Fibrous perovskite solar cell, preparation method thereof and laminated solar cell

Abstract

The invention provides a fibrous perovskite solar cell, a preparation method thereof and a laminated solar cell. The fibrous perovskite solar cell sequentially comprises a first electrode, a first carrier transport support layer, a second carrier transport support layer and a second electrode in the radial direction from inside to outside. The fibrous perovskite solar cell further comprises a perovskite light absorption layer, the first carrier transport support layer and the second carrier transport support layer are of a porous structure, and the perovskite light absorption layer is filled in the first carrier transport support layer and the second carrier transport support layer. The perovskite light absorption layer is filled in the carrier transmission support layer with the porous structure, so that layered deposition is avoided, the optical contact specific surface area of the cell is remarkably increased, contact and transfer of photoelectrons are facilitated, charge recombination and energy loss are reduced, and the photoelectric property of a device is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a fibrous perovskite solar cell, its preparation method, and a tandem solar cell. Background Technology

[0002] With rapid societal development and increasingly severe climate change, dependence on energy has intensified, making the development of renewable and affordable energy sources urgently needed. The International Renewable Energy Agency's "World Energy Transition Outlook 2022" report states that renewable energy's share of global electricity supply will increase from 25% in 2018 to 65% by 2030. Solar energy, as an ideal alternative to traditional energy sources, has attracted widespread attention. However, compared to traditional energy sources, solar energy's contribution to global energy development remains negligible, and the development of related technologies faces numerous severe challenges, such as low efficiency, poor stability, high cost, and difficulty in large-scale continuous production.

[0003] Due to the increasing demand for modern electronic products, integrated optoelectronic products are emerging in the form of lightweight, portable, and intelligent goods. In recent years, wearable / portable electronic products have seen a surge in demand. Integrating power generation devices such as solar cells into wearable devices or weaving them into clothing, combined with energy storage devices such as lithium batteries, enables uninterrupted operation around the clock. Whether integrated into wearable devices or woven into clothing, fibrous flexible solar cells are the most ideal device form. In military operations in northern regions without stable power supply and in harsh conditions in remote mountainous areas, integrating fibrous solar cells with energy storage devices into clothing can provide a power pack, solving the problem of continuous power supply for unreliable wearable devices. Therefore, the development and utilization of fibrous solar cells is currently an urgent need.

[0004] Traditional perovskite solar cells (PSCs) employ a layered structure. For example, patent JP2017224815A discloses a composite material comprising a perovskite compound and conductive nanofibers coated with metal oxides. This patent uses a PN junction for carrier transport, representing a traditional layered fiber perovskite structure with high electron transport efficiency, but a small specific surface area and severe charge recombination. Therefore, layered structures are difficult to deposit on fibers. Patent CN104103759A discloses a fibrous solar cell based on a perovskite-type organolead iodine compound. In its radial direction, from the inside out, it comprises titanium wires, a titanium dioxide layer, a perovskite-type organolead iodine compound layer, a conductive polymer layer, and a nanotube thin film layer. The cell is fibrous, with the perovskite-type organolead iodine compound serving as the primary photoelectric conversion material, and titanium wires and carbon nanotubes as the cell electrodes. In this patent, the perovskite-type organolead iodine compound layer is directly deposited between the titanium dioxide layer and the conductive polymer layer, resulting in severe charge recombination problems between the perovskite and the transport layer.

[0005] Therefore, how to avoid the difficulty of depositing layered structures on fibrous perovskite solar cells, while increasing the surface contact area between the fibrous perovskite light-absorbing layer and the transport layer to improve device performance, is an urgent technical problem to be solved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a fibrous perovskite solar cell, its fabrication method, and a tandem solar cell. The present invention employs a porous first and second carrier transport support layer to construct the support structure, allowing the perovskite light-absorbing layer to fill within both layers. This not only avoids layered deposition but also increases the surface contact area between the fibrous perovskite light-absorbing layer and the transport layer, thereby significantly improving the photocontact surface area of ​​the cell. This facilitates photoelectron contact and transfer, while reducing charge recombination and energy loss, resulting in a significant improvement in the device's photoelectric performance.

[0007] To achieve this objective, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a fibrous perovskite solar cell, wherein the fibrous perovskite solar cell comprises, in sequence along a radial direction from the inside to the outside, a first electrode, a first carrier transport support layer, a second carrier transport support layer, and a second electrode.

[0009] The fibrous perovskite solar cell further includes a perovskite light-absorbing layer. The first carrier transport support layer and the second carrier transport support layer have a porous structure, and the perovskite light-absorbing layer fills the first carrier transport support layer and the second carrier transport support layer.

[0010] This invention employs a porous first carrier transport support layer and a second carrier transport support layer to construct the support structure, allowing the perovskite light-absorbing layer to fill within the first and second carrier transport support layers. This not only avoids layered deposition but also increases the surface contact area between the fibrous perovskite light-absorbing layer and the transport layer, thereby significantly increasing the light contact specific surface area of ​​the battery. This is beneficial for the contact and transfer of photoelectrons, while reducing charge recombination and energy loss, resulting in a significant improvement in the photoelectric performance of the device.

[0011] It should be noted that the porous structure includes structures with open porosity, which is an indicator used to evaluate the properties of porous materials. In particular, the heterojunction structure formed by the porous support layer and the perovskite light-absorbing layer is distinctly different from the planar heterojunction structure.

[0012] Preferably, the first electrode is a conductive fiber.

[0013] Preferably, the conductive fiber comprises titanium wire.

[0014] Preferably, the diameter of the conductive fiber is 300-500μm, for example, it can be 300μm, 350μm, 400μm, 450μm or 500μm, and is preferably 350-450μm.

[0015] Preferably, the second electrode is a porous conductive layer.

[0016] Preferably, the conductive layer of the porous structure includes a mesoporous carbon electrode.

[0017] Preferably, the thickness of the conductive layer of the porous structure is 20-25 μm, for example, it can be 20 μm, 21 μm, 22 μm, 23 μm, 24 μm or 25 μm.

[0018] Preferably, the perovskite light-absorbing layer is filled within the second electrode.

[0019] Preferably, the charges transported by the first carrier transport support layer and the second carrier transport support layer are of opposite polarity.

[0020] Preferably, the first carrier transport support layer is an electron transport support layer, and the second carrier transport support layer is a hole transport support layer.

[0021] Preferably, the electron transport support layer comprises any one or a combination of at least two of the following: a mesoporous TiO2 layer, a mesoporous SnO2 layer, or a mesoporous ZnO2 layer.

[0022] Preferably, the thickness of the electron transport support layer is 700-1000nm, for example, it can be 700nm, 800nm, 900nm or 1000nm.

[0023] Preferably, the hole transport support layer comprises any one or a combination of at least two of the following: a mesoporous ZrO2 layer, a mesoporous Al2O3 layer, or a mesoporous NiOx layer.

[0024] It should be noted that the X in NiOx refers to the Ni in NiOx. 3+ with Ni 2+ The content of valence state ions is different.

[0025] Preferably, the thickness of the hole transport scaffold layer is 2-3 μm, for example, it can be 2 μm, 2.0 μm, 2.4 μm, 2.6 μm, 2.8 μm or 3 μm, etc.

[0026] Preferably, a dense first carrier transport layer is further disposed between the first electrode and the first carrier transport support layer.

[0027] The first carrier transport support layer and the dense first carrier transport layer transport the same charge.

[0028] In this invention, the purpose of setting a dense first carrier transport layer is to prevent the perovskite from directly contacting the electrode layer.

[0029] Preferably, the dense first carrier transport layer is a dense electron transport layer.

[0030] Preferably, the dense electron transport layer comprises a dense TiO2 layer.

[0031] Preferably, the thickness of the dense first carrier transport layer is 30-100nm, for example, it can be 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm.

[0032] Preferably, the chemical formula of the perovskite light-absorbing layer is ABX3, where A is CH3NH3. + CH(NH2)2 + Cs + or Rb + B is any combination of one or at least two of the following, where B is Pb. 2+ Sn 2+ Or Ge 2+ Any combination of one or at least two of them, X is Cl - ,Br - or I - Any one or at least two of them.

[0033] Preferably, the band gap of the perovskite light-absorbing layer is 1.53-1.58 eV, for example, it can be 1.53 eV, 1.54 eV, 1.55 eV, 1.56 eV, 1.57 eV or 1.58 eV.

[0034] In this invention, the band gap of the perovskite light-absorbing layer is limited to 1.53-1.58 eV. The corresponding perovskite solar cell has a higher photoelectric conversion efficiency than the wide bandgap perovskite solar cell and higher stability.

[0035] In a second aspect, the present invention provides a method for preparing a fibrous perovskite solar cell as described in the first aspect, the method comprising the following steps:

[0036] (a) A first carrier transport support layer is fabricated on the first electrode, then a second carrier transport support layer is fabricated, and then a second electrode is fabricated on the second carrier transport support layer;

[0037] (b) The perovskite precursor solution is placed into the first carrier transport support layer and the first carrier transport support layer, and after annealing, the fibrous perovskite solar cell is obtained.

[0038] The present invention does not limit the preparation method of the first carrier transport support layer and the second carrier transport support layer in step (a). For example, it can be any one of magnetron sputtering, screen printing, vacuum thermal evaporation or ALD atomic deposition.

[0039] The present invention does not limit the method of preparing the second electrode in step (a). For example, it can be any one of magnetron sputtering, screen printing, vacuum thermal evaporation or ALD atomic deposition.

[0040] Preferably, the concentration of the perovskite precursor solution in step (b) is 1-1.5 mol / L, for example, it can be 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L or 1.5 mol / L, etc.

[0041] In this invention, if the concentration of the perovskite precursor solution is too low, the growth rate of the perovskite film will be slow and the film thickness will be small; if the concentration of the perovskite precursor solution is too high, the deposition rate will gradually increase and the film thickness will gradually increase. However, excessively high solution concentration will also lead to particles and cracks on the film surface.

[0042] Preferably, before the perovskite precursor solution in step (b) is placed, the semi-finished product obtained in step (a) is annealed. The annealing temperature is 300-500℃, for example, 300℃, 350℃, 400℃, 450℃ or 500℃, and the holding time is 30-50min, for example, 30min, 35min, 40min, 45min or 50min.

[0043] Preferably, the annealing temperature in step (b) is 50-100℃, for example, 50℃, 60℃, 70℃, 80℃, 90℃ or 100℃, and the holding time is 8-12min, for example, 8min, 9min, 10min, 11min or 12min.

[0044] In this invention, the selection of annealing temperature and time has a direct impact on the crystallization degree and morphology of perovskite films. Appropriate annealing temperature and time can promote the crystallization of perovskite films and improve their quality and performance. Excessively high annealing temperature may lead to oxygen vacancy defects and pinholes, while excessively low annealing temperature may lead to a decrease in crystallinity, affecting the quality and performance of the film.

[0045] Preferably, the preparation method includes the following steps:

[0046] (a1) The conductive fibers are pretreated, and then the pretreated conductive fibers are mixed with a dense electron transport layer material and heat-treated at 800-1300℃ for 15-30 min to form a dense electron transport layer with a thickness of 30-100 nm.

[0047] (b1) An electron transport scaffold layer with a thickness of 700-1000 nm is deposited on the dense electron transport layer; then a hole transport scaffold layer with a thickness of 2-3 μm is deposited on the electron transport scaffold layer; then a porous conductive layer with a thickness of 20-25 μm is deposited on the hole transport scaffold layer.

[0048] (c1) Anneal the semi-finished product obtained in step (b1) at a temperature of 300-500℃ for a holding time of 30-50 minutes.

[0049] (d1) A perovskite precursor solution with a concentration of 1-1.5 mol / L is injected into the support structure obtained in step (c1), and wrapped with heat shrink tubing. The solution is then annealed at 50-100°C for 8-12 minutes to obtain the fibrous perovskite solar cell.

[0050] Thirdly, the present invention provides a tandem solar cell, the tandem solar cell comprising a base cell and a fibrous perovskite solar cell as described in the first aspect.

[0051] Preferably, an intermediate composite layer is further disposed between the bottom cell and the fibrous perovskite solar cell, the intermediate composite layer comprising a transparent metal oxide. Examples include ITO (indium tin oxide), IZO (indium zinc oxide), AZO (aluminum-doped zinc oxide), or ICO (cerium-doped indium oxide).

[0052] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] This invention employs a porous first carrier transport support layer and a second carrier transport support layer to construct the support structure, allowing the perovskite light-absorbing layer to fill within the first and second carrier transport support layers. This not only avoids layered deposition but also increases the surface contact area between the fibrous perovskite light-absorbing layer and the transport layer, thereby significantly increasing the light contact specific surface area of ​​the battery. This is beneficial for the contact and transfer of photoelectrons, while reducing charge recombination and energy loss, resulting in a significant improvement in the photoelectric performance of the device. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the structure of the fibrous perovskite solar cell prepared in Example 1 of the present invention.

[0056] Figure 2 This is a schematic diagram of the structure of the fibrous perovskite solar cell prepared in Comparative Example 1 of this invention.

[0057] Among them, 1-conductive fiber; 2-dense TiO2 layer; 3-mesoporous TiO2 layer; 4-mesoporous ZrO2 layer; 5-mesoporous carbon electrode; 6-perovskite light-absorbing layer; 7-Sprio-OMeTAD layer; 8-Ag electrode. Detailed Implementation

[0058] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0059] Example 1

[0060] This embodiment provides a fibrous perovskite solar cell, the structural schematic of which is shown below. Figure 1 As shown, the fibrous perovskite solar cell includes, in sequence from the inside to the outside, conductive fibers 1, dense TiO2 layer 2, mesoporous TiO2 layer 3, mesoporous ZrO2 layer 4 and mesoporous carbon electrode 5 along the radial direction from the inside to the outside.

[0061] The fibrous perovskite solar cell further includes a perovskite light-absorbing layer 6, which is filled within the mesoporous TiO2 layer 3, the mesoporous ZrO2 layer 4, and the mesoporous carbon electrode 5.

[0062] The conductive fiber 1 is a titanium wire with a diameter of 400 μm;

[0063] The thickness of the dense TiO2 layer 2 is 50 nm, the thickness of the mesoporous TiO2 layer 3 is 850 nm, the thickness of the mesoporous ZrO2 layer 4 is 2 μm, and the thickness of the mesoporous carbon electrode 5 is 20 μm.

[0064] The chemical formula of the perovskite light-absorbing layer 6 is FA. 0.95 MA 0.05 PbI3 with a band gap of 1.55 eV.

[0065] This embodiment also provides a method for preparing the above-mentioned fibrous perovskite solar cell, the method comprising the following steps:

[0066] (1) The titanium wire was ultrasonically cleaned in the washing solution, pure water, acetone and isopropanol respectively for 10 min, dried with a hair dryer, and then the pretreated titanium wire was mixed with dense TiO2 material and heat-treated at 1000℃ for 20 min to form a dense TiO2 layer with a thickness of 50 nm.

[0067] (2) A mesoporous TiO2 layer 3 is deposited on the dense TiO2 layer 2 using a magnetron sputtering device. The specific parameters include: axial horizontal rotation at a speed of 0.25 r / s, sputtering using DC pulse, sputtering power of 100 W, time of 30 min, and argon-oxygen ratio of 100:5.

[0068] Then, a mesoporous ZrO2 layer 4 is deposited on the mesoporous TiO2 layer 3 using screen printing equipment, with specific parameters including:

[0069] The mesoporous ZrO2 was diluted and mixed in terpineol by axial horizontal rotation at a speed of 0.25 r / s, and then the mesoporous ZrO2 was printed on the mesoporous TiO2 layer 3 by screen printing.

[0070] Then, a mesoporous carbon electrode 5 is deposited on the mesoporous ZrO2 layer 4 using screen printing equipment, with specific parameters including:

[0071] The mesoporous carbon was mixed in terpineol by axial horizontal rotation at a speed of 0.25 r / s, and then printed onto the mesoporous ZrO2 layer 4 by screen printing.

[0072] (3) Anneal the semi-finished product obtained in step (2) at a temperature of 400°C for 40 minutes.

[0073] (4) A perovskite precursor solution with a concentration of 1.2 mol / L was injected into the support structure obtained in step (3), and wrapped with heat shrink tubing. The solution was then annealed at 75°C for 10 min to obtain the fibrous perovskite solar cell.

[0074] The preparation steps of the perovskite precursor solution include: dissolving MAI, FAI, MACl and PbI2 in a mixed solvent composed of dimethyl sulfoxide and dimethylformamide, heating at 70°C and stirring continuously for 1 hour to completely dissolve them, thereby obtaining the perovskite precursor solution; wherein the concentration ratio of FAI:MAI:MACl = 0.95:0.05:0.14, the concentrations of FAI and PbI2 are both 1.5 mol / L, and the volume ratio of dimethyl sulfoxide to dimethylformamide is 1:9.

[0075] Example 2

[0076] This embodiment provides a fibrous perovskite solar cell, which includes, in a radial direction from the inside out, conductive fibers, a dense TiO2 layer, a mesoporous TiO2 layer, a mesoporous ZrO2 layer, and a mesoporous carbon electrode.

[0077] The fibrous perovskite solar cell further includes a perovskite light-absorbing layer, which fills the mesoporous TiO2 layer, the mesoporous ZrO2 layer and the mesoporous carbon electrode.

[0078] The conductive fiber is a titanium wire with a diameter of 300 μm;

[0079] The thickness of the dense TiO2 layer is 30 nm, the thickness of the mesoporous TiO2 layer is 700 nm, the thickness of the mesoporous ZrO2 layer is 2 μm, and the thickness of the mesoporous carbon electrode is 20 μm.

[0080] The chemical formula of the perovskite light-absorbing layer is FA. 0.95 MA 0.05 PbI3 with a band gap of 1.55 eV.

[0081] This embodiment also provides a method for preparing the above-mentioned fibrous perovskite solar cell, the method comprising the following steps:

[0082] (1) The titanium wire was ultrasonically cleaned in the washing solution, pure water, acetone and isopropanol respectively for 10 min, dried with a hair dryer, and then the pretreated titanium wire was mixed with dense TiO2 material and heat-treated at 800℃ for 30 min to form a dense TiO2 layer with a thickness of 30 nm.

[0083] (2) A mesoporous TiO2 layer is deposited on the dense TiO2 layer using a magnetron sputtering device. The specific parameters include: axial horizontal rotation at a speed of 0.25 r / s, sputtering using DC pulse, sputtering power of 100 W, time of 25 min, and argon-oxygen ratio of 100:5.

[0084] Then, a mesoporous ZrO2 layer is deposited on the mesoporous TiO2 layer using screen printing equipment, with specific parameters including:

[0085] The mesoporous ZrO2 was diluted and mixed in terpineol by axial horizontal rotation at a speed of 0.25 r / s, and then the mesoporous ZrO2 was printed onto the mesoporous TiO2 layer by screen printing.

[0086] Then, a mesoporous carbon electrode is deposited on the mesoporous ZrO2 layer using screen printing equipment, with specific parameters including:

[0087] The mesoporous carbon was mixed in terpineol by axial horizontal rotation at a speed of 0.25 r / s, and then printed onto the mesoporous ZrO2 layer by screen printing.

[0088] (3) Anneal the semi-finished product obtained in step (2) at a temperature of 300°C for 50 minutes.

[0089] (4) Inject a 1 mol / L perovskite precursor solution into the support structure obtained in step (3), wrap it with heat shrink tubing, and anneal it at 50°C for 12 min to obtain the fibrous perovskite solar cell.

[0090] The preparation steps of the perovskite precursor solution include: dissolving MAI, FAI, MACl and PbI2 in a mixed solvent composed of dimethyl sulfoxide and dimethylformamide, heating at 70°C and stirring continuously for 1 hour to completely dissolve them, thereby obtaining the perovskite precursor solution; wherein the concentration ratio of FAI:MAI:MACl = 0.95:0.05:0.14, the concentrations of FAI and PbI2 are both 1.5 mol / L, and the volume ratio of dimethyl sulfoxide to dimethylformamide is 1:9.

[0091] Example 3

[0092] This embodiment provides a fibrous perovskite solar cell, which includes, in a radial direction from the inside out, conductive fibers, a dense TiO2 layer, a mesoporous TiO2 layer, a mesoporous ZrO2 layer, and a mesoporous carbon electrode.

[0093] The fibrous perovskite solar cell further includes a perovskite light-absorbing layer, which fills the mesoporous TiO2 layer, the mesoporous ZrO2 layer and the mesoporous carbon electrode.

[0094] The conductive fiber is a titanium wire with a diameter of 500 μm;

[0095] The thickness of the dense TiO2 layer is 100 nm, the thickness of the mesoporous TiO2 layer is 1000 nm, the thickness of the mesoporous ZrO2 layer is 3 μm, and the thickness of the mesoporous carbon electrode is 25 μm.

[0096] The chemical formula of the perovskite light-absorbing layer is FA. 0.95 MA 0.05 PbI3 with a band gap of 1.55 eV.

[0097] This embodiment also provides a method for preparing the above-mentioned fibrous perovskite solar cell, the method comprising the following steps:

[0098] (1) The titanium wire was ultrasonically cleaned in the washing solution, pure water, acetone and isopropanol respectively for 10 minutes, dried with a hair dryer, and then the pretreated titanium wire was mixed with dense TiO2 material and heat-treated at 1300℃ for 15 minutes to form a dense TiO2 layer with a thickness of 100nm.

[0099] (2) A mesoporous TiO2 layer is deposited on the dense TiO2 layer using a magnetron sputtering device. The specific parameters include: axial horizontal rotation at a speed of 0.25 r / s, sputtering using DC pulse, sputtering power of 100 W, time of 35 min, and argon-oxygen ratio of 100:5.

[0100] Then, a mesoporous ZrO2 layer is deposited on the mesoporous TiO2 layer using screen printing equipment, with specific parameters including:

[0101] The mesoporous ZrO2 was diluted and mixed in terpineol by axial horizontal rotation at a speed of 0.25 r / s, and then the mesoporous ZrO2 was printed onto the mesoporous TiO2 layer by screen printing.

[0102] Then, a mesoporous carbon electrode is deposited on the mesoporous ZrO2 layer using screen printing equipment, with specific parameters including:

[0103] The mesoporous carbon was mixed in terpineol by axial horizontal rotation at a speed of 0.25 r / s, and then printed onto the mesoporous ZrO2 layer by screen printing.

[0104] (3) Anneal the semi-finished product obtained in step (2) at a temperature of 500°C for 30 minutes.

[0105] (4) A perovskite precursor solution with a concentration of 1.5 mol / L was injected into the support structure obtained in step (3), and wrapped with heat shrink tubing. The solution was then annealed at 100°C for 8 minutes to obtain the fibrous perovskite solar cell.

[0106] The preparation steps of the perovskite precursor solution include: dissolving MAI, FAI, MACl and PbI2 in a mixed solvent composed of dimethyl sulfoxide and dimethylformamide, heating at 70°C and stirring continuously for 1 hour to completely dissolve them, thereby obtaining the perovskite precursor solution; wherein the concentration ratio of FAI:MAI:MACl = 0.95:0.05:0.14, the concentrations of FAI and PbI2 are both 1.5 mol / L, and the volume ratio of dimethyl sulfoxide to dimethylformamide is 1:9.

[0107] Example 4

[0108] The difference between this embodiment and Embodiment 1 is that the mesoporous carbon electrode is replaced with a dense carbon layer.

[0109] The remaining preparation methods and parameters are consistent with those in Example 1.

[0110] Example 5

[0111] The difference between this embodiment and embodiment 1 is that a dense TiO2 layer is not set, that is, no dense TiO2 material is added for heat treatment in step (1).

[0112] The remaining preparation methods and parameters are consistent with those in Example 1.

[0113] Example 6

[0114] The difference between this embodiment and Example 1 is that the concentration of the perovskite precursor solution in step (4) is 0.8 mol / L.

[0115] The remaining preparation methods and parameters are consistent with those in Example 1.

[0116] Example 7

[0117] The difference between this embodiment and Example 1 is that the concentration of the perovskite precursor solution in step (4) is 2 mol / L.

[0118] The remaining preparation methods and parameters are consistent with those in Example 1.

[0119] Example 8

[0120] The difference between this embodiment and embodiment 1 is that the annealing temperature in step (4) is 30°C.

[0121] The remaining preparation methods and parameters are consistent with those in Example 1.

[0122] Example 9

[0123] The difference between this embodiment and embodiment 1 is that the annealing temperature in step (4) is 120°C.

[0124] The remaining preparation methods and parameters are consistent with those in Example 1.

[0125] Comparative Example 1

[0126] This comparative example provides a fibrous perovskite solar cell, the schematic diagram of which is shown below. Figure 2 As shown, the fibrous perovskite solar cell includes, in sequence from the inside to the outside, conductive fibers 1, dense TiO2 layer 2, mesoporous TiO2 layer 3, Sprio-OMeTAD layer 7 and Ag electrode 8 along the radial direction from the inside to the outside.

[0127] The fibrous perovskite solar cell further includes a perovskite light-absorbing layer 6, which is disposed between the mesoporous TiO2 layer 3 and the Sprio-OMeTAD layer 7;

[0128] The conductive fiber 1 is a titanium wire with a diameter of 400 μm;

[0129] The thickness of the dense TiO2 layer 2 is 50 nm, the thickness of the mesoporous TiO2 layer 3 is 850 nm, the thickness of the Sprio-OMeTAD layer 7 is 40 μm, and the thickness of the Ag electrode 8 is 300 nm.

[0130] The chemical formula of the perovskite light-absorbing layer 6 is CH3NH3PbI2Cl.

[0131] This comparative example also provides a method for preparing the above-mentioned fibrous perovskite solar cell, the method comprising the following steps:

[0132] (1) The titanium wire was ultrasonically cleaned in the washing solution, pure water, acetone and isopropanol respectively for 10 minutes, dried with a hair dryer, and then the pretreated titanium wire was mixed with dense TiO2 material and heat-treated at 800-1300℃ for 15-30 minutes to form a dense TiO2 layer 2.

[0133] (2) A mesoporous TiO2 layer 3 is deposited on the dense TiO2 layer 2 using a magnetron sputtering device. The specific parameters include: axial horizontal rotation at a speed of 0.25 r / s, sputtering using DC pulse, sputtering power of 100 W, time of 1 min, and argon-oxygen ratio of 100:5.

[0134] Then, a perovskite light-absorbing layer 6 is deposited on the mesoporous TiO2 layer 3 using a wire coating machine. Specific parameters include:

[0135] Rotate horizontally along the axis at a speed of 1 r / s, and anneal at 100℃ for 10 min.

[0136] (3) The titanium wire after depositing the perovskite light-absorbing layer 6 is immersed in Sprio-OMeTAD solution, the solvent is chlorobenzene, the concentration is 10mg / mL, the time is 30s, and it is annealed at 80℃ for 5min to form Sprio-OMeTAD layer 7.

[0137] (4) A 300 nm thick Ag electrode 8 is deposited on the Sprio-OMeTAD layer 7 using a vapor deposition equipment to obtain the fibrous perovskite solar cell.

[0138] Performance testing

[0139] The fibrous perovskite solar cells provided in the above embodiments and comparative examples were subjected to open-circuit voltage tests, short-circuit current tests, fill factor tests, and conversion efficiency tests. The test conditions were in accordance with the China Photovoltaic Industry Association group standard "Measurement Method of Current-Voltage (IV) Characteristics of Perovskite Photovoltaic Cells and Modules".

[0140] Specifically, a G2V Pico light source with an AAA rating was selected. Current and voltage data were collected using a source meter, and the fill factor and conversion efficiency were calculated based on the current-voltage curve. The efficiency degradation test was conducted under AAA-rated illumination at a standard AM1.5 intensity, i.e., 1000 W / m². 2 .

[0141] The test results are shown in Table 1.

[0142] Table 1

[0143]

[0144] analyze:

[0145] As shown in the table above, the present invention uses a porous first carrier transport support layer and a porous second carrier transport support layer to construct the support structure, so that the perovskite light-absorbing layer fills the first and second carrier transport support layers and also fills the porous electrode. This not only avoids layered deposition, but also significantly increases the optical contact surface area of ​​the battery, which is beneficial to the contact and transfer of photoelectrons. At the same time, it reduces charge recombination and energy loss, thus significantly improving the photoelectric performance of the device.

[0146] As can be seen from Examples 1 and 4, if the mesoporous carbon electrode is replaced with a dense carbon layer, the perovskite light-absorbing layer cannot fill the carbon electrode, which is not conducive to the transport of charge carriers, resulting in a certain degree of decrease in voltage and current.

[0147] As can be seen from Examples 1 and 5, if a dense TiO2 layer is not provided, it is impossible to prevent the diffusion of external impurities and air molecules inside the film, thereby protecting the internal materials from contamination and oxidation, resulting in a decrease in photoelectric conversion efficiency.

[0148] As can be seen from Examples 1 and 6-7, if the concentration of the perovskite precursor solution is too low, the growth rate of the perovskite film will be slow, the film thickness will be small, resulting in high current and low voltage, thus reducing the photoelectric conversion efficiency. If the concentration of the perovskite precursor solution is too high, the deposition rate will gradually increase and the film thickness will gradually increase at high concentrations. However, excessively high solution concentrations will also cause particles and cracks to appear on the film surface, resulting in low current and high voltage, thus reducing the photoelectric conversion efficiency.

[0149] As can be seen from Examples 1 and 8-9, if the annealing temperature in step (4) is too low, the crystallinity will decrease, affecting the quality of the film and the performance of the device; if the annealing temperature in step (4) is too high, oxygen vacancy defects and pinholes will occur, which will lead to low photoelectric conversion efficiency of perovskite solar cells.

[0150] As can be seen from Example 1 and Comparative Example 1, the photoelectric conversion efficiency of Example 1 is 1.32 percentage points higher than that of Comparative Example 1. Due to the use of a mesoporous fibrous perovskite preparation method, the resulting battery has a larger specific surface area, which is beneficial for the contact and transfer of photoelectrons, while reducing charge recombination and energy loss, thus improving the efficiency of the device to a certain extent.

[0151] In summary, the technical solution provided by this invention offers another novel and feasible approach for the preparation of fibrous perovskites, and is comparable to traditional fibrous perovskite methods.

[0152] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A fibrous perovskite solar cell, characterized in that, The fibrous perovskite solar cell includes, in a radial direction from the inside out, a first electrode, a first carrier transport support layer, a second carrier transport support layer, and a second electrode. The fibrous perovskite solar cell further includes a perovskite light-absorbing layer, and the first carrier transport support layer and the second carrier transport support layer have a porous structure. The perovskite light-absorbing layer fills the first carrier transport support layer and the second carrier transport support layer.

2. The fibrous perovskite solar cell according to claim 1, characterized in that, The first electrode is a conductive fiber; Preferably, the conductive fiber comprises titanium wire; Preferably, the diameter of the conductive fiber is 300-500 μm, and more preferably 350-450 μm.

3. The fibrous perovskite solar cell according to claim 1 or 2, characterized in that, The second electrode is a porous conductive layer; Preferably, the porous conductive layer includes a mesoporous carbon electrode; Preferably, the thickness of the conductive layer of the porous structure is 20-25 μm; Preferably, the perovskite light-absorbing layer is filled within the second electrode.

4. The fibrous perovskite solar cell according to any one of claims 1-3, characterized in that, The charges transported by the first charge carrier transport support layer and the second charge carrier transport support layer are of opposite polarity; Preferably, the first carrier transport support layer is an electron transport support layer, and the second carrier transport support layer is a hole transport support layer. Preferably, the electron transport support layer comprises any one or a combination of at least two of the following: a mesoporous TiO2 layer, a mesoporous SnO2 layer, or a mesoporous ZnO2 layer; Preferably, the thickness of the electron transport support layer is 700-1000 nm; Preferably, the hole transport support layer comprises any one or a combination of at least two of the following: a mesoporous ZrO2 layer, a mesoporous Al2O3 layer, or a mesoporous NiOx layer; Preferably, the thickness of the hole transport support layer is 2-3 μm.

5. The fibrous perovskite solar cell according to any one of claims 1-4, characterized in that, A dense first carrier transport layer is also disposed between the first electrode and the first carrier transport support layer; The first carrier transport support layer and the dense first carrier transport layer transport the same type of charge. Preferably, the dense first carrier transport layer is a dense electron transport layer; Preferably, the dense electron transport layer comprises a dense TiO2 layer; Preferably, the thickness of the dense first carrier transport layer is 30-100 nm.

6. The fibrous perovskite solar cell according to any one of claims 1-5, characterized in that, The chemical formula of the perovskite light-absorbing layer is ABX3, where A is CH3NH3. + CH(NH2)2 + Cs + or Rb + B is any combination of one or at least two of the following, where B is Pb. 2+ Sn 2+ Or Ge 2+ Any combination of one or at least two of them, X is Cl - ,Br - or I - Any one or at least two of them; Preferably, the band gap of the perovskite light-absorbing layer is 1.53-1.58 eV.

7. A method for preparing a fibrous perovskite solar cell according to any one of claims 1-6, characterized in that, The preparation method includes the following steps: (a) A first carrier transport support layer is fabricated on the first electrode, then a second carrier transport support layer is fabricated, and then a second electrode is fabricated on the second carrier transport support layer; (b) The perovskite precursor solution is placed into the first carrier transport support layer and the first carrier transport support layer, and after annealing, the fibrous perovskite solar cell is obtained.

8. The preparation method according to claim 7, characterized in that, The concentration of the perovskite precursor solution in step (b) is 1-1.5 mol / L; Preferably, before the perovskite precursor solution in step (b) is placed, the semi-finished product obtained in step (a) is annealed. The annealing temperature is 300-500℃ and the holding time is 30-50min. Preferably, the annealing temperature in step (b) is 50-100℃, and the holding time is 8-12 min.

9. The preparation method according to claim 7 or 8, characterized in that, The preparation method includes the following steps: (a1) The conductive fibers are pretreated, and then the pretreated conductive fibers are mixed with a dense electron transport layer material and heat-treated at 800-1300℃ for 15-30 min to form a dense electron transport layer with a thickness of 30-100 nm. (b1) An electron transport scaffold layer with a thickness of 700-1000 nm is deposited on the dense electron transport layer; then a hole transport scaffold layer with a thickness of 2-3 μm is deposited on the electron transport scaffold layer; then a porous conductive layer with a thickness of 20-25 μm is deposited on the hole transport scaffold layer. (c1) Anneal the semi-finished product obtained in step (b1) at a temperature of 300-500℃ for a holding time of 30-50 minutes. (d1) A perovskite precursor solution with a concentration of 1-1.5 mol / L is injected into the support structure obtained in step (c1), and wrapped with heat shrink tubing. The solution is then annealed at 50-100°C for 8-12 minutes to obtain the fibrous perovskite solar cell.

10. A tandem solar cell, characterized in that, The tandem solar cell includes a base cell and a fibrous perovskite solar cell as described in any one of claims 1-6.

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