Solar cell and manufacturing method therefor, electrical device, and power generating device

Abstract

A solar cell and a manufacturing method therefor, an electrical device, and a power generating device. The solar cell at least comprises a perovskite layer, the perovskite layer comprises a surfactant, the surfactant comprises lecithin, and the lecithin comprises a hydrophilic group. By adding the surfactant to the perovskite layer, when a perovskite precursor solution is deposited over a large area, the surfactant can increase the hydrophilicity of the perovskite precursor solution and an underlying substrate, facilitating the uniform spreading of the solution.

Description

Solar cell and its preparation method, power-consuming device and power-generating device

[0001] This application claims priority to Chinese patent application No. 2024102886612 filed on March 13, 2024, entitled “Solar cells, methods for preparing the same, electrical devices and power generation devices”. Technical Field

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

[0003] Solar cells have become a research hotspot in the photovoltaic field due to their simple fabrication process, low manufacturing cost, and excellent photoelectric conversion efficiency. The light-absorbing materials in perovskite layers offer advantages such as high extinction coefficients, high carrier mobility, long carrier lifetimes, and tunable band gaps. However, current technologies for preparing perovskite layers over large areas using solution-based methods often suffer from poor film coverage and uneven film formation, impacting the photoelectric conversion efficiency and stability of solar cells.

[0004] Summary of the Invention

[0005] In view of the above technical problems, the present application provides a solar cell and a preparation method thereof, an electrical device and a power generation device, which can improve the uniformity of film formation when preparing perovskite layers over a large area by a solution method.

[0006] The first technical solution adopted in the present application is: to provide a solar cell, which comprises at least a perovskite layer, the perovskite layer comprises a perovskite main body and a surfactant, the surfactant comprises lecithin, and the lecithin comprises a hydrophilic group.

[0007] In the technical solution of the embodiment of the present application, a surfactant is added to the perovskite layer, and the surfactant includes lecithin modified with a hydrophilic group, wherein the lecithin is the skeleton structure of the surfactant, and the hydrophilic group is used to increase the hydrophilicity of the perovskite precursor and the underlying substrate, and the contact angle is reduced, so that the perovskite precursor is easier to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0008] In some embodiments, the hydrophilic group includes at least one of a carboxyl group, a sulfonic acid group and a salt thereof, an amino group, a hydroxyl group, an amide group, a hydrazine group, and a thiol group.

[0009] In the technical solution of the embodiment of the present application, the hydrophilic groups taken from the above range can increase the hydrophilicity of the perovskite precursor solution and the underlying substrate, and the contact angle is reduced. Therefore, the perovskite precursor solution is easier to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution.

[0010] In some embodiments, the hydrophilic group-modified lecithin includes at least one of the following:

[0011] In the technical solution of the embodiment of the present application, the lecithin modified with hydrophilic groups within the above-mentioned range increases the hydrophilicity of the perovskite precursor solution and the underlying substrate, and reduces the contact angle, making it easier for the perovskite precursor solution to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0012] The second technical solution adopted in the present application is: to provide a method for preparing a solar cell, the method comprising: providing a substrate structure, the substrate structure being used to set a perovskite layer; setting a first perovskite precursor on the substrate structure, performing a first heat treatment to form a first prefabricated layer, or depositing the first prefabricated layer on the substrate structure; setting a second perovskite precursor on the first prefabricated layer, performing a second heat treatment, and the first prefabricated layer and the second perovskite precursor forming a perovskite layer; wherein the first perovskite precursor comprises a BX2 precursor, the second perovskite precursor comprises an AX precursor, A comprises inorganic cations and / or organic cations, B comprises inorganic cations and / or organic cations, and X comprises inorganic anions and / or organic anions; the first perovskite precursor and / or the second perovskite precursor further comprise a surfactant, and the surfactant comprises lecithin modified with a hydrophilic group.

[0013] In the technical solution of the embodiment of the present application, a two-step method is used to prepare a perovskite layer: a first prefabricated layer is prepared using a first perovskite precursor solution, a second perovskite precursor solution is arranged on the first prefabricated layer, and the perovskite layer is obtained after treatment. Wherein, a surfactant is added to the first perovskite precursor solution and / or the second perovskite precursor solution, which can increase the hydrophilicity of the first perovskite precursor solution and its underlying substrate and / or the hydrophilicity of the second perovskite precursor solution and its underlying substrate, so that the contact angle is reduced, so that the first perovskite precursor solution and / or the second perovskite precursor solution are easier to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0014] In some embodiments, when a first perovskite precursor solution is disposed on a substrate structure and subjected to heat treatment to form a first prefabricated layer, a contact angle of the first perovskite precursor solution on the substrate structure is 20 degrees to 35 degrees.

[0015] In the technical solution of the embodiment of the present application, the contact angle of the first perovskite precursor liquid on the substrate structure is taken from the above-mentioned range, which can increase the hydrophilicity of the first perovskite precursor liquid and the substrate structure, making the first perovskite precursor liquid easier to spread on the surface of the substrate structure, which is beneficial to improving the uniformity of the film layer formed by the first perovskite precursor liquid.

[0016] In some embodiments, after depositing the first prefabricated layer on the substrate structure, the contact angle of the second perovskite precursor solution on the first prefabricated layer is 20 degrees to 30 degrees.

[0017] In the technical solution of the embodiment of the present application, after the first prefabricated layer is deposited on the substrate structure, the contact angle of the second perovskite precursor on the first prefabricated layer is taken from the above-mentioned range, which can increase the hydrophilicity of the second perovskite precursor and the first prefabricated layer, making the second perovskite precursor easier to spread on the surface of the first prefabricated layer, which is beneficial to improving the uniformity of the film layer formed by the second perovskite precursor.

[0018] In some embodiments, the uniformity of the perovskite layer is 3% to 10%.

[0019] In the technical solution of the embodiment of the present application, the perovskite layer having uniformity within the above range can improve the photoelectric conversion efficiency and stability of the solar cell.

[0020] In some embodiments, in the first perovskite precursor solution, the molar amount of the surfactant is 0.001% to 0.15% of the molar amount of the B ion.

[0021] In the technical solution of the embodiment of the present application, the surfactant taken from the above range can improve the hydrophilicity of the first perovskite precursor solution and the substrate structure, making the first perovskite precursor solution easier to spread on the surface of the substrate structure.

[0022] In some embodiments, in the second perovskite precursor solution, the molar amount of the surfactant is 0.001% to 0.15% of the molar amount of A ions.

[0023] In the technical solution of the embodiment of the present application, the surfactant taken from the above range can improve the hydrophilicity of the second perovskite precursor solution and the first prefabricated layer, making the second perovskite precursor solution easier to spread on the surface of the first prefabricated layer.

[0024] The third technical solution adopted in the present application is to provide an electrical device, which includes the solar cell as described above or the solar cell prepared by the method for preparing the solar cell as described above.

[0025] Since the electric device of the present application includes the solar cell provided by the present application, it has at least the same advantages as the solar cell.

[0026] The fourth technical solution adopted in the present application is to provide a power generation device, which includes the solar cell as described above or the solar cell prepared by the method for preparing the solar cell as described above.

[0027] Since the power generation device of the present application includes the solar cell provided by the present application, it has at least the same advantages as the solar cell.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0030] FIG1 is a schematic structural diagram of a solar cell according to some embodiments of the present application;

[0031] FIG2 is a schematic structural diagram of an electric device according to some embodiments of the present application;

[0032] FIG3 is a schematic structural diagram of a power generation device according to some embodiments of the present application. DETAILED DESCRIPTION

[0033] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0035] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0036] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0038] In current technology, when preparing perovskite layers using the large-area solution method, problems such as poor film coverage and inability to form a normal film will occur. The reason is that in the large-area solution method preparation process, the solvent of the perovskite precursor solution cannot be completely spread on the surface of the underlying substrate, or the perovskite precursor solution has a high viscosity and the liquid discharge is slow, resulting in inability to form a uniform film.

[0039] The present application provides a solar cell 100 . The solar cell 100 includes at least a perovskite layer. The perovskite layer includes a surfactant. The surfactant includes lecithin. The lecithin includes a hydrophilic group.

[0040] Hydrophilic groups, also known as oleophobic groups, are groups of atoms that are soluble in water or have an affinity for water. They may attract water molecules or dissolve in water, and solid surfaces with these functional groups are easily wetted by water.

[0041] In the technical solution of the embodiment of the present application, a surfactant is added to the perovskite layer, and the surfactant includes lecithin modified with a hydrophilic group, wherein the lecithin is the skeleton structure of the surfactant, and the hydrophilic group is used to increase the hydrophilicity of the perovskite precursor solution and the underlying substrate, and the contact angle is reduced, so that the perovskite precursor solution is easier to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0042] In some embodiments, the hydrophilic group includes at least one of a carboxyl group, a sulfonic acid group and a salt thereof, an amino group, a hydroxyl group, an amide group, a hydrazine group, and a thiol group.

[0043] In the technical solution of the embodiment of the present application, the hydrophilic groups taken from the above range can increase the hydrophilicity of the perovskite precursor solution and the underlying substrate, and the contact angle is reduced. Therefore, the perovskite precursor solution is easier to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution.

[0044] In some embodiments, the hydrophilic group-modified lecithin includes at least one of the following:

[0045] In the technical solution of the embodiment of the present application, the lecithin modified with hydrophilic groups within the above-mentioned range increases the hydrophilicity of the perovskite precursor solution and the underlying substrate, and reduces the contact angle, making it easier for the perovskite precursor solution to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0046] In other embodiments, referring to FIG. 1 , the solar cell 100 may further include a transparent substrate layer, a transparent conductive layer, a hole transport layer, an electron transport layer, and an electrode layer.

[0047] The transparent substrate layer serves as a support for the solar cell 100 , and its light transmittance and strength need to meet the requirements of the solar cell 100 , including but not limited to glass or PET (polyethylene terephthalate), PI (polyimide), etc.

[0048] The function of the transparent conductive layer is to conduct photogenerated carriers. Common FTO (F-doped tin oxide) can filter out ultraviolet light that is destructive to the perovskite layer while conducting electricity. In addition, there are ITO (In-doped tin oxide), AZO (Al-doped zinc oxide), etc. The transparent conductive layer can choose a combination of one or more of these.

[0049] The hole transport layer is one or more materials that can transport holes and block electrons, such as 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), NiOx, poly-3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS), WO3, organic self-assembled small molecules SAMs, etc.

[0050] It should be noted that, in some embodiments, the solar cell 100 may not include a hole transport layer.

[0051] The electron transport layer is responsible for extracting electrons and blocking holes, and is generally one or more of TiO2, SnO2, ZnO, [6,6]-phenyl-C61-butyric acid isomethyl ester (PCBM), and C60.

[0052] It should be noted that, in some embodiments, the solar cell 100 may not include an electron transport layer.

[0053] The electrode layer is one or more of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, MoO3, SnO2, IWO, ITO, FTO, and AZO.

[0054] The second technical solution adopted in the present application is: providing a method for preparing a solar cell 100, the method comprising: providing a substrate structure, the substrate structure being used to set a perovskite layer; setting a first perovskite precursor on the substrate structure, performing a first heat treatment to form a first prefabricated layer, or depositing the first prefabricated layer on the substrate structure; setting a second perovskite precursor on the first prefabricated layer, performing a second heat treatment, and the first prefabricated layer and the second perovskite precursor forming a perovskite layer; wherein the first perovskite precursor comprises a BX2 precursor, the second perovskite precursor comprises an AX precursor, A comprises inorganic cations and / or organic cations, B comprises inorganic cations and / or organic cations, and X comprises inorganic anions and / or organic anions; the first perovskite precursor and / or the second perovskite precursor further comprise a surfactant, and the surfactant comprises lecithin modified with a hydrophilic group.

[0055] In the technical solution of the embodiment of the present application, a two-step method is used to prepare a perovskite layer: a first prefabricated layer is prepared using a first perovskite precursor solution, a second perovskite precursor solution is arranged on the first prefabricated layer, and the perovskite layer is obtained after treatment. Wherein, a surfactant is added to the first perovskite precursor solution and / or the second perovskite precursor solution, which can increase the hydrophilicity of the first perovskite precursor solution and its underlying substrate and / or the hydrophilicity of the second perovskite precursor solution and its underlying substrate, so that the contact angle is reduced, so that the first perovskite precursor solution and / or the second perovskite precursor solution are easier to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0056] In some embodiments, a two-step method is used to prepare a perovskite layer. The first step is to use a first perovskite precursor solution to form a first prefabricated layer, or to use a vacuum thermal evaporation method to deposit the first prefabricated layer; wherein the annealing temperature is 50°C to 90°C, and the formed first prefabricated layer has a loose and porous structure. The second step is to set a second perovskite precursor solution on the first prefabricated layer, and the annealing temperature is 90°C to 200°C to obtain a perovskite layer. The first perovskite precursor solution includes a BX2 precursor solution, the second perovskite precursor solution includes an AX precursor solution, A includes inorganic cations and / or organic cations, and may include MA + , FA + 、Cs +, Rb + At least one of; B includes inorganic cations and / or organic cations, which may include Pb 2+ 、Sn 2+ At least one of; X includes inorganic anions and / or organic anions, and may include Cl - Br - , I - The thickness of the perovskite layer prepared by the two-step method can be 300nm to 1000nm.

[0057] The surfactant is added to the first perovskite precursor solution to increase the hydrophilicity of the first perovskite precursor solution and the substrate structure; or the surfactant is added to the second perovskite precursor solution to increase the hydrophilicity of the second perovskite precursor solution and the first prefabricated layer; or the surfactant is added to the first perovskite precursor solution and the second perovskite precursor solution at the same time to increase the hydrophilicity of the perovskite precursor solution and its underlying substrate. When the surfactant is added to the perovskite precursor solution, the contact angle is reduced, making it easier for the first perovskite precursor solution and / or the second perovskite precursor solution to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0058] It should be noted that in the manufacturing process of the solar cell 100, the semi-finished structure formed before the step of setting the perovskite layer can be called a substrate structure. The substrate structure is used to set the first prefabricated layer, and the film layer used to receive the first perovskite precursor liquid and the film layer receiving the second perovskite precursor liquid can both become their respective lower substrates.

[0059] For example, in some embodiments, the substrate structure includes at least a base and a transparent electrode layer disposed on the base, and the perovskite layer can be disposed on the transparent electrode layer. In the process of preparing the perovskite layer, when the first step is to form a first prefabricated layer using a first perovskite precursor solution, the base and the transparent electrode layer can be referred to as the base structure, and the transparent electrode layer can be referred to as the lower substrate of the first perovskite precursor solution; when the second step is to form a second perovskite precursor solution on the first prefabricated layer using a second perovskite precursor solution, the base and the transparent electrode layer can be referred to as the base structure, and the first prefabricated layer can be referred to as the lower substrate of the second perovskite precursor solution.

[0060] In some embodiments, a hole transport layer or an electron transport layer may be further provided on the transparent electrode layer, and the perovskite layer may be provided on the hole transport layer or the electron transport layer, that is, the substrate structure includes a substrate, a transparent electrode layer provided on the substrate, a hole transport layer or an electron transport layer provided on the transparent electrode layer, and the perovskite layer may be provided on the hole transport layer or the electron transport layer. In the process of preparing the perovskite layer, when the first prefabricated layer is formed using a first perovskite precursor solution in the first step, the substrate, the transparent electrode layer, and the hole transport layer or the electron transport layer may be referred to as the substrate structure, and the hole transport layer or the electron transport layer may be referred to as the lower substrate of the first perovskite precursor solution; when the second prefabricated layer is provided using a second perovskite precursor solution in the second step, the substrate, the transparent electrode layer, and the hole transport layer or the electron transport layer may be referred to as the substrate structure, and the first prefabricated layer may be referred to as the lower substrate of the second perovskite precursor solution.

[0061] The solvent used in the first perovskite precursor solution and / or the second perovskite precursor solution may include at least one of DMF (N,N-dimethylacetamide), DMSO (dimethyl sulfoxide), and NMP (1-methyl-2-pyrrolidone).

[0062] The concentration of the first perovskite precursor solution and / or the second perovskite precursor solution may be 0.5 mol / L to 2 mol / L.

[0063] The two-step process for preparing the perovskite layer includes at least one of slit coating, doctor blade coating, screen printing, and spin coating. Alternatively, when a surfactant is added only to the second perovskite precursor solution to increase the hydrophilicity of the second perovskite precursor solution and the first prefabricated layer, the first prefabricated layer can be prepared by vacuum thermal evaporation.

[0064] In some embodiments, when a first perovskite precursor solution is disposed on a substrate structure and subjected to heat treatment to form a first prefabricated layer, a contact angle of the first perovskite precursor solution on the substrate structure is 20 degrees to 35 degrees.

[0065] In the technical solution of the embodiment of the present application, the contact angle of the first perovskite precursor on the substrate structure is taken from the above range, which can increase the hydrophilicity of the first perovskite precursor and the substrate structure, making it easier for the first perovskite precursor to spread on the surface of the substrate structure, which is beneficial to improving the uniformity of the film formed by the first perovskite precursor. The contact angle can be 20 degrees, 21 degrees, 23 degrees, 24 degrees, 25 degrees, 25.5 degrees, 27 degrees, 28 degrees, 30 degrees, 32 degrees, 35 degrees, etc.; or a range consisting of any two of the above values, for example, it can be 20 degrees to 25 degrees, 21 degrees to 35 degrees, 28 degrees to 30 degrees, etc.

[0066] In some embodiments, after depositing the first prefabricated layer on the substrate structure, the contact angle of the second perovskite precursor solution on the first prefabricated layer is 20 degrees to 30 degrees.

[0067] In the technical solution of the embodiment of the present application, after depositing the first prefabricated layer on the substrate structure, the contact angle of the second perovskite precursor on the first prefabricated layer is taken from the above range, which can increase the hydrophilicity of the second perovskite precursor and the first prefabricated layer, making it easier for the second perovskite precursor to spread on the surface of the first prefabricated layer, which is conducive to improving the uniformity of the film formed by the second perovskite precursor. The contact angle can be 20 degrees, 23 degrees, 25 degrees, 27 degrees, 28 degrees, 30 degrees, etc.; or a range consisting of any two of the above values, for example, it can be 20 degrees to 25 degrees, 23 degrees to 25 degrees, 23 degrees to 28 degrees, 25 degrees to 30 degrees, etc.

[0068] In some embodiments, the uniformity of the perovskite layer is 3% to 10%.

[0069] In the technical solutions of the embodiments of the present application, a perovskite layer having uniformity within the aforementioned range can improve the photoelectric conversion efficiency and stability of the solar cell 100. The uniformity of the perovskite layer can be 3%, 3.8%, 4%, 4.2%, 5%, 5.5%, 6%, 6.8%, 7%, 8%, 9%, 10%, etc.; or a range consisting of any two of the aforementioned values, for example, 3% to 5%, 5% to 10%, etc.

[0070] In some embodiments, in the first perovskite precursor solution, the molar amount of the surfactant is 0.001% to 0.15% of the molar amount of the B ion.

[0071] In the technical solution of the embodiment of the present application, the surfactant taken from the above range can improve the hydrophilicity of the first perovskite precursor and the substrate structure, so that the first perovskite precursor is easier to spread on the surface of the substrate structure. In the first perovskite precursor, the molar amount of the surfactant can be 0.001%, 0.003%, 0.005%, 0.01%, 0.05%, 0.1%, 0.12%, 0.15%, etc. based on the molar amount of the B ion; or it can be a range composed of any two of the above values, for example, it can be 0.001% to 0.005%, 0.003% to 0.12%, 0.01% to 0.05%, 0.001% to 0.1%, 0.05% to 0.15%. In some embodiments, in the first perovskite precursor, the molar amount of the surfactant can be selected as 0.001% to 0.1% of the molar amount of the B ion.

[0072] In some embodiments, after depositing the first pre-layer on the substrate structure, the molar amount of the surfactant in the second perovskite precursor solution is 0.001% to 0.15% of the molar amount of the A ion.

[0073] In the technical solution of the embodiment of the present application, the surfactant taken from the above range can improve the hydrophilicity of the second perovskite precursor and the first prefabricated layer, so that the second perovskite precursor is easier to spread on the surface of the first prefabricated layer. The ratio of the molar amount of the surfactant to the molar amount of the A ion can be 0.001%, 0.005%, 0.01%, 0.02%, 0.05%, 0.08%, 0.09%, 0.1%, 0.12%, 0.15%, etc.; or a range consisting of any two of the above values, for example, it can be 0.001% to 0.05%, 0.05% to 0.1%, etc. In some embodiments, after the first prefabricated layer is deposited on the substrate structure, the molar amount of the surfactant in the second perovskite precursor can be selected as 0.001% to 0.1% of the molar amount of the A ion.

[0074] In some embodiments, the thickness of the first prefabricated layer is 100 nm to 200 nm.

[0075] In the technical solutions of the embodiments of the present application, a thickness of the first prefabricated layer within the above-mentioned range facilitates subsequent reaction with the second perovskite precursor solution to form a perovskite layer. The perovskite layer also has an appropriate thickness, facilitating light absorption and conversion, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100. The thickness of the first prefabricated layer can be 100 nm, 110 nm, 125 nm, 138 nm, 150 nm, 167 nm, 189 nm, or 200 nm; or a range consisting of any two of the above-mentioned values, for example, 100 nm to 138 nm, 138 nm to 200 nm, etc.

[0076] 2 , the present application further provides an electrical device 1000 , comprising the solar cell 100 as described above.

[0077] In the present application, the solar cell 100 serves as a power source for the electrical device 1000; alternatively, the solar cell 100 can serve as an energy storage unit for the electrical device 1000. For example, the electrical device 1000 can be a lighting element, a display element, or a car.

[0078] 3 , the present application further provides a power generation device 2000, comprising the aforementioned solar cell 100. The power generation device 2000 may comprise the solar cell 100 and an energy storage device, which may be a secondary battery.

[0079] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0080] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0081] Example 1

[0082] (1) Take a 2 cm × 2 cm piece of FTO conductive glass and laser etch it to leave an insulating area. Then, ultrasonicate it with deionized water, detergent, ethanol, isopropyl alcohol, acetone, ethanol, and deionized water for 20 minutes, then blow dry it with nitrogen and set aside.

[0083] (2) Preparation of hole transport layer: NiOx nanoparticles with an average particle size of 5 nm were added to ethanol to form a solution with a concentration of 10 mg / L. The solution was spin-coated on a 2 cm × 2 cm FTO substrate at a speed of 3000 rpm and annealed at 200 °C for 15 min to obtain a hole transport layer with a thickness of 20 nm. The solution was then cooled naturally for later use.

[0084] (3) Preparation of perovskite layer:

[0085] Step 1: Prepare a PbI2 precursor solution with a concentration of 0.8 mol / L, using DMF as the solvent, add 0.001% lecithin + hydrazine, stir until dissolved, and use the slit coating method to deposit the perovskite skeleton layer, where the slit height is 0.1 μm, the coating speed is 20 mm / s, and the injection speed is 10 μl / s; after annealing at 70°C for 3 minutes, a first prefabricated layer with a thickness of 150 nm is obtained.

[0086] Step 2: Prepare a 1.2 mol / L FAI precursor solution with isopropanol as the solvent, add 0.001% lecithin + hydrazine, and use a slit coating method to deposit the perovskite organic layer. The slit height is 0.15 μm, the coating speed is 10 mm / s, and the injection speed is 15 μl / s. Anneal at 150°C for 30 minutes. After natural cooling, a perovskite layer with a thickness of 500 nm is obtained.

[0087] Before the first step or the second step, the precursor solutions in the first step and the second step can be sampled, and a contact angle test can be performed on the sample solution on the underlying substrate using a contact angle tester.

[0088] (4) Testing the thickness and uniformity of the perovskite film in step (3).

[0089] (5) Preparation of electron transport layer: A PCBM / BCP solution was spin-coated on the perovskite layer at a rotation speed of 3000 rpm or a PCBM / BCP layer was prepared by vacuum thermal evaporation to form an electron transport layer and a barrier layer, wherein the thickness of the PCBM electron transport layer was 15 nm and the thickness of the BCP barrier layer was 8 nm.

[0090] (6) Preparation of electrode layer: A Cu counter electrode is deposited on the electron transport layer using a mask with a specific pattern by thermal evaporation to obtain a solar cell.

[0091] Examples 2 to 32, Comparative Example 1

[0092] Similar to Example 1, except that the formula and process in step (3) were adjusted, see Table 1 for details.

[0093] The battery devices 1 to 30 obtained in the above Examples 1 to 29 and Comparative Example 1 were subjected to battery performance tests, and Table 1 was obtained.

[0094] 1. Thickness and uniformity test method:

[0095] Use a blade to scratch the surface of the battery device, and use a step meter to test the scratch position. The difference is the thickness, and the average value is taken from multiple point tests.

[0096] Nine points were selected on the surface of the battery device to test the thickness, and the uniformity was calculated as follows: (maximum thickness value - minimum thickness value) / (maximum thickness value + minimum thickness value).

[0097] 2. Vacuum evaporation process

[0098] The perovskite raw material was placed in a crucible, heated to 180°C at 50°C / min, the baffle was opened, and 200 nm was evaporated at a rate of 1 A / s.

[0099] 3. Photoelectric conversion efficiency test method:

[0100] Under standard simulated sunlight (AM1.5G, 100mW / cm 2 ) irradiation, the battery performance is tested and the IV curve is obtained. According to the IV curve and the data fed back by the test equipment, the short-circuit current Jsc (unit: mA / cm 2), open-circuit voltage Voc (V), maximum optical output current Jmpp (mA), and maximum optical output voltage Vmpp (V). The cell's fill factor (FF) (in %) is calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp). The cell's photoelectric conversion efficiency (PCE) (in %) is calculated using the formula PCE = Jsc × Voc × FF / Pw, where Pw represents the input power (in mW).

[0101] Table 1 Battery performance test (IV test)

[0102] As can be seen from the relevant data in Table 1, the battery devices 1 to 29 of Examples 1 to 29 all added a surfactant to the perovskite layer, and the surfactant included lecithin modified with a hydrophilic group, and the photoelectric conversion efficiency was higher than that of the device 30 of Comparative Example 1. This illustrates that the present application increases the hydrophilicity of the perovskite precursor solution and the underlying substrate by adding a surfactant including lecithin modified with a hydrophilic group to the perovskite layer, reduces the contact angle, and makes it easier for the perovskite precursor solution to spread on the surface of the underlying substrate, which is beneficial to improving the uniformity of the film layer formed by the perovskite precursor solution, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0103] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A solar cell comprising at least a perovskite layer, wherein: The perovskite layer includes a surfactant, the surfactant includes lecithin, and the lecithin includes a hydrophilic group.

2. The solar cell according to claim 1, wherein The hydrophilic group includes at least one of a carboxyl group, a sulfonic acid group and a salt thereof, an amino group, a hydroxyl group, an amide group, a hydrazine group, and a thiol group.

3. The solar cell according to claim 1 or 2, wherein: The hydrophilic group-modified lecithin comprises at least one of the following:

4. A method for preparing a solar cell, wherein: Providing a substrate structure for arranging a perovskite layer; Providing a first perovskite precursor solution on the substrate structure and performing a first heat treatment to form a first prefabricated layer, or depositing the first prefabricated layer on the substrate structure; Disposing a second perovskite precursor solution on the first prefabricated layer and performing a second heat treatment, so that the first prefabricated layer and the second perovskite precursor solution form a perovskite layer; In which, the first perovskite precursor solution includes a BX2 precursor solution, the second perovskite precursor solution includes an AX precursor solution, A includes inorganic cations and / or organic cations, B includes inorganic cations and / or organic cations, and X includes inorganic anions and / or organic anions; the first perovskite precursor solution and / or the second perovskite precursor solution also include a surfactant, and the surfactant includes lecithin modified with a hydrophilic group.

5. The method for preparing a solar cell according to claim 4, wherein: When the first perovskite precursor solution is provided on the substrate structure and subjected to heat treatment to form the first prefabricated layer, the contact angle of the first perovskite precursor solution on the substrate structure is 20 degrees to 35 degrees.

6. The method for preparing a solar cell according to claim 4 or 5, wherein: After depositing the first prefabricated layer on the substrate structure in the step, the contact angle of the second perovskite precursor liquid on the first prefabricated layer is 20 degrees to 30 degrees.

7. The method for preparing a solar cell according to any one of claims 4 to 6, wherein: The uniformity of the perovskite layer is 3% to 10%.

8. The method for preparing a solar cell according to any one of claims 4 to 7, wherein: In the first perovskite precursor solution, the molar amount of the surfactant is 0.001% to 0.15% of the molar amount of the B ion.

9. The method for preparing a solar cell according to any one of claims 4 to 8, wherein: In the second perovskite precursor solution, the molar amount of the surfactant is 0.001% to 0.15% of the molar amount of A ions.

10. An electrical device, wherein: The invention comprises a solar cell according to claim 1 to claim 3 or a solar cell prepared by the method for preparing a solar cell according to any one of claims 4 to 9.

11. A power generation device, wherein: The invention comprises a solar cell according to claim 1 to claim 3 or a solar cell prepared by the method for preparing a solar cell according to any one of claims 4 to 9.

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