Perovskite solar cells, thin-film composite electrodes and their preparation methods, power generation devices, and power consumption devices.

Abstract

This application discloses a perovskite solar cell, a thin-film composite electrode and its fabrication method, a power generation device, and a power consumption device. The perovskite solar cell sequentially comprises a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a thin-film composite electrode. The thin-film composite electrode includes a first metal layer disposed on the second charge transport layer; a conductive oxide layer disposed on the first metal layer; and a second metal layer disposed on the conductive oxide layer. In the perovskite solar cell of this application embodiment, the thin-film composite electrode is a semi-transparent electrode. The first metal layer is in contact with the charge transport layer, increasing the carrier extraction rate at the interface and reducing the carrier recombination probability at the interface, thereby increasing the open-circuit voltage of the device. The second metal layer can reduce the overall series resistance of the device, increase the fill factor, and ultimately improve the device efficiency, enabling it to have excellent photoelectric performance while maintaining transparency.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a perovskite solar cell, a thin-film composite electrode and its preparation method, a power generation device, and an electrical device. Background Technology

[0002] Perovskite solar cells have attracted widespread attention due to their superior performance. Existing perovskite solar cells generally consist of a charge transport layer and a thin electrode made of a transparent conductive oxide layer adjacent to it. Because the fabrication process of the transparent conductive oxide electrode requires significant energy and can damage the adjacent charge transport layer, a buffer layer made of materials such as molybdenum oxide is often placed between the transparent conductive oxide layer and the charge transport layer. However, the addition of this buffer layer reduces the photoelectric conversion efficiency of the cell and affects its transparency. Summary of the Invention

[0003] In view of the above problems, this application provides a perovskite solar cell, a thin-film composite electrode and its preparation method, a power generation device and a power consumption device, which can provide a semi-transparent thin-film composite electrode. When applied to a perovskite solar cell, the perovskite solar cell can have excellent photoelectric performance while ensuring transparency, thus making it more suitable for practical use.

[0004] In a first aspect, this application provides a perovskite solar cell, which sequentially comprises a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a thin-film composite electrode; the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer; or, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer; the thin-film composite electrode comprises: a first metal layer disposed on the second charge transport layer; a conductive oxide layer disposed on the first metal layer; and a second metal layer disposed on the conductive oxide layer.

[0005] In the technical solution of this application embodiment, the structural design of the perovskite solar cell can obtain a semi-transparent (transmittance ≥50%) perovskite solar device with a first metal layer-conductive oxide layer-second metal layer as a composite electrode. The introduction of the first metal layer on the side of the thin-film composite electrode that contacts the second charge transport layer can increase the carrier extraction rate at the interface, reduce the probability of carrier recombination at the interface, decrease non-radiative recombination, and thus increase the open-circuit voltage of the device. Introducing the second metal layer on the other side of the conductive oxide layer can reduce the overall series resistance of the device, increase the fill factor, and ultimately improve the device efficiency.

[0006] In some embodiments, the metal of the first metal layer is selected from at least one of gold, silver, copper, aluminum, cobalt, and alloys thereof; the metal of the second metal layer is selected from at least one of gold, silver, copper, aluminum, nickel, zinc, tin, iron, and alloys thereof. By defining the materials of the first and second metal layers, better matching of material energy levels can be achieved in the perovskite solar cell, thereby enabling the perovskite solar cell to exhibit good conductivity.

[0007] In some embodiments, the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer. The HOMO energy level order of each layer in the perovskite solar cell is as follows: perovskite absorber layer < second charge transport layer < first metal layer < conductive oxide layer < second metal layer. The perovskite solar cell is a formal device structure, wherein the work function of the first metal layer, conductive oxide layer, and second metal layer are all higher than the HOMO energy level of the second charge transport layer. That is, the work function of the first metal electrode, conductive oxide electrode, and second metal electrode shows a progressively increasing trend, which can ensure the effective transport of charge carriers among the three electrodes. Through the above technical solution, photo-excited holes in the perovskite layer of the perovskite solar cell can be smoothly extracted to the electrode terminals.

[0008] In some embodiments, the work function of the first metal layer is -5.15 to -4.2 eV; the work function of the conductive oxide layer is -5.10 to -4.1 eV; and the work function of the second metal layer is -4.95 to -3.5 eV. Furthermore, the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer increase sequentially. The absolute value of the difference in work function between adjacent layers is 0.02 eV to 0.3 eV. By further defining the work function range of each layer in the thin-film composite electrode, precise material selection of each layer in the thin-film electrode is facilitated. Simultaneously, the range of work function differences between layers is controlled to ensure the smooth extraction and transport of photogenerated carriers, enabling better extraction of photoexcited holes from the perovskite layer to the electrode terminals.

[0009] In some embodiments, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer. The LUMO energy level order of each layer in the perovskite solar cell is as follows: perovskite absorber layer > second charge transport layer > first metal layer > conductive oxide layer > second metal layer. The solar cell is an inverted device structure, wherein the work function of the first metal layer, conductive oxide layer, and second metal layer is lower than the LUMO energy level of the second charge transport layer. That is, the work function of the first metal electrode, conductive oxide electrode, and second metal electrode shows a progressively decreasing trend, which can ensure the effective transport of charge carriers among the three electrodes. Through the above technical solution, photoexcited electrons in the perovskite layer of the perovskite solar cell can be smoothly extracted to the electrode.

[0010] In some embodiments, the work function of the first metal layer is -4.95 to -3.5 eV; the work function of the conductive oxide layer is -5.00 to -3.65 eV; and the work function of the second metal layer is -5.30 to -3.75 eV. Furthermore, the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer decrease in that order. The absolute value of the difference in work function between adjacent layers is 0.02 eV to 0.3 eV. By further defining the work function range of each layer in the thin-film composite electrode, precise material selection of each layer in the thin-film electrode is facilitated. Simultaneously, the range of work function differences between layers is controlled to ensure the smooth extraction and transport of photogenerated carriers, enabling better extraction of photoexcited electrons from the perovskite layer to the electrode terminals.

[0011] In some embodiments, the thickness of the conductive oxide layer is 50–200 nm; the thicknesses of the first metal layer and the second metal layer are both 1–10 nm; and the sum of the thicknesses of the first metal layer and the second metal layer does not exceed 1 / 10 of the thickness of the conductive oxide layer. This technical solution enables the thin-film composite electrode to exert its photoelectric properties by controlling the lower limit of the thickness of each layer; and by controlling the upper limit of the thickness of each layer in the thin-film composite electrode, and strictly limiting the sum of the thicknesses of the first metal layer and the second metal layer to not exceed 1 / 10 of the thickness of the conductive oxide layer, it ensures that the total thickness of the thin-film composite electrode is not too thick, and that the metal layer thickness is relatively thin, thereby avoiding affecting the transparency of the thin-film composite electrode.

[0012] Secondly, this application provides a thin-film composite electrode disposed on a charge transport layer, the thin-film composite electrode comprising: a first metal layer disposed on the charge transport layer; a conductive oxide layer disposed on the first metal layer; and a second metal layer disposed on the conductive oxide layer.

[0013] In the technical solution of this application embodiment, the structural design of the thin-film composite electrode can obtain a semi-transparent (transmittance ≥50%) solar cell device without increasing the electrode contact resistance or raising the electrode deposition temperature. Introducing a first metal layer on the side of the thin-film composite electrode that contacts the charge transport layer can also increase the carrier extraction rate at the interface, reduce the probability of carrier recombination at the interface, decrease non-radiative recombination, and thus increase the open-circuit voltage of the device. Introducing a second metal layer on the other side of the conductive oxide layer can reduce the overall series resistance of the device, increase the fill factor, and ultimately improve the device efficiency.

[0014] In some embodiments, the thickness of the conductive oxide layer is 50–200 nm; the thicknesses of the first metal layer and the second metal layer are both 1–10 nm; and the sum of the thicknesses of the first metal layer and the second metal layer does not exceed 1 / 10 of the thickness of the conductive oxide layer. The thickness of the metal electrode affects the overall transmittance of the device. When the total thickness of the metal electrode is too thick, the transmittance of the device will be significantly reduced, making it unable to meet the application requirements of a semi-transparent device. Furthermore, by controlling the thickness of the metal layer in the thin-film composite electrode to be relatively thin, specifically, when the ratio of the total thickness of the metal electrode to the thickness of the conductive transparent electrode is <1 / 10, the device exhibits a semi-transparent state, and the photoelectric conversion efficiency of the thin-film composite electrode will be improved to a certain extent. This technical solution enables the thin-film composite electrode to exert its photoelectric properties by controlling the lower limit of the thickness of each layer in the thin-film composite electrode; by controlling the upper limit of the thickness of each layer in the thin-film composite electrode, and strictly limiting the sum of the thickness of the first metal layer and the second metal layer to no more than 1 / 10 of the thickness of the conductive oxide layer, the total thickness of the thin-film composite electrode is ensured not to be too thick, and the metal layer thickness is relatively thin, thereby avoiding affecting the transparency of the thin-film composite electrode.

[0015] In some embodiments, the thickness of the conductive oxide layer is 100–150 nm. By further limiting the thickness of the conductive oxide layer, a better balance can be achieved between the photoelectric properties and transparency of the thin-film composite electrode, ensuring that the conductivity is at a good level while maintaining the semi-transparency of the thin-film composite electrode.

[0016] Thirdly, this application provides a method for preparing a thin-film composite electrode according to the foregoing, wherein the thin-film composite electrode is disposed on a charge transport layer; the method includes the following steps:

[0017] 1) A first metal layer is disposed on the charge transport layer;

[0018] 2) A conductive oxide layer is disposed on the first metal layer;

[0019] 3) A second metal layer is disposed on the conductive oxide.

[0020] The technical solution of this application embodiment obtains a composite transparent electrode with a metal layer-transparent conductive oxide layer-metal layer structure by successively setting a first metal layer, a conductive oxide layer and a second metal layer on the charge transport layer.

[0021] In some embodiments, the first metal layer is prepared by vapor deposition, with a vacuum degree ≤5×10⁻⁶. -4 Pa, temperature ≤100℃, velocity ≤0.1A / s; the conductive oxide layer is prepared by vacuum sputtering or vacuum evaporation, with a vacuum degree ≤5×10 -4 Pa, velocity 0.1 A / s to 1 A / s; the second metal layer is prepared by vacuum sputtering or vacuum evaporation, with a vacuum degree ≤ 5 × 10⁻⁶. -4 Pa, with a rate of 0.1–0.5 A / s; it also includes the following steps: between step 1) and step 2), vacuum is maintained and the temperature is lowered to room temperature; steps 2) and 3) are continuous steps, and vacuum is maintained. By strictly limiting the preparation process of the first metal layer, the conductive oxide layer, and the second metal layer, and by strictly limiting that the vacuum between the conductive oxide layer and the first metal layer cannot be broken, and that the evaporation must be stopped for a period of time, and that the vacuum between the second metal layer and the conductive oxide layer cannot be broken, the metal-conductive oxide-metal composite electrode required by the technical solution of the present invention is obtained, which can be semi-transparent and the interlayer is not easy to peel off.

[0022] Fourthly, this application provides a power generation device that includes the perovskite solar cell described in the above embodiments.

[0023] Fifthly, this application provides an electrical device comprising a perovskite solar cell as described above, the perovskite solar cell being used to provide electrical energy.

[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0026] Figure 1 These are schematic diagrams of the structure of perovskite solar cells according to some embodiments of this application;

[0027] Figure 2 This is a schematic diagram of a thin-film composite electrode according to some embodiments of this application;

[0028] Figure 3 This is a schematic diagram of the energy levels of a formal device of a perovskite solar cell according to some embodiments of this application;

[0029] Figure 4 This is a schematic diagram of the energy levels of a perovskite solar cell inverted device according to some embodiments of this application;

[0030] Figure 5 These are open-circuit voltage performance diagrams of perovskite solar cells according to some embodiments of this application;

[0031] Figure 6 These are short-circuit current performance diagrams of perovskite solar cells according to some embodiments of this application;

[0032] Figure 7 This is a fill factor performance diagram of some embodiments of perovskite solar cells in this application;

[0033] Figure 8 These are power conversion efficiency performance diagrams of perovskite solar cells according to some embodiments of this application.

[0034] The reference numerals in the detailed embodiments are as follows:

[0035] Thin film composite electrode 1; second charge transport layer 2, perovskite absorber layer 3, first charge transport layer 4, transparent conductive glass 5; first metal layer 11, conductive oxide layer 12, second metal layer 13. Detailed Implementation

[0036] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0038] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0042] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0043] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0044] In the prior art, perovskite solar cells have attracted widespread attention due to their good performance. However, existing perovskite solar cells generally include a charge transport layer and a thin electrode made of transparent conductive oxide adjacent to it. Since the fabrication process of the transparent conductive oxide electrode requires a large amount of energy, it can damage the adjacent charge transport layer. Therefore, a buffer layer made of materials such as molybdenum oxide is needed between the transparent conductive oxide layer and the charge transport layer.

[0045] The inventors have noticed that placing a buffer layer between the charge transport layer and the electrode layer may reduce the photoelectric conversion efficiency of the battery and affect the battery's transparency.

[0046] To address the aforementioned issues, the applicant discovered that by depositing a first metal layer on the surface of a charge transport layer, then depositing a conductive oxide layer on the first metal layer, and finally depositing a second metal layer on the conductive oxide layer, a semi-transparent thin-film composite electrode is obtained, which ensures both transparency and high photoelectric conversion efficiency.

[0047] The thin-film composite electrode disclosed in this application can be applied to perovskite solar cells. The perovskite solar cell sequentially comprises a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a thin-film composite electrode. The first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer; or, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer. The thin-film composite electrode comprises: a first metal layer disposed on the second charge transport layer; a conductive oxide layer disposed on the first metal layer; and a second metal layer disposed on the conductive oxide layer. Through the above technical solution, a semi-transparent perovskite solar cell device with a first metal layer-conductive oxide layer-second metal layer as the composite electrode can be obtained, possessing both a certain degree of transparency and good photoelectric conversion efficiency.

[0048] The thin-film composite electrode disclosed in this application is fabricated by depositing the thin-film composite electrode on a charge transport layer. The process includes the following steps: 1) depositing a first metal layer on the charge transport layer; 2) depositing a conductive oxide layer on the first metal layer; and 3) depositing a second metal layer on the conductive oxide layer. This technical solution yields a composite transparent electrode with a metal layer-transparent conductive oxide layer-metal layer structure. This thin-film composite electrode ensures both transparency and high photoelectric conversion efficiency.

[0049] The perovskite solar cells disclosed in this application can be used in power generation devices, ensuring the transparency of the power generation device while also enabling it to have high photoelectric conversion efficiency. They can be applied to application scenarios that require both transparency and conductivity.

[0050] The perovskite solar cells disclosed in this application can be used in batteries for electrical devices, which include the perovskite solar cells described above. These perovskite solar cells are used to provide electrical energy and can be applied in application scenarios that require both transparency and conductivity.

[0051] For ease of explanation, the following embodiments use a thin-film composite electrode and a perovskite solar cell from one embodiment of this application as examples.

[0052] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a perovskite solar cell according to some embodiments of this application. For example... Figure 1 As shown, the perovskite solar cell has a layered structure, comprising a transparent conductive glass 5, a first charge transport layer 4, a perovskite absorber layer 3, a second charge transport layer 2, and a thin-film composite electrode 1 arranged sequentially; the first charge transport layer 4 is an electron transport layer, and the second charge transport layer 2 is a hole transport layer; or, the first charge transport layer 4 is a hole transport layer, and the second charge transport layer 2 is an electron transport layer; the thin-film composite electrode 1 comprises: a first metal layer 11 disposed on the second charge transport layer 2; a conductive oxide layer 12 disposed on the first metal layer 11; and a second metal layer 13 disposed on the conductive oxide layer 12.

[0053] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a thin-film composite electrode provided in some embodiments of this application. For example... Figure 2 As shown, the thin-film composite electrode has a three-layer structure, with metal layers on both sides and a conductive oxide layer in the middle. The metal layer-conductive oxide layer-metal layer form a three-layer composite thin-film electrode. In application, one of the metal layers is disposed on the charge transport layer.

[0054] According to some embodiments of this application, this application provides a thin-film composite electrode disposed on a charge transport layer. The thin-film composite electrode includes: a first metal layer disposed on the charge transport layer; a conductive oxide layer disposed on the first metal layer; and a second metal layer disposed on the conductive oxide layer.

[0055] The structural design of the thin-film composite electrode allows for the production of semi-transparent solar cell devices without increasing electrode contact resistance or raising electrode deposition temperature. Introducing a first metal layer on the side of the thin-film composite electrode that contacts the charge transport layer enhances the carrier extraction rate at the interface, reducing the probability of carrier recombination and minimizing non-radiative recombination, thereby increasing the open-circuit voltage of the device. Introducing a second metal layer on the other side of the conductive oxide layer reduces the overall series resistance of the device, improves the fill factor, and ultimately enhances the device efficiency.

[0056] According to some embodiments of this application, preferably, the thin-film composite electrode is directly disposed on the charge transport layer, and the thin-film composite electrode includes: a first metal layer directly disposed on the charge transport layer; a conductive oxide layer directly disposed on the first metal layer; and a second metal layer directly disposed on the conductive oxide layer.

[0057] According to some embodiments of this application, preferably, a modification layer is disposed between the charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer.

[0058] According to some embodiments of this application, the metal of the first metal layer is selected from at least one of gold, silver, copper, aluminum, cobalt and their alloys; the material of the conductive oxide layer is at least one of indium oxide doped with tin, indium oxide doped with tungsten, tin oxide doped with fluorine, zinc oxide doped with aluminum, indium zinc oxide, and zinc tin oxide; the metal of the second metal layer is selected from at least one of gold, silver, copper, aluminum, nickel, zinc, tin, iron and their alloys.

[0059] According to some embodiments of this application, preferably, the thickness of the conductive oxide layer is 50–200 nm; the thickness of both the first metal layer and the second metal layer is 1–10 nm; and the sum of the thicknesses of the first metal layer and the second metal layer does not exceed 1 / 10 of the thickness of the conductive oxide layer. The thickness of the metal electrode affects the overall transmittance of the device. When the total thickness of the metal electrode is too thick, it will significantly reduce the transmittance of the device, making it unable to meet the application requirements of a semi-transparent device. Furthermore, controlling the thickness of the metal layer in the thin-film composite electrode to be relatively thin, specifically, when the ratio of the total thickness of the metal electrode to the thickness of the conductive transparent electrode is <1 / 10, the device exhibits a semi-transparent state, and the photoelectric conversion efficiency of the thin-film composite electrode will be improved to a certain extent. This technical solution enables the thin-film composite electrode to exert its photoelectric properties by controlling the lower limit of the thickness of each layer in the thin-film composite electrode; by controlling the upper limit of the thickness of each layer in the thin-film composite electrode, and strictly limiting the sum of the thickness of the first metal layer and the second metal layer to no more than 1 / 10 of the thickness of the conductive oxide layer, the total thickness of the thin-film composite electrode is ensured not to be too thick, and the metal layer thickness is relatively thin, thereby avoiding affecting the transparency of the thin-film composite electrode.

[0060] According to some embodiments of this application, preferably, the thickness of the conductive oxide layer is 100–150 nm. By further limiting the thickness of the conductive oxide layer, a better balance can be achieved between the photoelectric properties and transparency of the thin-film composite electrode, ensuring that the conductivity is at a good level while maintaining the semi-transparency of the thin-film composite electrode.

[0061] According to some embodiments of this application, this application provides a perovskite solar cell, which sequentially includes a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a thin-film composite electrode; the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer; or, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer; the thin-film composite electrode includes: a first metal layer disposed on the second charge transport layer; a conductive oxide layer disposed on the first metal layer; and a second metal layer disposed on the conductive oxide layer.

[0062] The structural design of the perovskite solar cell can yield a semi-transparent perovskite solar device with a first metal layer-conductive oxide layer-second metal layer as a composite electrode.

[0063] According to some embodiments of this application, preferably, a first metal layer is directly disposed on the second charge transport layer, a conductive oxide layer is directly disposed on the first metal layer, and a second metal layer is directly disposed on the conductive oxide layer.

[0064] According to some embodiments of this application, preferably, a corresponding modification layer can be inserted between each of the transparent conductive glass, the first charge transport layer, the perovskite absorber layer, the second charge transport layer, and the thin-film composite electrode layer to improve the performance of the perovskite solar cell. The transparent conductive glass serves as the light-receiving surface of the perovskite solar cell.

[0065] According to some embodiments of this application, preferably, the metal of the first metal layer is selected from at least one of gold, silver, copper, aluminum, and cobalt, and alloys thereof; the metal of the second metal layer is selected from at least one of gold, silver, copper, aluminum, nickel, zinc, tin, and iron, and alloys thereof. By defining the materials of the first metal layer and the second metal layer, better matching of material energy levels can be achieved in the perovskite solar cell, thereby enabling the perovskite solar cell to exhibit good conductivity.

[0066] According to some embodiments of this application, preferably, the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer; the HOMO energy level order of each layer in the perovskite solar cell is as follows: perovskite absorber layer < second charge transport layer < first metal layer < conductive oxide layer < second metal layer. The perovskite solar cell is a formal device structure, wherein the work function of the first metal layer, conductive oxide layer, and second metal layer are all higher than the HOMO energy level of the second charge transport layer. That is, the work function of the first metal electrode, conductive oxide electrode, and second metal electrode shows a progressively increasing trend, which can ensure the effective transport of charge carriers among the three electrodes. Through the above technical solution, photo-excited holes in the perovskite layer of the perovskite solar cell can be smoothly extracted to the electrode terminals.

[0067] According to some embodiments of this application, preferably, the work function of the first metal layer is -5.15 to -4.2 eV; the work function of the conductive oxide layer is -5.10 to -4.1 eV; and the work function of the second metal layer is -4.95 to -3.5 eV; and the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer increase sequentially; the absolute value of the difference in work function between adjacent layers is 0.02 eV to 0.3 eV. By further limiting the work function range of each layer in the thin film composite electrode, the precise selection of materials for each layer in the thin film electrode is facilitated, while controlling the range of work function differences between layers ensures the smooth extraction and transport of photogenerated charge carriers, enabling better extraction of photoexcited holes from the perovskite layer to the electrode electrode.

[0068] According to some embodiments of this application, preferably, the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer; the LUMO energy level order of each layer in the perovskite solar cell is as follows: perovskite absorber layer > second charge transport layer > first metal layer > conductive oxide layer > second metal layer. The solar cell has an inverted device structure, wherein the work function of the first metal layer, conductive oxide layer, and second metal layer is lower than the LUMO energy level of the second charge transport layer. That is, the work function of the first metal electrode, conductive oxide electrode, and second metal electrode shows a progressively decreasing trend, which can ensure effective carrier transport between the three electrodes. Through the above technical solution, photoexcited electrons in the perovskite layer of the perovskite solar cell can be smoothly extracted to the electrode terminals.

[0069] According to some embodiments of this application, preferably, the work function of the first metal layer is -4.95 to -3.5 eV; the work function of the conductive oxide layer is -5.00 to -3.65 eV; and the work function of the second metal layer is -5.30 to -3.75 eV. Furthermore, the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer decrease in that order. The absolute value of the difference in work function between adjacent layers is 0.02 eV to 0.3 eV. By further defining the work function range of each layer in the thin-film composite electrode, precise material selection of each layer in the thin-film electrode is facilitated. Simultaneously, the range of work function differences between layers is controlled to ensure the smooth extraction and transport of photogenerated carriers, enabling better extraction of photoexcited electrons from the perovskite layer to the electrode terminals.

[0070] The terms HOMO and LUMO are abbreviations for Highest Occupied Molecular Orbital, referring to the highest occupied molecular orbital. The energy difference between HOMO and LUMO is called the "band gap," also known as the HOMO-LUMO energy level. This energy difference can sometimes be used to measure how easily a molecule can be excited; the smaller the band gap, the easier it is for the molecule to be excited. In organic semiconductors and quantum dots, HOMO is similar to the valence band in inorganic semiconductors, while LUMO is similar to the conduction band. The HOMO energy level refers to the top of the VBM valence band. The LUMO energy level refers to the bottom of the CBM conduction band.

[0071] For semiconductors, the work function refers to the minimum energy required for an electron to immediately escape from a stationary body; it is an inherent property and intrinsic characteristic of the material itself. Within the thin-film composite electrode, the energy levels between adjacent layers must maintain a certain difference. When the absolute value of the energy level difference is less than 0.02 eV, the built-in electric field of the electrode cannot be formed, preventing charge transfer in a specific direction; while when the absolute value of the energy level difference is greater than 0.3 eV, it will cause a significant voltage drop, which is detrimental to improving device performance.

[0072] According to some embodiments of this application, preferably, the thickness of the conductive oxide layer is 50–200 nm; the thickness of both the first metal layer and the second metal layer is 1–10 nm; and the sum of the thicknesses of the first metal layer and the second metal layer does not exceed 1 / 10 of the thickness of the conductive oxide layer. This technical solution, by controlling the lower limit of the thickness of each layer in the thin-film composite electrode, enables it to exert its photoelectric properties; by controlling the upper limit of the thickness of each layer in the thin-film composite electrode, and strictly limiting the total thickness of the first metal layer and the second metal layer to not exceed 1 / 10 of the thickness of the conductive oxide layer, it ensures that the total thickness of the thin-film composite electrode is not too thick, and that the metal layer thickness is relatively thin, thereby avoiding affecting the transparency of the thin-film composite electrode.

[0073] According to some embodiments of this application, the perovskite solar cell is a semi-transparent cell. This is because its total thickness is 52-220 nm, and the sum of the thicknesses of the first metal layer and the second metal layer is specifically limited to not exceeding 1 / 10 of the thickness of the conductive oxide layer. That is, the sum of the thicknesses of the metal layers in the thin-film composite electrode of this invention does not exceed 20 nm. Therefore, the transparency of the conductive oxide layer will not be significantly affected, allowing it to have semi-transparent characteristics and be used in glass devices.

[0074] According to some embodiments of this application, the material of the transparent conductive glass is selected from at least one of fluorine-doped indium oxide, indium-doped tin oxide, aluminum-doped zinc oxide, beryllium-doped zinc oxide, and indium-doped zinc oxide.

[0075] According to some embodiments of this application, the chemical formula of the perovskite light-absorbing layer is ABX3 or A2CDX6, where A represents a monovalent inorganic cation and / or an organic cation, B represents a divalent metal cation, C represents a monovalent metal cation, D represents a trivalent metal cation, and X represents an inorganic anion and / or an organic anion.

[0076] According to some embodiments of this application, the divalent metal cation is lead ion or tin ion.

[0077] According to some embodiments of this application, the perovskite light-absorbing layer has a band gap of 1.20–2.30 eV and a thickness of 200–1000 nm.

[0078] According to some embodiments of this application, the electron transport layer is selected from [6,6]-phenylC 61 Methyl butyrate, [6,6]-phenyl C 71 At least one of methyl butyrate, fullerene C60, fullerene C70, tin dioxide and zinc oxide, as well as derivatives of the above materials or materials modified by doping or passivation of the above materials.

[0079] According to some embodiments of this application, the hole transport layer is selected from at least one of 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirobisfluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], methoxytriphenylamine-fluoroformamidinium, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonium), poly-3-hexylthiophene, cuprous thiocyanate, nickel oxide, triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobisfluorene (CzPAF-SBF), and polythiophene, as well as derivatives of the above materials or materials modified by doping or passivation of the above materials.

[0080] According to some embodiments of this application, the material of the conductive oxide layer is at least one of tin-doped indium oxide, tungsten-doped indium oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, indium zinc oxide, and zinc tin oxide.

[0081] According to some embodiments of this application, this application provides a method for preparing a thin-film composite electrode as described above, wherein the thin-film composite electrode is disposed on a charge transport layer; the method includes the following steps:

[0082] 1) A first metal layer is disposed on the charge transport layer;

[0083] 2) A conductive oxide layer is disposed on the first metal layer;

[0084] 3) A second metal layer is disposed on the conductive oxide.

[0085] The technical solution of this application embodiment obtains a composite transparent electrode with a metal layer-transparent conductive oxide layer-metal layer structure by successively setting a first metal layer, a conductive oxide layer and a second metal layer on the charge transport layer.

[0086] According to some embodiments of this application, preferably, the first metal layer is prepared by vapor deposition, with a vacuum degree ≤ 5 × 10⁻⁶. -4Pa, temperature ≤100℃, velocity ≤0.1A / s; the conductive oxide layer is prepared by vacuum sputtering or vacuum evaporation, with a vacuum degree ≤5×10 -4 Pa, velocity 0.1 A / s to 1 A / s; the second metal layer is prepared by vacuum sputtering or vacuum evaporation, with a vacuum degree ≤ 5 × 10⁻⁶. -4 Pa, with a rate of 0.1–0.5 A / s; it also includes the following steps: between step 1) and step 2), vacuum is maintained and the temperature is lowered to room temperature; steps 2) and 3) are continuous steps, and vacuum is maintained. By strictly limiting the preparation process of the first metal layer, the conductive oxide layer, and the second metal layer, and by strictly limiting that the vacuum between the conductive oxide layer and the first metal layer cannot be broken, and that the evaporation must be stopped for a period of time, and that the vacuum between the second metal layer and the conductive oxide layer cannot be broken, the metal-conductive oxide-metal composite electrode required by the technical solution of the present invention is obtained, which can be semi-transparent and the interlayer is not easy to peel off.

[0087] The present application will be further described below with reference to specific embodiments.

[0088] Performance testing of perovskite solar cells:

[0089] Under standard simulated sunlight (AM 1.5G, 100mW / cm²) 2 Under irradiation, the battery performance was tested, and the IV curve was obtained.

[0090] Based on the IV curve and the data fed back by the testing equipment, the short-circuit current Jsc (unit mA), open-circuit voltage Voc (unit V), maximum optical output current Jmpp (unit mA), and maximum optical output voltage Vmpp (unit V) can be obtained.

[0091] The fill factor FF of the battery is calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp), in percent.

[0092] The photoelectric conversion efficiency (PCE) of the battery is calculated using the formula PCE = Jsc × Voc × FF / Pw, with the unit being %; Pw represents the input power, with the unit being mW.

[0093] To facilitate performance comparison, this invention uses the corresponding comparative values ​​of each embodiment as a standard and normalizes parameters such as short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency. This allows for a direct comparison of the improvements in device parameters and performance.

[0094] Example 1

[0095] Take a piece of ITO (indium tin oxide) conductive glass with a size of 2.0cm × 2.0cm, with no thickness limit; use laser etching to remove 0.35cm wide ITO layers from each of the opposite sides of the surface of the glass containing the ITO layer, exposing the glass substrate;

[0096] The etched ITO conductive glass was ultrasonically cleaned sequentially with water, acetone, and isopropanol, and the cleaning process was repeated at least twice.

[0097] The residual solvent on the surface of the ITO conductive glass is dried by blowing it with a nitrogen gun, and then the ITO conductive glass is placed in an ultraviolet ozone generator for further cleaning; the cleaning time is 5 to 30 minutes, and there is no specific limit.

[0098] Prepare an isopropanol solution of PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] with a mass-volume concentration of 2 mg / mL, that is, 2 mg of solute is dissolved in each milliliter of solvent;

[0099] The above-prepared PTAA solution was spin-coated onto an ITO conductive glass substrate treated with an ultraviolet ozone generator at a rate of 5000 rpm / s, and then annealed on a hot stage at 100°C for 10 minutes; the PTAA layer is the organic hole transport layer.

[0100] On the organic hole transport layer prepared above, a perovskite precursor solution was spin-coated at a rate of 1000–5000 rpm / s, followed by annealing at 100°C for 30 min and cooling to room temperature; wherein, the active material of the perovskite absorber layer is CsFAMA, and its specific composition is Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 PbI 0.93 Br 0.07 The concentration is 1.4 mol / L, and the solvent is a mixture of DMF (dimethylformamide) and DMSO (dimethyl sulfoxide) in a volume ratio of 4:1; the CsFAMA layer is a perovskite layer;

[0101] PC was spin-coated onto the perovskite layer prepared above at a rate of 1000–1500 rpm / s. 61 BM([6,6]-phenylC) 61 Methyl butyrate), then annealed at 100°C for 10 min, followed by spin coating with BCP (bath copper ester) at a rate of 5000 rpm / s; wherein, PC 61 The mass-volume concentration of BM is 20 mg / mL, meaning 20 mg of solute is dissolved in each milliliter of solvent; the solvent is chlorobenzene; the mass-volume concentration of BCP is 0.5 mg / mL, meaning 0.5 mg of solute is dissolved in each milliliter of solvent; the solvent is isopropanol; the PC... 61The BM layer is the electron transport layer; the BCP layer is the passivation layer; the work function of the second charge transport layer is -4.40 eV;

[0102] The prepared thin film was placed in a vapor deposition machine, and the vapor deposition vacuum was allowed to reach 5 × 10⁻⁶. -4 At a pressure below Pa, a 2 nm thick Cu metal electrode (work function -4.65 eV) is deposited at a rate of 0.1 A / s at a temperature of 30–50 °C. Maintaining this vacuum level, the electrode is cooled to room temperature. Then, using radio frequency magnetron sputtering, a 100 nm thick conductive oxide film is formed by sputtering tin-doped indium oxide (InO), a transparent conductive oxide. The work function of the tin-doped InO is -4.85 eV. Finally, maintaining this vacuum level, a 5 nm thick Au metal electrode (work function -5.1 eV) is deposited on the tin-doped InO transparent conductive oxide film at a rate of 0.2 A / s using either evaporation or sputtering, thus forming a complete composite thin-film electrode.

[0103] The perovskite solar cell obtained through the above steps is labeled as cell 1#. A schematic diagram of the energy levels of the perovskite light-absorbing layer, the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer in cell 1# is attached. Figure 3 As shown in Table 1, the photoelectric performance results of battery 1# are shown in Table 2, and its transparency data are shown in Table 2.

[0104] Example 2

[0105] Take a piece of ITO (indium tin oxide) conductive glass with a size of 2.0cm × 2.0cm, with no thickness limit; use laser etching to remove 0.35cm wide ITO layers from each of the opposite sides of the surface of the glass containing the ITO layer, exposing the glass substrate;

[0106] The etched ITO conductive glass was ultrasonically cleaned sequentially with water, acetone, and isopropanol, and the cleaning process was repeated at least twice.

[0107] The residual solvent on the surface of the ITO conductive glass is dried by blowing it with a nitrogen gun, and then the ITO conductive glass is placed in an ultraviolet ozone generator for further cleaning; the cleaning time is 5 to 30 minutes, and there is no specific limit.

[0108] Purchase commercially available SnO2 (tin dioxide) aqueous solution, Alfa brand, 15% aqueous colloidal dispersion; dilute it with 3 times the amount of distilled water and set aside.

[0109] On an ITO conductive glass substrate treated with ultraviolet ozone, at a rotation speed of 4000 rpm / s and 2000 rpm / s 2 The diluted SnO2 aqueous solution was spin-coated with an acceleration and then heated at 150°C for 15 min; the SnO2 layer is the electron transport layer.

[0110] On the electron transport layer prepared above, a perovskite precursor solution was spin-coated at a rate of 1000–4000 rpm / s, followed by annealing at 100°C for 30 min and cooling to room temperature; wherein, the active material of the perovskite absorber layer is CsFAMA, and its specific composition is Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 PbI 0.93 Br 0.07 The concentration is 1.4 mol / L, and the solvent is a mixture of DMF (dimethylformamide) and DMSO (dimethyl sulfoxide) in a volume ratio of 4:1; the CsFAMA layer is the perovskite layer.

[0111] On the perovskite layer prepared above, a hole transport layer Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene) was spin-coated at a rate of 3000 rpm / s using chlorobenzene as the solvent, with a mass-volume concentration of 72.3 mg / mL, meaning that 72.3 mg of solute was dissolved in each milliliter of solvent; the work function of the hole transport layer was -5.15 eV.

[0112] The prepared thin film was placed in a vapor deposition machine, and the vapor deposition vacuum was allowed to reach 5 × 10⁻⁶. -4 At a vacuum level below Pa, a 2 nm thick metal electrode Au (work function -5.1 eV) is deposited at a rate of 0.1 A / s at a deposition temperature of 30–50 °C. Maintaining this vacuum level, the electrode is cooled to room temperature. Then, using radio frequency magnetron sputtering, a transparent conductive oxide film of tin-doped indium oxide is sputtered to form a conductive oxide film with a thickness of 100 nm. The work function of the tin-doped indium oxide is -4.85 eV. Finally, maintaining this vacuum level, a metal electrode Ag (work function -4.6 eV) is deposited on the tin-doped indium oxide transparent conductive oxide film at a rate of 0.2 A / s using either evaporation or sputtering, with a thickness of 5 nm, thus forming a complete composite thin-film electrode.

[0113] The perovskite solar cell obtained through the above steps is labeled as cell 2#. A schematic diagram of the energy levels of the perovskite light-absorbing layer, the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer in cell 2# is attached. Figure 4 As shown in Table 1, the photoelectric performance results of battery #2 are shown in Table 2, and its transparency data are shown in Table 2.

[0114] Example 3

[0115] The fabrication process is the same as in Example 2, wherein the first metal layer is a 2nm thick cobalt layer (work function -5.0eV), the conductive oxide layer is a 100nm thick tin-doped indium oxide layer (work function -4.85eV), and the second metal layer is a 5nm thick nickel layer (work function -4.6eV). The photoelectric performance results of the battery obtained from this example are shown in Table 1, and the transparency data are shown in Table 2.

[0116] Examples 4 to 7

[0117] The preparation process is the same as in Example 2. The metal layer material and the thickness data of each layer are shown in Table 3 below. The photoelectric performance results of the obtained battery are shown in Table 1, and the transparency data are shown in Table 2.

[0118] Comparative Example 1

[0119] Similar to Example 1, except that in the final electrode fabrication, a 10 nm thick layer of molybdenum oxide was first thermally deposited as a buffer layer during the magnetron sputtering process, followed by direct sputtering of a 107 nm tin-doped indium oxide layer. The work function of the tin-doped indium oxide was -4.85 eV. The resulting perovskite solar cell was labeled as cell 1′#. The transparency data of cell 1′# is shown in Table 3, and its photoelectric properties have been normalized.

[0120] Comparative Example 2

[0121] Similar to Example 2, except that in the final electrode fabrication, a 10 nm thick layer of molybdenum oxide was first thermally deposited as a buffer layer during the magnetron sputtering process, followed by direct sputtering of a 107 nm tin-doped indium oxide layer. The work function of the tin-doped indium oxide was -4.85 eV. The resulting perovskite solar cell was labeled as cell 2′#. The transparency data of cell 2′# is shown in Table 3, and its photoelectric properties have been normalized.

[0122] The photoelectric performance results of batteries 1#, 2#, 1′#, and 2′ are attached. Figure 5 To be continued Figure 8 As shown.

[0123] Comparative Examples 3-7

[0124] Similar to Examples 3-7, except that in the final electrode preparation, a 10 nm thick molybdenum oxide layer is first thermally evaporated as a buffer layer during the magnetron sputtering process, and then the tin-doped indium oxide layer is sputtered directly. The work function of the tin-doped indium oxide is -4.85 eV. The thickness of the conductive oxide layer is the same as the total thickness of "metal layer-conductive oxide layer-metal layer" in Examples 3-7. The transparency data of the obtained perovskite solar cells are shown in Table 2, and their photoelectric properties are all normalized.

[0125] Table 1

[0126]

[0127] Table 2

[0128] Light transmittance Light transmittance Example 1 58.3％ Comparative Example 1 57.1％ Example 2 56.1％ Comparative Example 2 54.3％ Example 3 55.7％ Comparative Example 3 54.3％ Example 4 62.3％ Comparative Example 4 60.2％ Example 5 52.1％ Comparative Example 5 51.4％ Example 6 55.4％ Comparative Example 6 51.9％ Example 7 53.9％ Comparative Example 7 52.6％

[0129] Table 3

[0130]

[0131] The test results of Examples 1 to 7 and Comparative Examples 1 to 7 show that the performance of the "semi-transparent perovskite solar cell based on a metal-conductive oxide-metal composite electrode" is significantly better than that of the blank conductive oxide-based cell. This is manifested in two aspects: firstly, better light transmittance, maintaining its semi-transparent effect; and secondly, improved overall photoelectric performance. This is mainly due to the introduction of the first metal layer, i.e., the first metal electrode, which increases the carrier transport rate between the charge transport layer and the thin-film composite electrode; and the introduction of the second metal electrode, located on the other side of the conductive oxide layer, which reduces the overall series resistance of the device. These factors contribute to an increase in the device's turn-on voltage and fill factor, thereby improving the cell efficiency.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A perovskite solar cell, characterized in that, It sequentially comprises a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a thin-film composite electrode; the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer; or, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer; the thin-film composite electrode includes: A first metal layer is disposed on the second charge transport layer; A conductive oxide layer is disposed on the first metal layer; A second metal layer is disposed on the conductive oxide layer; When the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer, the HOMO energy level order of each layer in the perovskite solar cell is as follows: perovskite absorber layer < second charge transport layer < first metal layer < conductive oxide layer < second metal layer. Alternatively, if the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer, the LUMO energy level order of each layer in the perovskite solar cell is as follows: perovskite absorber layer > second charge transport layer > first metal layer > conductive oxide layer > second metal layer.

2. The perovskite solar cell according to claim 1, characterized in that, The metal of the first metal layer is selected from at least one of gold, silver, copper, aluminum, cobalt and their alloys; the metal of the second metal layer is selected from at least one of gold, silver, copper, aluminum, nickel, zinc, tin, iron and their alloys.

3. The perovskite solar cell according to claim 1, characterized in that, When the first charge transport layer is an electron transport layer and the second charge transport layer is a hole transport layer, the work function of the first metal layer is -5.15 ~ -4.2 eV; the work function of the conductive oxide layer is -5.10 ~ -4.1 eV; the work function of the second metal layer is -4.95 ~ -3.5 eV; and the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer increase sequentially; the absolute value of the difference in work function values ​​between two adjacent layers is 0.02 eV ~ 0.3 eV.

4. The perovskite solar cell according to claim 1, characterized in that, When the first charge transport layer is a hole transport layer and the second charge transport layer is an electron transport layer, the work function of the first metal layer is -4.95 ~ -3.5 eV; the work function of the conductive oxide layer is -5.00 ~ -3.65 eV; the work function of the second metal layer is -5.30 ~ -3.75 eV; and the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer decrease in that order; the absolute value of the difference in work function values ​​between adjacent layers is 0.02 eV ~ 0.3 eV.

5. The perovskite solar cell according to claim 1, characterized in that, The thickness of the conductive oxide layer is 50~200nm; the thickness of the first metal layer and the second metal layer is 1~10nm; the sum of the thicknesses of the first metal layer and the second metal layer does not exceed 1 / 10 of the thickness of the conductive oxide layer.

6. A thin-film composite electrode, characterized in that, The thin-film composite electrode, disposed on the charge transport layer, comprises: A first metal layer is disposed on the charge transport layer; A conductive oxide layer is disposed on the first metal layer; A second metal layer is disposed on the conductive oxide layer; The thickness of the conductive oxide layer is 100~150nm; the thickness of the first metal layer and the second metal layer is 1~10nm; the sum of the thicknesses of the first metal layer and the second metal layer does not exceed 1 / 10 of the thickness of the conductive oxide layer.

7. A method for preparing a thin-film composite electrode according to claim 6, characterized in that, The thin-film composite electrode is disposed on the charge transport layer; It includes the following steps: 1) A first metal layer is disposed on the charge transport layer; 2) A conductive oxide layer is disposed on the first metal layer; 3) A second metal layer is disposed on the conductive oxide.

8. The preparation method according to claim 7, characterized in that, The first metal layer is prepared by vapor deposition, with a vacuum degree ≤5×10 -4 Pa, temperature ≤100℃, velocity ≤0.1A / s; the conductive oxide layer is prepared by vacuum sputtering or vacuum evaporation, with a vacuum degree ≤5×10 -4 Pa, velocity 0.1 A / s to 1 A / s; the second metal layer is prepared by vacuum sputtering or vacuum evaporation, with a vacuum degree ≤ 5 × 10⁻⁶. -4 Pa, with a rate of 0.1~0.5 A / s; It also includes the following steps: Between steps 1) and 2), the vacuum level is maintained while the temperature is lowered to room temperature; Steps 2) and 3) are consecutive steps, and the vacuum level is maintained.

9. A power generation device, characterized in that, It includes the perovskite solar cell as described in any one of claims 1 to 5.

10. An electrical device, characterized in that, The electrical device includes a perovskite solar cell as described in any one of claims 1 to 5, wherein the perovskite solar cell is used to provide electrical energy.

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