Perovskite cell and preparation method thereof, laminated cell and photovoltaic module

Abstract

The invention provides a perovskite cell and a preparation method thereof, a laminated cell and a photovoltaic module. The perovskite cell comprises a substrate, a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer and an electrode layer which are sequentially arranged in a preset direction, and the first hole transport layer comprises a carbazole derivative with a carboxyl anchoring group. The second hole transport layer comprises a compound of foldable molecules containing phosphonic acid groups, and the tunneling layer is of a network structure. The technical scheme provided by the embodiment of the invention at least has the following advantages: 1, foldable molecules containing phosphonic acid groups cover the gaps of the first hole transport layer after being folded to serve as the second hole transport layer, so that the wettability (contact angle lt: 10 degrees) of the perovskite precursor is improved;

Description

Cross-reference to related applications

[0001] This application is a divisional application of Chinese invention patent application filed on September 16, 2025, with application number 202511320712.6 and invention title "A perovskite battery and its preparation method, tandem battery and photovoltaic module". Technical Field

[0002] This application relates to the photovoltaic field, and in particular to a perovskite solar cell and its preparation method, a tandem solar cell, and a photovoltaic module. Background Technology

[0003] In perovskite solar cells and tandem cells, the hole transport layer plays a crucial role in hole extraction and transport, suppressing carrier recombination, and improving the crystallization and film formation of perovskite materials. However, existing hole transport layers suffer from energy level mismatch. Therefore, continuously developing hole transport materials with excellent film formation properties, solvent resistance, thermal stability, hole mobility, and energy levels that match those of perovskite materials is a key factor in preparing efficient and stable perovskite solar cells. Summary of the Invention

[0004] This application provides a perovskite solar cell and its preparation method, a tandem solar cell, and a photovoltaic module, which at least helps to improve the wettability of the perovskite precursor.

[0005] According to some embodiments of this application, one aspect of this application provides a perovskite solar cell, comprising: a substrate, a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer sequentially disposed in a preset direction. The first hole transport layer comprises a carbazole derivative having a carboxyl anchoring group, the second hole transport layer comprises a compound containing a foldable molecule with a phosphonic acid group, and the tunneling layer has a network structure.

[0006] In some embodiments, the thickness of the first hole transport layer is 10 nm to 15 nm.

[0007] In some embodiments, the carbazole derivative having a carboxyl anchoring group includes at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid and [4-(9H-carbazole-9-yl)butyl]phosphonic acid. The carboxyl anchoring group refers to the hydroxyl group in the phosphonic acid.

[0008] In some embodiments, the thickness of the second hole transport layer is 1 nm to 4 nm.

[0009] In some embodiments, the compound containing a foldable molecule with a phosphonic acid group includes at least one of hexylphosphonic acid and decylphosphonic acid.

[0010] In some embodiments, the thickness of the tunneling layer is 3 nm to 5 nm.

[0011] In some embodiments, the material of the tunneling layer is nanocrystals, and the particle size of the nanocrystals is 3nm~7nm.

[0012] In some embodiments, the nanocrystals include at least one of ITO nanocrystals, FTO nanocrystals, IWO nanocrystals, and AZO nanocrystals.

[0013] In some embodiments, the method for preparing the ITO nanocrystals includes: Indium trichloride and tin tetrachloride are dissolved in a mixed solvent and heated to 110°C~130°C under vacuum to remove moisture and oxygen. Under nitrogen protection, the temperature is increased to 280℃~300℃ at a rate of 10℃ / min~20℃ / min, held for 1 hour, then cooled to 180℃~220℃ and held for 2 hours. After cooling to room temperature, the sample was washed with anhydrous ethanol, centrifuged, and the precipitate was collected to obtain ITO nanocrystals. The mixed solvent is a mixture of oleic acid, oleylamine and 1-octadecene in a volume ratio of 1:1:2 to 1:2:3.

[0014] In some embodiments, the method for preparing the IZO nanocrystals includes: Dissolve the indium source (such as indium nitrate or indium chloride) and the zinc source (such as zinc nitrate or zinc acetate) in a solvent (such as ethylene glycol methyl ether) in a predetermined ratio, and stir until completely dissolved; Add a stabilizer (such as ethanolamine) and stir at 60℃~70℃ for 60min~70min until a transparent and uniform sol is formed; The sol was left to stand at room temperature for 24 hours to form a gel. The gel was dried at 150°C for 15-20 minutes to remove organic solvents and moisture, and then annealed in a muffle furnace at 350°C-450°C for 30-60 minutes to decompose and crystallize the inorganic salts to form IZO nanocrystals.

[0015] In some embodiments, the method for preparing the FTO nanocrystals includes: Dissolve a tin source (such as tin tetrachloride) and a fluorine doping source (such as ammonium fluoride or hydrofluoric acid) in a solvent (such as deionized water and / or ethanol) in proportion and stir to form a homogeneous precursor solution. The precursor solution is atomized into micron-sized droplets using an atomizer (such as an ultrasonic atomizer); The micron-sized droplets are delivered onto a heated glass substrate using a carrier gas (such as compressed air or nitrogen).

[0016] The micron-sized droplets undergo a series of reactions on a glass substrate heated to 400℃~500℃, including solvent evaporation, precursor thermal decomposition, and oxidative crystallization, instantly forming an FTO nanocrystalline thin film.

[0017] To further optimize crystallinity and electrical properties, the deposited FTO nanocrystalline film can be post-annealed at 500℃~600℃ (air or nitrogen atmosphere, 30min~60min).

[0018] In some embodiments, the method for preparing the IWO nanocrystals includes: Indium source (such as indium oxide) and tungsten source (such as tungsten oxide) powders are mixed in a certain proportion, deionized water and dispersant (such as ammonium polyacrylate) are added, and the mixture is ground by ball milling or sand milling for 6 to 12 hours to form a uniform and fine slurry. The slurry is spray-dried to produce spherical powder with uniform particle size (-80 mesh to +200 mesh). The granulated powder is then filled into a mold and pressed into shape by cold isostatic pressing (CIP) at a pressure of 160 MPa to 300 MPa to obtain the target blank. The target blank was subjected to a high oxygen partial pressure atmosphere (oxygen pressure 1.0 × 10⁻⁶). 5 Pa ~ 1.0 × 10 8 Under the condition of Pa), sintering was carried out at 1400℃~1600℃ and held for 5h~12h to obtain high-density, low-resistivity IWO ceramic target material. Using the aforementioned IWO ceramic target, IWO nanocrystalline thin films are deposited on a suitable substrate via magnetron sputtering. Typical process parameters include: substrate temperature (room temperature to 300°C), sputtering power, operating gas pressure (a mixture of argon and a small amount of oxygen), and target-substrate distance.

[0019] In some embodiments, the method for preparing the AZO nanocrystals includes: Dissolve the zinc source (such as zinc nitrate or zinc acetate) and the aluminum source (such as aluminum nitrate or aluminum chloride) in a solvent (such as deionized water or ethanol) in proportion and stir until completely dissolved.

[0020] Acrylamide was added as an organic monomer, and N'N-methylenebisacrylamide was added as a crosslinking agent; Ammonium persulfate was added as an initiator and heated in a water bath at 60℃~70℃ to initiate a polymerization reaction, forming a gel in which a polymer network encapsulates metal ions. The gel was dried at 100℃~120℃, and then placed in a muffle furnace and calcined in an air atmosphere at 400℃~500℃ for 1h~2h to remove organic matter and crystallize AZO to obtain AZO nanopowder.

[0021] These four nanocrystalline materials and their preparation processes provide multiple approaches to optimize the performance of perovskite-TOPCon tandem solar cells: IZO nanocrystals: Their amorphous properties and tunable work function make them ideal as interface bonding layers or top electrodes, effectively reducing energy barriers, improving carrier collection efficiency, and requiring relatively low preparation temperatures.

[0022] FTO nanocrystals: Their excellent stability and high haze (if made into a specific structure) make them very suitable as the front electrode of a battery, as they can conduct electricity and effectively trap light, reducing reflection loss.

[0023] IWO nanocrystals: Their extremely high carrier mobility and high light transmittance in the near-infrared region make them an ideal front electrode material for tandem cells that require low resistance and high light transmittance, especially for bifacial power generation or cells that respond to the infrared spectrum.

[0024] AZO nanocrystals: As a low-cost, indium-free alternative, AZO can be used in electron transport layers or transparent electrodes. Although its conductivity may be slightly lower than that of ITO, its cost advantage is obvious, and it matches the energy levels of perovskites well.

[0025] In some embodiments, the electrode layer includes at least one of a TCO top electrode and a metal electrode.

[0026] According to some embodiments of this application, another aspect of this application provides a method for preparing a perovskite solar cell as described in the above embodiments, comprising the following steps: A substrate is provided, and a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer are sequentially formed on the substrate in a predetermined direction. The preparation steps of the first hole transport layer include: A first precursor solution comprising a first hole transport material is prepared, wherein the first hole transport material is a carbazole derivative having a carboxyl anchoring group. The first precursor liquid is coated onto the surface of the substrate and annealed at a first temperature to form the first hole transport layer. The fabrication steps of the second hole transport layer include: A second precursor solution comprising a second hole transport material is prepared, wherein the second hole transport material is a compound containing a foldable molecule with a phosphonic acid group; The second precursor liquid is deposited on the surface of the first hole transport layer by vapor deposition and annealed at a second temperature to form the second hole transport layer. The steps for preparing the tunneling layer include: Preparation of a third precursor solution containing tunneling layer material; The third precursor liquid is coated onto the surface of the second hole transport layer and annealed at a third temperature to form the tunneling layer. This tunneling layer has a continuous network structure.

[0027] In some embodiments, the third temperature > the first temperature > the second temperature.

[0028] In some embodiments, the first temperature is 100°C to 140°C.

[0029] In some embodiments, the second temperature is 80°C to 120°C.

[0030] In some embodiments, the third temperature is 130°C to 170°C.

[0031] In some embodiments, the preparation step of the first precursor solution includes: The first hole transport material and the first solvent are mixed to prepare a first precursor solution. In the first precursor solution, the first hole transport material has a first concentration of 0.1 mg / mL to 2 mg / mL. The preparation steps of the second precursor solution include: The second hole transport material and the second solvent are mixed and deoxygenated to obtain a second precursor solution. In the second precursor solution, the second hole transport material has a second concentration of 0.5 mmol / L to 1.5 mmol / L. The preparation steps of the third precursor solution include: The tunneling layer material is mixed with a third solvent to prepare a third precursor solution. In the third precursor solution, the tunneling layer material has a third concentration, which is 10 mg / mL to 30 mg / mL. The tunneling layer material includes nanocrystals.

[0032] In some embodiments, the first solvent, the second solvent, and the third solvent are each independently selected from at least one of acetic acid, ethanol, isopropanol, and chlorobenzene.

[0033] In some embodiments, coating the first precursor liquid onto the substrate surface includes: coating by spin coating, wherein the spin coating speed is 2000 rpm to 4000 rpm and the duration is 20 s to 40 s.

[0034] In some embodiments, coating the third precursor liquid onto the surface of the second hole transport layer includes: coating by spin coating, wherein the spin coating speed is 1000 rpm to 4000 rpm and the duration is 5 s to 20 s.

[0035] In some embodiments, in the vapor deposition method, the temperature of the surface of the first hole transport layer is controlled to be 60°C to 100°C, and the vacuum degree is 0.5 × 10⁻⁶. -3 Pa ~ 1.5 × 10 -3 Pa, deposition time is 15 min to 25 min.

[0036] According to some embodiments of this application, another aspect of this application provides a stacked battery, including: a perovskite battery as described in any of the above embodiments, or a perovskite battery prepared by the preparation method of a perovskite battery as described in any of the above embodiments, wherein the substrate is a bottom battery.

[0037] According to some embodiments of this application, another aspect of this application provides a method for preparing a tandem battery, comprising the following steps: A bottom cell is provided, and after pre-processing the bottom cell, a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer are sequentially formed on the bottom cell in a preset direction. The preparation steps of the first hole transport layer include: A first precursor solution comprising a first hole transport material is prepared, wherein the first hole transport material is a carbazole derivative having a carboxyl anchoring group. The first precursor liquid is coated onto the surface of the bottom battery and annealed at a first temperature to form the first hole transport layer. The fabrication steps of the second hole transport layer include: A second precursor solution comprising a second hole transport material is prepared, wherein the second hole transport material is a compound containing a foldable molecule with a phosphonic acid group; The second precursor liquid is deposited on the surface of the first hole transport layer by vapor deposition and annealed at a second temperature to form the second hole transport layer. The steps for preparing the tunneling layer include: Preparation of a third precursor solution containing tunneling material; The third precursor liquid is coated onto the surface of the second hole transport layer and annealed at a third temperature to form the tunneling layer.

[0038] In some embodiments, the bottom cell is a TOPCon silicon wafer, and the pretreatment method includes: After ultrasonic cleaning in acetone and isopropanol, TOPCon silicon wafers were subjected to ultraviolet ozone treatment to improve the n-axis of the TOPCon silicon wafers. + - A hydrophilic layer is formed on the poly-Si surface.

[0039] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: Multiple solar cells, wherein the solar cells are perovskite cells as described in any one of the above embodiments, or perovskite cells prepared by the preparation method of perovskite cells as described in any one of the above embodiments, or tandem cells as described in the above embodiments, or tandem cells prepared by the preparation method of tandem cells as described in any one of the above embodiments. A connecting component for connecting adjacent solar cells; An adhesive film covering the surface of the solar cell; A cover plate, the cover plate being located on the surface of the adhesive film away from the solar cell.

[0040] The technical solution provided in this application has at least the following advantages: 1. A dense layer with a thickness of 10nm~15nm is formed using a carbazole derivative containing a carboxyl anchoring group as the first hole transport layer. The work function is adjusted to 4.2 eV~5.0 eV, which can match the silicon energy level and is suitable for the assembly of tandem cells. 2. By using foldable molecules containing phosphonic acid groups to cover the gaps in the first hole transport layer after folding, a second hole transport layer is formed, which improves the wettability of the perovskite precursor (contact angle <10°). Attached Figure Description

[0041] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the stacked battery provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application; Figure 4 The flowchart corresponds to the fabrication method of the perovskite solar cell provided in the embodiments of this application.

[0043] Explanation of reference numerals in the attached figures: 1011, substrate; 1012, bottom cell; 1013, first hole transport layer; 1014, second hole transport layer; 1015, tunneling layer; 1016, perovskite functional layer; 1017, electron transport layer; 1018, electrode layer; 100, cell string; 101, solar cell; 111, connecting component; 120, cover plate. Detailed Implementation

[0044] As can be seen from the background technology, in existing tandem solar cells, there is an energy level mismatch problem between the hole transport layer and the bottom cell.

[0045] According to some embodiments of this application, one embodiment of this application provides a perovskite solar cell, such as... Figure 1 As shown, it includes: a substrate 1011, a first hole transport layer 1013, a second hole transport layer 1014, a tunneling layer 1015, a perovskite functional layer 1016, an electron transport layer 1017, and an electrode layer 1018 arranged sequentially in a preset direction. The first hole transport layer 1013 includes a carbazole derivative with a carboxyl anchoring group, the second hole transport layer 1014 includes a compound containing a foldable molecule with a phosphonic acid group, and the tunneling layer 1015 has a network structure.

[0046] In perovskite solar cell structures, the substrate plays a crucial role in both support and conductivity. Substrates include fluorine-doped tin oxide glass, indium-doped tin oxide glass, and flexible conductive substrates.

[0047] The main materials of the perovskite functional layer are perovskite compounds, such as methylammonium lead iodide. These materials possess excellent light absorption and photoelectric conversion properties, and their close contact with the organic hole transport layer, along with their good interfacial properties, facilitates the efficient extraction and transport of holes. They also work in conjunction with the electron transport layer to achieve efficient separation and transport of electrons and holes. Common electron transport layer materials include titanium dioxide (TiO2) and zinc oxide (ZnO), which efficiently transport electrons, collecting and transporting electrons generated by the perovskite functional layer to the electrodes. Electrode materials include gold (Au) and silver (Ag), which possess good conductivity and stability. The electrodes, as the charge output terminals of the battery, collect and export electrons transported from the electron transport layer to the external circuit, enabling the battery's electrical energy output.

[0048] In this embodiment, a dense layer with a thickness of 10nm~15nm is formed using a carbazole derivative containing a carboxyl anchoring group as the first hole transport layer. The work function is adjusted to 4.2 eV~5.0 eV, which can match the silicon energy level and is suitable for the assembly of tandem cells. A foldable molecule containing a phosphonic acid group is used to cover the gap of the first hole transport layer after folding, serving as the second hole transport layer to improve the wettability of the perovskite precursor (contact angle <10°).

[0049] In some embodiments, the thickness of the first hole transport layer is 10nm~15nm, specifically 10nm, 11nm, 12nm, 13nm, 14nm, or 15nm.

[0050] In some embodiments, the carbazole derivative having a carboxyl anchoring group includes at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid and [4-(9H-carbazole-9-yl)butyl]phosphonic acid.

[0051] In some embodiments, the thickness of the second hole transport layer is 1nm to 4nm, specifically 1nm, 2nm, 3nm, or 4nm.

[0052] In some embodiments, the compound containing a foldable molecule with a phosphonic acid group includes at least one of hexylphosphonic acid and decylphosphonic acid.

[0053] In some embodiments, the thickness of the tunneling layer is 3nm to 5nm, specifically 3nm, 4nm, or 5nm.

[0054] In some embodiments, the material of the tunneling layer is nanocrystals, and the particle size of the nanocrystals is 3nm~7nm, specifically 3nm, 4nm, 5nm, 6nm, or 7nm.

[0055] Using nanocrystals as a tunneling layer and as electron acceptors, a PN heterojunction is formed with the second hole transport layer, driving holes to transport upward and electrons to transport downward, thus achieving directional recombination of charge carriers (recombination rate <10 ns).

[0056] In some embodiments, the nanocrystals include at least one of ITO nanocrystals, FTO nanocrystals, IWO nanocrystals, and AZO nanocrystals.

[0057] In some embodiments, the electrode layer includes at least one of a TCO top electrode and a metal electrode.

[0058] According to some embodiments of this application, another aspect of this application provides a method for preparing a perovskite solar cell, which can be used to manufacture the perovskite solar cell as described in the above embodiments, comprising the following steps: A substrate is provided, and a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer are sequentially formed on the substrate in a predetermined direction. The preparation steps of the first hole transport layer include: A first precursor solution comprising a first hole transport material is prepared, wherein the first hole transport material is a carbazole derivative having a carboxyl anchoring group. The first precursor liquid is coated onto the surface of the substrate and annealed at a first temperature to form the first hole transport layer. The fabrication steps of the second hole transport layer include: A second precursor solution comprising a second hole transport material is prepared, wherein the second hole transport material is a compound containing a foldable molecule with a phosphonic acid group; The second precursor liquid is deposited on the surface of the first hole transport layer by vapor deposition and annealed at a second temperature to form the second hole transport layer. The steps for preparing the tunneling layer include: Preparation of a third precursor solution containing tunneling material; The third precursor liquid is coated onto the surface of the second hole transport layer and annealed at a third temperature to form the tunneling layer.

[0059] In some embodiments, the third temperature > the first temperature > the second temperature.

[0060] In some embodiments, the first temperature is 100℃~140℃, specifically 105℃, 110℃, 115℃, 120℃, 125℃, 135℃, or 140℃.

[0061] In some embodiments, the second temperature is 80℃~120℃, specifically 80℃, 85℃, 90℃, 95℃, 100℃, 115℃, or 120℃.

[0062] In some embodiments, the third temperature is 130℃~170℃, specifically 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, or 170℃.

[0063] In some embodiments, the preparation step of the first precursor solution includes: The first hole transport material and the first solvent are mixed to prepare a first precursor solution. In the first precursor solution, the first hole transport material has a first concentration of 0.1 mg / mL to 2 mg / mL, specifically 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, 0.5 mg / mL, 0.6 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, 1 mg / mL, 1.1 mg / mL, 1.2 mg / mL, 1.3 mg / mL, 1.4 mg / mL, 1.5 mg / mL, 1.6 mg / mL, 1.7 mg / mL, 1.8 mg / mL, 1.9 mg / mL, and 2 mg / mL. The preparation steps of the second precursor solution include: The second hole transport material and the second solvent are mixed and deoxygenated to obtain a second precursor solution. In the second precursor solution, the second hole transport material has a second concentration of 0.5 mmol / L to 1.5 mmol / L, specifically 0.5 mmol / L, 0.6 mmol / L, 0.7 mmol / L, 0.8 mmol / L, 0.9 mmol / L, 1 mmol / L, 1.1 mmol / L, 1.2 mmol / L, 1.3 mmol / L, 1.4 mmol / L, and 1.5 mmol / L. The preparation steps of the third precursor solution include: The tunneling layer material is mixed with a third solvent to prepare a third precursor solution. In the third precursor solution, the tunneling layer material has a third concentration, which is 10 mg / mL to 30 mg / mL, specifically 10 mg / mL, 12 mg / mL, 14 mg / mL, 16 mg / mL, 18 mg / mL, 20 mg / mL, 22 mg / mL, 24 mg / mL, 26 mg / mL, 28 mg / mL, or 30 mg / mL. The tunneling material comprises nanocrystals.

[0064] In some embodiments, the first solvent, the second solvent, and the third solvent are each independently selected from at least one of acetic acid, ethanol, isopropanol, and chlorobenzene.

[0065] In some embodiments, coating the first precursor liquid onto the substrate surface includes: coating by spin coating, wherein the spin coating speed is 2000 rpm to 4000 rpm, specifically 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, or 4000 rpm, and the duration is 20 s to 40 s, specifically 20 s, 25 s, 30 s, 35 s, or 40 s.

[0066] In some embodiments, coating the third precursor liquid onto the surface of the second hole transport layer includes: coating by spin coating, wherein the spin coating speed is 1000 rpm to 4000 rpm, specifically 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, or 4000 rpm, and the spin coating time is 5 s to 20 s, specifically 5 s, 10 s, 15 s, or 20 s.

[0067] In some embodiments, in the vapor deposition method, the temperature of the surface of the first hole transport layer is controlled to be 60°C to 100°C, specifically 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C, and the vacuum degree is 0.5 × 10⁻⁶. -3 Pa ~ 1.5 × 10 -3Pa, specifically 0.5 × 10 -3 Pa, 1×10 -3 Pa, 1.5 × 10 -3 Pa, deposition time is 15min~25min, specifically 15min, 16min, 17min, 18min, 19min, 20min, 21min, 22min, 23min, 24min, 25min.

[0068] According to some embodiments of this application, another aspect of this application provides a stacked battery, such as... Figure 2 As shown, it includes: the perovskite battery described in the above embodiments, or the perovskite battery prepared by the preparation method of the perovskite battery in the above embodiments. The perovskite battery includes a substrate, a first hole transport layer 1013, a second hole transport layer 1014, a tunneling layer 1015, a perovskite functional layer 1016, an electron transport layer 1017, and an electrode layer 1018 arranged sequentially in a preset direction. The first hole transport layer 1013 includes a carbazole derivative with a carboxyl anchoring group. The second hole transport layer 1014 includes a compound containing a foldable molecule with a phosphonic acid group. The tunneling layer 1015 has a network structure. The substrate is a bottom cell 1012.

[0069] In this embodiment, a carbazole derivative containing a carboxyl anchoring group is vertically assembled onto the n of TOPCon. + A dense layer with a thickness of 10 nm to 15 nm is formed on the polycrystalline silicon surface as the first hole transport layer, with its work function adjusted to 4.2 eV to 5.0 eV to match the silicon energy level. A second hole transport layer is formed by folding phosphonate-containing foldable molecules to cover the gaps in the first hole transport layer, improving the wettability of the perovskite precursor (contact angle <10°). Nanocrystals are used as a tunneling layer and as electron acceptors, forming a PN heterojunction with the second hole transport layer. This drives hole upward and electron downward transport, achieving directional carrier recombination (recombination rate <10 ns).

[0070] According to some embodiments of this application, another aspect of this application provides a method for preparing a tandem battery, comprising the following steps: A bottom cell is provided, and after pre-processing the bottom cell, a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer are sequentially formed on the bottom cell in a preset direction. The preparation steps of the first hole transport layer include: A first precursor solution comprising a first hole transport material is prepared, wherein the first hole transport material is a carbazole derivative having a carboxyl anchoring group. The first precursor liquid is coated onto the surface of the bottom battery and annealed at a first temperature to form the first hole transport layer. The fabrication steps of the second hole transport layer include: A second precursor solution comprising a second hole transport material is prepared, wherein the second hole transport material is a compound containing a foldable molecule with a phosphonic acid group; The second precursor liquid is deposited on the surface of the first hole transport layer by vapor deposition and annealed at a second temperature to form the second hole transport layer. The steps for preparing the tunneling layer include: Preparation of a third precursor solution containing tunneling layer material; The third precursor liquid is coated onto the surface of the second hole transport layer and annealed at a third temperature to form the tunneling layer.

[0071] In some embodiments, the bottom cell is a TOPCon silicon wafer, and the pretreatment method includes: After ultrasonic cleaning in acetone and isopropanol, TOPCon silicon wafers were subjected to ultraviolet ozone treatment to improve the n-axis of the TOPCon silicon wafers. + - A hydrophilic layer is formed on the poly-Si surface.

[0072] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, such as... Figure 3 As shown, it includes: Multiple solar cells 101, wherein the solar cells 101 are perovskite cells as described in any of the above embodiments, or perovskite cells prepared by the method of preparing perovskite cells as described in any of the above embodiments, or tandem cells as described in the above embodiments, or tandem cells prepared by the method of preparing tandem cells as described in any of the above embodiments. Connecting component 111, the connecting component 111 is used to connect adjacent solar cells 101 into a battery string 100; An adhesive film (not shown in the figure) covers the surface of the solar cell 101; Cover plate 120 is located on the surface of the film away from the solar cell 101.

[0073] The connecting component 111 includes interconnect solder ribbons and bus solder ribbons. The interconnect solder ribbons are tinned solder ribbons used to connect solar cells, collect and transmit current from solar cells. The bus solder ribbons are tinned solder ribbons used to connect cell strings and junction boxes, and transmit current from stacked cell strings.

[0074] The film can be an organic encapsulation film such as ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0075] The cover plate can be a glass cover plate, a plastic cover plate, or other cover plate with light transmission function. In some embodiments, the surface of the cover plate facing the encapsulation layer can be an uneven surface, thereby increasing the utilization rate of incident light.

[0076] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0077] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0078] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0079] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0080] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0081] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0082] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0083] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0084] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0085] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0086] Example 1 This embodiment provides a method for preparing a perovskite solar cell, such as... Figure 4 As shown, the specific steps include the following: S1. Provide a glass substrate and clean it for later use; S2. Dissolve [2-(9H-carbazole-9-yl)ethyl]phosphonic acid in ethanol at a concentration of 0.1 mg / mL to obtain a first precursor solution. Spin-coat the first precursor solution onto the cleaned glass substrate surface at a spin speed of 3000 rpm for 30 s. After spin-coating, anneal at 120°C for 10 min to form a first hole transport layer with a thickness of 12 nm. S3. Dissolve hexylphosphonic acid in ethanol at a concentration of 0.5 mmol / L, then add 0.1 vol% acetic acid. After nitrogen purging to remove oxygen, a second precursor solution is obtained. The second precursor solution is loaded into a vacuum deposition chamber and deposited at 80°C and 1×10⁻⁶ ppm. -3 Vapor deposition was performed on the surface of the first hole transport layer under a vacuum of Pa. After deposition, annealing was performed at 100°C to obtain a second hole transport layer with a thickness of 2 nm. S4. ITO nanocrystals with a particle size of 3 nm were dispersed in anhydrous ethanol at a concentration of 20 mg / mL to obtain a third precursor solution. The third precursor solution was spin-coated onto the surface of the second hole transport layer at a speed of 2500 rpm for 10 s. After spin-coating, the layer was annealed at 150 °C to obtain a tunneling layer with a thickness of 3 nm. S5. Take 50 μl of perovskite precursor solution and coat it on the surface of the organic hole transport layer. Spin coat at 3000 rpm for 20 seconds, and then anneal at 90℃ for 8 min to prepare a perovskite functional layer. The perovskite precursor solution is a mixture of CsI, PbI2, PbBr2, FAI and MAI in DMF and DMSO in a certain molar ratio. S6. A C60 thin film with a thickness of 15 nm is deposited on the surface of the perovskite functional layer using a vapor deposition machine, and then SnO2 is deposited using an ALD device to obtain the electron transport layer. S7. In a vacuum evaporation chamber, Ag (1000nm) is deposited on the electron transport layer to prepare a perovskite solar cell.

[0087] Example 2 This embodiment provides a method for preparing a perovskite battery. The difference from Embodiment 1 is that in the first precursor solution, [4-(9H-carbazole-9-yl)butyl]phosphonic acid is used instead of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

[0088] Example 3 This embodiment provides a method for preparing a perovskite battery. The difference from Embodiment 1 is that decylphosphonic acid is used instead of hexylphosphonic acid in the second precursor solution.

[0089] Example 4 This embodiment provides a method for preparing a perovskite solar cell. The difference from Embodiment 1 is that FTO nanocrystals are used instead of ITO nanocrystals in the third precursor solution.

[0090] Example 5 This embodiment provides a method for fabricating a tandem solar cell. The difference from Embodiment 1 is that a TOPcon silicon wafer is used instead of a glass substrate. The pretreatment method for the TOPcon silicon wafer is as follows: the TOPCon silicon wafer is ultrasonically cleaned in acetone and isopropanol, respectively, and then irradiated with ultraviolet light in an ozone environment for 10 minutes to improve the n-axis of the TOPCon silicon wafer. + - A hydrophilic layer is formed on the poly-Si surface.

[0091] Example 6 This embodiment provides a method for preparing a tandem battery. The difference from Embodiment 5 is that [4-(9H-carbazole-9-yl)butyl]phosphonic acid is used instead of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid.

[0092] Example 7 This embodiment provides a method for preparing a tandem battery. The difference from Embodiment 5 is that FTO nanocrystals are used instead of ITO nanocrystals.

[0093] Example 8 This embodiment provides a method for preparing a tandem battery, which differs from Embodiment 6 in that decylphosphonic acid is used instead of hexylphosphonic acid.

[0094] Comparative Example 1 This comparative example provides a method for preparing a perovskite solar cell. The difference from Example 1 is that the first hole transport layer is obtained by evaporation of nickel oxide using the PVD method.

[0095] Comparative Example 2 This comparative example provides a method for preparing a tandem battery. The difference from Example 5 is that the ITO nanocrystals have a particle size of 20 nm.

[0096] Table 1 shows a performance comparison of this embodiment with conventional perovskite / tandem solar cells, as well as the perovskite solar cell obtained in Comparative Example 1 and the tandem solar cell obtained in Comparative Example 2.

[0097] Table 1

[0098] By comparing Example 1 with Comparative Example 1, and Example 5 with conventional tandem solar cells and Comparative Example 2, it can be seen that, in terms of short-circuit current density (Jsc), the ultrathin ITO nanocrystalline layer (3nm) significantly reduces parasitic optical absorption (<3%), allowing more photons to be utilized by the perovskite functional layer. At the same time, the first hole transport layer matches the silicon energy level, improving carrier extraction. In terms of open-circuit voltage (Voc), the ITO nanocrystalline layer provides an excellent recombination interface, significantly reducing interface recombination losses. In terms of fill factor (FF), the good contact between the ITO nanocrystalline layer and the second hole transport layer significantly reduces contact resistance and series resistance.

[0099] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A perovskite solar cell, characterized in that, It includes: a substrate, a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer arranged sequentially in a preset direction, wherein the first hole transport layer includes a carbazole derivative having a carboxyl anchoring group.

2. The perovskite solar cell according to claim 1, characterized in that, The thickness of the first hole transport layer is 10nm~15nm.

3. The perovskite solar cell according to claim 1 or 2, characterized in that, The carbazole derivative having a carboxyl anchoring group includes at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid and [4-(9H-carbazole-9-yl)butyl]phosphonic acid.

4. The perovskite solar cell according to claim 1, characterized in that, The thickness of the second hole transport layer is 1nm~4nm.

5. The perovskite solar cell according to claim 1 or 4, characterized in that, The second hole transport layer comprises a compound containing foldable molecules with phosphonic acid groups.

6. The perovskite solar cell according to claim 5, characterized in that, The compound containing a foldable molecule with a phosphonic acid group includes at least one of hexylphosphonic acid and decylphosphonic acid.

7. The perovskite solar cell according to claim 1, characterized in that, The thickness of the tunneling layer is 3nm~5nm.

8. The perovskite solar cell according to claim 1 or 7, characterized in that, The material of the tunneling layer includes nanocrystals with a particle size of 3nm to 7nm.

9. The perovskite solar cell according to claim 8, characterized in that, The nanocrystals include at least one of ITO nanocrystals, FTO nanocrystals, IWO nanocrystals, AZO nanocrystals, and IZO nanocrystals.

10. The perovskite solar cell according to claim 9, characterized in that, The method for preparing the ITO nanocrystals includes: Indium trichloride and tin tetrachloride are dissolved in a mixed solvent and heated to 110°C~130°C under vacuum to remove moisture and oxygen. Under nitrogen protection, the temperature is increased to 280℃~300℃ at a rate of 10℃ / min~20℃ / min, held at that temperature, then cooled to 180℃~220℃ and held at that temperature. After cooling to room temperature, the sample was washed with anhydrous ethanol, centrifuged, and the precipitate was collected to obtain ITO nanocrystals. The mixed solvent is a mixture of oleic acid, oleylamine and 1-octadecene.

11. The perovskite solar cell according to claim 9, characterized in that, The preparation method of the IZO nanocrystals includes: Dissolve the indium source and zinc source in a solvent according to a predetermined ratio, and stir until completely dissolved; Add a stabilizer and stir at 60℃~70℃ to form a sol; The sol was allowed to stand at room temperature to age, forming a gel. After drying the gel, it is annealed at 350℃~450℃ to decompose and crystallize the inorganic salts to form IZO nanocrystals.

12. The perovskite solar cell according to claim 9, characterized in that, The preparation method of the FTO nanocrystals includes: The tin source and fluorine doping source are dissolved in a solvent and stirred to form a precursor solution; The precursor solution is atomized into micron-sized droplets; The micron-sized droplets are transported to a heated substrate using a carrier gas, whereby the droplets react on the substrate heated to 400°C to 500°C to form FTO nanocrystals.

13. The perovskite solar cell according to claim 9, characterized in that, The preparation method of the IWO nanocrystals includes: Indium source and tungsten source are mixed, deionized water and dispersant are added, and after grinding, a slurry is formed; The slurry is spray-dried to form spherical powder, and then cold isostatically pressed to obtain the target blank; The target blank is sintered in an oxygen atmosphere at 1400℃~1600℃ to obtain IWO ceramic target material; IWO nanocrystals were deposited using the IWO ceramic target via magnetron sputtering.

14. The perovskite solar cell according to claim 9, characterized in that, The preparation method of the AZO nanocrystals includes: Zinc and aluminum sources are dissolved in a solvent in a certain proportion. After dissolution, organic monomers and crosslinking agents are added. Ammonium persulfate was added as an initiator, and a polymerization reaction was carried out at 60℃~70℃ to form a gel with a polymer network encapsulating metal ions. The gel was dried at 100℃~120℃ and then calcined in air at 400℃~500℃ to remove organic matter and crystallize AZO to obtain AZO nanocrystals.

15. The perovskite solar cell according to any one of claims 10 to 14, characterized in that, The solvent includes at least one of ethylene glycol methyl ether, deionized water, and ethanol.

16. The perovskite solar cell according to claim 1, characterized in that, The electrode layer includes at least one of a TCO top electrode and a metal electrode.

17. A stacked battery, characterized in that, include: The perovskite battery according to any one of claims 1 to 16, wherein the substrate is a bottom cell.

18. A method for preparing a tandem battery, characterized in that, Includes the following steps: A bottom cell is provided, and after pre-processing the bottom cell, a first hole transport layer, a second hole transport layer, a tunneling layer, a perovskite functional layer, an electron transport layer, and an electrode layer are sequentially formed on the bottom cell in a preset direction. The preparation steps of the first hole transport layer include: A first precursor solution comprising a first hole transport material is prepared, wherein the first hole transport material is a carbazole derivative having a carboxyl anchoring group. The first precursor liquid is coated onto the surface of the bottom battery and annealed at a first temperature to form the first hole transport layer. The fabrication steps of the second hole transport layer include: A second precursor solution comprising a second hole transport material is prepared, wherein the second hole transport material is a compound containing a foldable molecule with a phosphonic acid group; The second precursor liquid is deposited on the surface of the first hole transport layer by vapor deposition and annealed at a second temperature to form the second hole transport layer. The steps for preparing the tunneling layer include: Preparation of a third precursor solution containing tunneling layer material; The third precursor liquid is coated onto the surface of the second hole transport layer and annealed at a third temperature to form the tunneling layer.

19. The method for preparing a tandem battery according to claim 18, characterized in that, The base battery is a TOPCon battery, and the pretreatment method includes: After ultrasonic cleaning in acetone and isopropanol, the TOPCon battery was subjected to ultraviolet ozone treatment to improve its performance. + - A hydrophilic layer is formed on the poly-Si surface.

20. A photovoltaic module, characterized in that, include: Multiple solar cells, wherein the solar cells are perovskite solar cells as described in any one of claims 1 to 16, or tandem solar cells as described in claim 17, or tandem solar cells prepared by the method for preparing tandem solar cells as described in claim 18 or 19; A connecting component for connecting adjacent solar cells; An adhesive film covering the surface of the solar cell; A cover plate, the cover plate being located on the surface of the adhesive film away from the solar cell.

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