Flexible fibrous perovskite solar cell

Abstract

The utility model provides a flexible fibrous perovskite solar cell, the flexible fibrous perovskite solar cell comprises a first fiber, a second fiber and a third fiber, the surface of the first fiber is coated with an electron transport layer, the surface of the second fiber is coated with a perovskite layer, and the surface of the third fiber is coated with an electron transport layer. The surface of the third fiber is coated with a hole transport layer; the first fiber and the third fiber are wound on the second fiber, and the first fiber and the third fiber are arranged at an interval. According to the flexible fibrous perovskite solar cell, the electron transport layer, the perovskite layer and the hole transport layer are respectively coated on different fibers, so that the three functional layers are separately arranged, the damage to the existing functional layer when a subsequent film layer is deposited can be avoided, and the flexible fibrous perovskite solar cell constructed on the basis has the advantages of high photoelectric conversion efficiency, good flexibility and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar cells, and relates to a perovskite solar cell, in particular to a flexible fibrous perovskite solar cell. Background Art

[0002] Fibrous perovskite solar cells have received extensive attention due to their unique advantages. As a clean and renewable energy source, solar energy is considered an ideal alternative to traditional fossil fuels, with almost unlimited supply and environmental harmlessness. With the development of wearable electronic devices and smart textiles, the demand for flexible, lightweight, and integrable energy supply devices is increasing day by day, which has promoted the development of fibrous solar cell technology.

[0003] In recent years, the photoelectric conversion efficiency (PCE) of fibrous perovskite solar cells has been significantly improved, from 3.3% to 15.7%. Due to their soft and braidable characteristics, fibrous cells can be made into flexible solar cell fabrics through textile technology and then integrated into clothing to provide energy for wearable devices. Compared with flexible solar cells based on planar substrates, fibrous solar cells have the advantages of better flexibility, three-dimensional light absorption, and easy preparation. Therefore, fibrous perovskite solar cells have broad application potential in the fields of wearable devices, portable power supplies, and smart textiles.

[0004] Fibrous perovskite solar cells mainly have coaxial and twisted structures. CN108878655A discloses a three-dimensional linear coaxial structure, similar to a cable, which consists of an inner electrode core, surrounded active material, and an outer electrode. CN105047822B discloses a twisted structure in which two or more single optical fibers containing different components are twisted together. A flexible fibrous perovskite solar cell is prepared by sequentially covering a functional layer, a perovskite light-absorbing layer, and silver nanowires on the surface of a carbon nanotube fiber as a working electrode, and then combining with another carbon nanotube fiber. However, both of the above structures include a structure of a transport layer / perovskite light-absorbing layer / transport layer. In this structure, depositing a transport layer on the perovskite layer is likely to damage the perovskite layer.

[0005] Therefore, how to avoid the damage of the existing functional layer caused by depositing subsequent film layers, so as to improve the photoelectric conversion efficiency and flexibility of fibrous perovskite solar cells, is a technical problem that needs to be solved urgently. Summary of the Utility Model

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present utility model is to provide a flexible fibrous perovskite solar cell. By separately coating an electron transport layer, a perovskite layer, and a hole transport layer on different fibers, the three functional layers are separately arranged, which can avoid the damage to the existing functional layers when depositing subsequent film layers. Based on this, the constructed flexible fibrous perovskite solar cell has the advantages of high photoelectric conversion efficiency and good flexibility.

[0007] To achieve this purpose, the present utility model adopts the following technical solutions:

[0008] In the first aspect, the present utility model provides a flexible fibrous perovskite solar cell, which includes a first fiber, a second fiber, and a third fiber. An electron transport layer is coated on the surface of the first fiber, a perovskite layer is coated on the surface of the second fiber, and a hole transport layer is coated on the surface of the third fiber;

[0009] The first fiber and the third fiber wind around the second fiber, and the first fiber and the third fiber are arranged at intervals.

[0010] By separately coating an electron transport layer, a perovskite layer, and a hole transport layer on different fibers, the three functional layers are separately arranged, which can avoid the damage to the existing functional layers when depositing subsequent film layers. Based on this, the constructed flexible fibrous perovskite solar cell has the advantages of high photoelectric conversion efficiency and good flexibility.

[0011] It should be noted that the first fiber coated with the electron transport layer and the third fiber coated with the hole transport layer are the two working electrodes of the flexible fibrous perovskite solar cell, and both are conductive fibers.

[0012] Preferably, the first fiber includes at least 1 root, such as 1 root, 2 roots, 3 roots, or 4 roots, etc. The third fiber includes at least 1 root, such as 1 root, 2 roots, 3 roots, or 4 roots, etc., but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable; the at least 1 root of the first fiber, the at least 1 root of the third fiber, and the second fiber are twisted together, and the second fiber is located at the center of the twist.

[0013] In the present utility model, through the above settings, it is beneficial for the first fiber coated with the electron transport layer and the third fiber coated with the hole transport layer to extract electrons and holes generated by the perovskite light-absorbing layer coated on the surface of the second fiber.

[0014] Preferably, the first fiber and the second fiber are wound around each other, and the third fiber winds along the winding path of the second fiber to separate the first fiber and the third fiber.

[0015] In the present utility model, through the above settings, it is beneficial to prevent the first fiber coating the electron transport layer and the third fiber coating the hole transport layer from directly contacting, which may cause direct recombination of electrons and holes.

[0016] Preferably, the first fiber and the third fiber are independently a metal fiber or a carbon nanotube fiber.

[0017] Preferably, the metal fiber includes a silver wire or a titanium wire.

[0018] Preferably, the diameters of the first fiber and the third fiber are independently 0.5 - 5 mm, for example, they can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm, etc. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0019] Preferably, the second fiber is a conductive fiber or a non - conductive fiber. Exemplarily, if it is a conductive fiber, the conductive fiber can be, for example, a silver wire, a titanium wire or a carbon nanotube fiber, etc.; if it is a non - conductive fiber, it can be, for example, a polyester fiber, a polyaramide fiber or a glass fiber, etc.

[0020] Preferably, the diameter of the second fiber is 0.5 - 5 mm, for example, it can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm, etc. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0021] Preferably, the electron transport layer includes any one of a C 60 layer, a SnO2 layer or a PCBM layer.

[0022] Preferably, the thickness of the electron transport layer is 20 - 100 nm, for example, it can be 20 nm, 40 nm, 60 nm, 80 nm or 100 nm, etc. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0023] Preferably, the hole transport layer includes any one of a nickel oxide layer, a PTAA (poly[bis(4 - phenyl)(2,4,6 - trimethylphenyl)amine]) layer or a Spiro - OMeTAD (2,2′,7,7′ - tetra(N,N - bis(4 - methoxyphenyl)amino) - 9,9′ - spirobifluorene) layer.

[0024] Preferably, the thickness of the hole transport layer is 20 - 200 nm, for example, it can be 20 nm, 50 nm, 100 nm, 150 nm or 200 nm, etc. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0025] Preferably, the thickness of the perovskite layer is 300 - 1000 nm, for example, it can be 300 nm, 500 nm, 700 nm, 900 nm, etc. However, it is not limited to the listed values, and other unlisted values within this range are also applicable.

[0026] It should be noted that the present invention does not limit the type of the perovskite layer. Those skilled in the art should understand that the perovskite layer conforms to the chemical general formula ABX3 (where A includes CH3NH3 + (MA + )、CH2(NH3)2(FA + ) or Cs + , any one or at least two combinations of them; B includes Pb 2+ and / or Sn 2+ , X includes I - , Br - or Cl - , any one or at least two combinations of them). Those skilled in the art can select appropriate perovskite compositions according to needs.

[0027] In a second aspect, the present invention provides a method for preparing a flexible fibrous perovskite solar cell as described in the first aspect. The preparation method includes the following steps:

[0028] (1) Coating an electron transport layer on the surface of the first fiber; coating a perovskite layer on the surface of the second fiber; coating a hole transport layer on the surface of the third fiber;

[0029] (2) Wrapping the first fiber coated with the electron transport layer and the third fiber coated with the hole transport layer around the second fiber coated with the perovskite layer, and the first fiber and the third fiber are arranged at intervals to obtain the flexible fibrous perovskite solar cell.

[0030] Preferably, the coating method of the electron transport layer in step (1) includes evaporation coating or solution impregnation. The specific steps of the evaporation coating method include: placing the first fiber in a vacuum chamber and depositing the electron transport layer on the surface of the first fiber by vacuum evaporation; the specific steps of the solution impregnation method include: placing the first fiber in a solution containing the electron transport layer material with a concentration of 10 - 80 mg / mL (for example, it can be 10 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 50 mg / mL, 60 mg / mL, 70 mg / mL or 80 mg / mL, etc.) for impregnation, and then taking it out and air-drying to complete the coating.

[0031] Preferably, the coating method of the perovskite layer in step (1) includes evaporation coating or solution dipping. The specific steps of the solution dipping method include: dipping the second fiber into a perovskite precursor solution with a concentration of 1.2 - 2 mol / L (such as 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L, or 2 mol / L, etc.), taking it out and transferring it to a vacuum oven for annealing treatment to complete the coating.

[0032] Preferably, the coating method of the hole transport layer in step (1) includes evaporation coating or solution dipping. The specific steps of the solution dipping method include: dipping the third fiber into a solution containing a hole transport layer material with a concentration of 10 - 80 mg / mL, taking it out and annealing to complete the coating.

[0033] The above preparation method is compatible with the traditional perovskite industry. All the film layers can be prepared by solution dipping method and also by chemical vapor deposition method. Therefore, the requirements for equipment are low and the process is simple.

[0034] The numerical ranges described in the present utility model not only include the point values exemplified above, but also any point values between the above numerical ranges not exemplified. Due to space limitations and for the sake of brevity, the specific point values included in the ranges of the present utility model are not exhaustively listed herein.

[0035] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0036] By separately coating the electron transport layer, perovskite layer, and hole transport layer on different fibers, the three functional layers are separately arranged, which can avoid the damage to the existing functional layers when depositing subsequent film layers. Based on this, the flexible fibrous perovskite solar cell constructed has the advantages of high photoelectric conversion efficiency and good flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the flexible fibrous perovskite solar cell provided in Embodiment 1 of the present utility model.

[0038] Figure 2 It is a schematic cross-sectional diagram of the flexible fibrous perovskite solar cell provided in Embodiment 5 of the present utility model.

[0039] Wherein, 1 - the first fiber; 2 - the second fiber; 3 - the third fiber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] It should be understood that in the description of the present utility model, the orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation to the present utility model. In addition, terms such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise stated, the meaning of "a plurality" is two or more.

[0041] It should be noted that in the description of the present utility model, unless otherwise clearly specified and limited, the terms "set", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood through specific circumstances.

[0042] The technical solution of the present utility model will be further described below with reference to the drawings and through specific embodiments.

[0043] Embodiment 1

[0044] This embodiment provides a flexible fibrous perovskite solar cell, and its structural schematic diagram is as Figure 1 shown. The flexible fibrous perovskite solar cell includes one first fiber 1, one second fiber 2, and one third fiber 3. An electron transport layer is coated on the surface of the first fiber 1, a perovskite layer is coated on the surface of the second fiber 2, and a hole transport layer is coated on the surface of the third fiber 3;

[0045] The first fiber 1 and the third fiber 3 wind around the second fiber 2, and the first fiber 1 and the third fiber 3 are spaced apart; the first fiber 1, the third fiber 3, and the second fiber 2 are twisted with each other, and the second fiber 2 is located at the center of the twist;

[0046] The first fiber 1, the second fiber 2, and the third fiber 3 are all silver wires, with a diameter of 0.5 mm and a length of 20 cm;

[0047] The electron transport layer is PC with a thickness of 40 nm61 The BM layer; the hole transport layer is a nickel oxide layer with a thickness of 40 nm; the perovskite layer is a FA 0.9 Cs 0.1 PbI3 layer.

[0048] This embodiment also provides a method for preparing the above flexible fibrous perovskite solar cell, and the preparation method includes the following steps:

[0049] (1) Select a silver wire as the first fiber 1, place it in a chlorobenzene solution containing PC 61 BM with a concentration of 10 mg / mL, soak for 10 min, take it out and air-dry for 15 min under a nitrogen atmosphere;

[0050] (2) Select a silver wire as the second fiber 2, place it in a perovskite precursor solution with a concentration of 1.76 mol / L and soak for 10 min, take it out and transfer it to a vacuum oven, reduce the air pressure to below 10 Pa within 1 min, control the internal temperature at 150 °C, and anneal for 10 min;

[0051] Among them, the preparation method of the perovskite precursor solution is as follows: in a mixed solvent of DMF (5 mL) and NMP (960 μL), add FAI (1.548 g), CsI (260 mg), PbI2 (4.841 g) and MACl (203 mg) to obtain a perovskite precursor solution, stir for 6 h and then filter with a 0.22 μm filter head;

[0052] (3) Select a silver wire as the third fiber 3, place it in an aqueous solution of nickel oxide nanoparticles with a concentration of 10 mg / mL and soak for 10 min, take it out and anneal at 150 °C for 10 min;

[0053] Among them, after the nickel oxide nanoparticles are dispersed in water, they need to be ultrasonicated for 30 min first, and then filtered with a 0.22 μm filter head before use;

[0054] (4) Twist the first fiber 1 coated with the PC 61 BM layer, the third fiber 3 coated with the nickel oxide layer around the second fiber 2 coated with the perovskite layer, control the twist to 20 times to form the flexible fibrous perovskite solar cell.

[0055] Example 2

[0056] This embodiment provides a flexible fibrous perovskite solar cell, which includes 1 first fiber, 1 second fiber and 1 third fiber. The surface of the first fiber is coated with an electron transport layer, the surface of the second fiber is coated with a perovskite layer, and the surface of the third fiber is coated with a hole transport layer;

[0057] The first fiber and the third fiber wind around the second fiber, and the first fiber and the third fiber are spaced apart; the first fiber, the third fiber and the second fiber are twisted together, and the second fiber is located at the center of the twist;

[0058] The first fiber is a titanium wire, and the second fiber and the third fiber are both silver wires, with a diameter of 0.5 mm and a length of 20 cm;

[0059] The electron transport layer is a C layer with a thickness of 20 nm; 60 The hole transport layer is a nickel oxide layer with a thickness of 40 nm; the perovskite layer is a FA 0.9 Cs 0.1 PbI3 layer.

[0060] This embodiment also provides a preparation method of the above flexible fibrous perovskite solar cell, and the preparation method includes the following steps:

[0061] (1) Select a titanium wire as the first fiber, place it in a vacuum evaporation chamber, keep the titanium wire substrate rotating all the time, reduce the air pressure in the vacuum chamber to below 10 -5 Pa, and then prepare the C layer by vacuum evaporation; 60 layer;

[0062] (2) Select a silver wire as the second fiber, immerse it in a perovskite precursor solution with a concentration of 1.76 mol / L for 10 min, take it out and transfer it to a vacuum oven, reduce the air pressure to below 10 Pa within 1 min, and control the internal temperature at 150 °C and anneal for 10 min;

[0063] Among them, the preparation method of the perovskite precursor solution is as follows: in a mixed solvent of DMF (5 mL) and NMP (960 μL), add FAI (1.548 g), CsI (260 mg), PbI2 (4.841 g) and MACl (203 mg) to obtain a perovskite precursor solution, stir for 6 h and then filter with a 0.22 μm filter head;

[0064] (3) Select a silver wire as the third fiber, immerse it in an aqueous solution of nickel oxide nanoparticles with a concentration of 10 mg / mL for 10 min, take it out and anneal at 150 °C for 10 min;

[0065] Among them, after the nickel oxide nanoparticles are dispersed in water, they need to be ultrasonicated for 30 min first, and then filtered with a 0.22 μm filter head before use;

[0066] (4) Coating the C 60The first fiber of the layer and the third fiber coated with the nickel oxide layer are twisted around the second fiber coated with the perovskite layer, and the twisting is controlled 20 times to form the flexible fibrous perovskite solar cell.

[0067] Example 3

[0068] This example provides a flexible fibrous perovskite solar cell. The flexible fibrous perovskite solar cell includes 1 first fiber, 1 second fiber, and 1 third fiber. The surface of the first fiber is coated with an electron transport layer, the surface of the second fiber is coated with a perovskite layer, and the surface of the third fiber is coated with a hole transport layer;

[0069] The first fiber and the third fiber are wound around the second fiber, and the first fiber and the third fiber are arranged at intervals; the first fiber, the third fiber, and the second fiber are twisted with each other, and the second fiber is located at the center of the twisting;

[0070] The first fiber, the second fiber, and the third fiber are all silver wires, with a diameter of 0.5 mm and a length of 20 cm;

[0071] The electron transport layer is a SnO2 layer with a thickness of 60 nm; the hole transport layer is a Spiro-MeOTAD layer with a thickness of 150 nm; the perovskite layer is a FA 0.9 Cs 0.1 PbI3 layer.

[0072] This example also provides a preparation method for the above flexible fibrous perovskite solar cell. The preparation method includes the following steps:

[0073] (1) Select a silver wire as the first fiber, dilute the SnO2 (15 wt%) colloidal aqueous solution (the volume ratio of the SnO2 colloidal aqueous solution to deionized water is 1:5) with deionized water, immerse the first fiber in the diluted solution containing SnO2 for 10 min, take it out and anneal it at 150 °C for 20 min to form an electron transport layer;

[0074] (2) Select a silver wire as the second fiber, immerse it in a perovskite precursor solution with a concentration of 1.76 mol / L for 10 min, take it out and transfer it to a vacuum oven, reduce the air pressure to below 10 Pa within 1 min, and control the internal temperature at 150 °C and anneal it for 10 min;

[0075] Among them, the preparation method of the perovskite precursor solution is as follows: In a mixed solvent of DMF (5 mL) and NMP (960 μL), add FAI (1.548 g), CsI (260 mg), PbI2 (4.841 g) and MACl (203 mg) to obtain a perovskite precursor solution, stir for 6 h and then filter with a 0.22 μm filter head;

[0076] (3) Select silver wire as the third fiber, immerse it in a chlorobenzene solution containing Spiro-MeOTAD with a concentration of 10 mg / mL for 10 min, and anneal it at 100 °C for 10 min after taking it out;

[0077] (4) Twist the first fiber coated with the SnO2 layer and the third fiber coated with the Spiro-MeOTAD layer around the second fiber coated with the perovskite layer, control the number of twists to be 20 times, and form the flexible fibrous perovskite solar cell.

[0078] Example 4

[0079] The difference between this example and Example 1 is that the first fiber, the second fiber and the third fiber are all carbon nanotube fibers with a tube diameter of 10 nm.

[0080] The remaining battery structures and method parameters are the same as those in Example 1.

[0081] Example 5

[0082] The difference between this example and Example 1 is that there are 2 first fibers and 2 second fibers.

[0083] The remaining battery structures and method parameters are the same as those in Example 1.

[0084] Figure 2 The cross-sectional schematic diagram of the flexible fibrous perovskite solar cell prepared in this example is shown.

[0085] Example 6

[0086] The difference between this example and Example 1 is that the first fiber and the second fiber are wound around each other, and the third fiber is wound along the winding path of the second fiber to separate the first fiber and the third fiber.

[0087] The remaining battery structures and method parameters are the same as those in Example 1.

[0088] Comparative Example 1

[0089] This comparative example provides a flexible fibrous perovskite solar cell, which includes a carbon nanofiber, and an oxide nickel layer and a perovskite layer (chemical composition is FA 0.9Cs 0.1 (PbI3), PC 61 Another carbon nanofiber of the PCBM layer and silver nanowires, and the two carbon nanofibers are twisted with each other.

[0090] The remaining battery structures and method parameters are the same as those in Example 1.

[0091] Performance Test

[0092] Open-circuit voltage test, short-circuit current test, fill factor test and conversion efficiency test were carried out on the flexible fibrous perovskite solar cells provided in the above examples and comparative examples. Among them, the first fiber coated with the electron transport layer and the third fiber coated with the hole transport layer were used as the working electrodes and connected to the source meter. The relevant parameter tests were carried out in accordance with the group standard of the China Photovoltaic Industry Association, "Measurement Method of Current-Voltage (I-V) Characteristics of Perovskite Photovoltaic Cells and Modules".

[0093] Specifically, a G2V Pico model light source was selected, and the light source level was AAA; the current and voltage data were collected by the source meter, and the fill factor and conversion efficiency were calculated according to the current-voltage curve; the efficiency decay test was carried out under the irradiation of a light source with a light source level of AAA and an intensity of standard AM1.5, that is, 1000 W / m 2 .

[0094] The test results are shown in Table 1.

[0095] Table 1

[0096]

[0097] Analysis:

[0098] As can be seen from the above table, the functional layers used in Examples 1, 2 and 4 are the functional layers commonly used in the inverted perovskite structure, while the functional layer used in Example 3 is the functional layer commonly used in the normal perovskite structure, indicating that both the normal and inverted perovskite battery materials can be applied to the fibrous perovskite battery structure provided by the present invention.

[0099] Comparing Example 1 with Comparative Example 1, it can be seen that in Comparative Example 1, a nickel oxide layer, a perovskite layer (chemical composition is FA 0.9 Cs 0.1 (PbI3), PC 61 BM layer were sequentially deposited on a single carbon fiber. Since the most common and lowest-cost deposition method on the fiber surface at present is the solution dipping method, Comparative Example 1 needs to soak the carbon fiber in the nickel oxide solution, perovskite solution and PC 61 BM solution in turn. The common solvents for nickel oxide are water and isopropyl alcohol, and the common solvent for perovskite is DMF, PC 61The common solvent for BM is chlorobenzene, and each layer of the solvent will affect the previously deposited layer, while Example 1 can avoid this influence.

[0100] The applicant declares that the above description is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model fall within the protection scope and the disclosure scope of the present utility model.

Claims

1. A flexible fibrous perovskite solar cell, characterized in that, The flexible fibrous perovskite solar cell includes a first fiber, a second fiber, and a third fiber. The surface of the first fiber is coated with an electron transport layer, the surface of the second fiber is coated with a perovskite layer, and the surface of the third fiber is coated with a hole transport layer; The first fiber and the third fiber wind around the second fiber, and the first fiber and the third fiber are spaced apart.

2. The flexible fibrous perovskite solar cell according to claim 1, wherein The first fiber includes at least 1 root, and the third fiber includes at least 1 root; The at least 1 root of the first fiber, the at least 1 root of the third fiber, and the second fiber are twisted together, and the second fiber is located at the center of the twist.

3. The flexible fibrous perovskite solar cell according to claim 1, wherein The first fiber and the second fiber wind around each other, and the third fiber winds along the winding path of the second fiber to separate the first fiber and the third fiber.

4. The flexible fibrous perovskite solar cell according to claim 1, characterized in that, The first fiber and the third fiber are independently a metal fiber or a carbon nanotube fiber.

5. The flexible fibrous perovskite solar cell according to claim 1, wherein The diameters of the first fiber and the third fiber are independently 0.5 - 5 mm.

6. The flexible fibrous perovskite solar cell according to claim 1, wherein The second fiber is a conductive fiber or a non-conductive fiber.

7. The flexible fibrous perovskite solar cell according to claim 1, wherein The diameter of the second fiber is 0.5 - 5 mm.

8. The flexible fibrous perovskite solar cell according to claim 1, wherein The electron transport layer includes any one of a C 60 layer, a SnO2 layer, or a PCBM layer; The thickness of the electron transport layer is 20 - 100 nm.

9. The flexible fibrous perovskite solar cell according to claim 1, characterized in that, The hole transport layer includes any one of a nickel oxide layer, a PTAA layer, or a Spiro-OMeTAD layer; The thickness of the hole transport layer is 20 - 200 nm.

10. The flexible fibrous perovskite solar cell according to claim 1, characterized in that, The thickness of the perovskite layer is 300 - 1000 nm.

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