Polymer-mediated organic ammonium salt composite interface passivation layer and applications thereof

Abstract

The application belongs to the technical field of perovskite solar cells, and particularly relates to a polymer-mediated organic ammonium salt composite interface passivation layer and application thereof. The application provides a polyvinyl fluoride-mediated organic ammonium salt composite interface passivation layer, the composite interface network can fix organic ammonium salt passivation components, inhibit self-aggregation behavior, and regulate release and adsorption of the organic ammonium salt on a perovskite surface, so that in-situ passivation of defects on the perovskite surface is realized. In addition, the polyvinyl fluoride-organic ammonium salt composite interface passivation layer can effectively reduce non-radiative recombination loss of a perovskite interface, and improve preparation repeatability, photovoltaic performance and operation stability of a perovskite solar cell and a perovskite / perovskite / silicon three-junction laminated solar cell.

Description

Technical Field

[0001] This invention belongs to the field of perovskite solar cell technology, specifically relating to a fluoropolymer-mediated organic ammonium salt composite interface passivation layer and its application in perovskite solar cells. Background Technology

[0002] Perovskite / silicon triple-junction tandem solar cells hold significant promise for low-cost, high-efficiency solar energy conversion. These devices, through the complementary spectral absorption of the perovskite sub-cells and the silicon substrate, are expected to further improve photoelectric conversion efficiency. However, the current highest photoelectric conversion efficiency of perovskite / silicon triple-junction tandem solar cells is still significantly lower than their theoretical efficiency limit of approximately 51%. Key challenges limiting further efficiency improvements include: difficulties in current matching between different sub-cells, the susceptibility to photoinduced halogen phase separation in the wide-bandgap perovskite layer, non-radiative recombination enhancement caused by interface and bulk defects, and voltage loss due to the multilayer stacked structure. Furthermore, monolithic triple-junction tandem devices are structurally complex, requiring multiple deposition and subsequent processing steps, making them susceptible to processing damage, resulting in lower repeatability and photoelectric conversion efficiency compared to double-junction tandem devices. Therefore, developing novel interface modulation methods is crucial for realizing the efficiency potential of perovskite / silicon triple-junction tandem solar cells.

[0003] Existing high-performance perovskite / silicon triple-junction tandem solar cells typically use methanemidine-rich perovskite as the intermediate sub-cell, with a bandgap generally between 1.51 and 1.56 eV. This composition is similar to that commonly used in high-efficiency single-junction perovskite solar cells, but insufficient current matching still exists in the triple-junction tandem structure. To improve the photocurrent generated by the intermediate perovskite sub-cell, it is usually necessary to increase the thickness of the intermediate bandgap perovskite layer. However, thicker intermediate bandgap perovskite films are more prone to crystallization defects, increasing the defect density on the surface and near-surface regions, thereby reducing the film's photoelectric performance and operational stability.

[0004] The aforementioned problems are even more pronounced in monolithic perovskite / silicon triple-junction tandem solar cells based on textured silicon substrates. While the submicron-scale pyramidal structure of the textured silicon surface is beneficial for light capture, its rough morphology affects the nucleation and growth of perovskite during solution processing, especially in thick, medium-bandgap perovskite films, where it is more likely to cause uneven lateral defect distribution and interfacial energy level differences. The resulting interfacial inhomogeneity can lead to defect-assisted recombination, localized leakage current, and current matching losses. Furthermore, surface recombination in medium-bandgap perovskite sub-cells significantly impacts device performance, and this layer also needs to withstand the heat treatment during the subsequent fabrication of wide-bandgap top-cell cells. Therefore, an interfacial passivation strategy suitable for medium-bandgap perovskites on textured silicon substrates not only needs to reduce defect density but also needs to possess spatially uniform coverage and good high-temperature processing tolerance. Summary of the Invention

[0005] To overcome the problems of self-aggregation of organic ammonium salt passivating agents, uneven spatial distribution of interfacial passivation, severe local non-radiative recombination, and easy volatilization of organic components under high-temperature and high-vacuum processes in existing perovskite solar cells, this invention proposes a polyvinyl fluoride-mediated organic ammonium salt composite interfacial passivation layer. This composite interfacial network can fix the organic ammonium salt passivation components, inhibit their self-aggregation behavior, and regulate their release and adsorption on the perovskite surface, thereby achieving uniform in-situ passivation of perovskite surface defects. Based on this, this invention was completed.

[0006] In a first aspect, the present invention provides a fluoropolymer-organic ammonium salt composite interface passivation layer, wherein the composite interface passivation layer is constructed by combining an organic ammonium salt passivating agent with a fluoropolymer and utilizing the F···HN hydrogen bond interaction formed between the ammonium group in the organic ammonium salt and the fluorine atom in the fluoropolymer to construct a fluoropolymer-organic ammonium salt composite interface network.

[0007] Furthermore, the fluoropolymer is polyvinyl fluoride.

[0008] Furthermore, the organic ammonium salt is selected from any one or more of the following: .

[0009] Furthermore, the organic ammonium salt is selected from one or more of phenylethyl ammonium bromide (PEABr), m-fluorophenylethyl ammonium bromide (mF-PEABr), ethylenediamine hydroiodide (EDADI), and / or propylenediamine hydroiodide (PDADI).

[0010] Furthermore, the volume ratio of the fluoropolymer to the organic ammonium salt solution is 0.5-1:0.5-1.

[0011] Furthermore, the volume ratio of the fluoropolymer to the organic ammonium salt solution is 1:1.

[0012] Furthermore, the fluoropolymer-organic ammonium salt composite interface passivation layer is selected from phenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer, m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer, ethylenediamine hydroiodate-polyvinyl fluoride composite passivation layer, or propylenediamine hydroiodate-polyvinyl fluoride composite passivation layer.

[0013] In one embodiment of the present invention, when the fluoropolymer is polyvinyl fluoride and the organic ammonium salt is phenylethyl ammonium bromide, the polyvinyl fluoride-organic ammonium salt composite interface passivation layer is a phenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer. When the fluoropolymer is polyvinyl fluoride and the organic ammonium salt is m-fluorophenylethyl ammonium bromide, the polyvinyl fluoride-organic ammonium salt composite interface passivation layer is a m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer. When the fluoropolymer is polyvinyl fluoride and the organic ammonium salt is ethylenediamine hydroiodate, the polyvinyl fluoride-organic ammonium salt composite interface passivation layer is an ethylenediamine hydroiodate-polyvinyl fluoride composite passivation layer. When the fluoropolymer is polyvinyl fluoride and the organic ammonium salt is propylenediamine hydroiodate, the polyvinyl fluoride-organic ammonium salt composite interface passivation layer is a propylenediamine hydroiodate-polyvinyl fluoride composite passivation layer.

[0014] In a second aspect, the present invention provides a method for preparing the fluoropolymer-organic ammonium salt composite interface passivation layer described in the first aspect, the preparation method comprising the following steps: S1. Preparation of fluoropolymer-organic ammonium salt composite passivation solution Fluoropolymer and organic ammonium salt were dissolved separately in solvents, mixed, and then ultrasonically treated to obtain a fluoropolymer-organic ammonium salt composite passivation solution. S2. Preparation of perovskite thin films The perovskite precursor solution was added to the substrate, and after spin-coating deposition, the sample was processed and annealed to obtain a perovskite film. S3. Preparation of perovskite composite passivation layer The fluorinated polymer-organic ammonium salt composite passivation solution prepared in S1 was dynamically spin-coated onto the surface of the perovskite film prepared in S2, and then annealed to form a fluorinated polymer-organic ammonium salt composite interface passivation layer.

[0015] Furthermore, in step S1, the solvent is selected from one or more of cyclohexanone, isopropanol, ethanol, chloroform, and phenethyl ether.

[0016] Furthermore, the solvent for the fluoropolymer is cyclohexanone, and the solvent for the organic ammonium salt is isopropanol.

[0017] Furthermore, in step S1, the volume ratio of the fluoropolymer to the organic ammonium salt solution is 0.5-1:0.5-1.

[0018] Furthermore, the volume ratio of the fluoropolymer to the organic ammonium salt solution is 1:1.

[0019] Furthermore, the fluoropolymer is polyvinyl fluoride.

[0020] Furthermore, the concentration of the polyvinyl fluoride solution is 0.1-0.6 mg / mL. -1 .

[0021] Preferably, the concentration of the polyvinyl fluoride solution is 0.2-0.4 mg / mL. -1 .

[0022] Furthermore, in step S1, the organic ammonium salt is selected from any one or more of the following: .

[0023] Furthermore, the organic ammonium salt is selected from one or more of phenylethyl ammonium bromide (PEABr), m-fluorophenylethyl ammonium bromide (mF-PEABr), ethylenediamine hydroiodide (EDADI), and / or propylenediamine hydroiodide (PDADI).

[0024] Further, in step S1, the concentration of phenylethyl ammonium bromide is 1-2 mg / mL. -1 The concentration of m-fluorophenylethyl ammonium bromide is 1-2 mg / mL. -1 The concentration of the ethylenediamine hydroiodate is 0.5-1.5 mg / mL. -1 The concentration of the propylenediamine hydroiodate is 0.1-1.0 mg / mL. -1 .

[0025] Furthermore, the concentration of the phenylethyl ammonium bromide is 1-1.5 mg / mL. -1 The concentration of m-fluorophenylethyl ammonium bromide is 1.2-1.7 mg / mL. -1 The concentration of the ethylenediamine hydroiodate is 0.5-1.0 mg / mL. -1 The concentration of the propylenediamine hydroiodate is 0.1-0.8 mg / mL. -1 .

[0026] Furthermore, in step S2, the perovskite precursor solution is selected from Cs 0.05 MA 0.1 FA 0.85 PbI3 or Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 3.

[0027] Furthermore, in step S2, the substrate is selected from ITO / NiO. x / Me-4PACz / Al2O3 or wafer / NiO x / Me-4PACz / Al2O3.

[0028] Furthermore, in step S2, when the perovskite precursor solution is Cs 0.05 MA 0.1 FA 0.85 When PbI3 is used, the deposition method is a one-step spin coating method, and the spin coating conditions are 1000-5000 rpm for 10-20 s; when the perovskite precursor solution is Cs 0.2 MA 0.1 FA 0.7Pb(Br 0.6 I 0.4 When )3, the deposition method is a two-step spin coating method, and the spin coating conditions are: first spin coating at 500-1500 rpm for 5-15 s, and then spin coating at 3000-6000 rpm for 20-60 s.

[0029] Furthermore, in step S2, when the perovskite precursor solution is Cs 0.05 MA 0.1 FA 0.85 When processing PbI3, the sample needs to be vacuum-treated at 0-5 Pa for 10-30 s.

[0030] Furthermore, in step S2, when the perovskite precursor solution is Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 When the sample is spin-coated, 100-200 μL of anisole should be added 10 seconds before the spin coating is finished.

[0031] Furthermore, the amount of anisole added is 100-150 μL.

[0032] Furthermore, in step S2, when the perovskite precursor solution is Cs 0.05 MA 0.1 FA 0.85 When PbI3 is used, the annealing conditions are 90-120 °C for 20-40 min; when the perovskite precursor solution is Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 When )3, the annealing conditions are 80-120 ℃ for 5-15 min.

[0033] Furthermore, when the perovskite precursor solution described in S2 is Cs 0.05 MA 0.1 FA 0.85 For PbI3, the spin coating conditions described in S3 are 3000-6000 rpm for 10-50 s, with an acceleration of 3000-6000 rpm / s. -1 The annealing conditions are 80-120 °C for 1-10 min; when the perovskite precursor solution is Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4At time 3, the spin coating conditions described in S3 are 3000-6000 rpm for 10-50 s, with an acceleration of 3000-6000 rpm / s. -1 The annealing conditions are 80-120 ℃ for 1-10 min.

[0034] Furthermore, in step S3, the fluoropolymer-organic ammonium salt composite interface passivation layer is selected from phenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer, m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer, ethylenediamine hydroiodide-polyvinyl fluoride composite passivation layer, or propylenediamine hydroiodide-polyvinyl fluoride composite passivation layer.

[0035] Thirdly, the present invention provides the application of the fluorinated polymer-organic ammonium salt composite interface passivation layer described in the first aspect in the preparation of perovskite solar cells.

[0036] Fourthly, the present invention provides a method for preparing a perovskite tandem solar cell based on the fluorinated polymer-organic ammonium salt composite interface passivation layer described in the first aspect, the method comprising the following steps: S1. Preparation of fluoropolymer-organic ammonium salt composite passivation solution Fluoropolymer and organic ammonium salt were dissolved separately in solvents, mixed, and then ultrasonically treated to obtain a fluoropolymer-organic ammonium salt composite passivation solution. S2. Preparation of mid-bandgap perovskite thin films and their composite passivation layers S21. Under argon atmosphere, PbI₂, CsI, FAI, MAI, PbCl₂, and MACl are dissolved in a mixed solvent of DMF and NMP to form CsI. 0.05 MA 0.1 FA 0.85 PbI3 perovskite precursor solution; the perovskite precursor solution was added to the substrate, and after spin-coating deposition, the sample was vacuum-treated and then annealed to obtain a medium-bandgap perovskite film. S22. The fluorinated polymer-organic ammonium salt composite passivation solution prepared in S1 is dynamically spin-coated onto the surface of the mid-bandgap perovskite film prepared in S21, and then annealed to form a fluorinated polymer-organic ammonium salt composite interface passivation layer. S3. Preparation of wide-bandgap perovskite thin films and their composite passivation layers S31. Under argon atmosphere, FAI, CsI, MABr, PbI2, PbBr2, MACl, and PbCl2 are dissolved in a mixed solvent of DMF and DMSO to form CsI. 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.43. Perovskite precursor solution: The perovskite precursor solution was added to the substrate and spin-coated. Anisole was added as an antisolvent before the spin coating was completed. The sample was then transferred and annealed to obtain a wide-bandgap perovskite film. S32. The fluorinated polymer-organic ammonium salt composite passivation solution prepared in S1 is dynamically spin-coated onto the surface of a wide-bandgap perovskite film and then annealed to form a fluorinated polymer-organic ammonium salt composite interface passivation layer. S4. Fabrication of Perovskite Tandem Solar Cells S41. Spin-coat the Me-4PACz ethanol solution onto the surface of the bottom cell, and anneal it to form a hole-selective contact layer. S42. Prepare a composite interface passivation layer on the surface of a mid-bandgap perovskite according to method S2, and deposit C. 60 layer, SnO x Together with IZO, they form an intermediate interconnect layer; S43. Spin-coating NiO onto the IZO layer x Nanoparticle layer was applied and annealed, followed by spin-coating with Me-4PACz ethanol solution and annealing. S44. Prepare a composite interface passivation layer on the surface of a wide-bandgap perovskite using the method in S3, and deposit C. 60 layer, SnO x and IZO; S45. Deposition of Ag electrode and MgF x An antireflection layer is added to obtain the perovskite / perovskite / silicon triple junction tandem solar cell of the present invention.

[0037] Furthermore, in step S1, the solvent is selected from one or more of cyclohexanone, isopropanol, ethanol, chloroform, and phenethyl ether.

[0038] Furthermore, the solvent for the fluoropolymer is cyclohexanone, and the solvent for the organic ammonium salt is isopropanol.

[0039] Furthermore, the fluoropolymer is polyvinyl fluoride.

[0040] Furthermore, the concentration of the polyvinyl fluoride solution is 0.1-0.6 mg / mL. -1 .

[0041] Preferably, the concentration of the polyvinyl fluoride solution is 0.2-0.4 mg / mL. -1 .

[0042] Furthermore, in step S1, the organic ammonium salt is selected from any one or more of the following: .

[0043] Furthermore, the organic ammonium salt is selected from one or more of phenylethyl ammonium bromide (PEABr), m-fluorophenylethyl ammonium bromide (mF-PEABr), ethylenediamine hydroiodide (EDADI), and / or propylenediamine hydroiodide (PDADI).

[0044] Further, in step S1, the concentration of phenylethyl ammonium bromide is 1-2 mg / mL. -1 The concentration of m-fluorophenylethyl ammonium bromide is 1-2 mg / mL. -1 The concentration of the ethylenediamine hydroiodate is 0.5-1.5 mg / mL. -1 The concentration of the propylenediamine hydroiodate is 0.1-1.0 mg / mL. -1 .

[0045] Furthermore, the concentration of the phenylethyl ammonium bromide is 1-1.5 mg / mL. -1 The concentration of m-fluorophenylethyl ammonium bromide is 1.2-1.7 mg / mL. -1 The concentration of the ethylenediamine hydroiodate is 0.5-1.0 mg / mL. -1 The concentration of the propylenediamine hydroiodate is 0.1-0.8 mg / mL. -1 .

[0046] Furthermore, in step S1, the volume ratio of the fluoropolymer to the organic ammonium salt solution is 0.5-1:0.5-1.

[0047] Furthermore, the volume ratio of the fluoropolymer to the organic ammonium salt solution is 1:1.

[0048] Furthermore, in step S21, the Cs 0.05 MA 0.1 FA 0.85 In the PbI3 perovskite precursor solution, the concentrations of each solute were 1.84 M PbI2, 0.09 M CsI, 1.53 M FAI, 0.18 M M MAI, 0.02 M PbCl2 and 0.02 M MACl, respectively; the solvent was DMF or DMSO, and the volume ratio of solute to solvent was 3:1.

[0049] Furthermore, in step S21, the substrate is selected from ITO / NiO. x / Me-4PACz / Al2O3 or wafer / NiO x / Me-4PACz / Al2O3.

[0050] Preferably, the substrate is a nin wafer / NiO x / Me-4PACz / Al2O3.

[0051] Furthermore, in step S21, the spin coating deposition method is a one-step spin coating method, and the spin coating conditions are 1000-5000 rpm and 10-20 s.

[0052] Furthermore, in step S21, the vacuum condition is maintained at 0-5 Pa for 10-30 s, and the annealing condition is 90-120 ℃ for 20-40 min.

[0053] Furthermore, in step S21, the optical bandgap of the mid-bandgap perovskite thin film is 1.56 eV.

[0054] Furthermore, in step S22, the spin coating conditions are 3000-6000 rpm for 10-50 s, with an acceleration of 3000-6000 rpm / s. -1 Annealing conditions are 80-120 ℃ for 1-10 min.

[0055] Furthermore, in step S22, the fluoropolymer-organic ammonium salt composite interface passivation layer is a m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer.

[0056] Furthermore, in step S31, the Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 )3 In the perovskite precursor solution, the concentrations of each solute were 1.84 M PbI2, 0.09 M CsI, 1.53 M FAI, 0.18 M M MAI, 0.02 M PbCl2 and 0.02 M MACl, respectively; the solvent was DMF or DMSO, and the volume ratio of solute to solvent was 3:1.

[0057] Furthermore, in step S31, the substrate is selected from ITO / NiO. x / Me-4PACz / Al2O3 or wafer / NiO x / Me-4PACz / Al2O3.

[0058] Preferably, the substrate is ITO / NiO. x / Me-4PACz / Al2O3.

[0059] Furthermore, in step S31, the spin coating deposition method is a two-step spin coating method, wherein the spin coating conditions are: first spin coating at 500-1500 rpm for 5-15 s, and then spin coating at 3000-6000 rpm for 20-60 s.

[0060] Furthermore, in step S31, the anisole is added 10 seconds before the end of spin coating, and the amount added is 100-200 μL.

[0061] Furthermore, the amount of anisole added is 100-150 μL.

[0062] Furthermore, in step S31, the annealing conditions are 80-120 °C for 5-15 min.

[0063] Furthermore, in step S31, the optical bandgap of the wide bandgap perovskite thin film is 1.95 eV.

[0064] Furthermore, in step S32, the spin coating conditions are 3000-6000 rpm for 10-50 s, with an acceleration of 3000-6000 rpm for s. -1 The annealing conditions are 80-120 °C for 1-10 min.

[0065] Furthermore, in step S32, the fluoropolymer-organic ammonium salt composite interface passivation layer is a propylene diamine hydroiodate-polyvinyl fluoride composite passivation layer.

[0066] Furthermore, in step S41, the bottom cell is a nanocrystalline silicon heterojunction bottom cell.

[0067] Furthermore, the bottom cell is an n-type nanocrystalline silicon heterojunction bottom cell.

[0068] Further, in step S41, the concentration of the Me-4PACz ethanol solution is 0.1-1.0 mg / mL. -1 .

[0069] Furthermore, the concentration of the Me-4PACz ethanol solution is 0.1-0.5 mg / mL. -1 .

[0070] Furthermore, in step S42, the C 60 The deposition method for the layer is thermal evaporation deposition, and the SnO layer is... x The deposition method is atomic layer deposition at 60-100 °C, and the deposition method of IZO is sputtering deposition.

[0071] Furthermore, in step S42, the C 60 The thickness of the layer is 1-10 nm, and the SnO x The thickness of the IZO is 20-40 nm, and the thickness of the IZO is 10-40 nm.

[0072] Furthermore, the C 60 The thickness of the layer is 3-8 nm, and the SnOx The thickness of the IZO is 25-35 nm, and the thickness of the IZO is 20-40 nm.

[0073] Furthermore, in step S43, the NiO x The thickness of the nanoparticle layer is 10-20 nm, and the annealing conditions are 80-120 ℃ for 1-10 min.

[0074] Further, in step S43, the concentration of the Me-4PACz ethanol solution is 0.1-1.0 mg / mL. -1 The spin coating conditions are 3000-5000 rpm for 10-20 s, and the annealing conditions are 80-120 ℃ for 5-15 min.

[0075] Furthermore, the concentration of the Me-4PACz ethanol solution is 0.1-0.5 mg / mL. -1 .

[0076] Furthermore, in step S44, the C 60 The deposition method for the layer is thermal evaporation deposition, and the SnO layer is... x The deposition method is atomic layer deposition at 80-120 °C, and the deposition method of IZO is sputtering deposition.

[0077] Furthermore, in step S44, the C 60 The thickness of the layer is 1-10 nm, and the SnO x The thickness of the IZO is 20-40 nm, and the thickness of the IZO is 10-40 nm.

[0078] Furthermore, the C 60 The thickness of the layer is 3-8 nm, and the SnO x The thickness of the IZO is 25-35 nm, and the thickness of the IZO is 20-40 nm.

[0079] Further, in step S45, the Ag electrode and MgF... x The antireflective layer was deposited using thermal evaporation deposition.

[0080] Further, in step S45, the thickness of the Ag electrode is 300-500 nm, and the MgF... x The thickness of the antireflective layer is 50-150 nm.

[0081] Furthermore, the thickness of the Ag electrode is 350-450 nm, and the MgF... x The thickness of the antireflective layer is 80-120nm.

[0082] Fifthly, the present invention provides a perovskite tandem solar cell prepared according to the method described in the fourth aspect, wherein the perovskite tandem solar cell is prepared by sequentially preparing a hole transport layer, a perovskite light-absorbing layer, a composite interface layer, an electron transport layer, a transparent conductive layer, and an electrode layer on a substrate or a bottom cell.

[0083] Furthermore, the perovskite tandem solar cell includes a perovskite / silicon tandem solar cell, a perovskite / perovskite tandem solar cell, and a perovskite / perovskite / silicon triple junction tandem solar cell.

[0084] Furthermore, the perovskite tandem solar cell is a perovskite / perovskite / silicon triple junction tandem solar cell.

[0085] Preferably, the perovskite / perovskite / silicon triple-junction tandem solar cell structure is textured silicon / ITO / Me-4PACz / mid-bandgap perovskite / passivation layer / C 60 / SnO2 / ITO / NiO x / Me-4PACz / Wide-bandgap perovskite / Passivation layer / C 60 / SnO2 / ITO / MgF x / Ag.

[0086] Beneficial effects (1) The fluoropolymer-organic ammonium salt composite interface passivation layer of the present invention does not use organic ammonium salt alone for surface passivation, but constructs a composite interface network through the F···HN hydrogen bonding between polyvinyl fluoride and organic ammonium salt; the organic ammonium salt is fixed and confined by polyvinyl fluoride, which inhibits the self-aggregation behavior of organic ammonium salt in solution and film formation process, so that the passivation component forms a more uniform spatial distribution on the perovskite surface; (2) The fluoropolymer-organic ammonium salt composite interface passivation layer of the present invention achieves uniform in-situ passivation of perovskite surface defects by regulating the release and adsorption of organic ammonium salt on the perovskite surface, thereby reducing non-radiative recombination loss. (3) The polyvinyl fluoride network remaining in the passivation layer of the fluoropolymer-organic ammonium salt composite interface of the present invention can serve as a stable interface skeleton, anchor the organic ammonium cations and formamidinium components on the surface, inhibit the volatilization of organic components during high temperature, high vacuum processes and long-term operation, reduce the generation of lead iodide, and improve the thermal stability of perovskite films. (4) The fluorinated polymer-organic ammonium salt composite interface passivation layer of the present invention reduces the spatial non-uniformity of the perovskite interface, improves the uniformity of the photoelectric properties of the perovskite interface, and makes the photoluminescence intensity distribution more concentrated. (5) The fluoropolymer-organic ammonium salt composite interface passivation layer of the present invention can be used in perovskite / perovskite / silicon triple junction tandem solar cells to improve the repeatability of device fabrication, photovoltaic performance and operational stability. Attached Figure Description

[0087] Figure 1 This is a schematic diagram illustrating the formation mechanism of the polymer-ammonium salt composite interface layer in this invention.

[0088] Figure 2 This is a schematic diagram illustrating the synergistic passivation effect between the fluorinated polymer-ammonium salt composite and the perovskite surface in this invention.

[0089] Figure 3 This is a schematic diagram of the perovskite / perovskite / silicon triple junction solar cell structure containing a composite interface layer in this invention.

[0090] Figure 4 This is a comparison diagram showing the effect of the composite interface layer in this invention on improving interface uniformity.

[0091] Figure 5 This is a comparison chart showing the results of improving stability using the composite interface layer in this invention.

[0092] Figure 6-9 These are the photoelectric performance diagrams and JV characteristic curves of the perovskite device before and after optimization by the composite interface layer in this invention. Note: Figure 6 The corresponding device structure is textured nin Si / TCO / Me-4PACz / 1.56 eV bandgap perovskite / passivation layer / C 60 / SnO2 / TCO / MgF2 / Ag; Figure 7 The corresponding device structure is planar nin Si / TCO / NiO x / Me-4PACz / 1.95 eV bandgap perovskite / passivation layer / C 60 / SnO2 / TCO / MgF2 / Ag; Figure 8 and Figure 9 The corresponding device structure is the perovskite / perovskite / silicon triple-junction stacked device structure in Implementation Case 4, consisting of textured silicon / ITO / Me-4PACz / mid-bandgap perovskite / passivation layer / C. 60 / SnO2 / ITO / NiO x / Me-4PACz / Wide-bandgap perovskite / Passivation layer / C 60 / SnO2 / ITO / MgF x / Ag.

[0093] Figure 10 This is a comparison diagram of the stability of the composite interface layer on the triplet device before and after optimization in this invention. Detailed Implementation

[0094] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the embodiments described below can be combined with each other as long as they do not conflict with each other.

[0095] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0096] Terminology Explanation In this invention, "SnO" x "Refers to non-stoichiometric tin oxide, where x represents the molar ratio of oxygen to tin, and the value of x is 1-2.

[0097] In this invention, "NiO" x "Refers to non-stoichiometric nickel oxide, where x represents the molar ratio of oxygen to nickel, and the value of x ranges from 2 to 3."

[0098] In this invention, "MgF" x "Refers to magnesium fluoride in non-stoichiometric form, where x represents the molar ratio of fluorine to magnesium, and the value of x ranges from 1.9 to 2."

[0099] Example 1: Preparation of polyvinyl fluoride-organic ammonium salt composite passivation solution 1. Preparation of polyvinyl fluoride solution Polyvinyl fluoride (PVF, catalog number BK-12341) was dissolved in cyclohexanone (catalog number 01182933) to prepare a solution with a concentration of 0.4 mg / mL. -1 Prepare a polyvinyl fluoride solution and stir to dissolve it completely.

[0100] 2. Preparation of organic ammonium salt solutions 1.5 mg mL respectively -1 Phenylacetyl ammonium bromide (catalog number 301041), 1.7 mg / mL -1 m-Fluorophenylethyl ammonium bromide (catalog number 301119), 1.0 mg mL -1 Ethylenediamine hydroiodide (catalog number 301097) and 0.5 mg mL -1 Propylene diamine hydroiodide (catalog number 301099) was dissolved in isopropanol (catalog number 01352405) to prepare an organic ammonium salt (AS) solution.

[0101] 3. Preparation of mixed ammonium salt-polymer passivation solution The polyvinyl fluoride mother liquor was mixed with an organic ammonium salt solution of twice the optimized concentration at a volume ratio of 1:1, and ultrasonically treated for 1 h to obtain a polyvinyl fluoride-organic ammonium salt composite passivation solution.

[0102] Preparation of bandgap perovskite thin films and their composite passivation layers in Example 2 1. Preparation of a 1.56 eV mid-bandgap perovskite precursor solution Under argon atmosphere, 1.84 M lead iodide (PbI₂, catalog number YXKJB), 0.02 M lead chloride (PbCl₂, catalog number YXKJB), 0.09 M cesium iodide (CsI, catalog number C2205), 1.53 M formamidinium iodide (FAI, catalog number MS150000), 0.18 M methylammonium iodide (MAI, catalog number MS101000), and 0.02 M methylammonium chloride (MACl, catalog number MS601000) were dissolved in a mixed solvent of N,N-dimethylformamide (DMF, catalog number 227056) and N-methylpyrrolidone (NMP, catalog number 328634) in a volume ratio of 4:1, and the solution was shaken to dissolve, forming CsI₂. 0.05 MA 0.1 FA 0.85 PbI3 perovskite precursor solution.

[0103] 2. Preparation of mid-bandgap perovskite thin films A 1.56 eV perovskite precursor solution was applied to the surface of a nin wafer / NiOx / Me-4PACz / Al2O3 substrate and deposited using a one-step spin-coating method at 2500 rpm for 12 s. After spin-coating, the sample was held at 0–5 Pa for 20 s, followed by annealing at 110 °C for 30 min to obtain a 1.56 eV mid-bandgap perovskite film.

[0104] 3. Preparation of polyvinyl fluoride-organic ammonium salt composite interface passivation layer The polyvinyl fluoride-organic ammonium salt composite passivation solution prepared in Example 1 was dynamically spin-coated onto the surface of a mid-bandgap perovskite film. The spin-coating conditions were 5000 rpm for 30 s, with an acceleration of 5000 rpm for 30 s. -1 Subsequently, it was annealed at 100 °C for 5 min to form a polyvinyl fluoride-organic ammonium salt composite interface passivation layer.

[0105] from Figure 6 The performance parameters show that the composite passivation layer used for 1.56 eV medium bandgap perovskite films is preferably a m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer.

[0106] Depend on Figure 1 and Figure 2As can be seen, compared to using organic ammonium salts alone for interface passivation, this invention combines polyvinyl fluoride (PVC) with organic ammonium salts, utilizing the F···HN hydrogen bond interactions formed between fluorine atoms in PVC and ammonium groups in organic ammonium salts to construct a PVC-organic ammonium salt composite interface network. This composite interface network can immobilize the organic ammonium salt passivation components, suppress the self-aggregation behavior between organic ammonium salts, and regulate their release and adsorption on the perovskite film surface, thereby achieving uniform in-situ passivation of perovskite surface defects.

[0107] Example 3: Preparation of wide-bandgap perovskite thin films and their composite passivation layers 1. Preparation of a 1.95 eV wide-bandgap perovskite precursor solution Under argon atmosphere, 1.84 M lead iodide (PbI₂), lead bromide (PbBr₂), 1.53 M formamidinium iodide (FAI), 0.09 M cesium iodide (CsI), 0.18 M methyl ammonium bromide (MABr, catalog number MS301000), 0.02 M methyl ammonium chloride (MACl), and 0.02 M lead chloride (PbCl₂, catalog number YXKJB) were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO, catalog number 276855) in a volume ratio of 3:1, and the solution was shaken to dissolve, forming CsI₂. 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 3. Perovskite precursor solution.

[0108] 2. Preparation of wide-bandgap perovskite thin films A 1.95 eV perovskite precursor solution was applied to an ITO / NiOx / Me-4PACz / Al2O3 substrate and deposited using a two-step spin-coating method. The spin-coating was first performed at 1000 rpm for 10 s, followed by a spin-coating at 4000 rpm for 40 s. Ten s before the end of the spin-coating, 150 μL of anisole was added as an antisolvent. The sample was then transferred to a hot plate and annealed at 100 °C for 10 min to obtain a 1.95 eV wide-bandgap perovskite film.

[0109] 3. Preparation of polyvinyl fluoride-organic ammonium salt composite interface passivation layer A polyvinyl fluoride-propylene diamine hydroiodide composite passivation solution was prepared according to the method in Example 1, wherein the concentration of propylene diamine hydroiodide was 0.5 mg / mL. -1 The concentration of polyvinyl fluoride was 0.2 mg / mL. -1The solvent is a mixture of isopropanol and cyclohexanone. The polyvinyl fluoride-propylene diamine hydroiodide composite passivation solution is dynamically spin-coated onto the surface of a wide-bandgap perovskite film and then subjected to thermal annealing to form a polyvinyl fluoride-organic ammonium salt composite interface passivation layer. The spin-coating conditions are 3000-6000 rpm for 10-50 s, with an acceleration of 3000-6000 rpm / s. -1 The annealing conditions are 80-120 ℃ for 1-10 min.

[0110] from Figure 7 The performance parameters show that the composite passivation layer used for 1.95 eV wide-bandgap perovskite films is preferably a propylene diamine hydroiodate-polyvinyl fluoride composite passivation layer.

[0111] Example 4: Fabrication of a perovskite / perovskite / silicon triple-junction tandem solar cell (1) An n-type nanocrystalline silicon heterojunction bottom cell with an 8 nm ITO layer is used as the bottom cell. Before use, the bottom cell is treated with ultraviolet ozone.

[0112] (2) A Me-4PACz ethanol (catalog number 459836) solution was spin-coated onto the surface of the bottom cell. The concentration of the Me-4PACz solution was 0.5 mg / mL. -1 The spin coating conditions were 4000 rpm for 15 s, followed by annealing at 100 ℃ for 10 min to form a hole selective contact layer.

[0113] (3) A 1.56 eV mid-bandgap perovskite light-absorbing layer was prepared according to the method in Example 2, and a m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer was formed on its surface. Then, a 7 nm C₂ was deposited by thermal evaporation. 60 A layer was then deposited; followed by atomic layer deposition of 30 nm SnO at 80 °C. x Subsequently, 20 nm IZO was sputtered to form an intermediate interconnect layer.

[0114] (4) Spin-coating NiO onto the IZO layer x A nanoparticle layer, 15 nm thick, was annealed at 100 °C for 5 min. Subsequently, a Me-4PACz ethanol solution with a concentration of 0.5 mg / mL was spin-coated. -1 The spin coating conditions were 4000 rpm for 15 s, followed by annealing at 100 ℃ for 10 min.

[0115] (5) A 1.95 eV wide-bandgap perovskite light-absorbing layer was prepared according to the method in Example 3, and a propylenediamine hydroiodide-polyvinyl fluoride composite passivation solution was dynamically spin-coated onto its surface. Subsequently, it was annealed at 100 °C for 10 min to form a composite interface passivation layer on the surface of the wide-bandgap perovskite. A 5 nm C₂ was deposited by thermal evaporation. 60 A layer was then deposited; subsequently, 27 nm SnO was deposited at 80 °C using atomic layer deposition. x Subsequently, 40 nm IZO was sputtered and deposited.

[0116] (6) A 400 nm Ag electrode and a 100 nm MgF2 electrode were deposited by thermal evaporation. x An antireflection layer is added to obtain a perovskite / perovskite / silicon triple-junction tandem solar cell.

[0117] The resulting perovskite / perovskite / silicon triple junction tandem solar cell structure is as follows: Textured silicon / ITO / Me-4PACz / Mid-bandgap perovskite / Passivation layer / C 60 / SnO2 / ITO / NiO x / Me-4PACz / Wide-bandgap perovskite / Passivation layer / C 60 / SnO2 / ITO / MgF x / Ag.

[0118] The passivation layer of the medium-band gap perovskite layer is a composite passivation layer of m-fluorophenylethyl ammonium bromide and polyvinyl fluoride, while the passivation layer of the wide-band gap perovskite layer is a composite passivation layer of propylenediamine hydroiodate and polyvinyl fluoride.

[0119] Figure 3 This diagram shows a schematic and cross-sectional view of a perovskite / perovskite / silicon triple-junction tandem solar cell structure fabricated based on the polyvinyl fluoride-organic ammonium salt composite interface passivation layer of this invention. The composite interface passivation layer can be disposed on the surfaces of the medium-bandgap perovskite layer and the wide-bandgap perovskite layer, serving as the interface passivation layer between the perovskite light-absorbing layer and the electron transport layer, respectively. This structure demonstrates that the composite interface passivation layer provided by this invention is compatible with the fabrication process of multilayer tandem devices and can be used to improve the passivation uniformity and stability of key perovskite interfaces in multi-junction solar cells.

[0120] Example 5: Effect of the polyvinyl fluoride-organic ammonium salt composite interface passivation layer 1. Characterization of the passivation layer at the interface of polyvinyl fluoride-organic ammonium salt composite Spatial-resolved photoluminescence assay was used to characterize the passivation layer of the polyvinyl fluoride-organic ammonium salt composite interface.

[0121] The photoluminescence distribution of a 1.56 eV perovskite thin film was measured using a MAPS-2024-Mark1-FLIM instrument from Waynelabs Instruments & Solutions. Figure 4 The photoluminescence distribution map above corresponds to the sample that did not undergo thermal evaporation deposition of 7 nm C. 60 layer, Figure 4 The photoluminescence distribution diagram below corresponds to the sample deposited by thermal evaporation at a density of 7 nm C. 60 layer.

[0122] Depend on Figure 4 It is evident that the photoluminescence distribution of the isolated organic ammonium salt passivated samples exhibits significant spatial inhomogeneity, manifesting as localized bright filamentous structures, clustered regions, or localized quenching regions, indicating that its interfacial recombination dynamics and charge extraction behavior are position-dependent. In contrast, after treatment with the polyvinyl fluoride-organic ammonium salt composite interfacial passivation layer provided by this invention, the perovskite film or device structure exhibits a smoother and more uniform photoluminescence distribution, with a narrower statistical distribution of photoluminescence intensity and fewer outliers.

[0123] 2. Thermal aging test of polyvinyl fluoride-organic ammonium salt composite interface The interfacial thermal aging test used a 1.56 eV perovskite film. The organic ammonium salt or polyvinyl fluoride-organic ammonium salt composite passivation solution prepared in Example 1 was dynamically spin-coated onto the surface of the 1.56 eV perovskite film to form an ammonium salt or polyvinyl fluoride-organic ammonium salt composite interfacial passivation layer, serving as the ammonium salt group and the composite group, respectively. The control group had no passivation layer. The three groups of samples were placed on a heating stage in air, with temperatures set to room temperature and 100 °C, and aged for 3 days. X-ray diffraction patterns of the three groups of samples before and after aging were measured using a PANalytical Empyrean diffractometer equipped with Cu Kα radiation (λ=1.5406 Å).

[0124] After thermal aging, the blank control sample and the sample passivated with organic ammonium salt alone easily showed enhanced lead iodide characteristic signals, indicating that the perovskite film underwent phase degradation and interface passivation failure. In contrast, after treatment with the polyvinyl fluoride-organic ammonium salt composite interface passivation layer provided by this invention, the formation of lead iodide in the perovskite film was significantly suppressed, indicating that the composite interface network can improve the thermal stability of the perovskite surface. Figure 5 As shown.

[0125] 3. Quantum yield test of photoluminescence at the polyvinyl fluoride-organic ammonium salt composite interface Three groups of perovskite thin film samples (ammonium salt group, composite group, and control group) before and after aging were subjected to PLQY (photoluminescence quantum yield) tests. The measurements were performed using an integrating sphere (Fluorolog, Horiba Jobin Yvon), an Andor Kymera 193i spectrometer, and a continuous wave laser with a wavelength of 660 nm. The photon flux of the laser was set to be equivalent to the level of one solar irradiance (1-sun).

[0126] Photoluminescence quantum yield tests show that, after applying the polyvinyl fluoride-organic ammonium salt composite interface passivation layer provided by this invention, the perovskite film can still maintain a high photoluminescence quantum yield after thermal aging, indicating that it can effectively suppress the generation of thermally induced defects and reduce nonradiative recombination losses. Figure 5 As shown.

[0127] 4. Analysis of volatile components at the interface of polyvinyl fluoride-organic ammonium salt composite The organic ammonium salt or polyvinyl fluoride-organic ammonium salt composite passivation solution prepared in Example 1 was dynamically spin-coated onto the surface of a 1.56 eV perovskite film to form an ammonium salt or polyvinyl fluoride-organic ammonium salt composite interface passivation layer, which served as the ammonium salt group and the composite group, respectively. The control group was the one without a passivation layer. The evaporated material from the three groups of samples after aging was collected and subjected to 1H NMR spectroscopy. 1 H nuclear magnetic resonance (NMR) 1 H NMR data were obtained using a Bruker 400 MHz nuclear magnetic resonance spectrometer.

[0128] Time-of-flight secondary ion mass spectrometry (TOF-SIMS 5) was used to perform time-of-flight secondary ion mass spectrometry (TOF-SIMS 5) on ammonium salt and composite perovskite film samples before and after aging. During the test, pulsed primary ions (1 keV) generated by an oxygen ion beam were used for sputtering, and Bi was used... + Analysis was performed using a pulsed primary ion beam (25 keV).

[0129] The composite interface passivation layer provided by this invention can inhibit the volatilization of formamidinium iodide and organic ammonium salts during heat treatment, demonstrating that the polyvinyl fluoride residual network can serve as a stable interface framework, anchoring surface organic ammonium cations and formamidinium components, thereby reducing the loss of interfacial organic components and interfacial degradation during high-temperature, high-vacuum processes and long-term operation. Figure 5 As shown.

[0130] 5. Photoelectric performance and maximum power point tracking test of polyvinyl fluoride-organic ammonium salt composite interface modified devices JV and steady-state current density / PCE tests were performed on various device structures prepared according to the embodiments of the present invention at room temperature and under N2 atmosphere. The tests were conducted using a solar simulator (Newport, Class A) with an illumination intensity of 100 mW cm⁻¹. -2 The system was calibrated using a Newport standard silicon solar cell; electrical parameters were acquired using a Keithley 2450 source meter. Voltage scans were performed along V... OC To J SC (Reverse scan) and J SC To V OC (Forward scan) Performed in two directions, scan rate 100 mV / s -1 The voltage step size is 10 mV. The effective area of ​​the device is defined by the aperture mask, which is 0.09 cm². 2 and 1 cm 2 .

[0131] Depend on Figure 6-9 It can be seen that, among different device structures, the device performance of samples passivated with organic ammonium salts alone is slightly higher than that of blank control samples. In contrast, after treatment with the polyvinyl fluoride-organic ammonium salt composite interface passivation layer provided by this invention, the PVF-mediated strategy continuously improves photoelectric performance and reproducibility in perovskite devices with different band gaps and structures, indicating that it serves as a composition-adaptive passivation platform rather than a specific salt treatment method.

[0132] Table 1 Figure 6-7 Corresponding passivation layer processing method

[0133] Table 2 Figure 8-9 Corresponding passivation layer processing method

[0134] The stability of the unpackaged device was evaluated under continuous simulated sunlight conditions. Illumination was provided by light-emitting diode (LED) lamps with an intensity equivalent to 1 sun, at 30–45 °C, without the use of UV filters. Maximum power point tracking (MPPT) testing was performed in a nitrogen-filled glove box using a dedicated MPPT testing system (YH-VMPPS-16).

[0135] Maximum power point tracking (MPPT) tests show that various perovskite solar cells using the composite interface passivation layer of this invention exhibit better operational stability, indicating that this invention not only improves the interface quality of the perovskite thin film but also enhances the long-term operational stability of perovskite devices. In a complete triple-junction device, MPPT results under single-light illumination at 45°C show that the device treated with the composite interface passivation layer retained 83.5% of its initial PCE after 1000 hours, while the control device retained only 56.5%. Figure 10 As shown. Therefore, the interface passivation treatment provided by this invention not only improves the initial efficiency of single-junction and triple-junction devices, but also significantly enhances their long-term operational stability.

[0136] The polyvinyl fluoride-organic ammonium salt composite interface passivation layer provided by this invention can fix and confine the organic ammonium salt passivation components through F···HN hydrogen bonding, inhibit the self-aggregation of organic ammonium salts, achieve uniform in-situ passivation of perovskite surface defects, and improve the uniformity of interfacial photoelectric properties. Simultaneously, the polyvinyl fluoride network can stabilize the surface organic ammonium cations and formamidinium components, inhibiting the volatilization of organic components and interfacial degradation during heat treatment, high-vacuum processes, and long-term operation. Therefore, the polyvinyl fluoride-organic ammonium salt composite interface passivation layer of this invention can effectively reduce the non-radiative recombination loss of the perovskite interface, and improve the fabrication repeatability, photovoltaic performance, and operational stability of perovskite solar cells and perovskite / perovskite / silicon triple-junction tandem solar cells.

[0137] Furthermore, by utilizing the polyvinyl fluoride-organic ammonium salt composite interface passivation layer provided by this invention, combined with existing perovskite solar cell fabrication technology in the field, those skilled in the art can apply it to perovskite solar cells, perovskite / silicon tandem solar cells, perovskite / perovskite tandem solar cells, and perovskite / perovskite / silicon triple junction tandem solar cells.

Claims

1. A fluoropolymer-organic ammonium salt composite interface passivation layer, characterized in that, The composite interface passivation layer combines an organic ammonium salt passivating agent with a fluoropolymer, utilizing the F···HN hydrogen bond interaction formed between the ammonium group in the organic ammonium salt and the fluorine atom in the fluoropolymer to construct a fluoropolymer-organic ammonium salt composite interface network.

2. The composite interface passivation layer as described in claim 1, characterized in that, The fluoropolymer is polyvinyl fluoride; the organic ammonium salt is selected from any one or more of the following: 。 3. The composite interface passivation layer as described in claim 1, characterized in that, The fluoropolymer-organic ammonium salt composite interface passivation layer is selected from phenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer, m-fluorophenylethyl ammonium bromide-polyvinyl fluoride composite passivation layer, ethylenediamine hydroiodate-polyvinyl fluoride composite passivation layer, or propylenediamine hydroiodate-polyvinyl fluoride composite passivation layer.

4. A method for preparing a fluoropolymer-organic ammonium salt composite interface passivation layer as described in claim 1, characterized in that, The preparation method includes the following steps: S1. Preparation of fluoropolymer-organic ammonium salt composite passivation solution Fluoropolymer and organic ammonium salt were dissolved separately in solvents, mixed, and then ultrasonically treated to obtain a fluoropolymer-organic ammonium salt composite passivation solution. S2. Preparation of perovskite thin films The perovskite precursor solution was added to the substrate, and after spin-coating deposition, the sample was processed and annealed to obtain a perovskite film. S3. Preparation of perovskite composite passivation layer The fluorinated polymer-organic ammonium salt composite passivation solution prepared in S1 was dynamically spin-coated onto the surface of the perovskite film prepared in S2, and then annealed to form a fluorinated polymer-organic ammonium salt composite interface passivation layer.

5. The preparation method according to claim 4, characterized in that, In step S1, the solvent is selected from one or more of cyclohexanone, isopropanol, ethanol, chloroform, and phenethyl ether; The volume ratio of the fluoropolymer to the organic ammonium salt solution is 0.5-1:0.5-1; The concentration of the fluoropolymer solution is 0.1-0.6 mg / mL. -1 ; The organic ammonium salt is selected from one or more of phenylethyl ammonium bromide, m-fluorophenylethyl ammonium bromide, ethylenediamine hydroiodate, and / or propylenediamine hydroiodate; the concentration of the phenylethyl ammonium bromide is 1-2 mg / mL. -1 The concentration of the m-fluorophenylethyl ammonium bromide is 1-2 mg / mL. -1 The concentration of the ethylenediamine hydroiodate is 0.5-1.5 mg / mL. -1 The concentration of the propylenediamine hydroiodate is 0.1-1.0 mg / mL. -1 .

6. The preparation method according to claim 4, characterized in that, In step S2, the perovskite precursor solution is selected from Cs 0.05 MA 0.1 FA 0.85 PbI3 or Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 3; The substrate is selected from ITO / NiO x / Me-4PACz / Al2O3 or wafer / NiO x / Me-4PACz / Al2O3; When the perovskite precursor solution described in S2 is Cs 0.05 MA 0.1 FA 0.85 For PbI3, the spin-coating deposition described in S2 is a one-step spin-coating method. The spin-coating conditions in S2 are 1000-5000 rpm for 10-20 s, the sample in S2 needs to be vacuum-treated at 0-5 Pa for 10-30 s, and the annealing conditions in S2 are 90-120 ℃ for 20-40 min. The spin-coating conditions in S3 are 3000-6000 rpm for 10-50 s, with an acceleration of 3000-6000 rpm / s. -1 The annealing conditions described in S3 are 80-120 ℃ for 1-10 min; When the perovskite precursor solution described in S2 is Cs 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 In step 3, the spin-coating deposition is a two-step spin-coating method. Step 2 involves spin-coating at 500-1500 rpm for 5-15 seconds, followed by spin-coating at 3000-6000 rpm for 20-60 seconds. Step 2 also involves adding 100-200 μL of anisole to the sample 10 seconds before the end of spin-coating. Step 3 involves annealing at 80-120 °C for 5-15 minutes. Step 4 further involves spin-coating at 3000-6000 rpm for 10-50 seconds, with an acceleration of 3000-6000 rpm. -1 The annealing conditions described in S3 are 80-120 °C for 1-10 min.

7. The application of the fluoropolymer-organic ammonium salt composite interface passivation layer as described in claim 1 in the preparation of perovskite solar cells.

8. A method for preparing a perovskite tandem solar cell based on the fluorinated polymer-organic ammonium salt composite interface passivation layer as described in claim 1, characterized in that, The preparation method includes the following steps: S1. Preparation of fluoropolymer-organic ammonium salt composite passivation solution Fluoropolymer and organic ammonium salt were dissolved separately in solvents, mixed, and then ultrasonically treated to obtain a fluoropolymer-organic ammonium salt composite passivation solution. S2. Preparation of mid-bandgap perovskite thin films and their composite passivation layers S21. Under argon atmosphere, PbI₂, CsI, FAI, MAI, PbCl₂, and MACl are dissolved in a mixed solvent of DMF and NMP to form CsI. 0.05 MA 0.1 FA 0.85 PbI3 perovskite precursor solution; The perovskite precursor solution was added to the substrate, and after spin-coating deposition, the sample was vacuum-treated and then annealed to obtain a medium-bandgap perovskite film. S22. The fluorinated polymer-organic ammonium salt composite passivation solution prepared in S1 is dynamically spin-coated onto the surface of the mid-bandgap perovskite film prepared in S21, and then annealed to form a fluorinated polymer-organic ammonium salt composite interface passivation layer. S3. Preparation of wide-bandgap perovskite thin films and their composite passivation layers S31. Under argon atmosphere, FAI, CsI, MABr, PbI2, PbBr2, MACl, and PbCl2 are dissolved in a mixed solvent of DMF and DMSO to form CsI. 0.2 MA 0.1 FA 0.7 Pb(Br 0.6 I 0.4 3. Perovskite precursor solution; A perovskite precursor solution was added to the substrate and spin-coated. Anisole was added as an antisolvent before the spin coating was completed. The sample was then transferred and annealed to obtain a wide-bandgap perovskite film. S32. The fluorinated polymer-organic ammonium salt composite passivation solution prepared in S1 is dynamically spin-coated onto the surface of a wide-bandgap perovskite film and then annealed to form a fluorinated polymer-organic ammonium salt composite interface passivation layer. S4. Fabrication of Perovskite Tandem Solar Cells S41. Spin-coat the Me-4PACz ethanol solution onto the surface of the bottom cell, and anneal it to form a hole-selective contact layer. S42. Prepare a composite interface passivation layer on the surface of a mid-bandgap perovskite according to method S2, and deposit C. 60 layer, SnO x Together with IZO, they form an intermediate interconnect layer; S43. Spin-coating NiO onto the IZO layer x Nanoparticle layer was applied and annealed, followed by spin-coating with Me-4PACz ethanol solution and annealing. S44. Prepare a composite interface passivation layer on the surface of a wide-bandgap perovskite using the method in S3, and deposit C. 60 layer, SnO x and IZO; S45. Deposition of Ag electrode and MgF x An antireflection layer is added to obtain a perovskite / perovskite / silicon triple-junction tandem solar cell.

9. The preparation method according to claim 8, characterized in that, In step S41, the bottom cell is a nanocrystalline silicon heterojunction bottom cell, and the concentration of the Me-4PACz ethanol solution is 0.1-1.0 mg / mL. -1 ; In step S42, the C 60 The deposition method for the layer is thermal evaporation deposition, and the SnO layer is... x The deposition method is atomic layer deposition at 60-100℃, and the deposition method for IZO is sputtering deposition; the C 60 The thickness of the layer is 1-10 nm, and the SnO x The thickness of the IZO is 20-40 nm, and the thickness of the IZO is 10-40 nm. In step S43, the NiO x The thickness of the nanoparticle layer is 10-20 nm, and the annealing conditions are 80-120 ℃ for 1-10 min; the concentration of the Me-4PACz ethanol solution is 0.1-1.0 mg / mL. -1 The spin coating conditions are 3000-5000 rpm for 10-20 s, and the annealing conditions are 80-120 ℃ for 5-15 min. In step S44, the C 60 The deposition method for the layer is thermal evaporation deposition, and the SnO layer is... x The deposition method is atomic layer deposition at 80-120℃, and the deposition method for IZO is sputter deposition; the C 60 The thickness of the layer is 1-10 nm, and the SnO x The thickness of the IZO is 20-40 nm, and the thickness of the IZO is 10-40 nm. In step S45, the Ag electrode and MgF x The antireflection layer was deposited using thermal evaporation deposition; the Ag electrode had a thickness of 300-500 nm, and the MgF... x The thickness of the antireflective layer is 50-150 nm.

10. A perovskite tandem solar cell prepared according to the method of claim 8, characterized in that, The perovskite tandem solar cell is fabricated on a substrate or bottom cell by sequentially forming a hole transport layer, a perovskite light-absorbing layer, a composite interface layer, an electron transport layer, a transparent conductive layer, and an electrode layer; the perovskite tandem solar cell includes perovskite / silicon tandem solar cell, perovskite / perovskite tandem solar cell, and perovskite / perovskite / silicon triple junction tandem solar cell.

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