Multi-junction perovskite cells and methods of making

Abstract

Embodiments of the present application provide a multi-junction perovskite cell and a preparation method, and relate to the field of perovskite cells. The multi-junction perovskite cell comprises a substrate layer, a first charge transport layer, a first passivation layer, a double-end amino small molecule connecting layer, a plurality of perovskite layers and a second passivation layer which are stacked; wherein two adjacent perovskite layers are bridged by the double-end amino small molecule connecting layer, and the band gaps of the plurality of perovskite layers are different. Since the double-end amino small molecule has good stability and conductivity, compared with the interconnection layer or the tunneling mode in the prior art, the multi-junction perovskite cell bridges the first perovskite layer and the second perovskite layer through the double-end amino small molecule connecting layer, can more stably conduct the gradient connection of the perovskite layer materials with different band gaps, and thus effectively expands the spectral response interval of the multi-layer perovskite cell.

Description

Technical Field

[0001] This invention relates to the field of perovskite battery technology, and more specifically, to a multi-junction perovskite battery and its preparation method. Background Technology

[0002] Any solar cell can only absorb light of a fixed wavelength, and most of its energy is lost due to thermal relaxation. Currently, the commonly used technology is to extend the spectral response range by stacking light-absorbing layers with different band gaps. However, most cell structures are quite complex, requiring interconnect layers or tunneling to achieve cell conduction.

[0003] Existing multi-junction perovskite solar cells suffer from complex and difficult conduction between light-absorbing layers with different band gaps. Summary of the Invention

[0004] This invention provides a multi-junction perovskite solar cell and its preparation method, which can effectively achieve conduction between light-absorbing layers with different band gaps, thereby effectively expanding the spectral response range of multilayer perovskite solar cells.

[0005] This invention can be implemented as follows:

[0006] This invention provides a multi-junction perovskite solar cell, comprising:

[0007] The multi-junction perovskite solar cell comprises a substrate layer, a first charge transport layer, a first passivation layer, multiple perovskite layers, and a second passivation layer stacked together. The multi-junction perovskite solar cell also includes a double-terminated amino small molecule linking layer.

[0008] In this configuration, one side surface of the substrate layer is in contact with the first charge transport layer, and the side surface of the first charge transport layer away from the substrate layer is in contact with the first passivation layer. Multiple perovskite layers are stacked, and adjacent perovskite layers are bridged by the double-terminated amino molecule connecting layer. The side surface of the first passivation layer away from the first charge transport layer is in contact with the perovskite layer stacked at the bottom, and the side surface of the perovskite layer stacked at the top away from the double-terminated amino molecule connecting layer is in contact with the second passivation layer. The band gaps of the multiple perovskite layers are all different.

[0009] Optionally, the number of perovskite layers is two, namely a first perovskite layer and a second perovskite layer. The surface of the first passivation layer away from the first charge transport layer is in contact with the first perovskite layer. The first perovskite layer and the second perovskite layer are in contact through the double-terminated amino small molecule linking layer. The surface of the second perovskite layer away from the double-terminated amino small molecule linking layer is in contact with the second passivation layer.

[0010] Optionally, the band gap of the plurality of perovskite layers gradually increases from bottom to top.

[0011] Optionally, the material of the dual-terminated amino small molecule linker layer includes at least one of branched alkanes or aromatic hydrocarbons.

[0012] Optionally, the dual-terminated amino small molecule linker layer is a dual-terminated amino small molecule film.

[0013] Optionally, the multi-junction perovskite solar cell further includes a second charge transport layer, which is stacked on the side of the second passivation layer away from the second perovskite layer.

[0014] This invention also provides a method for preparing multi-junction perovskite solar cells. The preparation method includes:

[0015] A first charge transport layer is deposited on one side of the substrate layer;

[0016] A first passivation layer is deposited on the side of the first charge transport layer away from the substrate layer;

[0017] A first perovskite layer is deposited on the side of the first passivation layer away from the first charge transport layer;

[0018] A double-terminated amino small molecule film is deposited once on the side of the first perovskite layer away from the first passivation layer;

[0019] A second perovskite layer with different band gaps was deposited and pre-cured by infrared heating to obtain a semi-dry second perovskite layer.

[0020] The semi-dry second perovskite layer is transferred onto the double-terminated amino small molecule film and then transferred to an annealing furnace for curing.

[0021] Optionally, the step of depositing a double-terminated amino small molecule film on the side of the first perovskite layer away from the first passivation layer includes:

[0022] At a vacuum degree of 1.0 × 10 -4 Pa to 3.0×10 -4 Evaporation was carried out at a temperature of 280℃-350℃ and an evaporation rate of 0.1A / s-1A / s, and then a double-terminated amino small molecule film was deposited.

[0023] Optionally, the step of pre-curing a second perovskite layer with different band gaps by infrared heating to obtain a semi-dry second perovskite layer includes:

[0024] On another flexible substrate, a second perovskite layer with different band gaps is deposited using inkjet printing, spin coating, or blade coating techniques. The layer is then pre-cured by infrared heating at 80°C for 5-10 minutes to obtain a semi-dry second perovskite layer.

[0025] Optionally, after the step of transferring the semi-dry second perovskite layer onto the double-terminated amino-based small molecule film and then transferring it to an annealing furnace for curing, the preparation method further includes:

[0026] A second passivation layer is deposited on the side of the second perovskite layer away from the double-terminated amino small molecule film.

[0027] The beneficial effects of the multi-junction perovskite solar cell and its preparation method of the present invention include, for example:

[0028] The multi-junction perovskite solar cell includes a substrate layer, a first charge transport layer, a first passivation layer, multiple perovskite layers, and a second passivation layer stacked together. The multi-junction perovskite solar cell also includes a double-terminated amino-molecule linking layer. One surface of the substrate layer is in contact with the first charge transport layer, and the surface of the first charge transport layer away from the substrate layer is in contact with the first passivation layer. The multiple perovskite layers are stacked together, and adjacent perovskite layers are bridged by the double-terminated amino-molecule linking layer. The surface of the first passivation layer away from the first charge transport layer is in contact with the perovskite layer stacked at the bottom, and the surface of the perovskite layer stacked at the top away from the double-terminated amino-molecule linking layer is in contact with the second passivation layer. The band gaps of the multiple perovskite layers are all different. Due to the good stability and conductivity of the double-terminated amino molecules, compared with the existing technology that uses interconnect layers or tunneling, this multi-junction perovskite solar cell bridges the first and second perovskite layers through a double-terminated amino molecule connecting layer. The conductivity of the upper and lower perovskite layers can be achieved with a single molecular material. Compared with the existing technology that achieves perovskite conductivity through multiple layers, it can more stably conduct the gradient connection of perovskite layer materials with different band gaps, thereby effectively expanding the spectral response range of the multi-layer perovskite cell. The double-terminated amino molecule connecting layer interconnects the first and second perovskite layers, and at the same time, the terminal amino groups passivate the defects on the perovskite surface.

[0029] This method for fabricating multi-junction perovskite solar cells includes: depositing a first charge transport layer on one side of a substrate; depositing a first passivation layer on the side of the first charge transport layer away from the substrate; depositing a first perovskite layer on the side of the first passivation layer away from the first charge transport layer; depositing a double-terminated amino small molecule film on the side of the first perovskite layer away from the first passivation layer; depositing a second perovskite layer with a different bandgap, pre-curing it using infrared heating to obtain a semi-dry second perovskite layer; transferring the semi-dry second perovskite layer onto the double-terminated amino small molecule film, and then transferring it to an annealing furnace for curing. In use, this method bridges the first and second perovskite layers using a thermal transfer technique, enabling more stable conduction of the gradient connections between perovskite layer materials with different bandgapes. This effectively expands the spectral response range of the multi-junction perovskite solar cell. Furthermore, the conductivity between the upper and lower perovskite layers can be achieved with a single molecular material, simplifying the structure of the multi-junction perovskite solar cell and making the process simpler. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the structure of a multi-junction perovskite solar cell provided in an embodiment of the present invention;

[0032] Figure 2 A process flow diagram of the fabrication method of multi-junction perovskite solar cells provided in the embodiments of the present invention.

[0033] Icons: 10 - Base layer; 20 - First charge transport layer; 30 - First passivation layer; 40 - First perovskite layer; 50 - Double-terminated amino small molecule linking layer; 60 - Second perovskite layer; 70 - Second passivation layer; 80 - Second charge transport layer; 90 - Transparent conductive layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0036] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," and "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this invention and simplifying the description, and therefore should not be construed as limiting this invention.

[0037] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0038] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0039] Any solar cell can only absorb light of a fixed wavelength, and most of its energy is lost due to thermal relaxation. Currently, the commonly used technology is to extend the spectral response range by stacking light-absorbing layers with different band gaps. However, most cell structures are quite complex, requiring interconnect layers or tunneling to achieve cell conduction.

[0040] In existing multi-junction cell structures, tunnel junctions or composite junctions are required to achieve connectivity between the upper and lower perovskite layers for the cell to function. This structure suffers from optical and electrical losses. Therefore, multi-junction perovskite cells in related technologies face the problem of complex and difficult conduction between light-absorbing layers with different band gaps.

[0041] Please refer to Figures 1-2 This embodiment provides a multi-junction perovskite solar cell. This multi-junction perovskite solar cell effectively improves the aforementioned technical problems, enabling effective conduction between light-absorbing layers with different band gaps, thereby effectively expanding the spectral response range of the multilayer perovskite solar cell.

[0042] Please refer to Figure 1The multi-junction perovskite solar cell includes a substrate layer 10, a first charge transport layer 20, a first passivation layer 30, a double-terminated amino molecule linking layer 50, multiple perovskite layers, a second passivation layer 70, a second charge transport layer 80, and a transparent conductive layer 90, all stacked together. One side surface of the substrate layer 10 is in contact with the first charge transport layer 20, and the side surface of the first charge transport layer 20 away from the substrate layer 10 is in contact with the first passivation layer 30. Multiple perovskite layers are stacked, and adjacent perovskite layers are bridged by the double-terminated amino molecule linking layer 50. The side surface of the first passivation layer 30 away from the first charge transport layer 20 is in contact with the bottom perovskite layer, and the side surface of the top perovskite layer away from the double-terminated amino molecule linking layer 50 is in contact with the second passivation layer 70. The band gaps of the multiple perovskite layers are all different.

[0043] Specifically, the perovskite solar cell structure in this embodiment is a double-junction structure. In other embodiments, the perovskite solar cell structure can also be a triple-junction structure, a quadruple-junction structure, or a quintuple-junction structure, which is not specifically limited here.

[0044] There are two perovskite layers, namely a first perovskite layer 40 and a second perovskite layer 60.

[0045] It should be noted that existing multi-junction cell structures require tunnel junctions or composite junctions to achieve interconnection between the upper and lower perovskite layers, which results in optical and electrical losses. To address this technical issue, the multi-junction perovskite cell provided in this embodiment directly strips away the tunnel junction or composite junction and fuses and interconnects it using a double-ended organic amine material, fundamentally changing the cell structure and improving efficiency.

[0046] Specifically, the double-terminated amino small molecule linking layer 50 is a double-terminated amino small molecule film, and the material of the double-terminated amino small molecule linking layer 50 includes at least one of branched alkanes or aromatic hydrocarbons.

[0047] The chemical formula of the double-terminated amino small molecule film in this embodiment can be represented by chemical formula 1 and chemical formula 2:

[0048] [Chemical Formula 1]

[0049]

[0050] [Chemical Formula 2]

[0051]

[0052] In this embodiment, the material of the double-terminated amino-terminated small molecule linker layer 50 is a branched-chain alkane. In other embodiments, the material of the double-terminated amino-terminated small molecule linker layer 50 can be an aromatic hydrocarbon structure or a branched-chain alkane. No specific limitations are imposed here.

[0053] Specifically, the amino groups at both ends of the chemical formula of the double-terminated amino small molecule film can bridge the first perovskite layer 40 and the second perovskite layer 60, enhancing the bonding ability between the film layers. At the same time, the amino groups at the ends can also effectively passivate defects on the surface of the contact layer.

[0054] It should be noted that the double-terminated amino small molecule linker layer 50 is a double-terminated amino small molecule film.

[0055] In this embodiment, the band gaps of the first perovskite layer 40 and the second perovskite layer 60 are different. The first perovskite layer 40 and the second perovskite layer 60 with different band gaps are connected by a double-terminated amino-molecule thin film.

[0056] Specifically, the dual-terminal amino-terminated small molecule linker layer 50 can interconnect the first perovskite layer 40 and the second perovskite layer 60 through its dual-terminal amino-terminated structure, while also passivating defects on the perovskite surface using the terminal amino groups. Moreover, the dual-terminal amino-terminated small molecule linker layer 50 is thin and has good conductivity, which can significantly improve the light transmittance of the battery and increase the short-circuit current of the battery.

[0057] In this embodiment, the band gaps of the multiple perovskite layers gradually increase from bottom to top. Specifically, the band gap of the first perovskite layer 40 ranges from 1.1 eV to 1.5 eV, and the absorption spectrum of the first perovskite layer 40 is in the range of 780 nm to 1120 nm. The band gap of the second perovskite layer 60 ranges from 1.6 eV to 1.8 eV, and the absorption spectrum of the second perovskite layer 60 is below 780 nm. In other embodiments, the band gaps of the multiple perovskite layers may gradually decrease from bottom to top, or the band gaps of the multiple perovskite layers may increase or decrease irregularly; no specific limitations are imposed here.

[0058] This multi-junction perovskite solar cell simplifies the cell structure by eliminating the composite junctions found in traditional tandem solar cells, greatly reducing the difficulty of cell fabrication and simplifying the process steps.

[0059] Please refer to Figure 2 The embodiments of the present invention also provide a method for preparing multi-junction perovskite solar cells, the method comprising:

[0060] S1: A first charge transport layer 20 is deposited on one side of the substrate 10 by magnetron sputtering.

[0061] Specifically, the substrate 10 is a cleaned fluorine-doped tin dioxide (FTO) or indium tin oxide (ITO), and the first charge transport layer 20 is a nickel oxide hole transport layer with a thickness of 10nm-25nm.

[0062] S2: A first passivation layer 30 is deposited on the side of the first charge transport layer 20 away from the substrate layer 10 using a scraping technique.

[0063] Specifically, the first passivation layer 30 is an aluminum oxide (Al2O3) film with a thickness of 1nm-5nm.

[0064] In this method, water is used as the oxygen source, and trimethylaluminum is used as the aluminum source. Ozone is used to deposit a uniform and dense ultrathin alumina film with a thickness of 1nm-10nm at a low temperature of 80℃-200℃.

[0065] The growth process using water as an oxygen source and trimethylaluminum as an aluminum source is as follows: the chamber reaction temperature is 80℃-200℃, the trimethylaluminum source is passed through for 100ms-500ms, then more inert gas is blown in to purge for 10s-30s to remove trimethylaluminum, water vapor is passed through for 100ms-800ms, nitrogen is purge for 10s-30s, and the above process is repeated 30-100 times.

[0066] S3: Deposit a first perovskite layer 40 on the side of the first passivation layer 30 away from the first charge transport layer 20.

[0067] Specifically, the first perovskite layer 40 is a perovskite thin film, and a perovskite thin film is deposited on the substrate in step S2 using vapor deposition, coating or inkjet technology.

[0068] Taking the perovskite thin film preparation method by vapor deposition as an example, on the substrate in step S2, a 200nm-300nm lead iodide (PbI2) thin film layer containing a small amount of lead chloride (PbCl2) and cesium bromide (CsBr) is deposited by vacuum vapor deposition, wherein the vapor deposition rate ratio of PbI2, PbCl2 and CsBr is 1:0.05:0.1.

[0069] After the above film is completed, it is transferred to the solution inkjet stage. Using an inkjet printer, an organic ammonium salt solution with a mass ratio of formamidinium hydroiodate, formamidinium hydrobromide, and methylamine hydrochloride of 90:9:9 and isopropanol as solvent is uniformly coated on the above film. After pre-curing by heating at 80°C for 5-10 minutes using infrared heating, it is then transferred to a high-temperature annealing furnace at 120°C-150°C for 10-30 minutes.

[0070] S4: A double-terminated amino small molecule film is deposited on the side of the first perovskite layer 40 away from the first passivation layer 30 using vapor deposition technology.

[0071] In this process, a double-terminated amino small molecule film can be deposited on the perovskite film in step S3 using vapor deposition, coating, or blade coating techniques.

[0072] Specifically, taking vapor deposition as an example, at a vacuum degree of 1.0 × 10⁻⁶-4 Pa to 3.0×10 -4 Evaporation was carried out at a temperature of 280℃-350℃ and an evaporation rate of 0.1A / s-1A / s, and then a double-terminated amino small molecule film was deposited.

[0073] S5: Deposit a second perovskite layer 60 with different band gaps, and then pre-cur it using infrared heating to obtain a semi-dry second perovskite layer 60.

[0074] Specifically, the second perovskite layer 60 is a perovskite thin film. On another flexible substrate, a perovskite thin film with different band gaps is deposited using inkjet printing, spin coating or blade coating technology. It is pre-cured at an infrared heating temperature of 80°C for 5-10 minutes to obtain a semi-dry perovskite thin film.

[0075] S6: The semi-dry second perovskite layer 60 is transferred onto a double-terminated amino small molecule film using thermal transfer technology, and then transferred to an annealing furnace for curing.

[0076] Specifically, a semi-dry perovskite film on another substrate is transferred to the substrate in step S4 using thermal transfer technology, and then transferred to a high-temperature (120℃-150℃, 10min-30min) annealing furnace for curing.

[0077] S7: Deposit a second passivation layer 70 on the side of the second perovskite layer 60 away from the double-terminated amino small molecule film.

[0078] S8: On the side of the second passivation layer 70 away from the second perovskite layer 60, a second charge transport layer 80 and a PVD sputtered transparent conductive layer 90 are sequentially deposited.

[0079] In summary, the embodiments of the present invention provide a multi-junction perovskite solar cell and its fabrication method. The multi-junction perovskite solar cell includes a substrate layer 10, a first charge transport layer 20, a first passivation layer 30, multiple perovskite layers, and a second passivation layer 70 stacked together. The multi-junction perovskite solar cell also includes a double-terminated amino small molecule linking layer 50. One side surface of the substrate layer 10 is in contact with the first charge transport layer 20, and the side surface of the first charge transport layer 20 away from the substrate layer 10 is in contact with the first passivation layer 30. Multiple perovskite layers are stacked together, and adjacent perovskite layers are bridged by the double-terminated amino small molecule linking layer 50. The side surface of the first passivation layer 30 away from the first charge transport layer 20 is in contact with the perovskite layer stacked at the bottom, and the side surface of the perovskite layer stacked at the top away from the double-terminated amino small molecule linking layer 50 is in contact with the second passivation layer 70. The band gaps of the multiple perovskite layers are all different. Due to the good stability and conductivity of the double-terminated amino molecules, as well as their high activity and easy oxidation, compared with the use of interconnect layers or tunneling methods in existing technologies, this multi-junction perovskite solar cell can more stably connect the first perovskite layer 40 and the second perovskite layer 60 by bridging the first perovskite layer 40 and the second perovskite layer 60 through the double-terminated amino molecule connecting layer 50. Moreover, only one layer of molecular material is needed to achieve the conduction of the upper and lower perovskite layers. Compared with the existing technology that achieves the conduction of perovskite through multiple layers, it can more stably conduct the gradient connection of perovskite layer materials with different band gaps, thereby effectively expanding the spectral response range of the multi-layer perovskite solar cell. The double-terminated amino molecule connecting layer 50 interconnects the first perovskite layer 40 and the second perovskite layer 60 while also using the terminal amino groups to passivate the defects on the perovskite surface.

[0080] The method for fabricating a multi-junction perovskite solar cell includes: depositing a first charge transport layer 20 on one side of a substrate 10; depositing a first passivation layer 30 on the side of the first charge transport layer 20 away from the substrate 10; depositing a first perovskite layer 40 on the side of the first passivation layer 30 away from the first charge transport layer 20; depositing a double-terminated amino small molecule film on the side of the first perovskite layer 40 away from the first passivation layer 30; depositing a second perovskite layer 60 with a different band gap, pre-curing it using infrared heating to obtain a semi-dry second perovskite layer 60; transferring the semi-dry second perovskite layer 60 onto the double-terminated amino small molecule film, and then transferring it to an annealing furnace for curing. In use, the fabrication method of this multi-junction perovskite solar cell utilizes thermal transfer technology to bridge the first perovskite layer 40 and the second perovskite layer 60 with a double-terminated amino small molecule connecting layer 50. This enables more stable conduction of the gradient connection of perovskite layer materials with different band gaps, thereby effectively expanding the spectral response range of the multi-layer perovskite solar cell. Furthermore, the conduction of the upper and lower perovskite layers can be achieved with a single molecular material, simplifying the structure of the multi-junction perovskite solar cell and making the process simpler.

[0081] Comparative Example

[0082] Compared with the multi-junction perovskite solar cell in the examples, the multi-junction perovskite solar cell in this comparative example does not have a double-terminated amino small molecule connecting layer 50. The first perovskite layer 40 and the second perovskite layer 60 are in direct contact, and the other structures are the same as those in the examples.

[0083] Table 1 shows a comparison of the battery performance parameters of the multi-junction perovskite cells in the examples and the comparative examples:

[0084] Table 1

[0085] <![CDATA[Jsc(mA / cm 2 )]]> Voc(V) FF PCE (%) Example 25.32 1.226 0.836 25.95 Comparative Example 16.04 1.997 0.782 25.03

[0086] In Table 1, Jsc represents the short-circuit current density, Voc represents the open-circuit voltage, FF represents the fill factor, and PCE represents the cell conversion efficiency. Table 1 shows that the multi-junction perovskite cell in the comparative example has the worst cell conversion efficiency. Regarding the short-circuit current density, the example cell is 9.28 mA / cm² higher than the comparative example. 2 Regarding open-circuit voltage, the embodiment is 0.771V lower than the comparative example. Regarding fill factor, the embodiment is 0.054 higher than the comparative example. Regarding cell conversion efficiency, the embodiment is 0.92% higher than the comparative example. This more clearly demonstrates that the multi-junction perovskite solar cell provided by this embodiment outperforms existing products in several key performance indicators, thus improving cell conversion efficiency.

[0087] It should be noted that in the comparative example, the multiple perovskite layers of the multi-junction perovskite solar cell are stacked sequentially, so the open-circuit voltage of the cell is the sum of the voltages of the multiple layers. However, in the embodiment, the multiple perovskite layers of the multi-junction perovskite solar cell are fused together through a double-terminated amino-terminated small molecule linker 50, and are not simply stacked; it is equivalent to a single, integrated cell. Therefore, the open-circuit voltage of this multi-junction perovskite solar cell is lower than that of the comparative example.

[0088] In summary, the short-circuit current and fill factor of the multi-junction perovskite solar cell in the embodiment are significantly improved compared with those in the comparative example. Although the open-circuit voltage of the multi-junction perovskite solar cell in the embodiment is lower than that in the comparative example, the final cell conversion efficiency of the embodiment is significantly improved compared with that of the comparative example.

[0089] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-junction perovskite solar cell, comprising a substrate layer (10), a first charge transport layer (20), a first passivation layer (30), a plurality of perovskite layers, and a second passivation layer (70) stacked together, characterized in that, It also includes a double-terminated amino small molecule linker layer (50); In this configuration, one side surface of the substrate layer (10) is in contact with the first charge transport layer (20), and the side surface of the first charge transport layer (20) away from the substrate layer (10) is in contact with the first passivation layer (30). Multiple perovskite layers are stacked, and two adjacent perovskite layers are connected by the double-terminated amino molecule linking layer (50). The side surface of the first passivation layer (30) away from the first charge transport layer (20) is in contact with the perovskite layer stacked at the bottom, and the side surface of the perovskite layer stacked at the top away from the double-terminated amino molecule linking layer (50) is in contact with the second passivation layer (70). The band gaps of the multiple perovskite layers are all different.

2. The multi-junction perovskite solar cell according to claim 1, characterized in that, The number of perovskite layers is two, namely a first perovskite layer (40) and a second perovskite layer (60). The first passivation layer (30) is in contact with the first perovskite layer (40) on the side away from the first charge transport layer (20). The first perovskite layer (40) and the second perovskite layer (60) are in contact through the double-terminated amino small molecule linking layer (50). The second perovskite layer (60) is in contact with the second passivation layer (70) on the side away from the double-terminated amino small molecule linking layer (50).

3. The multi-junction perovskite solar cell according to claim 1, characterized in that, The band gap of the multiple perovskite layers gradually increases from bottom to top.

4. The multi-junction perovskite solar cell according to claim 1, characterized in that, The material of the dual-terminal amino small molecule linker layer (50) includes at least one of branched alkanes or aromatic hydrocarbons.

5. The multi-junction perovskite solar cell according to claim 4, characterized in that, The dual-terminated amino small molecule linker layer (50) is a dual-terminated amino small molecule film.

6. The multi-junction perovskite solar cell according to claim 2, characterized in that, The multi-junction perovskite solar cell further includes a second charge transport layer (80), which is stacked on the side of the second passivation layer (70) away from the second perovskite layer (60).

7. A method for preparing a multi-junction perovskite solar cell, characterized in that, The preparation method includes: A first charge transport layer (20) is deposited on one side of the base layer (10); A first passivation layer (30) is deposited on the side of the first charge transport layer (20) away from the base layer (10); A first perovskite layer (40) is deposited on the side of the first passivation layer (30) away from the first charge transport layer (20); A double-terminated amino small molecule film is deposited once on the side of the first perovskite layer (40) away from the first passivation layer (30); A second perovskite layer (60) with different band gaps is deposited and pre-cured by infrared heating to obtain a semi-dry second perovskite layer (60); The semi-dry second perovskite layer (60) is transferred onto the double-terminated amino small molecule film and then transferred to an annealing furnace for curing.

8. The method for preparing a multi-junction perovskite solar cell according to claim 7, characterized in that, The step of depositing a double-terminated amino small molecule film on the side of the first perovskite layer (40) away from the first passivation layer (30) includes: At a vacuum degree of 1.0 × 10 -4 Pa to 3.0×10 -4 Evaporation was carried out at a temperature of 280℃-350℃ and an evaporation rate of 0.1A / s-1A / s, and then a double-terminated amino small molecule film was deposited.

9. The method for preparing a multi-junction perovskite solar cell according to claim 7, characterized in that, The steps for obtaining a semi-dry second perovskite layer (60) after pre-curing it by infrared heating after depositing a second perovskite layer (60) with different band gaps include: On another flexible substrate, a second perovskite layer (60) with different band gaps is deposited using inkjet printing, spin coating or blade coating techniques. The layer is then pre-cured at an infrared heating temperature of 80°C for 5-10 minutes to obtain a semi-dry second perovskite layer (60).

10. The method for preparing a multi-junction perovskite solar cell according to claim 7, characterized in that, After the step of transferring the semi-dry second perovskite layer (60) onto the double-terminated amino small molecule film and then transferring it to an annealing furnace for curing, the preparation method further includes: A second passivation layer (70) is deposited on the side of the second perovskite layer (60) away from the double-terminated amino small molecule film.

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