments of the present application, within the above ranges of Young's modulus, creep strain, and creep recovery rate, it can achieve fitting with adjacent substrates, film layers, or stress compensation layers, and more easily achieve the adjustment of the position of the neutral plane.

[0035] In any embodiment of the present application, the thickness of the viscoelastic layer is 5 μm to 15 μm.

[0036] In the embodiments of the present application, within the above thickness range, without significantly increasing the overall thickness of the solar cell, it can achieve fitting with adjacent substrates, film layers, or stress compensation layers, and more easily achieve the adjustment of the position of the neutral plane.

[0037] In any embodiment of the present application, the viscoelastic layer includes at least one of polyurethane, rubber-based, and polyacrylate pressure-sensitive adhesives.

[0038] In the embodiments of the present application, the provided specific materials enable the viscoelastic layer made of the above materials to achieve fitting with adjacent substrates, film layers, or stress compensation layers, and more easily achieve the adjustment of the position of the neutral plane.

[0039] In any embodiment of the present application, the encapsulation layer includes at least one of polymethyl methacrylate (PET), polyethylene naphthalate (PEN), and polycarbonate (PC).

[0040] In the embodiments of the present application, the provided specific materials enable the encapsulation layer made of the above materials to block the influence of the ambient atmosphere on the solar cell body.

[0041] In any embodiment of the present application, the functional layer satisfies at least one of the conditions (1) to (3):

[0042] (1) The functional layer includes a perovskite layer and a charge carrier transport layer. The charge carrier transport layer is located on one side of the perovskite layer and is used to transport charge carriers.

[0043] (2) The functional layer includes a first electrode layer, a first charge carrier transport layer, a perovskite layer, a second charge carrier transport layer, and a second electrode layer that are stacked in sequence. The first electrode layer is provided on a substrate and is a transparent conductive oxide thin film. The first charge carrier transport layer is a hole transport layer, and the second charge carrier transport layer is an electron transport layer, or the first charge carrier transport layer is an electron transport layer, and the second charge carrier transport layer is a hole transport layer.

[0044] (3) The functional layer includes a functional layer of a perovskite tandem solar cell.

[0045] In a second aspect, an embodiment of the present application provides a method for manufacturing a solar cell, including:

[0046] Providing a solar cell body, the solar cell body including a substrate and a functional layer that are stacked; the functional layer includes a plurality of film layers that are stacked.

[0047] Providing 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 includes at least one stress compensation layer.

[0048] 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.

[0049] The embodiment of the present application considers the interaction between the structures of each layer of the solar cell, so that the formed protective layer matches the solar cell body. The neutral plane of the solar cell is close to or located on the functional layer that is prone to failure, reducing the failure risk of the functional layer and improving the bending resistance performance of the solar cell.

[0050] In any implementation manner of the present application, the step of providing a protective layer on at least one side of the solar cell body includes:

[0051] Providing a protective layer on at least one side of the solar cell body according to preset parameters. The protective layer includes at least one stress compensation layer, and the preset parameters include the thickness of each stress compensation layer and the Young's modulus of the stress compensation material used to form the stress compensation layer.

[0052] Wherein, the method for determining the preset parameters includes:

[0053] According to the attribute parameters of the solar cell main body and the position parameters of the neutral plane, preset parameters are determined. The attribute parameters include the thickness of the substrate and the Young's modulus of the substrate material for forming the substrate, as well as the thickness of each film layer and the Young's modulus of the film layer material for forming the film layer. The position parameters include the distance between the neutral plane and the side of the stress compensation layer away from the neutral plane.

[0054] In the embodiments of the present application, the preset parameters of the protective layer are determined by the attribute parameters of the solar cell main body and the position parameters of the neutral plane, so that the formed protective layer matches the solar cell main body, and the neutral plane of the solar cell formed by the protective layer and the solar cell main body is close to or located on the functional layer prone to failure, thereby reducing the failure risk of the functional layer and further improving the bending resistance performance of the solar cell.

[0055] In any implementation manner of the present application, the preset parameters further include the Poisson's ratio of the stress compensation material for forming the stress compensation layer, and the attribute 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 film layer.

[0056] The embodiments of the present application consider the influence of the lateral deformation of each layer structure on the position parameters of the neutral plane, and improve the accuracy of the position adjustment of the neutral plane.

[0057] In any implementation manner of the present application, the protective layer includes a stress compensation main body and a first bending part; the first bending part is formed by extending from the stress compensation main body. The solar cell main 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 main body. The step of setting the protective layer on at least one side of the solar cell main body according to the preset parameters includes:

[0058] According to the preset parameters, the stress compensation main body is set on the first surface;

[0059] The first bending part is bent to the side surface; or

[0060] According to the preset parameters, the first bending part is set on the side surface;

[0061] The stress compensation main body is bent to the first surface.

[0062] In the embodiments of the present application, the protective layer is set on the first surface and the side surface of the solar cell main body according to the preset parameters, which not only improves the bending resistance performance of the solar cell, but also improves the protection degree of the side surface of the solar cell, and further extends the service life of the solar cell.

[0063] In any implementation manner of the present application, the protective layer further includes a second bending portion, which is formed by extending from the first bending portion. The solar cell body further includes a second surface disposed opposite to the first surface, and the second surface is the other one of the light-receiving surface and the backlight surface of the solar cell body. Among them,

[0064] After the step of bending the first bending portion to the side, it further includes: bending the second bending portion to the second surface; or

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

[0066] The step of disposing the first bending portion on the side is: disposing the second bending portion on the second surface and bending the first bending portion to the side.

[0067] In the embodiments of the present application, the protective layer is disposed on the first surface, the side surface, and the 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 protection degree of the second surface of the solar cell, and prolongs the service life of the solar cell.

[0068] In any implementation manner of the present application, protective layers are disposed on both sides of the solar cell body. The protective layer includes a stress compensation main body and a joint portion, and the joint portion is formed by extending from at least one stress compensation layer in the stress compensation main body. The preset parameters include a first sub-preset parameter and a second sub-preset parameter. The steps of disposing the protective layer on at least one side of the solar cell body according to the preset parameters include:

[0069] Disposing one of the protective layers on one side of the solar cell body according to the first sub-preset parameter;

[0070] Disposing the other protective layer on the other side of the solar cell body according to the second sub-preset parameter; and

[0071] Setting a water and oxygen barrier adhesive between the two joint portions, where the first sub-preset parameter and the second sub-preset parameter are different.

[0072] In the embodiments of the present application, the protective layers are disposed 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 in the functional layer prone to failure, thereby reducing the failure risk of the functional layer, further improving the bending resistance of the solar cell, and increasing the service life of the solar cell.

[0073] In any implementation manner of the present application, in the step of determining the preset parameters according to the attribute parameters of the solar cell main 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, the Young's modulus of the substrate material for forming the substrate, the thicknesses of several film layers, and the Young's modulus of the film layer materials for forming the several film layers satisfy:

[0074]

[0075] 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, and j = 1 means that j starts taking values from 1.

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

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

[0078] The preset parameters further include the Poisson's ratio of the stress compensation material for forming the stress compensation layer, the attribute 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 film layer;

[0079] 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 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 film layers, the Young's modulus of the film layer materials for forming each film layer, and the Poisson's ratio of the film layer materials for forming each film layer satisfy:

[0080]

[0081]

[0082] 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's ratio.

[0083] The third aspect of the present application provides an electrical device, including a solar cell prepared by any of the preparation methods provided in the first aspect or a solar cell provided in any of the second aspects.

[0084] The fourth aspect of the present application provides a power generation device, including a solar cell prepared by any of the preparation methods provided in the first aspect or a solar cell provided in any of the second aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0086] Figure 1 is the first schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0087] Figure 2 is the second schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0088] Figure 3 is the third schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0089] Figure 4 is the fourth schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0090] Figure 5 is the fifth schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0091] Figure 6 is the schematic diagram of the sixth structure of the solar cell provided by the embodiment of the present application;

[0092] Figure 7 is the seventh schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0093] Figure 8 is the eighth schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0094] Figure 9 is the ninth schematic structural diagram of the solar cell provided by the embodiment of the present application;

[0095] Figure 10 It is the tenth structural schematic diagram of the solar cell provided by the embodiment of the present application;

[0096] Figure 11 It is the structural schematic diagram of the electrical equipment provided by the embodiment of the present application;

[0097] Figure 12 It is the structural schematic diagram of the power generation equipment provided by the embodiment of the present application;

[0098] Figure 13 They are the photos of the solar cell before and after the bending experiment provided by the comparative example of the present application. The left figure is before the bending experiment, and the right figure is after the bending experiment.

[0099] Explanation of the reference numerals in the drawings:

[0100] 100 - solar cell, 10 - main body of the solar cell, 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 main body, 202 - first bending part, 203 - second bending part, 103 - second surface, A1 - first region, A2 - second region, 204 - joint part, 30 - water and oxygen barrier adhesive, 211 - viscoelastic layer, 212 - encapsulation layer, 213 - highly elastic layer, 2111 - first viscoelastic layer, 2112 - second viscoelastic layer, 2113 - third viscoelastic layer, 2121 - first encapsulation layer, 2122 - second encapsulation layer, 1000 - electrical equipment, 2000 - power generation equipment. Detailed implementation manners

[0101] The present application will be further described below in conjunction with the detailed implementation manners. It should be understood that these detailed implementation manners are only used to illustrate the present application and not to limit the scope of the present application.

[0102] For the sake of simplicity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, each individually disclosed point or single numerical value itself can be used as a lower limit or an upper limit and combined with any other point or single numerical value or combined with other lower limits or upper limits to form a range not explicitly recited.

[0103] In the description of this document, unless otherwise specified, the term "or" is inclusive. That is, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": 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).

[0104] In the description of this document, it should be noted that, unless otherwise specified, "above" and "below" include the corresponding numbers, and in "one or several", "several" means two or more.

[0105] Unless otherwise specified, the terms used in this application have the well-known 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 by various common measurement methods in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0106] 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. The perovskite materials are attached to the substrate structure by means such as coating or spin coating to form a perovskite layer. Before the formation of the perovskite layer material, several functional film layers can be pre-formed on the substrate structure. An electrode layer can be pre-formed on the substrate structure; or an electrode layer and a carrier transport layer can be pre-formed on the substrate structure in sequence, where the carrier transport layer is an electron-hole layer or a hole transport layer; or an electrode layer, a carrier transport layer, and a passivation layer can 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 perovskite layer material generally do not have strong interaction forces between them. When a perovskite solar cell including a flexible substrate is bent, its perovskite layer is stretched or compressed under the influence of the bending action. After undergoing multiple repeated bends, the perovskite layer is prone to produce creases, cracks, or even fractures, resulting in the device performance of the perovskite solar cell being affected, and in severe cases, even causing device damage. Therefore, it is of great significance to improve the bending resistance of solar cells.

[0107] In the prior art, the means of directly improving the film layer performance or adding a protective film layer are usually adopted to improve the bending resistance of solar cells. However, the above methods ignore the influence of the interaction between the film layer structures on the bending resistance of solar cells, resulting in poor improvement effects or even having the opposite effect.

[0108] Taking a flexible perovskite solar cell as an example, the thickness of a conventional flexible substrate is about 50 μm to 200 μm, and the total thickness of other film layers attached to the flexible substrate is about 1 μm. Therefore, in a complete flexible perovskite solar cell, its neutral plane is located on the flexible substrate (at about the position of 1 / 2 of the total film thickness). The film layers far from the neutral plane are subjected to greater stress during the bending process and are prone to generate greater strain, which will bring a greater risk of failure to each film layer or the interface of each film layer. By means of directly improving the film layer performance to improve the bending resistance of the solar cell, since the structure of each film layer of the device does not change significantly and the position of its neutral plane does not change significantly, the stress on each film layer 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 means of adding a protective film layer, although the film layer structure of the device has changed, since the existing setting idea is still to improve the bending resistance of the whole 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 film layer structures on the bending resistance of the solar cell, which easily leads to that each functional film layer of the flexible perovskite solar cell with the added protective film layer is still in the region with greater stress, and the bending resistance of the flexible perovskite solar cell will not be significantly improved, and even play the opposite role.

[0109] To solve the above technical problems, an embodiment of the present application provides a preparation method of a solar cell. By the attribute parameters of the solar cell main body and the position parameters of the neutral plane, the preset parameters of the protective layer are determined, and the protective layer is arranged on at least one side of the solar cell main body according to the determined preset parameters of the protective layer to improve the bending resistance of the solar cell.

[0110] The technical solution described in the embodiment of the present application is applicable to solar cells and preparation methods, and electrical equipment. The solar cell disclosed in the present application can be used in the field of solar power stations and can also be used in the field of lighting, and the present application does not make any restrictions.

[0111] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the solar cell provided by the embodiment of the present application.

[0112] See Figure 1, embodiments of the present application provide a solar cell 100. The solar cell 100 includes a solar cell main body 10 and a protective layer 20. Among them, the solar cell main body 10 includes a substrate 11 and a functional layer 12 arranged in a stacked manner. The functional layer 12 includes a plurality of film layers 121 arranged in a stacked manner. The protective layer 20 is disposed on at least one side of the solar cell main 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. Among them, 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 within 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 within 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.

[0113] Among them, the solar cell 100 refers to a device that directly converts light energy into electrical energy through the photovoltaic effect. Generally speaking, the solar cell 100 includes the first-generation solar cells represented by crystalline silicon solar cells, the second-generation solar cells represented by thin-film solar cells prepared from direct-bandgap semiconductors such as copper indium gallium selenide (CIGS), gallium arsenide (GaAs), and cadmium telluride (CdTe), and the third-generation solar cells represented by dye-sensitized solar cells (DSSCs), organic photovoltaic cells (OPVs), and perovskite solar cells (PSCs).

[0114] The solar cell main body 10 refers to the main structure that forms the solar cell 100.

[0115] 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 fields such as portable electronic products, flexible display devices, and wearable electronic devices. In some embodiments, the substrate 11 has a certain light transmittance, and can enable external light to pass through the substrate 11 to reach the functional layer 12.

[0116] The functional layer 12 refers to the main structure that realizes the photovoltaic effect of the solar cell. The functional layer 12 includes a plurality of film layers 121, and each film layer 121 can realize a part of the functions of the photovoltaic effect. When the flexible solar cell 100 is bent, the functional layer 12 is stretched or compressed under the influence of the bending action. After experiencing multiple repeated bends, it is easy to generate creases, cracks, and even fractures, resulting in the easy failure of the solar cell 100.

[0117] Taking a single-junction perovskite solar cell as an example, a plurality of film layers 121 at least include a first electrode layer, a perovskite layer, and a second electrode layer, where 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. By setting the metal electrode layer, the resistivity of the solar cell 100 is reduced, and the cell efficiency of the solar cell 100 is improved. In some embodiments, the plurality of film layers 121 further include at least one charge carrier transport layer, which is disposed 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 charge carrier transport layers, namely an electron transport layer and a hole transport layer. One is disposed between the first electrode layer and the perovskite layer, and the other is disposed 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 that are sequentially stacked. It should be noted that the single-junction perovskite solar cell provided above can be applied alone or to devices such as a perovskite-perovskite tandem cell, a perovskite-silicon tandem cell, or a perovskite-heterojunction tandem cell. The present application does not make any limitations.

[0118] 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, which can also reduce the influence of the external environmental atmosphere on the solar cell body 10 in addition to the foregoing functions.

[0119] The protective layer 20 can be disposed only on one side of the solar cell body 10 (as shown in Figure 1 ), or on opposite sides of the solar cell body 10 (as shown in Figure 5 ), or can cover the whole of the solar cell body 10 (as shown in Figure 3 ). There can also be other common setting methods in the art, which will not be elaborated in the present application.

[0120] The stress compensation layer 21 refers to a single-layer substructure of the protective layer 20, which is provided on at least one side of the solar cell body 10. By adding the stress compensation layer 21, the position of the neutral plane S is changed to be located at or near the functional layer 12. When the solar cell body 10 is bent, the bending force acting on the functional layer 12 can be reduced. The Young's modulus of the film material forming the film layer 121 has the meaning well-known in the art and can be tested by using the equipment and methods known in the art. For example, the pulse excitation method is used to test the Young's modulus of the material.

[0121] Among them, the neutral plane S refers to the plane in the physical structure that is neither subjected to tensile stress nor compressive stress. Since the neutral plane S is not subjected to stress, its shape only depends on the properties of the material and the shape of the cross-section. In most cases, the neutral plane S is a plane perpendicular to the main axis. The plane-section assumption holds that the position of the neutral plane S in the cross-section is unchanged, that is, no matter where the cross-section is bent, the position of the neutral plane S is the same. The plane-section assumption is a basic engineering assumption, which provides a simple and practical method for the calculation of bending deformation in material mechanics, and this assumption is feasible for most engineering materials and common bending shapes.

[0122] For the scheme where 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 value, during the bending process of the solar cell 100, the stress on the functional layer 12 is small and it is not easy to fail during the bending process, and the bending resistance performance of the solar cell 100 can be effectively improved.

[0123] The embodiments of the present application consider the interaction between the structures of each layer 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 easily failed functional layer 12, reducing the failure risk of the functional layer 12 and improving the bending resistance performance of the solar cell 100.

[0124] It should be noted that the solar cell body 10 includes a plurality of battery modules arranged in an array, and each battery module includes a plurality of battery monomers. The protective layer 20 can cover the solar cell body 10 as a whole or can be arranged corresponding to each battery module one by one.

[0125] Please refer to Figure 2 , Figure 2 which is the second structural schematic diagram of the solar cell provided by the embodiments of the present application.

[0126] See Figure 2 , the solar cell 100 provided by the embodiments of the present application and Figure 1The difference between the solar cell 100 provided by the illustrated embodiment is as follows: In the solar cell 100 provided by 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, and the first surface 101 is one of the light-receiving surface and the backlight surface of the solar cell body 10. The protective layer 20 includes a stress compensation body 201 and a first bending portion 202, and the first bending portion 202 is at least formed by extending at least one stress compensation layer 21 in the stress compensation body 201. The stress compensation body 201 is disposed on the first surface 101, and the first bending portion 202 is disposed on the side surface 102.

[0127] Among them, 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 has adhesiveness, and the stress compensation body 201 can be disposed on the first surface 101 by means of pasting, or can be disposed on the first surface 101 by other means such as hot pressing, etc., which is specifically set according to needs. In other embodiments, the first surface 101 can also be the light-receiving surface of the solar cell body 10.

[0128] In some embodiments, the thickness of the first bending portion 202 can be the same as the thickness of the stress compensation body 201 to simplify the manufacturing process.

[0129] In some embodiments, the thickness of the first bending portion 202 can be different from the thickness of the stress compensation body 201, that is, the first bending portion 202 can be formed by extending a part of the stress compensation layer 21 in the stress compensation body 201 to reduce the layer thickness of the side surface 102 of the solar cell 100, or the first bending portion 202 can be other layers added on the extended area of the stress compensation body 201, such as a heat conduction layer, a hydrophobic layer, etc., to add other functions on the side surface 102 of the solar cell 100, such as a heat conduction function, a hydrophobic function, etc. In some embodiments, when the first bending portion 202 is bent to the side surface 102, it can cover the entire side surface 102 or a part of the side surface 102.

[0130] The stress compensation body 201 is used to realize the main function of the stress compensation layer 21. Specifically, it is used to reduce the bending force received by the functional layer 12 when the solar cell body 10 is bent. The first bending portion 202 is used to further protect the side surface 102 of the solar cell body 10. The first bending portion 202 can be disposed on all the side surfaces 102 or a part of the side surfaces 102. The embodiment of the present application provides a solution in which the first bending portion 202 is disposed on all the side surfaces 102.

[0131] In the embodiments of the present application, through the provision of the first bending portion 202, on the one hand, it can reduce the occurrence of curling at the edge of the stress compensation main body 201, and on the other hand, it can improve the protection effect on the side surface 102 of the solar cell main body 10.

[0132] Please refer to Figure 3 , Figure 3 which is the third structural schematic diagram of the solar cell provided by the embodiments of the present application.

[0133] Refer to Figure 3 , the difference between the solar cell 100 provided by the embodiments of the present application and the solar cell 100 provided by the embodiments shown in Figure 2 is that the protective layer 20 of the solar cell 100 provided by the embodiments of the present application further includes a second bending portion 203, and the second bending portion 203 is at least formed by extending at least one stress compensation layer 21 in the first bending portion 202. The solar cell main body 10 further includes a second surface 103 disposed opposite to the first surface 101, and the second surface 103 is the other one of the light-receiving surface and the backlight surface of the solar cell main body 10. The second bending portion 203 is disposed on the second surface 103.

[0134] Among them, the second bending portion 203 is used to further improve the protection degree of the solar cell main body 10 and match with the stress compensation main body 201 to further improve the bending resistance performance of the solar cell 100. The second bending portion 203 can be disposed on all of the second surface 103 or on a part of the second surface 103. The embodiments of the present application provide a solution in which the second bending portion 203 is disposed on all of the second surface 103.

[0135] It should be noted that the stress compensation main body 201, the first bending portion 202, and the second bending portion 203 can adopt the same material to simplify the manufacturing process; they can also adopt different materials. The stress compensation main body 201, the first bending portion 202, and the second bending portion 203 are preset with different materials according to the size of the solar cell main body 10. When it is bent, the protective layer 20 is disposed on each surface of the solar cell main body 10 along the preset bending scheme, which is convenient for customizing materials according to requirements.

[0136] In the embodiments of the present application, through the provision of the second bending portion 203, the protection effect on the second surface 103 of the solar cell main body 10 is further improved, and the solution in which the second bending portion 203 is disposed on all of the second surface 103 is beneficial to isolating the solar cell main body 10 as a whole from the external environment and improving the service life.

[0137] In addition, the second bending portion 203 may only cover a partial area of the second surface 103, that is, the covering area is the edge position of the second surface 103, so as to improve the curling situation at the edge of the first bending portion 202 when there is only the first bending portion 202, thereby increasing the overall reliability of the protective layer 20.

[0138] Please refer to Figure 4 , Figure 4 which is the fourth structural schematic diagram of the solar cell provided by the embodiment of the present application.

[0139] Refer to Figure 4 , the difference between the solar cell 100 provided by the embodiment of the present application and Figure 3 the solar cell 100 provided by the embodiment shown in

[0140] is that: the second surface 103 of the solar cell 100 provided by the embodiment of the present application has a first region A1 and a second region A2. The second bending portion 203 is disposed in the second region A2 of the second surface 103. The solar cell 100 further includes another protective layer 20, and this protective layer 20 is disposed in the first region A1.

[0141] In the embodiment of the present application, a scheme in which the second bending portion 203 is disposed on a part of the second surface 103 is provided. The materials of the two protective layers 20 of the solar cell 100 may be the same or different, and their thicknesses may be the same or different, and are specifically set according to preset parameters.

[0142] Please refer to Figure 5 , Figure 5 which is the fifth structural schematic diagram of the solar cell provided by the embodiment of the present application.

[0143] Refer to Figure 5 , the difference between the solar cell 100 provided by the embodiment of the present application and Figure 1 the solar cell 100 provided by the embodiment shown in

[0144] Among them, the water and oxygen barrier adhesive 30 refers to an adhesive structure that can resist the intrusion of moisture and / or oxygen in the external environment into the solar cell body 10. In some embodiments, the joint 204 is disposed on the side surface 102 of the solar cell body 10, one end of which is joined to the joint 204 of one protective layer 20, and the other end is joined to the joint 204 of another protective layer 20. In some embodiments, the water and oxygen barrier adhesive 30 is disposed on all the side surfaces 102 of the solar cell body 10. In combination with the arrangement of the protective layer 20, it resists the water and oxygen intercommunication between the solar cell body 10 and the outside world, and improves the degree of protection of the solar cell body 10.

[0145] The materials of the protective layers 20 on both sides of the solar cell body 10 may be the same or different, and the thicknesses of the two may be the same or different, which are specifically set according to preset parameters.

[0146] In the embodiments of the present application, by providing the protective layers 20 on both sides of the solar cell body 10, it is beneficial to flexibly select the materials of the matching protective layers 20 according to preset parameters, and further beneficial to make the neutral plane S of the solar cell 100 approach or be located on the easily failed functional layer 12, thereby reducing the failure risk of the functional layer 12. At the same time, by providing the joint 204 and disposing the water and oxygen barrier adhesive 30 directly between the two joints 204, the ability of the solar cell 100 to resist the intrusion of moisture and / or oxygen in the external environment is further improved.

[0147] Please refer to Figure 6 , Figure 6 which is a schematic diagram of the sixth structure of the solar cell provided by the embodiment of the present application.

[0148] Refer to Figure 6 ,the difference between the solar cell 100 provided by the embodiment of the present application and the solar cell 100 provided by the embodiment shown in Figure 5 is that there is a gap between the water and oxygen barrier adhesive 30 of the solar cell 100 provided by the embodiment of the present application and the solar cell body 10.

[0149] In the embodiments of the present application, the gap provides space for the deformation generated during the bending process of the solar cell 100, and further improves the bending resistance of the solar cell 100.

[0150] In any embodiment of the present application, the width of the gap is 0.1 cm to 1 cm.

[0151] Among them, in some embodiments, the width of the gap can 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, etc., or a range composed of any two of the above values. For example, it can 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, etc.

[0152] In the embodiments of the present application, within the above width range, a suitable space is provided for the deformation generated during the bending process of the solar cell 100, improving the bending resistance of the solar cell 100.

[0153] Please refer to Figure 7 , Figure 7 which is the seventh structural schematic diagram of the solar cell provided by the embodiments of the present application.

[0154] Refer to Figure 7 , the difference between the solar cell 100 provided by the embodiments of the present application and the solar cell 100 provided by the embodiment shown in Figure 1 is that the solar cell 100 provided by the embodiments of the present application includes at least two stress compensation layers 21, one of which is a viscoelastic layer 211 and the other is a packaging layer 212. The viscoelastic layer 211 is located between the solar cell main body 10 and the packaging layer 212.

[0155] Among them, the viscoelastic layer 211 refers to a layer structure with viscosity and elasticity, which is used to fit with the solar cell main body 10, and to enable the packaging layer 212 to fit with the solar cell main body 10 through the viscoelastic layer 211. Through the setting of the viscoelastic layer 211, it is easier to adjust the position of the neutral plane S. Generally speaking, the Young's modulus of the viscoelastic layer 211 is between 10 kPa and 80 kPa, with greater flexibility, and it is easier to achieve a larger neutral plane position adjustment through a thinner thickness. The packaging layer 212 has a barrier property and is used to block the influence of the ambient atmosphere on the solar cell main body 10. In some embodiments, the Young's modulus of the packaging layer 212 is between 1000 MPa and 8000 MPa, and the Poisson's ratio is 0 to 0.5. It can be understood that due to the viscosity and flexibility of the viscoelastic layer 211, it is easier to match with other stress compensation layers 21 to better adjust the position of the neutral plane S in the solar cell 100 and better improve the protection degree for the solar cell main body 10.

[0156] Through the setting of the viscoelastic layer 211 and the packaging layer 212 in the embodiments of the present application, it is easier to adjust the position of the neutral plane S.

[0157] Please refer to Figure 8 , Figure 8 which is the eighth structural schematic diagram of the solar cell provided by the embodiments of the present application.

[0158] See Figure 8 , the difference between the solar cell 100 provided by the embodiment of the present application and Figure 7 the solar cell 100 provided by the embodiment shown is that: the protective layer 20 of the solar cell 100 provided by the embodiment of the present application includes a stress compensation main body 201, a first bending part 202 and a second bending part 203. Among them, the stress compensation main body 201 is disposed on the entire first surface 101. The stress compensation main body 201 of this embodiment is formed by at least two stress compensation layers 21, one of which is a viscoelastic layer 211 and the other is a packaging layer 212; the first bending part 202 is formed by extending the packaging layer 212 that forms the stress compensation main body 201 and is disposed on the entire side surface 102. The second bending part 203 is formed by extending the packaging layer 212 that forms the first bending part 202 and is disposed on the entire second surface 103.

[0159] In the embodiment of the present application, through the setting of the viscoelastic layer 211 and the packaging layer 212, it is easier to adjust the position of the neutral plane S.

[0160] Please refer to Figure 9 , Figure 9 which is the ninth structural schematic diagram of the solar cell provided by the embodiment of the present application.

[0161] See Figure 9 , the difference between the solar cell 100 provided by the embodiment of the present application and Figure 1 the solar cell 100 provided by the embodiment shown is that: the solar cell 100 includes at least four stress compensation layers 21, and the four stress compensation layers 21 are a first viscoelastic layer 2111, a high-elasticity layer 213, a second viscoelastic layer 2112, and a packaging layer 212 arranged in sequence. The first viscoelastic layer 2111 is attached to the solar cell main body 10.

[0162] Among them, the high-elasticity layer 213 is used to reduce the overall thickness of the solar cell 100, and can enable the adjacent substrate 11 or film layer 121 or stress compensation layer 21 to slow down the stress and deformation suffered by itself by extruding the high-elasticity layer 213. In some embodiments, the high-elasticity layer 213 refers to a film layer with a relatively large Young's modulus relative to the first viscoelastic layer 2111 and the second viscoelastic layer 2112, and it is easier to realize the transfer of the neutral plane S from the substrate 11 to the functional layer 12. Viscoelastic layers 211 are provided on both opposite sides of the high-elasticity layer 213, which can realize the adhesion between the high-elasticity layer 213 and the solar cell main body 10 and the adhesion between the high-elasticity layer 213 and the packaging layer 212.

[0163] In the embodiment of the present application, through the above settings, it can enable the adjacent substrate 11 or film layer 121 or stress compensation layer 21 to slow down the stress and deformation suffered by itself by extruding the high-elasticity layer 213, and further improve the bending resistance of the solar cell 100.

[0164] Please refer to Figure 10 , Figure 10 which is the tenth structural schematic diagram of the solar cell provided by the embodiment of the present application.

[0165] Refer to Figure 10 , the difference between the solar cell 100 provided by the embodiment of the present application and the solar cell 100 provided by the embodiment shown in Figure 1 is that: the solar cell 100 includes at least six stress compensation layers 21. Four of the stress compensation layers 21 are a first viscoelastic layer 2111, a high-elasticity layer 213, a second viscoelastic layer 2112, and a first encapsulation layer 2121 arranged in sequence, and are provided on one side of the solar cell body 10, wherein the first viscoelastic layer 2111 is attached to the solar cell body 10.

[0166] The other two stress compensation layers 21 are sequentially stacked on the other side of the solar cell body 10 to form another protective layer 20. These two stress compensation layers 21 are a third viscoelastic layer 2113 and a second encapsulation layer 2122 in sequence, wherein the third viscoelastic layer 2113 is attached to the solar cell body 10.

[0167] The embodiment of the present application further improves the bending resistance of the solar cell 100 by providing protective layers 20 on both sides of the solar cell body 10.

[0168] In any embodiment of the present application, the Young's modulus of the high-elasticity layer 213 is 500 MPa to 5000 MPa.

[0169] Among them, in some embodiments, the Young's modulus of the high-elasticity 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, etc., or a range composed of any two of the above values. For example, it can be 500 MPa to 1500 MPa, 1200 MPa to 2500 MPa, 2200 MPa to 3500 MPa, 3000 MPa to 5000 MPa, etc.

[0170] In the embodiment of the present application, within the above range of Young's modulus, the adjacent substrate 11 or film layer 121 or stress compensation layer 21 can slow down the stress and deformation suffered by itself by extruding the high-elasticity layer 213.

[0171] In any embodiment of the present application, the thickness of the high-elasticity layer 213 is 5 μm to 200 μm.

[0172] Among them, in some embodiments, the thickness of the highly elastic layer 213 is 5μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 160μm, 170μm, 180μm, 190μm, 200μm, etc., or a range composed of any two of the above values. For example, it can be 5μm to 50μm, 40μm to 100μm, 80μm to 150μm, 140μm to 200μm, etc.

[0173] In the embodiments of the present application, within the above thickness range, without significantly increasing the overall thickness of the solar cell 100, adjacent substrates 11 or film layers 121 or stress compensation layers 21 can slow down the stress and deformation they suffer by extruding the highly elastic layer 213.

[0174] In any embodiment of the present application, the highly elastic layer 213 includes at least one of silica gel and polyurethane elastomer.

[0175] Among them, in some embodiments, the silica gel contains a polydimethylsiloxane component.

[0176] In the embodiments of the present application, through the provided specific materials, it is easier to achieve the transfer of the neutral plane S from the substrate 11 to the functional layer 12 for the highly elastic layer 213 made of the above materials.

[0177] In any embodiment of the present application, at room temperature, the Young's modulus of the viscoelastic layer 211 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%.

[0178] Among them, room temperature is also called general temperature or room temperature, and is generally defined as 25°C. In engineering in our country, room temperature is calculated as 20°C, which is the temperature in spring and autumn in most places in our country, such as the circulating water temperature (natural water temperature). The Young's modulus, creep amount, and creep recovery rate of the viscoelastic layer 211 have meanings well-known in the art, and can be tested using equipment and methods known in the art. In some embodiments, the above three parameters can all be tested by a rheometer.

[0179] Among them, the method for testing the Young's modulus using a rheometer is: adopting the dynamic test mode in the rheometer, and measuring the dynamic response by oscillating a sample. In the dynamic test, the sample is placed on a vibrating plate or vibrating string, and the vibrating plate or vibrating string vibrates at a constant frequency and amplitude. The response of the sample can be obtained by measuring the displacement and force on the vibrating plate or vibrating string.

[0180] The method for testing the creep variable and the creep recovery rate using a rheometer is as follows: The creep test mode in the rheometer is adopted, and it studies the creep behavior of a sample by measuring the response of the sample changing with time under a constant stress or strain. In the creep test, the sample is placed in a sample chamber with a fixed shape, and the stress or strain in the sample chamber is applied to the sample.

[0181] In some embodiments, at room temperature, the Young's modulus of the viscoelastic layer 211 can 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, etc., or a range composed of any two of the above values. For example, it can be 10 kPa to 40 kPa, 20 kPa to 50 kPa, 30 kPa to 60 kPa, 40 kPa to 70 kPa, etc. At room temperature, the creep variable of the viscoelastic layer 211 can be 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200%, 205%, 210%, 215%, 220%, etc., or a range composed of any two of the above values. For example, it can be 150% to 180%, 160% to 190%, 170% to 200%, 180% to 210%, etc. 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%, etc., or a range composed of any two of the above values. For example, it can be 90% to 130%, 100% to 140%, 110% to 150%, 120% to 160%, etc.

[0182] In the embodiments of the present application, within the above ranges of Young's modulus, creep variable, and creep recovery rate, the bonding with the adjacent substrate 11, or the film layer 121, or the stress compensation layer 21 can be achieved, and it is easier to adjust the position of the neutral plane S.

[0183] In any embodiment of the present application, the thickness of the viscoelastic layer 211 is 5 μm to 15 μm.

[0184] Among them, in some embodiments, the thickness of the viscoelastic layer 211 can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, etc., or a range composed of any two of the above values. For example, it can be 5 μm to 12 μm, 6 μm to 13 μm, 7 μm to 14 μm, 8 μm to 15 μm, etc.

[0185] In the embodiments of the present application, within the above thickness range, without significantly increasing the overall thickness of the solar cell 100, it is possible to achieve adhesion to the adjacent substrate 11, or the film layer 121, or the stress compensation layer 21, and it is easier to adjust the position of the neutral plane S.

[0186] In any embodiment of the present application, the viscoelastic layer 211 includes at least one of polyurethane and polyacrylate.

[0187] In the embodiments of the present application, the specific materials provided enable the viscoelastic layer 211 made of the above materials to achieve adhesion to the adjacent substrate 11, or the film layer 121, or the stress compensation layer 21, and it is easier to adjust the position of the neutral plane S.

[0188] 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).

[0189] In the embodiments of the present application, the specific materials provided enable the encapsulation layer 212 made of the above materials to block the influence of the ambient atmosphere on the solar cell body 10.

[0190] In any embodiment of the present application, the functional layer 12 satisfies at least one of the conditions (1) to (3):

[0191] (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 for transporting carriers; in some embodiments, a passivation layer is provided between the perovskite layer and the carrier transport layer;

[0192] (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 provided on the substrate and is a transparent conductive oxide thin film; the first carrier transport layer is a hole transport layer, 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;

[0193] (3) The functional layer 12 includes a full perovskite stacked solar cell functional layer.

[0194] Among them, the perovskite layer is used to absorb the photon energy of sunlight, generate electron-hole pairs, and separate the electron-hole pairs into free electrons and holes under the action of the built-in electric field. The holes and electrons are respectively collected by two different electrodes, and the two electrodes are connected into a circuit to generate photocurrent. The carrier transport layer refers to the structural layer that transports the electrons or holes generated by the perovskite layer excited by photons. The hole transport layer is used to collect and transport holes to achieve effective separation of electrons and holes. The electron transport layer, also known as the electron collection layer, is used to transport electrons and block the recombination of electron holes. The passivation layer is used to passivate the defects of the perovskite layer. The all-perovskite tandem solar cell refers to a solar cell in which two perovskite absorption layers with different bandgaps are stacked. This tandem solar cell can effectively broaden the absorption spectrum of the cell and reduce the thermal relaxation loss. The functional layer of the all-perovskite tandem solar cell refers to the main structure of the all-perovskite tandem solar cell that realizes the photovoltaic effect.

[0195] The solution of adjusting the position of the neutral plane S of the solar cell 100 in the embodiments of the present application to improve the bending resistance performance of the solar cell 100 can be applied to various different types of solar cells 100.

[0196] To achieve the above object, a second aspect of the present application provides a method for manufacturing a solar cell, including:

[0197] S1: Provide a solar cell body 10, the solar cell body 10 includes a substrate 11 and a functional layer 12 arranged in a stacked manner; the functional layer 12 includes a plurality of film layers 121 arranged in a stacked manner.

[0198] S2: Arrange 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, and the protective layer 20 includes at least one stress compensation layer 21.

[0199] Among them, 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.

[0200] The embodiments of the present application consider the interaction between the structures of each layer of the solar cell 100, so that the formed protective layer 20 matches the solar cell body 10. The neutral plane S of the solar cell 100 is close to or located on the easily failed functional layer 12, reducing the failure risk of the functional layer 12 and improving the bending resistance performance of the solar cell 100.

[0201] In any embodiment of the present application, the step of S2 "providing a protective layer 20 on at least one side of the solar cell body 10" includes:

[0202] Providing a protective layer 20 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, and 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.

[0203] Among them, the method for determining the preset parameters includes:

[0204] Determining the preset parameters according to 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, and 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.

[0205] Among them, the preset parameters refer to the parameters for preparing the protective layer 20 determined in advance.

[0206] The embodiments of the present application determine the preset parameters of the protective layer 20 through 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 easily failed functional layer 12, thereby reducing the failure risk of the functional layer 12 and improving the bending resistance of the solar cell 100.

[0207] In any embodiment of the present application, the preset parameters further include the Poisson's ratio of the stress compensation material used to form the stress compensation layer 21, and the property parameters further 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.

[0208] Among them, the Poisson's ratio of the stress compensation material for forming the stress compensation layer 21 has the meaning well known in the art and can be tested by known equipment and methods in the art. For example, the Poisson's ratio of the material is tested by the optical interference measurement method. The embodiments of the present application consider the influence of the lateral deformation of each layer structure on the position parameters of the neutral plane S, and improve the accuracy of adjusting the position of the neutral plane S.

[0209] 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:

[0210] S211: Setting the stress compensation body 201 on the first surface 101 according to the preset parameters.

[0211] S212: Bend the first bending portion 202 to the side surface 102.

[0212] Among them, in some embodiments, the stress compensation main body 201 can be disposed on the first surface 101 first, and then the first bending portion 202 is bent to the side surface 102; or the protective layer 20 can be pre-bent so that a part of the protective layer 20 is the stress compensation main body 201, and the other part is bent into the first bending portion 202, and then the pre-bent protective layer 20 is disposed on the first surface 101 and the side surface 102 of the solar cell main body 10.

[0213] It should be noted that the preset parameters of the stress compensation main 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 bending portion 202 will not affect the change of the position parameters of the neutral plane S of the solar cell 100.

[0214] In some embodiments, in S2, the step of disposing the protective layer 20 on at least one side of the solar cell main body 10 according to the preset parameters includes:

[0215] S221: According to the preset parameters, dispose the first bending portion 202 on the side surface 102.

[0216] Among them, in some embodiments, the first bending portion 202 has adhesiveness, and the first bending portion 202 can be disposed on the side surface 102 by means of pasting, or the first bending portion 202 can be disposed on the side surface 102 by other means such as hot pressing, etc., and it is specifically set according to needs.

[0217] S222: Bend the stress compensation main body 201 to the first surface 101.

[0218] Among them, in some embodiments, the first bending portion 202 can be disposed on the side surface 102 first, and then the stress compensation main body 201 is bent to the first surface 101; or the protective layer 20 can be pre-bent so that a part of the protective layer 20 is the stress compensation main body 201, and the other part is bent into the first bending portion 202, and then the pre-bent protective layer 20 is disposed on the first surface 101 and the side surface 102 of the solar cell main body 10.

[0219] In the embodiments of the present application, the protective layer 20 is disposed on the first surface 101 and the side surface 102 of the solar cell main body 10 according to the preset parameters, which not only improves the bending resistance performance of the solar cell 100, but also improves the protection degree of the side surface 102 of the solar cell 100, and further extends the service life of the solar cell 100.

[0220] In any implementation manner of the present application, the protective layer 20 further includes a second bending portion 203, the second bending portion 203 is formed by extending from the first bending portion 202, the solar cell main body 10 further includes a second surface 103 disposed opposite to the first surface 101, and the second surface 103 is the other one of the light-receiving surface and the backlight surface of the solar cell main body 10.

[0221] In some embodiments, after the step of bending the first bending portion 202 to the side surface 102 in S212, it further includes: bending the second bending portion 203 to the second surface 103.

[0222] In some embodiments, after the step of disposing the first bending portion 202 on the side surface 102 in S221, it further includes: bending the second bending portion 203 to the second surface 103.

[0223] 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.

[0224] Among them, there are various ways to dispose the protective layer 20 on the solar cell main body 10, which are not limited in the present application, as long as the protective layer 20 can be disposed on the surface of the solar cell main body 10. Specifically, in some embodiments, the protective layer 20 includes a stress compensation main body 201, a first bending portion 202, and a second bending portion 203 that are connected in sequence. When disposing the protective layer 20 on the solar cell main body 10, it can be disposed on the solar cell main body 10 in the order of the stress compensation main body 201, the first bending portion 202, and the second bending portion 203; it can also be disposed on the solar cell main body 10 in the order of the first bending portion 202, the second bending portion 203, and the stress compensation main body 201; it can also be disposed on the solar cell main body 10 in the order of the second bending portion 203, the first bending portion 202, and the stress compensation main body 201.

[0225] 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 is the backlight surface of the solar cell body 10. The stress compensation body 201 is disposed on the first surface 101, and the second bending portion 203 is disposed on the second surface 103; the thickness of the second bending portion 203 is less than the thickness of the stress compensation body 201, or the thickness of the second bending portion 203 is equal to 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; or the thickness of the second bending portion 203 is less 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 easily failed functional layer 12, further improving the bending resistance of the solar cell 100.

[0226] In the embodiments of the present application, the protective layer 20 is disposed 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 protection degree of the second surface 103 of the solar cell 100, and extends the service life of the solar cell 100.

[0227] In addition, the second bending portion 203 may 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 that 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.

[0228] In any implementation manner of the present application, protective layers 20 are disposed on both sides of the solar cell body 10, and each protective layer 20 includes a stress compensation body 201 and a joint portion 204. The joint portion 204 is formed by extending at least one stress compensation layer 21 in the stress compensation body 201, and the preset parameters include a first sub-preset parameter and a second sub-preset parameter.

[0229] Among them, 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 compensation layer 21, or may be formed by extending several stress compensation layers 21. In some embodiments, the extending direction of the joint portion 204 is the same as the extending direction of the stress compensation layer 21.

[0230] In S2, the step of disposing the protective layer 20 on at least one side of the solar cell body 10 according to the preset parameters includes:

[0231] S231: Set one of the protective layers 20 on one side of the solar cell body 10 according to the first sub preset parameter.

[0232] S232: Set the other protective layer 20 on the other side of the solar cell body 10 according to the second sub preset parameter.

[0233] S233: Set the water oxygen barrier adhesive 30 between the two joints 204, where the first sub preset parameter is different from the second sub preset parameter.

[0234] Among them, in some embodiments, by setting different first sub preset parameters and second sub preset parameters, the design of the protective layers 20 on the opposite sides of the solar cell body 10 is differentiated, so that the neutral plane S approaches or enters the functional layer 12 from the initial position, improving the bending resistance performance of the solar cell 100 and prolonging the service life of the solar cell 100. For example, set a protective layer A on the light receiving surface of the solar cell body 10 according to the first sub preset parameter, and set a protective layer B on the backlight surface of the solar cell body 10 according to the second sub preset parameter; the thickness of the stress compensation main body 201 of the protective layer A is less than the thickness of the stress compensation main body 201 of the protective layer B, and / or the Young's modulus of the stress compensation main body 201 of the protective layer A is greater than the Young's modulus of the stress compensation main body 201 of the protective layer B.

[0235] In the embodiments of the present application, the protective layers 20 are respectively set on both sides of the solar cell body 10 according to different preset parameters, so that the parameters of the protective layers 20 on both sides of the solar cell body 10 are differentiated, so that the neutral plane S of the solar cell 100 approaches or is located at the easily failed functional layer 12, thereby reducing the failure risk of the functional layer 12, and further improving the bending resistance performance of the solar cell 100 and increasing the service life of the solar cell 100.

[0236] In any implementation manner of the present application, in the method for determining the preset parameter in S2, in the step of determining the preset parameter according to the attribute parameter of the solar cell body 10 and the position parameter of the neutral plane S, 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 for forming the stress compensation layer 21, the thickness of the substrate 11 and the Young's modulus of the substrate material for forming the substrate 11, the thickness of the plurality of film layers 121 and the Young's modulus of the film layer material for forming the plurality of film layers 121 satisfy:

[0237]

[0238] Among them, h refers to the distance from the neutral plane S to 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 j starts taking values from 1.

[0239] An embodiment of the present application provides a specific method for determining the preset parameters of the protective layer 20. Through the above method, the formed protective layer 20 is matched with the solar cell main body 10. The neutral plane S of the solar cell 100 formed by the protective layer 20 and the solar cell main body 10 is close to or located on the easily failed functional layer 12, thereby reducing the failure risk of the functional layer 12, improving the bending resistance performance of the solar cell 100, and increasing the service life of the solar cell 100. It can be understood that an embodiment of the present application provides a specific method for determining the preset parameters of the protective layer 20, and other methods capable of determining the preset parameters of the protective layer 20 can also be used.

[0240] In any implementation manner of the present application, in the step of determining the preset parameters according to the attribute parameters of the solar cell main body 10 and the position parameters of the neutral plane S, the preset parameters further include the Poisson's ratio of the stress compensation material for forming the stress compensation layer 21, the attribute parameters further include the Poisson's ratio of the base material for forming the base 11, and the Poisson's ratio of the film layer material for forming each film layer 121.

[0241] The distance from the neutral plane S to 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 for forming the stress compensation layer 21, the Poisson's ratio of the stress compensation material for forming the stress compensation layer 21, the thickness of the base 11, the Young's modulus of the base material for forming the base 11, the Poisson's ratio of the base material for forming the base 11, the thicknesses of several film layers 121, the Young's modulus of the film layer material for forming each film layer 121, and the Poisson's ratio of the film layer material for forming each film layer 121 satisfy:

[0242]

[0243]

[0244] Among them, h refers to the distance from the neutral plane S to 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 j starts taking values from 1, and ν refers to the Poisson's ratio.

[0245] Embodiments of the present application provide a specific method for determining the preset parameters of the protective layer 20 by considering the influence of the lateral deformation of each layer structure on the position parameter of the neutral plane S. Through the above method, the formed protective layer 20 is matched with the solar cell main body 10. The neutral plane S of the solar cell 100 formed by the protective layer 20 and the solar cell main body 10 is close to or located on the easily failed functional layer 12, thereby reducing the failure risk of the functional layer 12, improving the bending resistance performance of the solar cell 100, and increasing the service life of the solar cell 100.

[0246] Among them, taking the example of setting the protective layer 20 on the backlight side of the solar cell main body 10 according to the preset parameters, and the protective layer 20 includes a stress compensation layer 21, the application of the above formula will be described:

[0247] First, the solar cell main 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 that are sequentially stacked. A protective layer 20 is provided on the side of the second electrode layer away from the substrate, and the protective layer 20 only includes a stress compensation layer 21.

[0248] Among them, 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 unknowns.

[0249] The thickness of the second electrode layer is t2, 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, 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, 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, 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, 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, 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.

[0250] To set the neutral plane S within the functional layer 12, the distance h from the neutral plane S to the side of the stress compensation layer 21 away from the substrate is within the range of t1 to t1 + t2 + t3 + t4 + t5 + t6.

[0251] One method is as follows: First, determine the thickness t1 of the stress compensation layer 21. Substitute the thickness t1 of the stress compensation layer 21 and the parameters of the substrate 11 and each film layer 121 of the solar cell body 10 into the above formula to obtain the value ranges of the Young's modulus E1 and Poisson's ratio ν1 of the stress compensation material forming the stress compensation layer 21. Then, according to the value ranges of the Young's modulus E1 and Poisson's ratio ν1 of the stress compensation material forming the stress compensation layer 21, screen the suitable stress compensation material for forming the stress compensation layer 21. According to the above process, the preset parameters of the stress compensation layer 21 are obtained (including the thickness t1 of the stress compensation layer 21, the Young's modulus E1 of the stress compensation material forming the stress compensation layer 21, and Poisson's ratio ν1).

[0252] Another method is as follows: First, determine the Young's modulus E1 and Poisson's ratio ν1 of the stress compensation material forming the stress compensation layer 21. Substitute the Young's modulus E1 and Poisson's ratio ν1 of the stress compensation material forming the stress compensation layer 21 and the parameters of the substrate 11 and each film layer 121 of the solar cell body 10 into the above formula to obtain the value range of the thickness t1 of the stress compensation layer 21. According to the above process, the preset parameters of the stress compensation layer 21 are obtained (including the thickness t1 of the stress compensation layer 21, the Young's modulus E1 of the stress compensation material forming the stress compensation layer 21, and Poisson's ratio ν1).

[0253] Please refer to Figure 11 , Figure 11 which is a schematic structural diagram of the electrical device provided by the embodiment of the present application.

[0254] Refer to Figure 11 , the third aspect of the present application provides an electrical device 1000, including the solar cell 100 formed by any of the preparation methods provided in the first aspect or the solar cell 100 provided in any of the second aspects.

[0255] In the embodiment of the present application, the solar cell 100 serves as the power source of the electrical device 1000 to realize the normal operation of the electrical device 1000. The electrical device 1000 adopts the solar cell 100 provided by the present application and at least has the same advantages as the solar cell 100, which can improve the battery performance of the electrical device 1000. Exemplarily, the electrical device 1000 may include lighting devices, display devices, or new energy vehicles, etc.

[0256] Please refer to Figure 12 , Figure 12 which is a schematic structural diagram of the power generation device provided by the embodiment of the present application.

[0257] Refer to Figure 12, a fourth aspect of the present application provides a power generation device 2000, including a solar cell 100 prepared by any of the preparation methods provided in the first aspect or a solar cell 100 provided in any of the second aspects.

[0258] In an embodiment of the present application, the solar cell 100 serves as an energy source of the power generation device 2000 to achieve the electrical energy output of the power generation device 2000. The power generation device 2000 adopts the solar cell 100 provided in the present application and at least has the same advantages as the solar cell 100, which can improve the power generation performance of the power generation device 2000. Exemplarily, the power generation device 2000 can be applied to fields such as building electricity, wearable device electricity, smartphone electricity, vehicle-mounted battery electricity, etc.

[0259] The beneficial effects of the present application will be further described below in conjunction with embodiments.

[0260] 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 in conjunction with 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 in no way limits the present application and its application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0261] Embodiment 1

[0262] The preparation of the solar cell 100, the structural schematic diagram is as Figure 7 shown:

[0263] I. Provide a solar cell body 10, and determine the initial position parameters of the neutral plane S according to the attribute parameters of the solar cell body 10.

[0264] The solar cell body 10 of this embodiment includes a substrate 11 and a plurality of film layers 121 stacked in sequence. 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 in sequence.

[0265] Among them, the attribute parameters of the above substrate 11 and each film layer 121 are as shown in Table 1. Among them, 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.

[0266] Table 1 Attribute parameters of each film layer of the solar cell body

[0267]

[0268] Note: In the embodiments of this application, the lateral deformation of materials is not considered temporarily, and the Poisson's ratio is zero. PET is polyethylene terephthalate; ITO is indium tin oxide; the molecular formula of perovskite is FAPbI3; C60 is fullerene C60; BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; Cu is copper.

[0269] Substitute the parameters of the above-mentioned substrate 11 and each film layer 121 into the above formula (1), and the initial position parameter of the neutral plane S is calculated to be 5×10 4 nm, that is, it is close to the position of 1 / 2 of the thickness of the substrate 11.

[0270] Second, adjust the position of the neutral plane S and design the structure of the solar cell 100. Here, it is designed according to the Figure 7 shown structure. The solar cell 100 includes two stress compensation layers 21, one of which is a viscoelastic layer 211 and the other is a packaging layer 212. The packaging 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 packaging layer 212 is arranged on the side of the viscoelastic layer 211 away from the substrate 11. The preset material of the packaging layer 212 is PET, and the Young's modulus is 3×10 6 GPa. The preset material of the viscoelastic layer 211 is polyacrylate, the thickness is 10 μm, and the Young's modulus is 50 kPa. In this embodiment, the lateral deformation of the protective layer 20 is not considered, that is, the Poisson's ratio of each layer material forming the protective layer 20 in this embodiment is 0.

[0271] Substitute the above parameters into the above formula (1), and when the thickness of the packaging layer 212 is calculated to be 120 μm, the neutral plane S is located on the functional layer 12.

[0272] At the same time, when the thickness range of the packaging layer 212 is within 97 μm to 141 μm, the effect of regulating the position of the neutral plane S to be close to or located on the functional layer 12 can be better achieved. Specifically, when the thickness of the packaging layer 212 is 97 μm, the neutral plane S is located 10 μm below the functional layer 12, and when the thickness of the packaging layer 212 is 141 μm, the neutral plane S is located 10 μm above the functional layer 12.

[0273] Embodiment 2

[0274] The difference between this embodiment and Embodiment 1 is that this embodiment is in accordance with Figure 8The structure shown is designed. The protective layer 20 includes a stress compensation body 201, a first bending part 202, and a second bending part 203. Among them, the stress compensation body 201 is disposed on the entire first surface 101, and the first surface 101 is the backlight surface of the solar cell body 10. The stress compensation body 201 in this embodiment is formed by at least two stress compensation layers 21, one of which is a viscoelastic layer 211 and the other is an encapsulation layer 212. Among them, the viscoelastic layer 211 is disposed on the side of the functional layer 12 away from the substrate 11; the first bending part 202 is formed by extending the encapsulation layer 212 forming the stress compensation body 201 and is disposed on the entire side surface 102. The second bending part 203 is formed by extending the encapsulation layer 212 forming the first bending part 202 and is disposed on the entire second surface 103.

[0275] The material of the preset encapsulation layer 212 is PET, and the Young's modulus is 3×10 6 GPa. The material of the preset viscoelastic layer 211 is polyacrylate, the thickness is 10 μm, and the Young's modulus is 50 kPa. The material of the preset first bending part 202 is PET, and the Young's modulus is 1×10 6 GPa. The material of the preset second bending part 203 is PET, and the Young's modulus is 2×10 6 GPa, and the thickness is 25 μm. Substituting the above parameters into the above formula (1), when the thickness range of the encapsulation layer 212 is calculated to be 90 μm, the neutral plane S is located on the functional layer 12.

[0276] Embodiment 3

[0277] The difference between this embodiment and Embodiment 1 is that this embodiment is designed according to the Figure 10 structure shown. It is preset that protective layers 20 are disposed on both sides of the solar cell body 10. The solar cell 100 includes at least six stress compensation layers 21. Four stress compensation layers 21 are a first viscoelastic layer 2111, a high-elastic layer 213, a second viscoelastic layer 2112, and a first encapsulation layer 2121 arranged in sequence, and are disposed on one side of the solar cell body 10, specifically on the side of the functional layer 12 away from the substrate 11. Among them, the first viscoelastic layer 2111 is attached to the solar cell body 10. The other two stress compensation layers 21 are a third viscoelastic layer 2113 and a second encapsulation layer 2122 arranged in sequence, and are disposed on the other side of the solar cell body 10. Among them, the third viscoelastic layer 2113 is attached to the solar cell body 10.

[0278] It is preset that the materials of the first encapsulation layer 2121 and the second encapsulation layer 2122 are both PET. It is preset that 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 6GPa. Next, it is preset that the materials of the first viscoelastic layer 2111, the second viscoelastic layer 2112, and the third viscoelastic layer 2113 are all polyacrylate, the thicknesses are all 10 μm, and the Young's moduli are all 50 kPa. Then, it is preset that the material of the highly elastic layer 213 is polyurethane, and the Young's modulus is 1×10 6 Gpa.

[0279] Substitute the above parameters into the above formula (1), and calculate that the thickness of the highly elastic layer 213 is 96 μm, so as to ensure that the neutral plane S is located on the functional layer 12.

[0280] Example 4

[0281] The difference between this example and Example 1 is that in this example, it is first preset that the thickness of the encapsulation layer 212 is 80 μm, and the material is PET. It is preset that the material of the viscoelastic layer 211 is polyacrylate, the thickness is 10 μm, and the Young's modulus is 50 kPa. The position parameter of the neutral plane S, that is, the distance from the neutral plane S to the side of the protective layer 20 away from the neutral plane S, is 91 μm.

[0282] Substitute the above parameters into the above formula (1), and calculate that the Young's modulus parameter of the encapsulation layer 212 is 1.25×10 6 GPa, so as to ensure that the neutral plane S is located on the functional layer 12.

[0283] Example 5

[0284] The difference between this example and Example 1 is that in this example, it is preset that the material of the encapsulation layer 212 is PET, and the Young's modulus is 1×10 6 GPa. Substitute the above parameters into the above formula (1), and calculate that the thickness of the encapsulation layer 212 is 72 μm, and the neutral plane S is located on the functional layer 12.

[0285] At the same time, when the thickness range of the encapsulation layer 212 is within 56 μm to 88 μm, the effect of better realizing the regulation of the position of the neutral plane S close to or located on the functional layer 12 can be achieved. 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.

[0286] Comparative Example

[0287] The difference between this comparative example and Example 1 is that in this comparative example, the protective layer 20 is not provided.

[0288] Bending performance test method:

[0289] By adjusting the position of the sensor, the bending radius is set to 10 mm; the sample is fixed on the clamping table and fixed by clamping pressure. The bending frequency is set to 3 bending cycles per second, and the number of bending times is 10,000 times; the bending operation mode adopts single-sided slide rail operation. The bending resistance performance is evaluated by testing the change in the photoelectric conversion efficiency of the battery before and after bending.

[0290] Test method for photoelectric conversion efficiency:

[0291] By changing the bias voltage point and measuring the current simultaneously, the I-V characteristics of the sample under test can be obtained.

[0292] 1) Place the test fixture with the sample battery on the sample rack so that it is located in the measurement plane, and ensure that the sample battery is located at the center of the exit light spot of the solar simulator (or the normal line of the photovoltaic cell is parallel to the center line of the exit light beam of the solar simulator light source).

[0293] 2) Use the solar simulator of Guangyan, which meets the national standard IEC61215 for testing. Calibrate the intensity of the light with a crystalline silicon solar cell to make it reach one sun intensity. Under the condition of an irradiance of 1000 W / m 2 Install a mask on the sample battery under test, and control the temperature of the sample battery with a temperature monitoring device so that during the measurement process, the temperature of the sample under test is maintained at (30 ± 5 °C).

[0294] 3) Set the scanning direction, voltage range, scanning interval voltage, scanning interval time, etc. Among them, the scanning interval is not greater than 0.02 V, and the interval time between adjacent two points is not less than 0.3 s. Measure the forward and reverse scan current-voltage characteristics of the sample battery under test, and record the open-circuit voltage V OC , short-circuit current J SC . Calculation formula: Fill factor FF = J m *V m / V OC *J SC , 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 .

[0295] Table 2 Test results of the bending performance of the solar cells in the examples and comparative examples of this application

[0296]

[0297] Note: In the bending performance test of this application, the bending radius is set to 10 mm.

[0298] As can be seen from Table 2, when the neutral plane S is adjusted to the functional layer 12 or near the functional layer 12 by adding the protective layer 20 in the embodiments of the present invention, more than 90% of the initial photoelectric conversion efficiency can be retained after 10,000 bends. When the neutral plane s is not adjusted (Comparative Example 1), the solar cell will be severely damaged, and the retention rate of its initial photoelectric conversion efficiency is only less than 10% after 10,000 bends. Figure 13 Fig. Figure 13 shows the photos of the solar cell 100 provided in Comparative Example 1 of the present application before and after the bending experiment. The left figure is before the bending experiment, and the right figure is after the bending experiment. It can be seen that the surface of the solar cell 100 is significantly damaged after the bending experiment.

[0299] In several embodiments provided in the present 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 only illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed couplings or direct couplings or communication connections to each other can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0300] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0301] The above description is only the implementation manner of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present application by the same token.

Claims

1. A solar cell, characterized in that, Comprising: A solar cell main body, including a substrate and a functional layer arranged in a stacked manner; the functional layer includes several film layers arranged in a stacked manner; A protective layer, arranged on at least one side of the solar cell main body along the stacking direction of the substrate and the functional layer, the protective layer including 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, characterized in that, The protective layer includes a stress compensation main body and a first bending part, the first bending part is at least formed by extending at least one stress compensation layer in the stress compensation main body, the solar cell main 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 main body, the stress compensation main body is arranged on the first surface, and the first bending part is arranged on the side surface.

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

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

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

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

7. The solar cell according to claim 6, characterized in that, 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, characterized in that, 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 main body and the packaging layer.

9. The solar cell according to any one of claims 1 to 7, characterized in that, The solar cell includes at least four stress compensation layers, and the four stress compensation layers are a viscoelastic layer, a highly elastic layer, a viscoelastic layer, and a packaging layer arranged in sequence, and the viscoelastic layer far from the packaging layer is attached to the solar cell main body.

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

11. The solar cell according to claim 9 or 10, characterized in that, The thickness of the highly elastic layer is 5 μm to 200 μm.

12. The solar cell according to any one of claims 9 to 11, characterized in that, The highly elastic layer includes at least one of silica gel and polyurethane elastomer.

13. The solar cell according to any one of claims 8 to 12, characterized in that, At room temperature, the Young's modulus of the viscoelastic layer is 10 kPa to 80 kPa, the creep variable 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, characterized in that, The thickness of the viscoelastic layer is 5 μm to 15 μm.

15. The solar cell according to any one of claims 8 to 14, characterized in that, The viscoelastic layer includes at least one of polyurethane and polyacrylate.

16. The solar cell according to any one of claims 8 to 15, characterized in that, 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, characterized in that, The functional layer satisfies at least one of the following conditions (1) to (3): (1) The functional layer includes a perovskite layer and a charge transport layer. The charge transport layer is located on one side of the perovskite layer and is used for transporting charges. (2) 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 disposed on a substrate and is a transparent conductive oxide thin film. The first charge transport layer is a hole transport layer, and 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. (3) The functional layer includes a functional layer of a perovskite tandem solar cell.

18. A method for preparing a solar cell, characterized in that, It includes: 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 disposed 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.

19. The manufacturing method of a solar cell according to claim 18, wherein, The step of disposing a protective layer on at least one side of the solar cell body includes: Disposing a protective layer on at least one side of the solar cell body according to preset parameters. The protective layer includes at least one stress compensation layer. The preset parameters include 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 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 between the neutral plane and the side of the stress compensation layer away from the neutral plane.

20. The method for preparing a solar cell according to claim 19, wherein The preset parameters further include the Poisson's ratio of the stress compensation material used to form the stress compensation layer. The property parameters further include the Poisson's ratio of the substrate material used to form the substrate and the Poisson's ratio of the film layer material used to form each film layer.

21. The manufacturing method of the solar cell according to any one of claims 18 to 20, characterized in that, The protective layer includes a stress compensation body and a first bending portion; the first bending portion is formed by extending at least part of a stress compensation layer in 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 preset parameters includes: Disposing the stress compensation body on the first surface according to the preset parameters; Bending the first bending portion to the side surface; or Disposing the first bending portion on the side surface according to the preset parameters; Bending the stress compensation body to the first surface.

22. The manufacturing method of the solar cell according to claim 21, wherein, The protective layer further includes a second bending portion, the second bending portion is formed by extending at least part of a stress compensation layer in the first bending 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 bending portion to the side surface, it further includes: bending the second bending portion to the second surface; or After the step of disposing the first bending portion on the side surface, it further includes: bending the second bending portion to the second surface; or The step of disposing the first bending portion on the side surface is: disposing the second bending portion on the second surface and bending the first bending portion to the side surface.

23. The manufacturing method of the solar cell according to any one of claims 18 to 20, characterized in that, 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 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 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.

24. The method for preparing a solar cell according to any one of claims 18 to 23, 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 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 thicknesses of several film layers and the Young's modulus of the film layer materials used to form the several 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.

25. The manufacturing method of the solar cell according to claim 24, characterized in that, 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 preset parameters further include the Poisson's ratio of the stress compensation material for forming the stress compensation layer, the attribute parameters further include the Poisson's ratio of the base material for forming the base, and the Poisson's ratio of the film layer material for forming each film layer; 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 Poisson's ratio of the stress compensation material for forming the stress compensation layer, the thickness of the base, the Young's modulus of the base material for forming the base, the Poisson's ratio of the base material for forming the base, the thicknesses of several film layers, the Young's modulus of the film layer material for forming each film layer, and the Poisson's ratio of the film layer material for forming each film layer satisfy: where 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, j = 1 means starting from j taking values from 1, and ν refers to the Poisson's ratio.

26. An electrical device, characterized in that, It includes the solar cell according to any one of claims 1 to 17 or the solar cell formed by the preparation method according to any one of claims 18 to 25.

27. A power generation device, characterized in that, It includes the solar cell according to any one of claims 1 to 17 or the solar cell formed by the preparation method according to any one of claims 18 to 25.

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