Intermetallic compound back electrode preparation method, intermetallic compound back electrode and perovskite solar cell

Abstract

The invention relates to an intermetallic compound back electrode preparation method, an intermetallic compound back electrode and a perovskite solar cell, and the method comprises the steps: preparing an intermetallic compound raw material in a vacuum melting manner; the intermetallic compound back electrode is prepared from an intermetallic compound raw material by any one of vacuum evaporation, electron beam evaporation or magnetron sputtering. The conductivity of the intermetallic compound electrode is higher than that of a carbon electrode, a transparent conductive compound and the like, so that low series resistance of the perovskite solar cell can be ensured. The high corrosion resistance and stability of the intermetallic compound are utilized to solve the problem of diffusion reaction between the halide and the metal back electrode in the existing perovskite cell, and the long-term stability of the perovskite solar cell is realized.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a method for preparing an intermetallic compound back electrode, an intermetallic compound back electrode and a perovskite solar cell. Background Art

[0002] The new generation of thin-film perovskite solar cells have shown great potential in various applications due to their advantages in low material cost, simple manufacturing, and high flexibility. In the past decade, perovskite solar cells have attracted great research attention due to their significant improvement in power conversion efficiency (PCE) from 3.8% to 26.1%. Organic-inorganic hybrid perovskite solar cells exhibit remarkable optoelectronic properties, including tunable band gap, long carrier diffusion length, low exciton binding energy, and high carrier mobility. In addition to their performance advantages, the simple solution-processed fabrication feature adds manufacturing advantages for the scalable application of perovskite solar cells. The significant improvement in the performance of perovskite solar cells is attributed to the extensive research efforts done in optimizing the perovskite composition, regulating charge dynamics, engineering interface contacts, and passivating defects.

[0003] Although the basic understanding of perovskite solar cells and controllable material processing have been well achieved, there are still problems with long-term stability. Studies have shown that halide ions migrate to the metal counter electrode, causing the halide to react with the metal layer, and metal corrosion problems can lead to serious perovskite deterioration and device degradation. Therefore, the development of more corrosion-resistant metal back electrode materials is of great significance to improving the long-term stability of perovskite solar cells. Summary of the invention

[0004] In view of this, the present application proposes a method for preparing an intermetallic compound back electrode, an intermetallic compound back electrode and a perovskite solar cell to solve the above problems.

[0005] According to one aspect of the present application, a method for preparing an intermetallic compound back electrode is provided, comprising the following steps: The intermetallic compound raw materials are prepared by vacuum melting; The intermetallic compound raw material is subjected to any one of vacuum evaporation, electron beam evaporation or magnetron sputtering to prepare the intermetallic compound back electrode.

[0006] As an optional embodiment of the present application, optionally, the intermetallic compound raw material includes: Any one of Fe-Al intermetallic compounds, Ni-Al intermetallic compounds, Ti-Al intermetallic compounds, Cr-Al intermetallic compounds, Ni-Y intermetallic compounds, Ni-W intermetallic compounds, Ni-Mo intermetallic compounds, W-Fe intermetallic compounds, Fe-Mo intermetallic compounds, Ti-Cu intermetallic compounds, Ti-Fe intermetallic compounds, and Ti-Ni intermetallic compounds.

[0007] As an optional embodiment of the present application, optionally, the intermetallic compound raw material further includes: Any one of Au-Al intermetallic compound, Ti-Au intermetallic compound, Ag-Al intermetallic compound, Ag-Y intermetallic compound, Au-Y intermetallic compound, Pt-Ti intermetallic compound, Al-Pt intermetallic compound, Pt-Y intermetallic compound.

[0008] As an optional embodiment of the present application, optionally, when vacuum evaporation is used to prepare the intermetallic compound back electrode, the evaporation vacuum degree is set to be less than 10 -3 Pa, and the evaporation rate of vacuum evaporation is 0.01-5 Å / s.

[0009] As an optional embodiment of the present application, optionally, when electron beam evaporation is used to prepare the intermetallic compound back electrode, the vacuum degree of the electron beam evaporation is set to be less than 10 -3 Pa, and the evaporation rate of electron beam evaporation is 0.01-5 Å / s.

[0010] As an optional embodiment of the present application, optionally, when magnetron sputtering is used to prepare the intermetallic compound back electrode, the initial vacuum degree of sputtering is set to 5×10 -4 Pa, the working gas is argon, the sputtering power is 100-350W, and the sputtering time is 20min-90min.

[0011] According to another aspect of the present application, an intermetallic compound back electrode is provided, which is prepared by using any of the above-mentioned intermetallic compound back electrode preparation methods.

[0012] According to another aspect of the present application, a perovskite solar cell is provided, comprising: Transparent substrate; A first transparent conductive electrode is disposed on the transparent substrate; a hole transport layer, disposed on the first transparent conductive electrode; A perovskite light absorbing layer, disposed on the hole transport layer; An electron transport layer, disposed on the perovskite light absorbing layer; A buffer layer, disposed on the electron transport layer; The intermetallic compound back electrode prepared by any of the above-mentioned methods for preparing an intermetallic compound back electrode is arranged on the buffer layer.

[0013] As an optional implementation scheme of the present application, optionally, it also includes: The second transparent conductive electrode is arranged between the buffer layer and the intermetallic compound back electrode.

[0014] As an optional embodiment of the present application, optionally, the transparent substrate includes any one of rigid glass, flexible glass, PEN, PET or PI.

[0015] Beneficial effects of this application: The method for preparing the back electrode of an intermetallic compound provided in the present application adopts vacuum melting to prepare the raw material of the intermetallic compound, and adopts any one of vacuum evaporation, electron beam evaporation or magnetron sputtering to prepare the intermetallic compound electrode film. An intermetallic compound is a compound between metal and ceramic, and the interatomic bond is between the metal bond and the covalent bond (or ionic bond), and some contain directional covalent bonds. The interatomic bond is stronger than the metal bond in the currently commonly used pure metal electrode, so it can maintain higher stability during the use of the perovskite battery. In addition, the conductivity of the intermetallic compound electrode is stronger than that of the carbon electrode and the transparent conductive compound, which can ensure the lower series resistance of the perovskite solar cell. Moreover, the intermetallic compound of each system is composed of multiple components, and the intermetallic compound component with a suitable work function can be selected to match a specific perovskite solar cell to form an ohmic contact, optimize the energy level matching, and improve the efficiency of the perovskite solar cell.

[0016] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0018] Figure 1 The flow chart of the method for preparing the intermetallic compound back electrode of the present invention is shown; Figure 2 A schematic diagram showing the structure of a perovskite solar cell of the present invention is shown; Figure 3 A box plot of photoelectric performance parameters of a perovskite solar cell device according to Example 1 of the present invention is shown; Figure 4A comparison diagram of IV test curves of perovskite solar cells with different electrodes in Example 2 of the present invention is shown; Figure 5 A comparison of thermal stability curves at 85° C. of perovskite solar cells with different electrodes in Example 2 of the present invention is shown; Figure 6 A comparison diagram of IV curves of perovskite solar cells with different electrodes in Example 3 of the present invention is shown. DETAILED DESCRIPTION

[0019] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0020] Among them, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0023] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0024] The main purpose of the present invention is to provide an intermetallic compound back electrode for perovskite solar cells, and to use the high corrosion resistance and stability of the intermetallic compound to solve the diffusion reaction problem between the halide and the metal back electrode in the existing perovskite cells, thereby achieving the long-term stability of the perovskite solar cells.

[0025] like Figure 1 As shown, on one hand, the present application provides a method for preparing an intermetallic compound back electrode, comprising the following steps: S100, preparing intermetallic compound raw materials by vacuum melting; In this step, a vacuum melting method is used to prepare an intermetallic compound back electrode for a perovskite solar cell, wherein, according to the physical vapor deposition method used in the subsequent treatment, an evaporation intermetallic compound raw material or an intermetallic compound sputtering target is selected for preparation.

[0026] S200, preparing an intermetallic compound back electrode by using the intermetallic compound raw material through vacuum evaporation, electron beam evaporation or magnetron sputtering.

[0027] In this step, the preparation of the finished intermetallic compound back electrode is achieved by physical vapor deposition (PVD). Among them, physical vapor deposition includes any one of vacuum evaporation, electron beam evaporation or magnetron sputtering. The evaporated intermetallic compound raw material is prepared into the corresponding intermetallic compound back electrode based on vacuum evaporation or electron beam evaporation, and the intermetallic compound sputtering target is prepared into the intermetallic compound back electrode based on magnetron sputtering.

[0028] It should be noted that the electrode for perovskite solar cells provided in this application is an intermetallic compound, wherein the intermetallic compound is a compound between metal and ceramic, the interatomic bond is between the metal bond and the covalent bond (or ionic bond), and some contain directional covalent bonds, and the interatomic bonding force is stronger than the metal bond in the currently commonly used pure metal electrode, so it can maintain higher stability during the use of the perovskite battery. In addition, the conductivity of the intermetallic compound electrode is stronger than that of the carbon electrode and the transparent conductive compound, etc., which can ensure the lower series resistance of the perovskite solar cell. Moreover, the intermetallic compound of each system is composed of multiple components, and the intermetallic compound component with a suitable work function can be selected to match a specific perovskite solar cell to form an ohmic contact, optimize the energy level matching, and improve the efficiency of the perovskite solar cell.

[0029] As an optional embodiment of the present application, optionally, the intermetallic compound raw material includes: any one of Fe-Al intermetallic compounds, Ni-Al intermetallic compounds, Ti-Al intermetallic compounds, Cr-Al intermetallic compounds, Ni-Y intermetallic compounds, Ni-W intermetallic compounds, Ni-Mo intermetallic compounds, W-Fe intermetallic compounds, Fe-Mo intermetallic compounds, Ti-Cu intermetallic compounds, Ti-Fe intermetallic compounds, and Ti-Ni intermetallic compounds.

[0030] In this embodiment, the raw material of the intermetallic compound is preferably an intermetallic compound of cheap metal components for mass production of the production line, specifically including any one of Fe-Al intermetallic compounds, Ni-Al intermetallic compounds, Ti-Al intermetallic compounds, Cr-Al intermetallic compounds, Ni-Y intermetallic compounds, Ni-W intermetallic compounds, Ni-Mo intermetallic compounds, W-Fe intermetallic compounds, Fe-Mo intermetallic compounds, Ti-Cu intermetallic compounds, Ti-Fe intermetallic compounds, and Ti-Ni intermetallic compounds, and vacuum evaporation, electron beam evaporation or magnetron sputtering are selected according to actual production needs to prepare the electrode film. In this embodiment, cheap metals are applied to mass production on the production line, which can greatly save the cost of raw materials.

[0031] As an optional embodiment of the present application, optionally, the intermetallic compound raw material also includes: any one of Au-Al intermetallic compounds, Ti-Au intermetallic compounds, Ag-Al intermetallic compounds, Ag-Y intermetallic compounds, Au-Y intermetallic compounds, Pt-Ti intermetallic compounds, Al-Pt intermetallic compounds, and Pt-Y intermetallic compounds.

[0032] In this embodiment, the intermetallic compound raw material is preferably a series of precious metal intermetallic compounds suitable for laboratory research and development, specifically including any one of Au-Al intermetallic compounds, Ti-Au intermetallic compounds, Ag-Al intermetallic compounds, Ag-Y intermetallic compounds, Au-Y intermetallic compounds, Pt-Ti intermetallic compounds, Al-Pt intermetallic compounds, and Pt-Y intermetallic compounds.

[0033] It should be noted that some common materials suitable for use as metal electrodes are often limited to higher processing temperatures during the actual preparation process due to their high melting points. Adding appropriate metal elements can form intermetallic compounds with lower melting points, which can effectively reduce the difficulty of preparation. This application can use both cheap intermetallic compound systems suitable for mass production on production lines and intermetallic compound systems containing precious metals for laboratory research, which can be flexibly selected according to actual production needs.

[0034] As an optional embodiment of the present application, optionally, when vacuum evaporation is used to prepare the intermetallic compound back electrode, the evaporation vacuum degree is set to be less than 10 -3 Pa, and the evaporation rate of vacuum evaporation is 0.01-5 Å / s.

[0035] In this embodiment, when the intermetallic compound back electrode is prepared by vacuum evaporation, the pre-melted intermetallic compound can be placed in the evaporation crucible as the raw material, or a fixed proportion of metal materials can be placed in the evaporation crucible according to the composition of the intermetallic compound, and the temperature is gradually raised to the evaporation temperature. In the vacuum evaporation, the evaporation vacuum degree needs to be controlled to be less than 10 -3 Pa, the evaporation rate of vacuum evaporation is 0.01-5 Å / s, and the thickness of the corresponding deposited intermetallic compound back electrode film is between 80 and 500 nm, thereby realizing the preparation of the intermetallic compound back electrode.

[0036] As an optional embodiment of the present application, optionally, when electron beam evaporation is used to prepare the intermetallic compound back electrode, the vacuum degree of the electron beam evaporation is set to be less than 10 -3 Pa, and the evaporation rate of electron beam evaporation is 0.01-5 Å / s.

[0037] In this embodiment, when the intermetallic compound back electrode is prepared by electron beam evaporation, the pre-melted intermetallic compound can be placed in the evaporation crucible as the raw material, and the power is gradually increased. The vacuum degree of the electron beam evaporation is controlled to be less than 10 -3 Pa, the evaporation rate of electron beam evaporation is 0.01-5 Å / s, and the thickness of the deposited intermetallic compound electrode film is between 80-500nm, realizing the preparation of the back electrode.

[0038] As an optional embodiment of the present application, optionally, when magnetron sputtering is used to prepare the intermetallic compound back electrode, the initial vacuum degree of sputtering is set to 5×10 -4 Pa, the working gas is argon, the sputtering power is 100-350W, and the sputtering time is 20min-90min.

[0039] In this embodiment, when magnetron sputtering is used to prepare the intermetallic compound back electrode, a metal compound target material with a certain composition or dual-target magnetron sputtering can be prepared in advance. When sputtering is performed, the vacuum degree of sputtering is initially maintained at 5×10 -4 Pa, the working gas is argon, the purity of argon is ≥99.99%, and the gas pressure is about 1 Pa. The sputtering power is kept constant between 100-350W, and the thickness of the deposited intermetallic compound electrode film is between 80-500nm, so as to realize the preparation of the back electrode.

[0040] It can be seen that the intermetallic compound electrode of the present application can be prepared by PVD methods such as vacuum evaporation, electron beam evaporation and magnetron sputtering, and the intermetallic compound raw materials of the present application include cheap intermetallic compound systems suitable for mass production of production lines, as well as intermetallic compound systems containing precious metals that can be used for laboratory research. The prepared intermetallic compound electrode can be applied to both flexible perovskite solar cells and rigid perovskite solar cells, and the corrosion-resistant metal back electrode material can effectively improve the long-term stability of perovskite solar cells.

[0041] According to another aspect of the present application, an intermetallic compound back electrode is provided, which is prepared by using any of the above-mentioned intermetallic compound back electrode preparation methods.

[0042] This application innovatively uses intermetallic compounds as the back electrode of perovskite solar cells to achieve high stability and high efficiency of perovskite solar cells.

[0043] like Figure 2 As shown, according to another aspect of the present application, a perovskite solar cell is provided, comprising: a transparent substrate 1; a first transparent conductive electrode 2, disposed on the transparent substrate 1; a hole transport layer 3, disposed on the first transparent conductive electrode 2; a perovskite light absorption layer 4, disposed on the hole transport layer 3; an electron transport layer 5, disposed on the perovskite light absorption layer 4; a buffer layer 6, disposed on the electron transport layer 5; an intermetallic compound back electrode 7 prepared by any of the above-mentioned intermetallic compound back electrode preparation methods, disposed on the buffer layer 6.

[0044] The perovskite solar cell of this embodiment uses the intermetallic compound back electrode prepared by the intermetallic compound back electrode preparation method described in any of the above items to prepare the battery. Specifically, a transparent substrate, a first transparent conductive electrode, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer and the above-mentioned intermetallic compound back electrode are arranged in sequence from bottom to top. That is, the intermetallic compound back electrode is directly prepared on the buffer layer. When preparing a perovskite solar cell, a corresponding transparent substrate is selected according to actual needs, and a layer of transparent conductive oxide, that is, the first transparent conductive electrode, is deposited on the transparent substrate in sequence, a hole transport layer is deposited on the transparent conductive oxide, a perovskite light absorption layer is coated on the hole transport layer, an electron transport layer is deposited on the perovskite light absorption layer, a buffer layer is prepared on the electron transport layer, and finally an intermetallic compound back electrode is prepared on the buffer layer.

[0045] As an optional embodiment of the present application, optionally, it also includes: a second transparent conductive electrode, which is arranged between the buffer layer and the intermetallic compound back electrode.

[0046] The perovskite solar cell provided in this embodiment is provided with a transparent substrate, a first transparent conductive electrode, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer, a second transparent conductive electrode and the above-mentioned intermetallic compound back electrode in order from bottom to top, that is, the intermetallic compound back electrode is prepared on the second transparent conductive electrode. Among them, the first transparent conductive electrode and the second transparent conductive electrode are preferably transparent conductive oxides such as FTO, ITO, AZO, etc., and the deposition method includes atomic layer deposition ALD, magnetron sputtering and reactive plasma deposition RPD, etc.

[0047] As an optional embodiment of the present application, optionally, the transparent substrate includes any one of rigid glass, flexible glass, PEN, PET or PI. That is, when preparing a perovskite solar cell, the transparent substrate is preferably flexible glass or rigid glass, or any one of PET, PEN, PI polymer materials.

[0048] In order to illustrate that the perovskite solar cell using an intermetallic compound back electrode of the present invention has better performance, a comparative analysis of the perovskite solar cells prepared under the same conditions is now conducted.

[0049] Example 1 A perovskite battery device, the battery device structure is sequentially provided with a transparent glass substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer and an intermetallic compound electrode from bottom to top. Among them, the intermetallic compound electrode of this embodiment is FeAl 2The electrode was prepared by vacuum deposition. When evaporating the electrode, Fe and Al metal particles were placed in the evaporation crucible in a ratio of 1:2. The temperature was slowly raised until all the metal particles melted. The plating rate was controlled to be 2 Å / s to prepare an intermetallic compound electrode with a film thickness of 150 nm. At the same time, an Ag electrode of the same thickness was prepared at the same plating rate for comparison. The area of ​​a single cell was 0.09 cm 2 . Figure 3 Shown is a box plot of the photoelectric performance parameters of perovskite solar cell devices, including open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE). Under the same conditions, the battery device with NiAl intermetallic compounds as electrodes has a higher open circuit voltage, a lower short circuit current density, and a more stable photoelectric conversion efficiency.

[0050] Example 2 A perovskite solar cell device uses NiAl intermetallic compound as an electrode and is deposited by vacuum evaporation. During the evaporation, small NiAl particles that have been melted in advance are placed in an evaporation crucible, and the temperature is slowly increased until all the metal particles are melted. The plating rate is controlled to be 2 Å / s, and a metal compound electrode with a film thickness of 150 nm is prepared. At the same time, an Ag electrode of the same thickness is prepared at the same plating rate for comparison. The area of ​​a single cell is 0.09 cm 2 . Figure 4 The IV test curves of two different electrode perovskite solar cell devices are shown. Figure 5 The figure shows the 85°C thermal stability curves of two perovskite solar devices with different electrodes. Under the same conditions, the solar cell with NiAl intermetallic compound as electrode has better properties and is more stable.

[0051] Example 3 A perovskite solar cell module is provided with a glass substrate, a transparent conductive glass, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a buffer layer and a metal electrode in order from bottom to top. 2 The size of FTO glass substrate is used, and the sub-cells are divided by laser scribing P1, and then the hole transport layer is prepared by magnetron sputtering, the organic-inorganic hybrid perovskite layer is prepared by slit coating, and the electron transport layer and buffer layer are prepared by vacuum evaporation. Laser scribing P2 is used to prepare for the formation of a series circuit, and then vacuum evaporation is used to prepare NiAl intermetallic compound electrodes. Finally, laser scribing P3 is used to cut the intermetallic compound, and finally a perovskite solar cell module is formed. The IV curve of the module is as follows Figure 6 As shown, the active area of ​​the module is 164cm 2 , fill factor 76.5%, short-circuit current 127.30 mA, open-circuit voltage 25.8 V, photoelectric conversion efficiency 15.32%, and excellent photoelectric performance.

[0052] It can be seen that the present application adopts an intermetallic compound back electrode to prepare a perovskite solar cell. The intermetallic compound electrode serves as the output end of the perovskite cell and is arranged behind the buffer layer or transparent electrode layer of the cell, which effectively ensures the long-term stability of the perovskite solar cell and overcomes the problem of diffusion reaction between the halide and the metal back electrode in the perovskite solar cell.

[0053] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing an intermetallic compound back electrode, characterized in that: The steps include: The intermetallic compound raw materials are prepared by vacuum melting; The intermetallic compound raw material is subjected to any one of vacuum evaporation, electron beam evaporation or magnetron sputtering to prepare the intermetallic compound back electrode.

2. The method for preparing an intermetallic compound back electrode according to claim 1, characterized in that: The intermetallic compound raw material comprises: Any one of Fe-Al intermetallic compounds, Ni-Al intermetallic compounds, Ti-Al intermetallic compounds, Cr-Al intermetallic compounds, Ni-Y intermetallic compounds, Ni-W intermetallic compounds, Ni-Mo intermetallic compounds, W-Fe intermetallic compounds, Fe-Mo intermetallic compounds, Ti-Cu intermetallic compounds, Ti-Fe intermetallic compounds, and Ti-Ni intermetallic compounds.

3. The method for preparing an intermetallic compound back electrode according to claim 1, characterized in that: The intermetallic compound raw material further includes: Any one of Au-Al intermetallic compound, Ti-Au intermetallic compound, Ag-Al intermetallic compound, Ag-Y intermetallic compound, Au-Y intermetallic compound, Pt-Ti intermetallic compound, Al-Pt intermetallic compound, Pt-Y intermetallic compound.

4. The method for preparing an intermetallic compound back electrode according to claim 1, characterized in that: When vacuum evaporation is used to prepare the intermetallic compound back electrode, the evaporation vacuum is set to less than 10 -3 Pa, and the evaporation rate of vacuum evaporation is 0.01-5 Å / s.

5. The method for preparing an intermetallic compound back electrode according to claim 1, characterized in that: When electron beam evaporation is used to prepare the back electrode of the intermetallic compound, the vacuum degree of the electron beam evaporation is set to be less than 10 -3 Pa, and the evaporation rate of electron beam evaporation is 0.01-5 Å / s.

6. The method for preparing an intermetallic compound back electrode according to claim 1, characterized in that: When magnetron sputtering is used to prepare the back electrode of the intermetallic compound, the initial vacuum degree of sputtering is set to 5×10 -4 Pa, the working gas is argon, and the sputtering power is 100-350W.

7. An intermetallic compound back electrode, characterized in that: The intermetallic compound back electrode is prepared by the method for preparing the intermetallic compound back electrode according to any one of claims 1 to 6.

8. A perovskite solar cell, characterized in that: include: Transparent substrate; A first transparent conductive electrode is disposed on the transparent substrate; a hole transport layer, disposed on the first transparent conductive electrode; A perovskite light absorbing layer, disposed on the hole transport layer; An electron transport layer, disposed on the perovskite light absorbing layer; A buffer layer, disposed on the electron transport layer; The intermetallic compound back electrode prepared by the method for preparing an intermetallic compound back electrode according to any one of claims 1 to 6 is arranged on the buffer layer.

9. The perovskite solar cell according to claim 8, characterized in that: Also includes: The second transparent conductive electrode is arranged between the buffer layer and the intermetallic compound back electrode.

10. The perovskite solar cell according to claim 8, characterized in that: The transparent substrate includes any one of rigid glass, flexible glass, PEN, PET or PI.

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