Solar cell and manufacturing method therefor, electric device, and power generation device

Abstract

A solar cell and a manufacturing method therefor, an electric device, and a power generation device. A light absorption layer in the solar cell comprises a light absorption material and an additive. The additive comprises a first group and a second group. The first group includes at least one of a phenyl group, an alkyl group, an aniline group, and a carbazolyl group, and the second group includes at least one of a carboxyl group, a phosphate group, and an ammonium group. The provision of the additive in the light absorption layer reduces the defects of the light absorption layer and achieves the effect of passivating the light absorption layer.

Description

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

[0001] This application claims priority to Chinese patent application No. 2024102698384 filed on March 8, 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, which use perovskite-type organic metal halide semiconductors as light-absorbing materials, are a new generation of solar cells with high photoelectric conversion rates. However, the presence of numerous defect sites in the light-absorbing layer affects the 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 reduce the defects of the light absorption layer and improve the photoelectric conversion efficiency and stability of the solar cell.

[0006] The first technical solution adopted in the present application is: to provide a solar cell, the solar cell includes at least a light absorption layer, the light absorption layer includes a light absorption material and an additive, the additive includes a first group and a second group, the first group includes at least one of a phenyl group, an alkyl group, an aniline group, and a carbazole group, and the second group includes at least one of a carboxyl group, a phosphate group, and an ammonium group.

[0007] Since the light absorbing material in the light absorbing layer has a large number of defects, such as grain boundaries, dislocations, vacancies, etc., the existence of these defects affects the photoelectric conversion efficiency and stability of the solar cell. Therefore, in the technical solution of the embodiment of the present application, by setting additives in the light absorbing layer and mixing the additives with the light absorbing material, the defect sites in the light absorbing layer can be compensated, the bulk crystallization of the perovskite can be optimized, and the defects of the light absorbing layer can be reduced. At the same time, during the crystallization process of the light absorbing layer, the perovskite crystallization can squeeze a large amount of additives to the lower interface, passivating the lower interface of the light absorbing layer. The lower interface is the interface of the light absorbing layer toward the light incident side of the solar cell, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0008] In some embodiments, the light absorbing layer includes a passivation region and a main region, the passivation region is located at the interface of the light absorbing layer facing the light incident side of the solar cell, and the content of the additive in the passivation region is greater than the content of the additive in the main region.

[0009] In the technical solution of the embodiments of the present application, the additives are distributed in the passivation region and the main region of the light-absorbing layer. Because the functional groups in the additives interact strongly with the lower interface of the light-absorbing layer (the lower interface is the interface of the light-absorbing layer facing the light-incident side of the solar cell), the additives spontaneously align in a directional manner. Furthermore, during the crystallization of the light-absorbing layer, the perovskite crystals squeeze a large amount of the additives to the lower interface. As a result, the additives are concentrated at the lower interface of the light-absorbing layer, resulting in a greater additive content in the passivation region than in the main region. The additives form a passivation layer at the lower interface of the light-absorbing layer, which can passivate the lower interface of the light-absorbing layer, thereby reducing defects at the lower interface of the light-absorbing layer and improving the photoelectric conversion efficiency and stability of the solar cell.

[0010] In some embodiments, the light absorbing material comprises perovskite. Perovskite solar cells have high stability, high light conversion efficiency, and low cost.

[0011] In some embodiments, the thickness of the passivation region is 0.01 nm to 20 nm.

[0012] In the technical solution of the embodiment of the present application, the thickness of the passivation zone is within the above range, which can better passivate the lower interface of the light absorption layer, which is the interface of the light absorption layer toward the light incident side of the solar cell, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0013] In some embodiments, the mass fraction of the additive in the light absorbing layer is 0.01% to 0.1%.

[0014] In the technical solution of the embodiment of the present application, by controlling the mass fraction of the additive in the light absorbing layer within the above range, the additive can passivate the light absorbing layer to reduce defects in the light absorbing layer and improve the photoelectric conversion efficiency and stability of the solar cell.

[0015] In some embodiments, the thickness of the light absorbing layer is 150 nm to 600 nm.

[0016] In the technical solution of the embodiment of the present application, the thickness of the light absorption layer is within the above range, which can achieve efficient photoelectric conversion and improve the energy conversion efficiency of the solar cell.

[0017] In some embodiments, the solar cell further comprises a first electrode, a second electrode, a first charge transport layer, and a second charge transport layer. The first electrode is located near the light incident side; the light absorbing layer is located between the first electrode and the second electrode; the first charge transport layer is located between the first electrode and the light absorbing layer; and the second charge transport layer is located between the second electrode and the light absorbing layer. One of the first charge transport layer and the second charge transport layer is an electron transport layer, and the other is a hole transport layer.

[0018] In some embodiments, a hole transport layer is provided on a side of the light absorbing layer facing the light incident side of the solar cell.

[0019] In the technical solution of the embodiment of the present application, a hole transport layer is provided on the side of the light absorption layer facing the light incident side of the solar cell. The functional groups in the additives have a strong effect on the hole transport layer, and the additives are spontaneously arranged in a direction in the hole transport layer, thereby reducing defects between the light absorption layer and the hole transport layer and improving the photoelectric conversion efficiency and stability of the solar cell.

[0020] In some embodiments, the chemical formula of the additive includes at least one of the following:

[0021] In the technical solution of the embodiment of the present application, the additives taken from the above range can enter the crystal lattice of the light absorbing layer and promote the crystallization of the light absorbing layer, thereby passivating the light absorbing layer.

[0022] In some embodiments, the chemical formula of the additive further includes at least one of the following:

[0023] In the technical solution of the embodiment of the present application, the additives taken from the above range can enter the crystal lattice of the light absorbing layer and promote the crystallization of the light absorbing layer, thereby passivating the light absorbing layer.

[0024] The second technical solution adopted in the present application is: providing a method for preparing a solar cell, the method comprising: providing a substrate structure, the substrate structure being used to set a light absorption layer; setting a mixed solution formed by mixing a perovskite precursor liquid and an additive on the substrate structure, and heat-treating it to form a light absorption layer, wherein the light absorption layer comprises a light absorption material and an additive, the additive comprises a first group and a second group, the first group comprises at least one of a phenyl group, an alkyl group, an aniline group, and a carbazole group, and the second group comprises at least one of a carboxyl group, a phosphate group, and an ammonium group.

[0025] In the technical solution of the embodiment of the present application, by setting additives in the light absorbing layer, it is possible to compensate for defect sites in the light absorbing layer, optimize the bulk crystallization of the light absorbing material, and reduce defects in the light absorbing layer. At the same time, during the crystallization process of the light absorbing layer, the perovskite crystallization can squeeze a large amount of additives to the lower interface. The lower interface is the interface of the light absorbing layer facing the light incident side of the solar cell, passivating the lower interface of the light absorbing layer, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0026] In some embodiments, in the mixed solution, the concentration of the additive in the perovskite precursor solution is 0.01 mg / mL to 2 mg / mL.

[0027] In the technical solution of the embodiment of the present application, the additives taken from the above concentration range can passivate the light absorbing layer to reduce the defects of the light absorbing layer and improve the photoelectric conversion efficiency and stability of the solar cell.

[0028] In some embodiments, during the heat treatment process, the temperature is first raised to 50°C to 90°C at a heating rate of 1°C / min to 10°C / min, kept warm for 0 to 20 minutes, and then raised to 100°C to 150°C, kept warm for 5 to 50 minutes.

[0029] In the technical solution of the present embodiment, the purpose of the staged temperature increase is to control the nucleation and crystallization rate of the light absorbing layer: the initial low temperature reduces the number of nuclei, and the subsequent temperature increase promotes grain growth, thereby obtaining a high-quality light absorbing layer film. Furthermore, the first low temperature step facilitates the aggregation of additives at the lower interface of the light absorbing layer, forming a passivation layer. The lower interface is the interface of the light absorbing layer facing the light incident side of the solar cell.

[0030] 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.

[0031] 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.

[0032] Since the 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.

[0033] 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

[0034] 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:

[0035] FIG1 is a schematic structural diagram of a solar cell according to some embodiments of the present application;

[0036] FIG2 is a schematic structural diagram of an electrical device according to some embodiments of the present application;

[0037] FIG3 is a schematic structural diagram of a power generation device according to some embodiments of the present application. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The present application provides a solar cell 100, which includes at least a light absorption layer, the light absorption layer includes perovskite and an additive, the additive includes a first group and a second group, the first group includes at least one of a phenyl group, an alkyl group, an aniline group, and a carbazole group, and the second group includes at least one of a carboxyl group, a phosphate group, and an ammonium group.

[0044] Since the light absorbing material in the light absorbing layer has a large number of defects, such as grain boundaries, dislocations, vacancies, etc., the existence of these defects affects the photoelectric conversion efficiency and stability of the solar cell 100. Therefore, in the technical solution of the embodiment of the present application, by setting additives in the light absorbing layer and mixing the additives with the light absorbing material, the defect sites in the light absorbing layer can be compensated, the bulk crystallization of the perovskite can be optimized, and the defects of the light absorbing layer can be reduced. At the same time, during the crystallization process of the light absorbing layer, the perovskite crystallization can squeeze a large amount of additives to the lower interface, passivating the lower interface of the light absorbing layer. The lower interface is the interface of the light absorbing layer toward the light incident side of the solar cell 100, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0045] In some embodiments, the light absorbing layer includes a passivation region and a main region. The passivation region is close to a side of the light absorbing layer facing the light incident side of the solar cell 100 . The content of the additive in the passivation region is greater than that in the main region.

[0046] In the technical solution of the embodiments of the present application, the additives are distributed in the passivation region and the bulk region of the light-absorbing layer. Because the functional groups in the additives strongly interact with the lower interface of the light-absorbing layer (the lower interface being the interface of the light-absorbing layer facing the light-incident side of the solar cell 100), the additives spontaneously align in a directional manner. Furthermore, during the crystallization of the light-absorbing layer, the perovskite crystals squeeze a large amount of the additives toward the lower interface. Consequently, the additives are concentrated at the lower interface of the light-absorbing layer, resulting in a greater additive content in the passivation region than in the bulk region. The additives form a passivation layer at the lower interface of the light-absorbing layer, which can passivate the lower interface of the light-absorbing layer, thereby reducing defects at the lower interface of the light-absorbing layer and improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0047] In some embodiments, the light absorbing material comprises a perovskite.

[0048] In the technical solution of the embodiment of the present application, the perovskite solar cell has high stability, high light conversion efficiency and low cost. The components of the perovskite can be ABX3 or A2CDX6, where A includes inorganic or organic or organic-inorganic mixed cations, which can be MA + , FA + 、Cs + , Rb + At least one of; B includes an inorganic cation, which may be Pb 2+ 、Sn 2+ At least one of; C includes inorganic or organic or organic-inorganic mixed cations, commonly Ag + 、Cu + 、Au + , FA + , GA + ; D includes inorganic cations, which can be Bi 3+、Sb 3+ , and In 3+ At least one of; X includes an inorganic anion, which may be Cl - Br - , I - At least one of.

[0049] In some embodiments, the thickness of the passivation region is 0.01 nm to 20 nm.

[0050] In the technical solution of the embodiment of the present application, the characterization method of the thickness of the passivation region is characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS). The light absorbing layer is peeled off from the substrate of the solar cell 100 using a UV curing glue or AB glue method to obtain a sample. The peeled surface of the sample is tested to detect the characteristic structure of the additive in the passivation region. The thickness of the passivation region can be calculated based on the sample etching rate. The thickness of the passivation region is in the range of 0.01nm to 20nm, which can better passivate the lower interface of the light absorbing layer. The lower interface is the interface of the light absorbing layer toward the light incident side of the solar cell 100, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100. The thickness of the passivation region can be 0.01nm, 1nm, 5nm, 9.6nm, 11.2nm, 15nm, 17.5nm, 20nm, or a range consisting of any two of the above values, for example, 0.01nm to 5nm, 5nm to 9.6nm, 9.6nm to 15nm, 15nm to 20nm, etc.

[0051] In some embodiments, the mass fraction of the additive in the light absorbing layer is 0.01% to 0.1%.

[0052] In the technical solution of the embodiment of the present application, the method for characterizing the mass fraction of the additive in the light absorbing layer is thermogravimetric analysis (TGA). The light absorbing layer is scraped off from the substrate of the solar cell 100 with a blade to obtain a sample. The sample is tested to detect the mass fraction of the additive in the light absorbing layer. By controlling the mass fraction of the additive in the light absorbing layer to be between 1×10 -1 %~1×10 -2 %, the additive can passivate the light absorbing layer to reduce defects in the light absorbing layer and improve the photoelectric conversion efficiency and stability of the solar cell 100. The mass fraction of the additive in the light absorbing layer can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.08%, 0.09%, 0.1%, or a range consisting of any two of the foregoing values, for example, 0.01% to 0.04%, 0.04% to 0.08%, 0.08% to 0.1%, or 0.03% to 0.09%.

[0053] In some embodiments, the thickness of the light absorbing layer is 150 nm to 600 nm.

[0054] In the technical solutions of the embodiments of the present application, the thickness of the light absorbing layer is within the above range, which can achieve efficient photoelectric conversion and improve the energy conversion efficiency of the solar cell 100. The thickness of the light absorbing layer can be 150 nm, 200 nm, 260 nm, 350 nm, 400 nm, 450 nm, 550 nm, 600 nm, or a range consisting of any two of the above values, for example, 150 nm to 260 nm, 260 nm to 400 nm, or 400 nm to 600 nm.

[0055] In some embodiments, referring to FIG1 , the solar cell 100 may further include a first electrode, a first charge transport layer, a second charge transport layer, and a second electrode. The first electrode is located near the light incident side; the light absorbing layer is located between the first electrode and the second electrode; the first charge transport layer is located between the first electrode and the light absorbing layer; and the second charge transport layer is located between the second electrode and the light absorbing layer. One of the first charge transport layer and the second charge transport layer is an electron transport layer, and the other is a hole transport layer.

[0056] The first electrode is a transparent substrate layer, which serves as a support for the solar cell 100 . Both 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.

[0057] The transparent base layer includes a transparent conductive layer, which is used to conduct photogenerated carriers. Common FTO (F-doped tin oxide) can filter out ultraviolet light that is destructive to the light absorption layer 111 while conducting electricity. In addition, there are ITO (In-doped tin oxide), AZO (Al-doped zinc oxide), etc. The transparent conductive layer can select one or more combinations of these.

[0058] 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.

[0059] 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.

[0060] The second electrode is an electrode layer, including one or more of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, MoO3, SnO2, IWO, ITO, FTO, and AZO.

[0061] In some embodiments, a hole transport layer is provided on a side of the light absorbing layer facing the light incident side of the solar cell 100 .

[0062] In the technical solution of the embodiment of the present application, a hole transport layer is provided on the side of the light absorption layer facing the light incident side of the solar cell 100. The functional groups in the additives have a strong effect on the hole transport layer, and the additives are spontaneously arranged in a direction in the hole transport layer, thereby reducing defects between the light absorption layer and the hole transport layer and improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0063] In some embodiments, the chemical formula of the additive includes at least one of the following:

[0064] In the technical solution of the embodiment of the present application, the additives taken from the above range can enter the lattice of the light absorbing layer and promote the crystallization of the light absorbing layer, thereby passivating the light absorbing layer. Phenylphosphoric acid (CAS: 1571-33-1) The CAS number is 25069-75-4, Chloromethylphosphonic acid (CAS: 2565-58-4) It is L-aspartic acid hydrochloride (CAS: 17585-59-0).

[0065] In some embodiments, the chemical formula of the additive further includes at least one of the following:

[0066] In the technical solution of the embodiment of the present application, the additives taken from the above range can enter the lattice of the light absorbing layer and promote the crystallization of the light absorbing layer, thereby passivating the light absorbing layer. and / or and / or and / or When adding and / or and / or The obtained mixed additive also has the effect of passivating the light absorbing layer. [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid, CAS number is 2747959-96-0, Octyl ammonium chloride (CAS: 1838-08-0), It is glycine hydrochloride (CAS: 6000-43-7).

[0067] 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 light absorption layer; setting a mixed solution formed by mixing a perovskite precursor solution and an additive on the substrate structure, and heat-treating it to form a light absorption layer, wherein the light absorption layer comprises a light absorption material and an additive, the additive comprising a first group and a second group, the first group comprising at least one of a phenyl group, an alkyl group, an aniline group, and a carbazole group, and the second group comprising at least one of a carboxyl group, a phosphate group, and an ammonium group.

[0068] It should be noted that in the manufacturing process of solar cell 100, any semi-finished structure formed before the step of providing the light absorbing layer can be referred to as a substrate structure. For example, in some embodiments, the substrate structure includes at least a base and a transparent electrode layer provided on the base, and the light absorbing layer can be provided on the transparent electrode layer. In some embodiments, a hole transport layer or an electron transport layer can also be provided on the transparent electrode layer, and the light absorbing layer can be provided on the hole transport layer or the electron transport layer.

[0069] In the technical solution of the embodiment of the present application, by setting additives in the light absorbing layer, defect sites in the light absorbing layer can be compensated, the bulk crystallization of the light absorbing material can be optimized, and the defects of the light absorbing layer can be reduced. At the same time, during the crystallization process of the light absorbing layer, the perovskite crystallization can squeeze a large amount of additives to the lower interface, passivating the lower interface of the light absorbing layer. The lower interface is the interface of the light absorbing layer toward the light incident side of the solar cell 100, thereby improving the photoelectric conversion efficiency and stability of the solar cell 100.

[0070] The components of the perovskite precursor solution can be ABX3 or A2CDX6, where A includes inorganic or organic or organic-inorganic mixed cations, which can be MA + , FA + 、Cs + , Rb + At least one of; B includes an inorganic cation, which may be Pb 2+ 、Sn 2+ At least one of; C includes inorganic or organic or organic-inorganic mixed cations, commonly Ag + 、Cu + 、Au + , FA + , GA + ; D includes inorganic cations, which can be Bi 3+ 、Sb 3+ , and In 3+ At least one of; X includes an inorganic anion, which may be Cl - Br- , I - At least one of.

[0071] In some embodiments, the components of the perovskite precursor solution may be FA 1-a-b Cs a MA b Pb(I 1-y Br y ), where 0 <a、b,y<1,0≤a+b<1。

[0072] The solvent used in the perovskite precursor solution may include at least one of DMF (N,N-dimethylacetamide), DMSO (dimethyl sulfoxide), and NMP (1-methyl-2-pyrrolidone).

[0073] The concentration of the perovskite precursor solution may be 0.5 mol / L to 2 mol / L.

[0074] In some embodiments, in the mixed solution, the concentration of the additive in the perovskite precursor solution is 0.01 mg / mL to 2 mg / mL.

[0075] In the technical solution of the embodiment of the present application, the additive in a concentration range of 0.01 mg / mL to 1 mg / mL can passivate the light absorbing layer to reduce defects in the light absorbing layer and improve the photoelectric conversion efficiency and stability of the solar cell 100. The concentration of the additive in the perovskite precursor solution can be 0.01 mg / mL, 0.05 mg / mL, 0.10 mg / mL, 0.12 mg / mL, 0.15 mg / mL, 0.16 mg / mL, 0.18 mg / mL, 1 mg / mL, 1.25 mg / mL, 1.5 mg / mL, 2 mg / mL, or a range consisting of any two of the above values, for example, 0.01 mg / mL to 0.1 mg / mL, 0.1 mg / mL to 0.15 mg / mL, 0.15 mg / mL to 1 mg / mL, 1 mg / mL to 1.5 mg / mL, 1.5 mg / mL to 2 mg / mL, etc.

[0076] In some embodiments, during the heat treatment process, the temperature is first raised to 50°C to 90°C at a heating rate of 1°C / min to 10°C / min, kept warm for 0 to 20 minutes, and then raised to 100°C to 150°C and kept warm for 5 to 50 minutes.

[0077] In the technical solution of the embodiment of the present application, the purpose of the staged temperature increase is to control the nucleation and crystallization rate of the light absorbing layer: first, the temperature is low to reduce the number of nuclei, and then the temperature is increased to allow the grains to grow, so as to obtain a high-quality light absorbing layer film. At the same time, the low temperature in the first step is conducive to the aggregation of additives at the lower interface of the light absorbing layer to form a passivation layer. The lower interface is the interface of the light absorbing layer facing the light incident side of the solar cell 100. The first heating rate can be 1°C / min, 2°C / min, 4°C / min, 5°C / min, 6°C / min, 8.1°C / min, 9.5°C / min, 10°C / min, or a range consisting of any two of the above values, for example, it can be 1°C / min to 6°C / min, 6°C / min to 10°C / min, etc. The temperature of the first heating step can be 50°C, 65°C, 71.5°C, 79°C, 82.5°C, 88°C, 90°C, or a range consisting of any two of the above values, for example, it can be 50°C to 71.5°C, 71.5°C to 79°C, or 79°C to 90°C. The heating rate of the second step can be 5°C / min to 20°C / min, and the temperature of the second step can be 100°C to 150°C.

[0078] 1 , the present application further provides an electrical device 1000 , comprising the solar cell 100 as described above.

[0079] 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.

[0080] 2 , 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.

[0081] 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.

[0082] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0083] Example 1

[0084] (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.

[0085] (2) Preparation of hole transport layer: 10 mg / mL of 20 nm NiOx nanoparticles were dissolved in isopropyl alcohol (IPA) to form a NiOx nanoparticle solution, which was spin-coated on a 2 cm × 2 cm FTO substrate at a speed of 3000 rpm. The solution was annealed at 200 °C for 15 min and cooled naturally to obtain a hole transport layer with a thickness of 20 nm for use.

[0086] (3) Preparation of perovskite precursor solution: In a FA solution with a concentration of 1 mol / L 0.87 Cs 0.1 MA 0.03 0.3 mg / mL of Me-4PACz was added to the PbI3 perovskite precursor solution, stirred, and then sealed for later use.

[0087] (4) Preparation of light absorption layer: After UV ozone treatment for 15 min, the surface of the NiOx substrate was cleaned by air blowing. An appropriate amount of perovskite precursor solution was applied and spin-coated at 4000 rpm for 20 s or at a coating speed of 5 mm / s to prepare a wet film. The substrate was then vacuumed for 30 s, heated to 60°C at 5°C / min, heated for 1 min, then heated to 140°C at 10°C / min, heated for 15 min, and cooled naturally to obtain the light absorption layer. The thickness of the passivation region of the light absorption layer was 1 nm.

[0088] (5) Preparation of electron transport layer: A PCBM / BCP solution was spin-coated on the light absorption 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 with a thickness of 25 nm.

[0089] (6) Preparation of electrode layer: A Cu counter electrode with a thickness of 100 nm was deposited on the electron transport layer using a thermal evaporation method using a mask with a specific pattern to obtain a solar cell.

[0090] Example 2

[0091] Similar to Example 1, except that:

[0092] Adjust step (3) of Example 1 to:

[0093] Preparation of perovskite precursor solution: Add 0.01 mg / mL of phenylphosphoric acid to a 0.5 M FAPbI3 perovskite precursor solution, stir to prepare a perovskite precursor solution, and seal for later use.

[0094] Adjust step (4) of Example 1 to:

[0095] Preparation of the light-absorbing layer: After UV-ozone treatment for 15 minutes, the NiOx substrate surface was cleaned by air-blowing. An appropriate amount of perovskite precursor solution was applied by spin coating at 4000 rpm for 20 seconds, or by coating at a speed of 5 mm / s to prepare a wet film. The substrate was then vacuumed for 30 seconds, heated at 1°C / min to 60°C for 10 seconds, then heated at 5°C / min to 140°C for 20 minutes. The substrate was then cooled naturally to obtain the light-absorbing layer. The thickness of the passivation region of the light-absorbing layer was 0.1 nm.

[0096] Example 3

[0097] Similar to Example 1, except that:

[0098] Adjust step (3) of Example 1 to:

[0099] Preparation of perovskite precursor solution: in a 1.2 M FA 0.85 Cs 0.15 1 mg / mL of triphenylamine acetate was added to the PbI3 perovskite precursor solution, stirred, and then sealed for later use.

[0100] Adjust step (4) of Example 1 to:

[0101] Light Absorption Layer Preparation: After UV-ozone treatment for 15 minutes, the NiOx substrate surface was cleaned by air-blowing. An appropriate amount of perovskite precursor solution was applied by spin coating at 4000 rpm for 20 seconds, or by coating at a speed of 5 mm / s to prepare a wet film. The substrate was then vacuumed for 30 seconds, heated at 5°C / min to 50°C for 1 minute, then heated at 10°C / min to 150°C for 10 minutes. The substrate was then cooled naturally to obtain the light absorption layer. The thickness of the passivation region of the light absorption layer was 10 nm.

[0102] Example 4

[0103] Similar to Example 1, except that:

[0104] Adjust step (3) of Example 1 to:

[0105] Preparation of perovskite precursor solution: in a 1.2 M FA 0.85 Cs 0.15 Pb(I 0.95 Br 0.05 )3 Add 2 mg / mL of octyl ammonium chloride to the perovskite precursor solution, stir to prepare a perovskite precursor solution, and seal for later use.

[0106] Adjust step (4) of Example 1 to:

[0107] Light Absorption Layer Preparation: After UV-ozone treatment for 15 minutes, the NiOx substrate surface was cleaned by air-blowing. An appropriate amount of perovskite precursor solution was applied by spin coating at 4000 rpm for 20 seconds, or by coating at a speed of 5 mm / s to prepare a wet film. The substrate was then vacuumed for 30 seconds, heated to 70°C at 3°C / min for 3 minutes, then heated to 150°C at 10°C / min for 15 minutes. The substrate was then cooled naturally to obtain the light absorption layer. The thickness of the passivation region of the light absorption layer was 20 nm.

[0108] Examples 5 to 9

[0109] Similar to Example 1, except that the additives and their concentrations were adjusted, see Table 1.

[0110] Comparative Example 1

[0111] Similar to Example 1, except that:

[0112] Adjust step (3) of Example 1 to:

[0113] Preparation of perovskite precursor solution: in a 1M FA 0.87 Cs 0.1 MA 0.03 No additives were used in the PbI3 perovskite precursor solution.

[0114] Comparative Example 2

[0115] Similar to Example 1, except that:

[0116] Adjust step (3) of Example 1 to:

[0117] Perovskite precursor solution preparation: No additives were used in the FAPbI3 perovskite precursor solution with a concentration of 1 M.

[0118] Adjust step (4) of Example 1 to:

[0119] Preparation of the light-absorbing layer: After UV-ozone treatment for 15 minutes, the NiOx substrate surface was cleaned by air-blowing. A passivation zone was then spin-coated on the NiOx substrate. 0.3 mg / mL of Me-4PACz was added to achieve a passivation zone thickness of 1 nm. An appropriate amount of perovskite precursor solution was then spin-coated at 4000 rpm for 20 seconds, or at a coating speed of 5 mm / s to form a wet film. The solution was then vacuumed for 30 seconds, heated at 10°C / min to 150°C for 15 minutes, and cooled naturally to obtain the light-absorbing layer.

[0120] The battery devices 1 to 11 obtained in the above Examples 1 to 9 and Comparative Examples 1 to 2 were subjected to battery performance tests, and Table 1 was obtained.

[0121] Photoelectric conversion efficiency test method:

[0122] 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).

[0123] Table 1 Battery performance test (IV test)

[0124] It can be seen from the relevant data in Table 1 that the battery devices 1 to 9 of Examples 1 to 9 all use additives in the light absorbing layer, and their photoelectric conversion efficiency is higher than that of Comparative Examples 1 to 2. Among them, Comparative Example 2 uses additives to spin-coat the passivation zone at the lower interface of the light absorbing layer, but does not mix the additives into the perovskite of the light absorbing layer, and its photoelectric conversion efficiency has no obvious advantage. This shows that the present application provides additives in the light absorbing layer, and the additives are mixed with the perovskite, which can compensate for the defect sites in the light absorbing layer, optimize the bulk crystallization of the perovskite, and reduce the defects of the light absorbing layer. At the same time, during the crystallization process of the light absorbing layer, the perovskite crystallization can squeeze a large amount of additives to the lower interface, passivate the lower interface of the light absorbing layer, thereby improving the photoelectric conversion efficiency and stability of the solar cell.

[0125] 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 light absorbing layer, wherein: The light absorbing layer includes a light absorbing material and an additive, the additive includes a first group and a second group, the first group includes at least one of a phenyl group, an alkyl group, an aniline group, and a carbazole group, and the second group includes at least one of a carboxyl group, a phosphate group, and an ammonium group.

2. The solar cell according to claim 1, wherein The light absorbing layer includes a passivation region and a main region. The passivation region is located at the interface of the light absorbing layer toward the light incident side of the solar cell. The content of the additive in the passivation region is greater than the content of the additive in the main region.

3. The solar cell according to claim 1, wherein The light absorbing material includes perovskite.

4. The solar cell according to any one of claims 1 to 3, wherein The thickness of the passivation region is 0.01 to 20 nm.

5. The solar cell according to any one of claims 1 to 4, wherein The mass fraction of the additive in the light absorbing layer is 0.01% to 0.1%.

6. The solar cell according to any one of claims 1 to 5, wherein: The thickness of the light absorbing layer is 150 nm to 600 nm.

7. The solar cell according to any one of claims 1 to 6, wherein: The solar cell further comprises: a first electrode, close to the light incident side; a second electrode, wherein the light absorbing layer is located between the first electrode and the second electrode; a first charge transport layer, located between the first electrode and the light absorbing layer; a second charge transport layer, located between the second electrode and the light absorbing layer; Wherein, one of the first charge transport layer and the second charge transport layer is an electron transport layer, and the other is a hole transport layer.

8. The solar cell according to any one of claims 1 to 7, wherein A hole transport layer is provided on a side of the light absorbing layer facing the light incident side of the solar cell.

9. The solar cell according to any one of claims 1 to 8, wherein The chemical formula of the additive includes at least one of the following:

10. The solar cell according to claim 9, wherein The chemical formula of the additive also includes at least one of the following:

11. A method for preparing a solar cell, wherein: include: Providing a substrate structure, wherein the substrate structure is used to set a light absorbing layer; A mixed solution formed by mixing a perovskite precursor liquid and an additive is placed on the substrate structure, and heat treated to form the light absorption layer, wherein the light absorption layer includes a light absorption material and the additive, and the additive includes a first group and a second group, the first group includes at least one of a phenyl group, an alkyl group, an aniline group, and a carbazole group, and the second group includes at least one of a carboxyl group, a phosphate group, and an ammonium group.

12. The method for preparing a solar cell according to claim 11, wherein: In the mixed solution, the concentration of the additive in the perovskite precursor solution is 0.01 mg / mL to 2 mg / mL.

13. The method for preparing a solar cell according to claim 11 or 12, wherein: During the heat treatment process, the temperature is first raised to 50°C to 90°C at a heating rate of 1°C / min to 10°C / min, kept warm for 0 to 20 minutes, and then raised to 100°C to 150°C, kept warm for 5 to 50 minutes.

14. An electrical device, wherein: The invention comprises a solar cell according to any one of claims 1 to 10 or a solar cell prepared by the method for preparing a solar cell according to any one of claims 11 to 13.

15. A power generation device, wherein: The invention comprises a solar cell according to any one of claims 1 to 10 or a solar cell prepared by the method for preparing a solar cell according to any one of claims 11 to 13.

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