Perovskite solar cell, film composite electrode and manufacturing method, power generation device, power consumption device

Abstract

This application discloses a perovskite solar cell, a film composite electrode and a manufacturing method thereof, a power generating device, and a power consuming device. The perovskite solar cell includes a transparent conductive glass, a first charge transport layer, a perovskite absorption layer, a second charge transport layer, and a film composite electrode, in order, the 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 the embodiment of this application, the film composite electrode is a semi-transparent electrode, the first metal layer contacts the charge transport layer, improves the carrier extraction rate at the interface, reduces the carrier recombination probability at the interface, and improves the open circuit voltage of the device, and the second metal layer can reduce the series resistance of the entire device and improve the fill factor, ultimately improving the efficiency of the device, ensuring its transparency and providing excellent photoelectric performance.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202210113364.5, entitled "Perovskite Solar Cell, Film Composite Electrode and Manufacturing Method, Power Generating Device, and Power Consuming Device," filed on January 30, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the field of battery technology, in particular to perovskite solar cells, film composite electrodes and manufacturing methods, power generating devices, and power consuming devices. [Background technology]

[0003] Perovskite solar cells have attracted widespread attention due to their good performance. In the prior art, perovskite solar cells generally include a charge transport layer and a thin-layer electrode made of transparent conductive oxide adjacent thereto. The energy required for the manufacturing process of the transparent conductive oxide electrode is large, which may cause damage to the adjacent charge transport layer, so a buffer layer made of a material such as molybdenum oxide is installed between the transparent conductive oxide layer and the charge transport layer. However, the installation of the buffer layer reduces the photoelectric conversion efficiency of the cell and affects the transparency of the cell. Summary of the Invention

[0004] In view of the above problems, the present application provides a perovskite solar cell, a film composite electrode and a manufacturing method thereof, a power generating device, and a power consuming device. By providing a semi-transparent film composite electrode and applying it to a perovskite solar cell, the transparency of the perovskite solar cell can be ensured and the perovskite solar cell can have excellent photoelectric performance, thereby improving its practicality.

[0005] According to a first aspect, the present application provides a perovskite solar cell, the cell comprising, in order, a transparent conducting glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a film composite electrode, wherein 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, and the 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.

[0006] In the technical solution of the embodiment of the present application, the structure design of the perovskite solar cell can obtain a semi-transparent (light transmittance ≧50%) perovskite solar cell device with a composite electrode of a first metal layer-conductive oxide layer-second metal layer, where the film composite electrode can further improve the carrier extraction rate at the interface by introducing a first metal layer on the side contacting the second charge transport layer, reduce the carrier recombination probability at the interface, and reduce non-radiative recombination, thereby improving the open circuit voltage of the device, and introduce a second metal layer on the other side of the conductive oxide layer to reduce the series resistance of the entire device, improve the fill factor, and ultimately improve the device efficiency.

[0007] 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, and 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 limiting the materials of the first metal layer and the second metal layer, a suitable match of material energy levels can be achieved in the perovskite solar cell, so that the perovskite solar cell can exhibit good conductive performance.

[0008] In some embodiments, the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and the order of the HOMO levels of each layer in the perovskite solar cell is perovskite absorption layer<second charge transport layer<first metal layer<conductive oxide layer<second metal layer. The perovskite solar cell has a forward device structure, in which the work functions of the three electrodes, the first metal layer, the conductive oxide layer, and the second metal layer, are all higher than the HOMO level of the second charge transport layer, that is, the work functions of the first metal electrode, the conductive oxide electrode, and the second metal electrode tend to increase stepwise, and the effective transport of carriers between the three electrodes can be ensured. The above technical solution allows the photoexcited holes in the perovskite layer of the perovskite solar cell to be smoothly guided to the electrode end.

[0009] 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, 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 and the second metal layer are gradually increased, and the absolute value of the work function difference between the two adjacent layers is 0.02 eV to 0.3 eV. The work function range of each layer in the film composite electrode is further limited to facilitate accurate material selection of each layer in the film electrode, and the range of the work function difference between each layer is controlled to ensure smooth extraction and transport of photoinduced carriers, thereby better realizing the smooth extraction of photoexcited holes in the perovskite layer to the electrode end.

[0010] In some embodiments, the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the order of LUMO levels of each layer in the perovskite solar cell is perovskite absorption layer>second charge transport layer>first metal layer>conductive oxide layer>second metal layer. The solar cell has an inverted device structure, in which the work functions of the three electrodes, the first metal layer, the conductive oxide layer, and the second metal layer, are all lower than the LUMO level of the second charge transport layer, that is, the work functions of the first metal electrode, the conductive oxide electrode, and the second metal electrode tend to decrease stepwise, and the effective transport of carriers between the three electrodes can be ensured. The above technical solution allows the photoexcited electrons in the perovskite layer of the perovskite solar cell to be smoothly guided to the electrode end.

[0011] 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, the work function of the second metal layer is -5.30 to -3.75 eV, and the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide and the second metal layer are gradually decreased, and the absolute value of the work function difference between the two adjacent layers is 0.02 eV to 0.3 eV. The work function range of each layer in the film composite electrode is further limited to facilitate accurate material selection of each layer in the film electrode, and the range of the work function difference between each layer is controlled to ensure smooth extraction and transport of photoinduced carriers, thereby better realizing the smooth extraction of photoexcited electrons in the perovskite layer to the electrode end.

[0012] In some embodiments, the thickness of the conductive oxide layer is 50-200 nm, the thickness 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 is 1 / 10 or less of the thickness of the conductive oxide layer. The technical solution controls the lower limit of the thickness of each layer in the film composite electrode to ensure that the photoelectric performance of the film composite electrode is exerted, and controls the upper limit of the thickness of each layer in the film composite electrode and strictly limits the sum of the total thickness of the first metal layer and the second metal layer to 1 / 10 or less of the thickness of the conductive oxide layer to ensure that the total thickness of the film composite electrode is not too thick and the thickness of the metal layer is thin, thereby avoiding the influence on the transparency of the film composite electrode.

[0013] According to a second aspect, the present application provides a film composite electrode disposed on a charge transport layer, the film composite electrode including 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.

[0014] In the technical solution of the embodiment of the present application, the structure design of the film composite electrode can obtain a semi-transparent (light transmittance ≧50%) solar cell device while ensuring that the contact resistance of the electrode is not increased and the deposition temperature of the electrode is not increased. The film composite electrode can further improve the carrier extraction speed at the interface, reduce the carrier recombination probability at the interface, and reduce the non-radiative recombination by introducing a first metal layer on the side of the film composite electrode that contacts the charge transport layer, thereby improving the open circuit voltage of the device; and can reduce the series resistance of the entire device and improve the fill factor by introducing a second metal layer on the other side of the conductive oxide layer, thereby improving the device efficiency.

[0015] In some embodiments, the conductive oxide layer has a thickness of 50-200 nm, the first metal layer and the second metal layer have a thickness of 1-10 nm, and the sum of the thicknesses of the first metal layer and the second metal layer is 1 / 10 or less of the conductive oxide layer. The thickness of the metal electrode affects the light transmittance of the entire device. If the total thickness of the metal electrodes is too thick, the light transmittance of the device will be greatly reduced, and the application requirements of the semi-transparent device will not be met. Furthermore, when the thickness of the metal layer in the film composite electrode is controlled to be thin, specifically, the ratio of the total thickness of the metal electrodes to the thickness of the conductive transparent electrode is <1 / 10, the device will exhibit a semi-transparent state, and the photoelectric conversion efficiency of the film composite electrode will be improved to a certain extent. This technical solution controls the lower limit of the thickness of each layer in the film composite electrode so that the photoelectric performance of the film composite electrode can be exerted; it controls the upper limit of the thickness of each layer in the film composite electrode and strictly limits the sum of the total thickness of the first metal layer and the second metal layer to 1 / 10 or less of the thickness of the conductive oxide layer, thereby ensuring that the total thickness of the film composite electrode is not too thick and the thickness of the metal layer is thin, thereby avoiding the influence on the transparency of the film composite electrode.

[0016] In some embodiments, the thickness of the conductive oxide layer is 100-150 nm. By further limiting the thickness of the conductive oxide layer, the photoelectric performance and transparency of the film composite electrode can be well balanced, and the film composite electrode can be kept semi-transparent while maintaining a high level of electrical conductivity.

[0017] According to a third aspect, the present application provides a method for producing the aforementioned film composite electrode, the film composite electrode being disposed on a charge transport layer, the method comprising: 1) depositing a first metal layer over the charge transport layer; 2) depositing a conductive oxide layer over the first metal layer; 3) depositing a second metal layer over the conductive oxide layer.

[0018] The technical solution of the embodiments of the present application is to stack a first metal layer, a conductive oxide layer and a second metal layer on the charge transport layer to obtain a composite transparent electrode with a metal layer-transparent conductive oxide layer-metal layer structure.

[0019] In some embodiments, the method for producing the first metal layer is evaporation, and the degree of vacuum is ≦5×10 -4 Pa, the temperature is ≦100° C., the speed is ≦0.1 A / s, and the method for producing the conductive oxide layer is vacuum sputtering or vacuum deposition, and the degree of vacuum is ≦5×10 -4 Pa, the rate is 0.1 A / s to 1 A / s, the method for producing the second metal layer is vacuum sputtering or vacuum deposition, and the degree of vacuum is ≦5×10 -4 The vacuum pressure is 0.1 Pa, the speed is 0.1-0.5 A / s, and the method further includes a step of maintaining the vacuum and cooling to room temperature between step 1) and step 2), and step 2) and step 3) are consecutive steps, and the vacuum is maintained. The manufacturing process of the first metal layer, the conductive oxide layer and the second metal layer is strictly limited, the vacuum between the conductive oxide layer and the first metal layer is strictly limited so as not to be broken, and the deposition is temporarily stopped so as not to be broken between the second metal layer and the conductive oxide layer, thereby obtaining a metal-conductive oxide-metal composite electrode of the technical solution of the present invention, which can be made semi-transparent, and is not easily delaminated.

[0020] According to a fourth aspect, the present application provides a power generating device including the perovskite solar cell according to any of the above embodiments.

[0021] According to a fifth aspect, the present application provides an electrical power consuming device, the electrical power consuming device comprising a perovskite solar cell as described above, the perovskite solar cell being adapted to supply electrical energy.

[0022] The above description is merely an outline of the technical solution of the present application. In order to make the technical solution of the present application more clearly understood and implemented according to the content of the specification, and to make the above and other objectives, features and advantages of the present application more clearly understood, the following specific embodiments of the present application are given below. [Brief description of the drawings]

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are used only to illustrate the preferred embodiments and are not to be considered as limiting the present application. And, in the drawings, the same parts are represented by the same drawing symbols. In the drawings, [Figure 1] FIG. 1 is a structural schematic diagram of a perovskite solar cell according to some embodiments of the present application. [Diagram 2] FIG. 1 is a schematic diagram of a film composite electrode according to some embodiments of the present application. [Diagram 3] FIG. 2 is a schematic energy level diagram of a forward device of a perovskite solar cell according to some embodiments of the present application. [Figure 4] FIG. 2 is a schematic energy level diagram of an inverted device of a perovskite solar cell according to some embodiments of the present application. [Diagram 5] FIG. 2 is an open circuit voltage performance diagram of perovskite solar cells according to some embodiments of the present application. [Figure 6] FIG. 2 is a short circuit current performance diagram of perovskite solar cells according to some embodiments of the present application. [Figure 7] FIG. 2 is a fill factor performance diagram of perovskite solar cells according to some embodiments of the present application. [Figure 8] FIG. 2 is a photoelectric conversion efficiency performance diagram of perovskite solar cells according to some embodiments of the present application.

[0024] The drawing symbols in specific embodiments are as follows:

[0025] A film composite electrode 1, a second charge transport layer 2, a perovskite absorber layer 3, a first charge transport layer 4, a transparent conductive glass 5, a first metal layer 11, a conductive oxide layer 12, a second metal layer 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The following detailed description will be given of the embodiments of the technical solution of the present application in conjunction with the drawings. The following embodiments are provided to more clearly explain the technical solution of the present application, and are merely examples, which cannot limit the scope of protection of the present application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art, and the terms used herein are used only to describe specific embodiments and are not intended to limit the present application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the description of the drawings above are intended to cover the non-exclusive "including".

[0028] In the description of the embodiments of the present application, the terms "first", "second", etc. are used only for the purpose of distinguishing different objects, and are not understood to express or imply relative importance, or to imply the number, specific order, or primary-subordinate relationship of the subject technical features. In the description of the embodiments of the present application, "plurality" means two or more, unless otherwise specified.

[0029] When referring to an "embodiment" in this specification, it means that a particular feature, structure, or characteristic described in conjunction with the embodiment 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 all the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiment described in this specification may be combined with other embodiments.

[0030] In the description of the embodiments of the present application, the term "and / or" merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B can represent three cases: A alone, a combination of A and B, and B alone. In addition, the character " / " in this specification generally indicates that the related objects before and after are in an "or" relationship.

[0031] In describing the embodiments of the present application, the term "plurality" refers to two or more (including two); similarly, "multiple groups" refers to two or more groups (including two groups); and "multiple sheets" refers to two or more (including two sheets).

[0032] In describing the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial direction," "radial direction," "circumferential direction," and the like are based on the orientations or positional relationships shown in the accompanying drawings, and are for the convenience or simplification of the description of the embodiments of the present application, and are not intended to indicate or imply that the devices or elements referred to have a specific orientation and are required to be constructed and operated in a specific orientation, and should not be understood as limiting the embodiments of the present application.

[0033] In the description of the embodiments of the present application, unless otherwise clearly specified or limited, the technical terms "attached", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, they may be fixedly connected, detachably connected, or integrated. They may be mechanically connected or electrically connected. They may be directly connected, indirectly connected via an intermediate medium, or the internal communication of both elements or the interaction relationship of both elements. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present application according to the specific situation.

[0034] In the prior art, perovskite solar cells have attracted widespread attention due to their good performance, but the perovskite solar cells in the prior art generally include a charge transport layer and a thin-layer electrode made of transparent conductive oxide adjacent thereto. The energy required in the manufacturing process of the transparent conductive oxide electrode is large, which may cause damage to the adjacent charge transport layer, so it is necessary to install a buffer layer made of a material such as molybdenum oxide between the transparent conductive oxide layer and the charge transport layer.

[0035] The present inventors have found that providing a buffer layer between the charge transport layer and the electrode layer may cause a decrease in the photoelectric conversion efficiency of the cell and affect the transparency of the cell.

[0036] In order to solve the above problems, the applicant has discovered through research that a translucent film composite electrode can be obtained by forming a first metal layer on the surface of a charge transport layer, forming a conductive oxide layer on the first metal layer, and finally forming a second metal layer on the conductive oxide layer, thereby ensuring the transparency and providing high photoelectric conversion efficiency.

[0037] The film composite electrode disclosed in the embodiments of the present application may be applied to a perovskite solar cell, which comprises a transparent conductive glass, a first charge transport layer, a perovskite absorption layer, a second charge transport layer, and a film composite electrode, in order, 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, and the 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. The above technical solution can provide a semi-transparent perovskite solar cell device with a first metal layer-conductive oxide layer-second metal layer composite electrode, which has a certain transparency and good photoelectric conversion efficiency.

[0038] When manufacturing the film composite electrode according to the embodiment of the present application, the film composite electrode is disposed on a charge transport layer, which includes the steps of 1) disposing a first metal layer on the charge transport layer, 2) disposing a conductive oxide layer on the first metal layer, and 3) disposing a second metal layer on the conductive oxide layer. The above technical solution can obtain a composite transparent electrode with a structure of metal layer-transparent conductive oxide layer-metal layer, and the film composite electrode can ensure its transparency and have high photoelectric conversion efficiency.

[0039] The perovskite solar cell disclosed in the examples of the present application may be applied to a power generation device, and can ensure the transparency of the power generation device while providing it with high photoelectric conversion efficiency, and can be applied to application scenes that require both transparency and conductivity.

[0040] The perovskite solar cell disclosed in the embodiments of the present application may be applied to a battery of a power consuming device, the power consuming device including the perovskite solar cell described above, the perovskite solar cell being used to supply electrical energy and may be applied to application scenarios requiring both transparency and electrical conductivity.

[0041] For the sake of convenience, the following examples will be described using a film composite electrode and a perovskite solar cell according to one embodiment of the present application as an example.

[0042] Referring to Figure 1, Figure 1 is a schematic diagram of a perovskite solar cell according to some embodiments of the present application. As shown in Figure 1, the perovskite solar cell has a layered structure, and includes a transparent conductive glass 5, a first charge transport layer 4, a perovskite absorption layer 3, a second charge transport layer 2, and a film composite electrode 1, which are sequentially arranged, and 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, and the film composite electrode 1 includes a first metal layer 11 arranged on the second charge transport layer 2, a conductive oxide layer 12 arranged on the first metal layer 11, and a second metal layer 13 arranged on the conductive oxide layer 12.

[0043] Referring to Fig. 2, Fig. 2 is a structural schematic diagram of a film composite electrode according to some embodiments of the present application. As shown in Fig. 2, the film composite electrode has a three-layer structure, with metal layers on both sides and a conductive oxide layer in the middle, forming a three-layer film composite electrode of metal layer-conductive oxide layer-metal layer. When the film composite electrode is used, one of the metal layers is disposed on the charge transport layer.

[0044] According to some embodiments of the present application, the present application provides a film composite electrode disposed on a charge transport layer, the film composite electrode including 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.

[0045] The structure design of the film composite electrode ensures that the contact resistance of the electrode is not increased and the deposition temperature of the electrode is not increased, and a semi-transparent solar cell device can be obtained. The film composite electrode can further improve the carrier extraction rate at the interface by introducing a first metal layer on the side contacting the charge transport layer, reduce the carrier recombination probability at the interface, and reduce the non-radiative recombination, thereby improving the open circuit voltage of the device; and the film composite electrode can reduce the series resistance of the entire device and improve the fill factor by introducing a second metal layer on the other side of the conductive oxide layer, thereby improving the device efficiency.

[0046] According to some embodiments of the present application, preferably, the film composite electrode is disposed directly on the charge transport layer, and the film composite electrode includes a first metal layer disposed directly on the charge transport layer, a conductive oxide layer disposed directly on the first metal layer, and a second metal layer disposed directly on the conductive oxide layer.

[0047] According to some embodiments of the present application, a modification layer is preferably provided between the charge transport layer, the first metal layer, the conductive oxide layer and the second metal layer.

[0048] According to some embodiments of the present application, the metal of the first metal layer is selected from at least one of gold, silver, copper, aluminum, cobalt, and alloys thereof, 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, and 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.

[0049] According to some embodiments of the present application, preferably, the thickness of the conductive oxide layer is 50-200 nm, the thickness 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 is 1 / 10 or less of the thickness of the conductive oxide layer. The thickness of the metal electrode affects the light transmittance of the entire device. If the total thickness of the metal electrodes is too thick, the light transmittance of the device will be greatly reduced, and the application requirements of the translucent device will not be met. Furthermore, when the thickness of the metal layer in the film composite electrode is controlled to be thin, specifically, the ratio of the total thickness of the metal electrodes to the thickness of the conductive transparent electrode is <1 / 10, the device will exhibit a translucent state, and the photoelectric conversion efficiency of the film composite electrode will be improved to a certain extent. This technical solution controls the lower limit of the thickness of each layer in the film composite electrode so that the photoelectric performance of the film composite electrode can be exerted; it controls the upper limit of the thickness of each layer in the film composite electrode and strictly limits the sum of the total thickness of the first metal layer and the second metal layer to 1 / 10 or less of the thickness of the conductive oxide layer, thereby ensuring that the total thickness of the film composite electrode is not too thick and the thickness of the metal layer is thin, thereby avoiding the influence on the transparency of the film composite electrode.

[0050] According to some embodiments of the present application, the thickness of the conductive oxide layer is preferably 100 to 150 nm. By further limiting the thickness of the conductive oxide layer, the photoelectric performance and transparency of the film composite electrode can be well balanced, and the film composite electrode can be kept semi-transparent while maintaining its electrical conductivity at a high level.

[0051] According to some embodiments of the present application, the present application provides a perovskite solar cell, the cell comprising, in order, a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a film composite electrode, the first charge transport layer being an electron transport layer and the second charge transport layer being a hole transport layer, or the first charge transport layer being a hole transport layer and the second charge transport layer being an electron transport layer, the film composite electrode comprising 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.

[0052] The structural design of the perovskite solar cell can provide a semi-transparent perovskite solar cell device with a composite electrode of a first metal layer-a conductive oxide layer-a second metal layer.

[0053] According to some embodiments of the present application, preferably, a first metal layer is disposed directly on the second charge transport layer, a conductive oxide layer is disposed directly on the first metal layer, and a second metal layer is disposed directly on the conductive oxide layer.

[0054] According to some embodiments of the present application, preferably, the transparent conductive glass, the first charge transport layer, the perovskite absorption layer, the second charge transport layer and the film composite electrode layer may be interposed with corresponding modification layers to improve the performance of the perovskite solar cell. The transparent conductive glass is the light incident surface of the perovskite solar cell.

[0055] According to some embodiments of the present application, the metal of the first metal layer is preferably selected from at least one of gold, silver, copper, aluminum, cobalt, and alloys thereof, and 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 limiting the materials of the first metal layer and the second metal layer, a suitable matching of material energy levels can be achieved in the perovskite solar cell, so that the perovskite solar cell can exhibit good conductive performance.

[0056] According to some embodiments of the present application, preferably, the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and the order of the HOMO levels of each layer in the perovskite solar cell is perovskite absorption layer<second charge transport layer<first metal layer<conductive oxide layer<second metal layer. The perovskite solar cell has a forward device structure, in which the work functions of the three electrodes, the first metal layer, the conductive oxide layer, and the second metal layer, are all higher than the HOMO level of the second charge transport layer, that is, the work functions of the first metal electrode, the conductive oxide electrode, and the second metal electrode tend to increase stepwise, and the effective transport of carriers between the three electrodes can be ensured. The above technical solution allows the photoexcited holes in the perovskite layer of the perovskite solar cell to be smoothly guided to the electrode end.

[0057] According to some embodiments of the present 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, 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 and the second metal layer are gradually increased, and the absolute value of the work function difference between the two adjacent layers is 0.02 eV to 0.3 eV. The work function range of each layer in the film composite electrode is further limited to facilitate accurate material selection of each layer in the film electrode, and the range of the work function difference between each layer is controlled to ensure smooth extraction and transport of photoinduced carriers, thereby better realizing the smooth extraction of photoexcited holes in the perovskite layer to the electrode end.

[0058] According to some embodiments of the present application, preferably, the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the LUMO level order of each layer in the perovskite solar cell is perovskite absorption layer>second charge transport layer>first metal layer>conductive oxide layer>second metal layer. The solar cell has an inverted device structure, in which the work functions of the three electrodes, the first metal layer, the conductive oxide layer, and the second metal layer, are all lower than the LUMO level of the second charge transport layer, that is, the work functions of the first metal electrode, the conductive oxide electrode, and the second metal electrode tend to decrease stepwise, so as to ensure the effective transport of carriers between the three electrodes. The above technical solution allows the photoexcited electrons in the perovskite layer of the perovskite solar cell to be smoothly guided to the electrode end.

[0059] According to some embodiments of the present 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, the work function of the second metal layer is -5.30 to -3.75 eV, and the work function values ​​of the second charge transport layer, the first metal layer, the conductive oxide and the second metal layer are gradually decreased, and the absolute value of the work function difference between the two adjacent layers is 0.02 eV to 0.3 eV. The range of the work function of each layer in the film composite electrode is further limited to facilitate accurate material selection of each layer in the film electrode, and the range of the work function difference between each layer is controlled to ensure smooth extraction and transport of photoinduced carriers, thereby better realizing the smooth extraction of photoexcited electrons in the perovskite layer to the electrode end.

[0060] The term HOMO is an abbreviation of the English term Highest Occupied Molecular Orbital, meaning the highest occupied molecular orbital. The term LUMO is an abbreviation of the English term Lowest Unoccupied Molecular Orbital, meaning the lowest unoccupied molecular orbital. The energy difference between HOMO and LUMO is called the "energy band gap", and the energy difference is called the HOMO-LUMO level, which can be used to evaluate whether a molecule is easily excited, and the smaller the band gap, the easier it is to excite a molecule. The HOMO in organic semiconductors and quantum dots is similar to the valence band in inorganic semiconductors, and the LUMO is similar to the conduction band. The HOMO level refers to the top of the VBM valence band. The LUMO level refers to the bottom of the CBM conduction band.

[0061] For semiconductors, the work function refers to the minimum energy required for an electron to immediately escape from a fixed body, which is an inherent property and characteristic of the material itself. In the film composite electrode, the energy levels between the two adjacent layers must maintain a certain difference. If the absolute value of the energy level difference is smaller than 0.02 eV, the built-in electric field of the electrode cannot be formed, and the charge cannot move along a certain direction. If the absolute value of the energy level difference is larger than 0.3 eV, it will cause a large loss of open circuit voltage, which is unfavorable to the improvement of device performance.

[0062] According to some embodiments of the present application, preferably, the thickness of the conductive oxide layer is 50-200 nm, the thickness 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 is 1 / 10 or less of the thickness of the conductive oxide layer. The technical solution controls the lower limit of the thickness of each layer in the film composite electrode to ensure the photoelectric performance of the film composite electrode, controls the upper limit of the thickness of each layer in the film composite electrode, and strictly limits the sum of the total thickness of the first metal layer and the second metal layer to 1 / 10 or less of the thickness of the conductive oxide layer, thereby ensuring that the total thickness of the film composite electrode is not too thick and the thickness of the metal layer is thin, thereby avoiding the influence on the transparency of the film composite electrode.

[0063] According to some embodiments of the present application, the perovskite solar cell is a semi-transparent cell, and has a total thickness of 52 to 220 nm, and the sum of the thicknesses of the first metal layer and the second metal layer is particularly limited to 1 / 10 or less of the thickness of the conductive oxide layer. In other words, the sum of the thicknesses of the metal layers in the film composite electrode of the present invention is a maximum of 20 nm or less, so that the film composite electrode can be provided with semi-transparent properties without significantly affecting the transparency of the conductive oxide layer, and can be used in glass devices.

[0064] According to some embodiments of the present 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.

[0065] According to some embodiments of the present application, the chemical formula of the perovskite light absorbing layer is ABX3 or A2CDX6, where A represents a positive monovalent inorganic and / or organic cation, B represents a positive divalent metal cation, C represents a positive monovalent metal cation, D represents a positive trivalent metal cation, and X represents an inorganic and / or organic anion.

[0066] According to some embodiments of the present application, the positive divalent metal cation is a lead ion or a tin ion.

[0067] According to some embodiments of the present application, the perovskite light absorbing layer has a band gap of 1.20-2.30 eV and a thickness of 200-1000 nm.

[0068] According to some embodiments of the present application, the electron transport layer comprises a [6,6]-phenyl C 61 Butyric acid methyl ester, [6,6]-phenyl C 71 The material is selected from at least one of butyric acid methyl ester, fullerene C60, fullerene C70, tin dioxide and zinc oxide, and derivatives of the above materials or materials modified by doping or passivation of the above materials.

[0069] According to some embodiments of the present application, the hole transport layer is selected from at least one of 2,2',7,7'-tetra(N,Np-methoxyanilino)-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], methoxytriphenylamine-fluoroformamidine, poly(3,4-ethylenedioxythiophene), poly(styrenesulfone), poly-3-hexylthiophene, cuprous thiocyanate, nickel oxide, triptycene-based triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobifluorene (CzPAF-SBF) and polythiophene, and derivatives of the above materials or modified materials by doping or passivation of the above materials.

[0070] According to some embodiments of the present 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.

[0071] According to some embodiments of the present application, the present application provides a method for manufacturing the aforementioned film composite electrode, the film composite electrode being disposed on a charge transport layer, the method comprising: 1) depositing a first metal layer over the charge transport layer; 2) depositing a conductive oxide layer over the first metal layer; 3) depositing a second metal layer over the conductive oxide layer.

[0072] The technical solution of the embodiments of the present application is to stack a first metal layer, a conductive oxide layer and a second metal layer on the charge transport layer to obtain a composite transparent electrode with a metal layer-transparent conductive oxide layer-metal layer structure.

[0073] According to some embodiments of the present application, the method for producing the first metal layer is preferably deposition, and the vacuum degree is ≦5×10-4 Pa, the temperature is ≦100° C., the speed is ≦0.1 A / s, and the method for producing the conductive oxide layer is vacuum sputtering or vacuum deposition, and the degree of vacuum is ≦5×10 -4 Pa, the rate is 0.1 A / s to 1 A / s, the method for producing the second metal layer is vacuum sputtering or vacuum deposition, and the degree of vacuum is ≦5×10 -4 The vacuum pressure is 0.1 Pa, the speed is 0.1-0.5 A / s, and the method further includes a step of maintaining the vacuum and cooling to room temperature between step 1) and step 2), and step 2) and step 3) are consecutive steps, and the vacuum is maintained. The manufacturing process of the first metal layer, the conductive oxide layer and the second metal layer is strictly limited, the vacuum between the conductive oxide layer and the first metal layer is strictly limited so as not to be broken, and the deposition is temporarily stopped so as not to be broken between the second metal layer and the conductive oxide layer, thereby obtaining a metal-conductive oxide-metal composite electrode of the technical solution of the present invention, which can be made semi-transparent, and is not easily delaminated.

[0074] The present application will be further described below in conjunction with specific examples.

[0075] Perovskite solar cell performance testing:

[0076] Standard simulated sunlight (AM1.5G, 100mW / cm 2 ) the cell performance was tested and the IV curves were obtained.

[0077] Based on the IV curve and the data fed back from the test equipment, the short circuit current Jsc (unit: mA), the open circuit voltage Voc (unit: V), the maximum optical output current Jmpp (unit: mA) and the maximum optical output voltage Vmpp (unit: V) can be obtained.

[0078] Calculate the fill factor FF of the battery by the formula FF = Jsc × Voc / (Jmpp × Vmpp), the unit is %;

[0079] The photoelectric conversion efficiency PCE of the battery was calculated by the formula PCE=Jsc×Voc×FF / Pw, in which the unit is %, and Pw represents the input power in mW.

[0080] In order to facilitate the comparison of performance, the present invention normalizes parameters such as short circuit current, open circuit voltage, fill factor, and photoelectric conversion efficiency based on the numerical values ​​of comparative examples corresponding to each embodiment, allowing intuitive comparison of device parameters and performance improvement.

[0081] Example 1

[0082] Take an ITO (indium tin oxide) conductive glass with a specification of 2.0 cm x 2.0 cm, with no thickness limit, and use a laser etching method to remove the ITO layer on each of the opposing sides of the surface containing the ITO layer of the glass, with a width of 0.35 cm, to expose the glass base;

[0083] The ITO conductive glass after etching is ultrasonically cleaned at least twice using water, acetone, and isopropanol in sequence.

[0084] After drying the residual solvent on the surface of the ITO conductive glass with a nitrogen gas spray gun, the ITO conductive glass is further cleaned in an ultraviolet ozone machine, and the cleaning time is 5 to 30 minutes, but is not limited thereto.

[0085] A solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) in isopropanol was prepared. The mass / volume concentration was 2 mg / mL, i.e., 2 mg of solute was dissolved in 1 milliliter of solvent.

[0086] On an ITO conductive glass substrate treated by an ultraviolet ozone machine, the above prepared PTAA solution is spin-coated at a speed of 5000 rpm / s, and then annealed on a hot stage at 100°C for 10 minutes, and the PTAA layer is an organic hole transport layer.

[0087] On the organic hole transport layer prepared above, spin-coat the perovskite precursor solution at a speed of 1000-5000 rpm / s, and anneal at 100°C for 30 min, and then cool to room temperature, where 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, the solvent is a mixture of DMF (dimethylformamide) and DMSO (dimethylsulfoxide) in a volume ratio of 4:1, and the CsFAMA layer is a perovskite layer.

[0088] On the perovskite layer produced above, PC was rotated at a speed of 1000 to 1500 rpm / s. 61 BM ([6,6]-phenyl C 61 The substrate was spin-coated with PC (butyric acid methyl ester) and annealed at 100°C for 10 min, followed immediately by spin-coating with BCP (bathocuproine) at a speed of 5000 rpm / s. 61 The mass volume concentration of BM was 20 mg / mL, i.e., 20 mg of solute was dissolved in 1 milliliter of solvent, and the solvent was chlorobenzene. The mass volume concentration of BCP was 0.5 mg / mL, i.e., 0.5 mg of solute was dissolved in 1 milliliter of solvent, and the solvent was isopropanol. 61 The BM layer is an electron transport layer, the BCP layer is a passivation layer, and the work function of the second charge transport layer is −4.40 eV.

[0089] The above-prepared thin piece was placed in a deposition machine, and the deposition vacuum was set at 5×10 -4After the pressure reaches below 1 Pa, a metal electrode Cu (work function -4.65 eV) with a thickness of 2 nm is deposited at a rate of 0.1 A / s, the deposition temperature is 30-50°C, the vacuum is maintained so as not to break, the metal electrode is cooled to room temperature, and a high-frequency magnetron sputtering method is used to sputter a transparent conductive oxide called tin-doped indium oxide to form a conductive oxide film, the film thickness is 100 nm, and the work function of the tin-doped indium oxide is -4.85 eV. Finally, the vacuum is maintained so as not to break, and a metal electrode Au (work function -5.1 eV) is plated on the transparent conductive oxide film of tin-doped indium oxide at a rate of 0.2 A / s by deposition or sputtering, the thickness is 5 nm, and a complete composite film electrode is formed.

[0090] The perovskite solar cell obtained by the above steps is denoted as Cell 1#, and the energy level schematic diagram of the perovskite light absorption layer, the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer in Cell 1# is shown in FIG. 3, the photoelectric performance result of Cell 1# is shown in Table 1, and its transparency data is shown in Table 2.

[0091] Example 2

[0092] Take an ITO (indium tin oxide) conductive glass with a specification of 2.0 cm x 2.0 cm, with no thickness limit, and use a laser etching method to remove the ITO layer on each of the opposing sides of the surface containing the ITO layer of the glass, with a width of 0.35 cm, to expose the glass base;

[0093] The ITO conductive glass after etching is ultrasonically cleaned at least twice using water, acetone, and isopropanol in sequence.

[0094] After drying the residual solvent on the surface of the ITO conductive glass with a nitrogen gas spray gun, the ITO conductive glass is further cleaned in an ultraviolet ozone machine, and the cleaning time is 5 to 30 minutes, but is not limited thereto.

[0095] Purchase a commercially available SnO2 (tin dioxide) solution, alfa brand 15% hydrocolloid dispersion, and dilute it with three times the amount of distilled water in preparation for use.

[0096] On an ITO conductive glass substrate treated with an ultraviolet ozone machine, the rotation speed was 4000 rpm / s, 2000 rpm / s 2 The diluted SnO2 aqueous solution is spin-coated at an acceleration of 100° C. and heated at 150° C. for 15 minutes, and the SnO2 layer is an electron transport layer.

[0097] On the above-prepared electron transport layer, spin-coat the perovskite precursor solution at a speed of 1000-4000 rpm / s, and anneal at 100°C for 30 min, and then cool to room temperature, where 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, the solvent is a mixture of DMF (dimethylformamide) and DMSO (dimethylsulfoxide) in a volume ratio of 4:1, and the CsFAMA layer is a perovskite layer.

[0098] On the perovskite layer prepared above, a hole transport layer Spiro-OMeTAD (2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene) is spin-coated at a speed of 3000 rpm / s, the solvent is chlorobenzene, the mass volume concentration is 72.3 mg / mL, i.e., 72.3 mg of solute is dissolved in 1 milliliter of solvent, and the work function of the hole transport layer is -5.15 eV;

[0099] The above-prepared thin piece was placed in a deposition machine, and the deposition vacuum was set at 5×10 -4After the pressure reaches below 1 Pa, a metal electrode Au (work function -5.1 eV) is deposited at a speed of 0.1 A / s to a thickness of 2 nm, the deposition temperature is 30-50°C, the vacuum is maintained so as not to break, the film is cooled to room temperature, and a high-frequency magnetron sputtering method is used to sputter a transparent conductive oxide called tin-doped indium oxide to form a conductive oxide film, the film thickness is 100 nm, and the work function of the tin-doped indium oxide is -4.85 eV. Finally, the vacuum is maintained so as not to break, and a metal electrode Ag (work function -4.6 eV) is plated on the transparent conductive oxide film of tin-doped indium oxide at a speed of 0.2 A / s by deposition or sputtering, the thickness is 5 nm, and a complete composite film electrode is formed.

[0100] The perovskite solar cell obtained by the above steps is denoted as cell 2#, and the energy level schematic diagram of the perovskite light absorption layer, the second charge transport layer, the first metal layer, the conductive oxide layer, and the second metal layer in cell 2# is shown in FIG. 4, the photoelectric performance result of cell 2# is shown in Table 1, and its transparency data is shown in Table 2.

[0101] Example 3

[0102] The manufacturing process is the same as that of Example 2, in which the first metal layer is a 2 nm thick cobalt layer (work function -5.0 eV), the conductive oxide layer is a 100 nm thick tin-doped indium oxide layer (work function -4.85 eV), and the second metal layer is a 5 nm thick nickel layer (work function -4.6 eV), and the photoelectric performance results of the cell obtained in this example are as shown in Table 1, and the transparency data are as shown in Table 2.

[0103] Examples 4 to 7

[0104] The manufacturing process is the same as in Example 2, the metal layer material and the thickness data of each layer are as shown in Table 3, the photoelectric performance results of the obtained cell are as shown in Table 1, and the transparency data are as shown in Table 2.

[0105] Comparative Example 1

[0106] The same as in Example 1, except that in the manufacture of the final electrode part, a 10 nm thick molybdenum oxide is first thermally evaporated as a buffer layer in the magnetron sputtering process, and then a 107 nm tin-doped indium oxide layer is directly sputtered, and the work function of the tin-doped indium oxide is -4.85 eV. The obtained perovskite solar cell is designated as cell 1'#, and the transparency data of cell 1'# are shown in Table 3, and the photoelectric performances are all normalized.

[0107] Comparative Example 2

[0108] The same as in Example 2, except that in the manufacture of the final electrode part, a 10 nm thick molybdenum oxide is first thermally evaporated as a buffer layer in the magnetron sputtering process, and then a 107 nm tin-doped indium oxide layer is directly sputtered, and the work function of the tin-doped indium oxide is -4.85 eV. The obtained perovskite solar cell is designated as cell 2'#, and the transparency data of cell 2'# are shown in Table 3, and the photoelectric performances are all normalized.

[0109] The photoelectric performance results of the battery 1#, the battery 2#, the battery 1'# and the battery 2'# are shown in FIGS.

[0110] Comparative Examples 3 to 7

[0111] The same as in Examples 3 to 7, except that when manufacturing the final electrode part, first, a 10 nm thick molybdenum oxide is thermally evaporated to serve as a buffer layer in the magnetron sputtering process, and then a tin-doped indium oxide layer is directly sputtered. The work function of the tin-doped indium oxide is -4.85 eV, and 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 to 7, respectively. The transparency data of the obtained perovskite solar cell is as shown in Table 2, and the photoelectric performances are all normalized.

[0112] [Table 1]

[0113] [Table 2]

[0114] [Table 3]

[0115] As can be seen from the detection results of the above Examples 1 to 7 and Comparative Examples 1 to 7, the performance of the "semitransparent perovskite solar cell based on metal-conductive oxide-metal composite electrode" is obviously superior to that of the blank conductive oxide-based cell, exhibiting higher light transmittance and keeping the effect of its semitransparency intact, while showing an overall improvement in photoelectric performance. This is mainly because the introduction of the first metal layer, i.e., the first metal electrode, improves the carrier transport rate between the charge transport layer and the film composite electrode, and the introduction of the second metal electrode located on the other side of the conductive oxide layer reduces the series resistance of the entire device, promoting the overall improvement of the device open circuit voltage and fill factor, and further improving the cell efficiency.

[0116] Finally, it should be explained that the above-mentioned embodiments are only used to explain the technical solution of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art can still understand that the technical solution described in the above-mentioned embodiments can be modified or equivalently substituted for some or all of the technical features therein, and such modifications or substitutions do not cause the essence of the corresponding technical solution to depart from the scope of the technical solution of each embodiment of the present application, and all of them shall be included in the scope of the claims and the specification of the present application. In particular, as long as there is no structural contradiction, each technical feature mentioned in each embodiment may be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, and includes all technical solutions included in the claims.

Claims

1. A perovskite solar cell comprising, in order, a transparent conductive glass, a first charge transport layer, a perovskite absorber layer, a second charge transport layer, and a film composite electrode, wherein 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, and the film composite electrode is 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.

2. 2. The perovskite solar cell according to claim 1, wherein the metal of the first metal layer is selected from at least one of gold, silver, copper, aluminum, and cobalt, and alloys thereof, and 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.

3. 2. The perovskite solar cell according to claim 1, wherein the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and the order of HOMO levels of each layer in the perovskite solar cell is perovskite absorption layer < second charge transport layer < first metal layer < conductive oxide layer < second metal layer.

4. The perovskite solar cell according to claim 3, characterized in that the first metal layer has a work function of -5.15 to -4.2 eV, the conductive oxide layer has a work function of -5.10 to -4.1 eV, the second metal layer has a work function of -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 gradually, and the absolute value of the work function difference between two adjacent layers is 0.02 eV to 0.3 eV.

5. 2. The perovskite solar cell according to claim 1, wherein the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the order of LUMO levels of each layer in the perovskite solar cell is perovskite absorption layer>second charge transport layer>first metal layer>conductive oxide layer>second metal layer.

6. The perovskite solar cell according to claim 5, characterized in that the first metal layer has a work function of -4.95 to -3.5 eV, the conductive oxide layer has a work function of -5.00 to -3.65 eV, the second metal layer has a work function of -5.30 to -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 gradually, and the absolute value of the work function difference between two adjacent layers is 0.02 eV to 0.3 eV.

7. 2. The perovskite solar cell according to claim 1, wherein the conductive oxide layer has a thickness of 50 to 200 nm, the first metal layer and the second metal layer each have a thickness of 1 to 10 nm, and the sum of the thicknesses of the first metal layer and the second metal layer is 1 / 10 or less of the thickness of the conductive oxide layer.

8. a film composite electrode disposed on the charge transport layer, the film composite electrode comprising: a first metal layer disposed on the charge transport layer; a conductive oxide layer disposed on the first metal layer; a second metal layer disposed on the conductive oxide layer.

9. The film composite electrode according to claim 8, characterized in that the conductive oxide layer has a thickness of 50 to 200 nm, the first metal layer and the second metal layer each have a thickness of 1 to 10 nm, and the sum of the thicknesses of the first metal layer and the second metal layer is 1 / 10 or less of the thickness of the conductive oxide layer.

10. 10. The film composite electrode according to claim 9, wherein the conductive oxide layer has a thickness of 100 to 150 nm.

11. A method for producing a film composite electrode according to any one of claims 8 to 10, comprising the steps of: providing the film composite electrode on a charge transport layer; 1) depositing a first metal layer over the charge transport layer; 2) depositing a conductive oxide layer over the first metal layer; and 3) providing a second metal layer on the conductive oxide layer.

12. The method for producing the first metal layer is vapor deposition, and the degree of vacuum is ≦5×10 －４ Pa, the temperature is ≦100° C., the speed is ≦0.1 A / s, and the method for producing the conductive oxide layer is vacuum sputtering or vacuum deposition, and the degree of vacuum is ≦5×10 －４ Pa, the rate is 0.1 A / s to 1 A / s, the method for producing the second metal layer is vacuum sputtering or vacuum deposition, and the degree of vacuum is ≦5×10 －４ Pa and a rate of 0.1 to 0.5 A / s, said method comprising: Between step 1) and step 2), the method further comprises the step of maintaining the vacuum and cooling to room temperature; The method of claim 11, wherein steps 2) and 3) are successive steps and a vacuum is maintained.

13. A power generating device comprising the perovskite solar cell according to any one of claims 1 to 7.

14. 8. An electrical power consuming device comprising the perovskite solar cell according to any one of claims 1 to 7, wherein the perovskite solar cell is used to supply electrical energy.

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