Two-dimensional perovskite / crystalline silicon laminated solar cell and preparation method thereof
The preparation of two-dimensional perovskite/crystalline silicon stacked solar cells through hot air assisted method solves the problems of high equipment costs and poor stability, and achieves efficient photoelectric conversion and low-cost industrial production.
Patent Information
- Application Number
- CN202510807849.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-17
- Publication Date
- 2025-08-26
AI Technical Summary
In large-scale production of existing perovskite/silicon stacked solar cells, there are problems such as high equipment cost, high energy consumption and poor stability, making it difficult to achieve both efficient photoelectric conversion and low cost.
Two-dimensional perovskite/crystalline silicon stacked solar cells were prepared by hot air assisted method. By vertically growing high-quality two-dimensional perovskite films on large-area silicon base cells, combining specific solvent combinations and hot air treatment, quantum well structures were formed to optimize band gaps and stability.
It has achieved the preparation of large-area high-quality perovskite films, improved the photoelectric conversion efficiency and stability, reduced production costs, and is suitable for industrial production.
Smart Images
Figure CN120548019A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of solar cells, and more particularly to a two-dimensional perovskite / crystalline silicon stacked solar cell prepared based on a hot air assisted method. Background Art
[0002] In recent years, perovskite materials, with their superior optoelectronic properties and tunable bandgap characteristics, have sparked a technological revolution in the photovoltaic field and quickly become the pinnacle of photovoltaic technology. When scientists first applied perovskite to solar cells in 2012, their efficiency was less than 10%. However, within just a decade, their efficiency has approached that of single-crystalline silicon cells, making them one of the fastest-growing photovoltaic technologies. Despite the emergence of various solar cell designs, crystalline silicon (Si), as the foundational semiconductor in single-junction devices, continues to dominate the photovoltaic market due to its mature process system, stable long-term performance, and efficiency ceiling exceeding 25%. However, the efficiency of any single cell is limited by the Shockley-Queisser equation (theoretical maximum efficiency of a single cell is 33%), resulting in a maximum theoretical conversion efficiency of silicon-based solar cells not exceeding 29.1%.
[0003] Researchers have also discovered that perovskite cells have a narrow spectral absorption range, primarily absorbing high-energy photons with wavelengths less than 800nm, while silicon cells have a longer spectral absorption range, primarily absorbing photons with wavelengths greater than 800nm. Due to the complementary spectral properties of these two types of solar cells, perovskite / silicon tandem solar cells have emerged. This involves combining crystalline silicon and perovskite thin-film cells, with the wide-bandgap perovskite layer absorbing short-wavelength light and the narrow-bandgap silicon layer capturing long-wavelength light. This theoretically increases the photoelectric conversion efficiency to over 43%, exceeding that of single-crystal silicon cells or pure perovskite cells.
[0004] Currently, existing perovskite / silicon tandem solar cells are all based on three-dimensional perovskites. While their photoelectric conversion efficiency is slightly higher than that of two-dimensional perovskites, their sensitivity to humidity, light, and thermal stress severely hinders their commercialization. In this context, two-dimensional perovskites, by introducing bulky organic spacer cations to create quantum well structures, offer the advantage of significantly improving the stability of the perovskite material and suppressing ion migration issues. Consequently, two-dimensional perovskite / silicon tandem solar cells have become a key approach to breaking through the bottleneck of industrialization.
[0005] Currently, the commonly used technologies for preparing perovskites in the industry include spin coating, doctor blade coating, and deposition methods. The performance of perovskite solar cells depends largely on the quality of the perovskite film. Spin coating is simple to operate, produces uniform, continuous films, and exhibits high crystallinity. However, it is only suitable for preparing small samples and is not suitable for industrial production. Furthermore, approximately 90% of the solution is discarded during the spin coating process, resulting in low raw material utilization.
[0006] Existing technologies have recently developed processes for large-area fabrication. For example, vacuum evaporation is used to fabricate large-area perovskite solar cells. While this method achieves high film uniformity and improves efficiency and stability, it requires a vacuum environment and a precision evaporation source, resulting in high equipment costs and increased production costs. Maintaining a high vacuum and high-temperature evaporation consumes significant energy, hindering the industrialization of the cells.
[0007] The core goal of overcoming these technical challenges is to develop a large-scale production process for perovskite solar cells, significantly reducing the unit production cost while maintaining their efficient photoelectric conversion performance and long-term stability, thereby breaking through the dilemma of achieving both efficiency and cost in the industrialization process and accelerating the process of this technology from laboratory to large-scale application. Summary of the Invention
[0008] In view of this, the present invention provides a two-dimensional perovskite / crystalline silicon stacked solar cell and a preparation method thereof.
[0009] One of the purposes of the present invention is to provide a two-dimensional perovskite / crystalline silicon stacked solar cell, the structure of which from bottom to top is a silicon bottom cell, a composite layer, a hole transport layer, a two-dimensional perovskite top cell, a charge transport layer, and a transparent electrode.
[0010] The two-dimensional perovskite top cell comprises a two-dimensional perovskite film, and the two-dimensional perovskite film is A2B n- 1Pb n I 3n+1 , n = 1-5; where A is BA + 、PA + 、TBA + 、PEA + One of them, B is FA + 、TMA + 、MA + One of them.
[0011] The beneficial effects of adopting the above technical means are: two-dimensional perovskites, due to their unique structural and chemical properties, show significant stability advantages, which are outstanding in terms of structural stability, chemical stability, thermal stability, light stability and humidity stability. In order to further improve the efficiency of perovskite / crystalline silicon stacked cells, the introduction of two-dimensional perovskites can effectively solve the fatal problem of instability of perovskite sub-cells. Compared with isotropic three-dimensional perovskites, two-dimensional perovskites exhibit anisotropy due to the insertion of large-sized organic spacer layers. The perovskite layer acts as a "well", and the dielectric layer formed by the organic spacer layer acts as an "obstacle". Therefore, the two-dimensional perovskite naturally forms a quantum well (QW) structure. This leads to quantum confinement and dielectric confinement effects, resulting in significant changes in band gap, exciton binding energy and charge transport.
[0012] A second objective of the present invention is to provide a method for preparing two-dimensional perovskite / crystalline silicon tandem solar cells. Considering the need to produce high-quality, vertically oriented two-dimensional perovskites on large, textured silicon substrates, conventional spin-coating perovskite preparation processes appear unsuitable. Therefore, the hot air-assisted method, due to its large-area applicability, lack of spin-coating requirements, rapid crystallization, and strong environmental adaptability, can be expanded to the preparation of two-dimensional perovskite / crystalline silicon tandem cells. This method can achieve the goal of large-scale perovskite production, while maintaining high conversion rates for perovskite cells and reducing costs.
[0013] The specific steps include:
[0014] Step 1: Prepare silicon bottom cell;
[0015] Step 2: Preparation of two-dimensional perovskite top cell by hot air assisted method:
[0016] 1) Preparation of precursor solution; 2) Substrate preparation; 3) Hot air treatment;
[0017] Step 3: Assembly of 2D perovskite / silicon tandem cells:
[0018] A pin structure is adopted, specifically including: FTO (fluorine-doped tin oxide) as a transparent conductive substrate, NiO nickel oxide as a hole transport layer (HTL), a two-dimensional perovskite top cell as a light absorption layer, PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) as an electron transport layer (ETL), BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline) as an intermediate layer, and Au as a metal cathode.
[0019] Furthermore, the step 2 is specifically as follows:
[0020] 1) Preparation of precursor solution
[0021] Weigh raw material A, raw material B, and PbI2 according to the stoichiometric ratio, dissolve them in a mixed solvent of dimethyl sulfoxide and N,N-dimethylformamide, and heat and stir to obtain a precursor solution;
[0022] 2) Substrate preparation
[0023] Using nickel oxide-coated fluorine-doped tin oxide as a substrate;
[0024] 3) Hot air treatment
[0025] The precursor solution is dropped onto the substrate in step 2), the temperature is adjusted, and hot air is injected to prepare a two-dimensional perovskite film.
[0026] Preferably, the stoichiometric ratio is 2:n-1:n, where n=1-5.
[0027] Preferably, the raw material containing A is selected from one of BAI (butylammonium iodide), PAI (tetrapentylammonium iodide), TBAI (tetrabutylammonium iodide), and PEAI (phenethylammonium iodide); the raw material containing B is selected from one of FAI (formamidine iodide), TMAI (tetramethylammonium iodide), and MAI (methylammonium iodide).
[0028] Preferably, the volume ratio of dimethyl sulfoxide and N,N-dimethylformamide in the mixed solvent is 7:3; the Pb 2+ The concentration is 0.9M.
[0029] Preferably, the heating and stirring temperature is 70° C. and the time is ≥ 8 h.
[0030] Preferably, the dropping is to drop 2 μL of the precursor solution onto the substrate of 1.5 cm×1.5 cm.
[0031] Preferably, the range of the adjusted temperature is from room temperature to 200°C; the hot air is injected by keeping the distance between the hot air gun and the substrate at 5 cm, injecting hot air at an injection angle of 20° and an air flow rate of 350 L / min.
[0032] It can be seen from the above technical solutions that, compared with the prior art, the present invention has the following beneficial effects:
[0033] The inherent quantum confinement and dielectric confinement effects of two-dimensional perovskites enable them to exhibit remarkable wide-bandgap controllability and structural stability. Their anisotropic structure and the introduction of organic spacer cations not only optimize the bandgap but also enhance the material's water resistance and chemical stability. Through the synergistic effect of multiple control methods, two-dimensional perovskites can achieve broad spectral absorption from the ultraviolet to the near-infrared, making them particularly suitable for the top cell requirements of perovskite / crystalline silicon tandem solar cells, providing an ideal material choice for achieving efficient and stable tandem solar cells.
[0034] Due to the large area applicability of hot air assistance, the preparation area can exceed 25cm 2 High-quality perovskite films with highly uniform crystallinity and optoelectronic properties were produced.
[0035] In addition, a two-dimensional perovskite film with vertical orientation and high charge transfer efficiency was prepared by a hot air assisted method combined with a specific solvent combination, so that the stacked battery has efficient photoelectric conversion performance. Furthermore, by changing the air flow temperature (AFT), the main properties of the film, such as crystal orientation, phase purity and micromorphology, can be simply optimized. This is because the presence of hot air accelerates the escape rate of solvent molecules in the Pb-I colloid, making it easier for the colloid to be converted into an ordered perovskite structure. This rapid conversion process promotes the anisotropic growth of the crystal, so that the crystal preferentially grows in the direction perpendicular to the substrate, thereby achieving excellent crystal orientation.
[0036] Crystal orientation is one of the key factors that determine the quality of perovskite films. The present invention can induce the crystal to form a vertically upward crystal orientation based on the use of hot air assistance to promote directional carrier transport and effectively reduce recombination, thereby improving the photoelectric conversion efficiency of the two-dimensional perovskite / silicon stack. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0038] Figure 1 Flowchart of the preparation method of two-dimensional perovskite / silicon stacked cells.
[0039] Figure 2 Schematic diagram of the specific structure of the two-dimensional perovskite / silicon stacked cell.
[0040] Figure 3 Schematic diagram of the hot air-assisted preparation process of two-dimensional perovskite. DETAILED DESCRIPTION
[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0042] Currently, the commonly used technologies for preparing perovskites in the industry include spin coating, doctor blade coating, and deposition methods. The performance of perovskite solar cells depends largely on the quality of the perovskite film. Spin coating is simple to operate, produces uniform, continuous films, and has high crystallinity. However, it is only suitable for preparing small-area samples and is not suitable for industrial production. In addition, approximately 90% of the solution is discarded during the spin coating process, resulting in low raw material utilization. Among existing technologies, related processes for large-area preparation have recently been developed. For example, vacuum evaporation is used to prepare large-area perovskite solar cells. Although the film uniformity is high and the efficiency and stability are improved, the evaporation process requires a vacuum environment and a precision evaporation source, which is costly and increases the production cost. Maintaining the high vacuum and high-temperature evaporation requires a large amount of energy, which is not conducive to the industrialization of the battery.
[0043] The hot air-assisted method specifically refers to the use of high-temperature hot air as a heat source to achieve a relatively stable temperature in the local area of the coating head, thereby improving the quality and stability of the film. The principle of this method is: under the action of high-temperature air or nitrogen, the solvent on the surface of the substrate evaporates rapidly, accelerating the formation of perovskite crystal nuclei. Secondly, the hot air-assisted method can still produce high-quality perovskite films under high humidity conditions. Experiments have shown that even under conditions of relative humidity as high as 94%, the prepared perovskite film still has good crystallinity and optoelectronic properties; it can also be carried out at room temperature and pressure, without the need to operate in an inert environment such as a glove box, which greatly simplifies the preparation process and reduces costs.
[0044] The present invention is described in detail below in conjunction with specific solutions.
[0045] Example 1
[0046] A method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell, comprising the following steps:
[0047] 1. Preparation of silicon bottom cells.
[0048] Wafer preparation: using n-type doping <100> Directional Czochralski (CZ) silicon wafer with a resistivity of 1-4Ω·cm.
[0049] Surface treatment:
[0050] Backside texturing: The backside of the silicon wafer is processed using a standard texturing process to form a 3-5μm pyramid structure to enhance the absorption of near-infrared light.
[0051] Lightly texturizing the front side of the silicon wafer: Using a relatively low concentration of alkali solution, the front side of the silicon wafer is lightly textured to form a 0.5-1μm pyramid structure to accommodate the subsequent deposition of the perovskite solution. This also prevents excessive surface roughness from excessive etching. The alkali concentration is selected to be between 1% and 5%.
[0052] Thin film deposition: A hydrogenated amorphous silicon (ia-Si:H) layer approximately 5 nm thick is deposited on each side of the silicon wafer. An n-type nanocrystalline silicon oxide (nc-SiOx:H) layer approximately 15 nm thick is deposited on the front side, and a p-type nanocrystalline silicon (nc-Si:H) layer approximately 20 nm thick is deposited on the back side.
[0053] Transparent Conductive Oxide (TCO) Deposition: A 100nm thick In2O3-based transparent conductive oxide layer is deposited on the back side, followed by a silver layer. A 10nm thick transparent conductive oxide layer is deposited on the front side.
[0054] Laser cutting: The silicon bottom cell is cut into a substrate of 2.03 cm × 2.03 cm for the subsequent preparation of stacked cells.
[0055] 2. Preparation of two-dimensional perovskite top film using hot air assisted method:
[0056] Preparation of precursor solution:
[0057] BAI (butylammonium iodide), MAI (methylammonium iodide) and PbI2 (lead iodide) with a stoichiometric ratio of 2:3:4 were dissolved in a mixed solvent of DMSO (dimethyl sulfoxide) and DMF (N,N-dimethylformamide) with a volume ratio of 7:3 to achieve Pb 2+ The concentration is 0.9M, heated to 70°C, and stirred for not less than 8 hours. There is no specific requirement for the stirring speed.
[0058] The choice of alternative materials for BAI and MAI depends on specific application requirements and performance targets. For example, BAI can be replaced by PAI (pentylammonium iodide), TBAI (tetrabutylammonium iodide), or PEAI (phenylethylammonium iodide); while FAI (formamidine iodide) and TMAI (tetramethylammonium iodide) can replace MAI. These specific materials can enhance the performance of two-dimensional perovskite devices by adjusting interlayer spacing, optimizing interface energy level alignment, or improving stability.
[0059] Substrate preparation: NiO (nickel oxide)-coated FTO (fluorine-doped tin oxide) was used as the substrate. The hydrophilicity of NiO facilitates the spreading of the precursor solution.
[0060] Hot air treatment: 2 μL of the precursor solution was added dropwise to a 1.5 cm x 1.5 cm substrate. The solution quickly spread to form a liquid film. The precursor solution was treated with a stream of hot air (temperature adjustable). The hot air injection angle was approximately 20°, the distance between the hot air gun and the substrate was approximately 5 cm, and the air flow rate was set to 350 L / min.
[0061] Solar cells with perovskite thin films can be prepared at different temperatures, such as room temperature (RT), 70°C, 100°C, 150°C and 200°C, so as to obtain the temperature with the best performance for preparing solar cells.
[0062] After hot air treatment, the final two-dimensional perovskite film is formed without further annealing, and its chemical formula is (BA)2(MA)3Pb4I 13 .
[0063] 3. Preparation of each layer:
[0064] The NiO hole transport layer was prepared by spin coating an ethanol solution containing 0.1 M Ni(CH3COO)2·4H2O and 0.1 M NH2CH2CH2OH at 1600 rpm for 30 seconds, followed by annealing at 450°C for 30 minutes in air.
[0065] PCBM electron transport layer: spin coating of 20 mg / mL PCBM / chlorobenzene solution at 4000 rpm for 40 seconds.
[0066] BCP interlayer: Spin-coat a saturated BCP solution in isopropanol at 6000 rpm for 20 seconds.
[0067] Au electrode: An 80 nm thick Au layer was deposited by thermal evaporation.
[0068] Example 2
[0069] A method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell differs from Example 1 in that:
[0070] Preparation of the precursor solution: corresponding to n=1, the ratio of BAI:MAI:PbI2 is 2:0:1, aiming to form a 2D perovskite with n=1, namely BA2PbI4.
[0071] Example 3
[0072] A method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell differs from Example 1 in that:
[0073] Preparation of the precursor solution: corresponding to n=2, the ratio of BAI:MAI:PbI2 is 2:1:2, aiming to form a 2D perovskite with n=2, namely BA2MAPb2I7.
[0074] Example 4
[0075] A method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell differs from Example 1 in that:
[0076] Preparation of the precursor solution: corresponding to n=3, where the ratio of BAI:MAI:PbI2 is 2:2:3, aiming to form n=3 2D perovskite, namely BA2MA2Pb3I 10 .
[0077] Example 5
[0078] A method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell differs from Example 1 in that:
[0079] Preparation of the precursor solution: corresponding to n=5, the ratio of BAI:MAI:PbI2 is 2:4:5, aiming to form n=5 2D perovskite, namely BA2MA4Pb5I 16 .
[0080] When the molar ratio of BAI:MAI:PbI2 added in the present invention is 2:3:4, n=4, the compound (BA)2(MA)3Pb4I 13 The band gap Eg is about 1.7eV. At this time, the two-dimensional perovskite top cell can achieve wide spectrum absorption from ultraviolet to near infrared, showing good crystallinity and photoelectric properties.
[0081] Due to the quantum confinement effect, the band gap of two-dimensional perovskites is much larger than that of three-dimensional perovskites, and decreases monotonically with the increase of n value. For example, the band gap of MAPbI3 is 1.52eV, and the band gap of (BA)2MA is 1.52eV. n-1 Pb n I 3n+1 The band gap of perovskite decreases from 2.42eV (n=1) to 1.85eV (n=5), and the corresponding quantum well thickness increases from about 0.64nm (n=1) to 3.14nm (n=5). The increase in n value can shorten the inorganic interlayer spacing, reduce the deformation of the Pb-I-Pb angle, and weaken the quantum confinement effect. In addition, the interlayer spacing and interaction of the inorganic layers can be adjusted by organic spacer cations, thereby adjusting the band gap. For example, (BA)2MA3Pb4I 13 The band gap (1.70eV) is lower than that of (3AMP)MA3Pb4I 13 (1.87 eV) and (4AMP)MA3Pb4I 13 (1.89eV), where AMP is an organic spacer cation used in two-dimensional perovskites. It is a nitrogen-containing heterocyclic compound with a pyridine ring and an aminomethyl (-CH2NH2) side chain. The structure of AMP enables it to be inserted into the perovskite lattice, thus forming a two-dimensional perovskite material with a specific structure.
[0082] This demonstrates that the inherent quantum confinement and dielectric confinement effects of two-dimensional perovskites enable them to exhibit remarkable wide-bandgap controllability and structural stability. Their anisotropic structure and the introduction of organic spacer cations not only optimize the bandgap but also enhance the material's water resistance and chemical stability. Through the synergistic effect of multiple control methods, two-dimensional perovskites can achieve broad spectral absorption from the ultraviolet to the near-infrared, making them particularly suitable for the top cell requirements of perovskite / crystalline silicon tandem solar cells, providing an ideal material choice for achieving efficient and stable tandem solar cells.
[0083] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A two-dimensional perovskite / crystalline silicon tandem solar cell, characterized in that: The structure from bottom to top is silicon bottom cell, composite layer, hole transport layer, two-dimensional perovskite top cell, charge transport layer, and transparent electrode.
2. A two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 1, characterized in that: The two-dimensional perovskite top cell comprises a two-dimensional perovskite film, and the two-dimensional perovskite film is A2B n-1 Pb n I 3n+1 , n = 1-5; Among them, A is BA + 、PA + 、TBA + 、PEA + One of them, B is FA + 、TMA + 、MA + One of them.
3. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 1, characterized in that: The following steps are involved: Step 1: Prepare silicon bottom cell; Step 2: Preparation of two-dimensional perovskite top cell by hot air assisted method: 1) Preparation of precursor solution; 2) Substrate preparation; 3) Hot air treatment; Step 3: Assembly of 2D perovskite / silicon tandem cells: Fluorine-doped tin oxide is used as the transparent conductive substrate, nickel oxide as the hole transport layer, two-dimensional perovskite film as the light absorption layer, [6,6]-phenyl-C61-butyric acid methyl ester as the electron transport layer, 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline as the intermediate layer, and Au as the metal cathode.
4. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 3, characterized in that: The step 2 is specifically as follows: 1) Preparation of precursor solution Weigh raw material A, raw material B, and PbI2 according to the stoichiometric ratio, dissolve them in a mixed solvent of dimethyl sulfoxide and N,N-dimethylformamide, and heat and stir to obtain a precursor solution; 2) Substrate preparation Using nickel oxide-coated fluorine-doped tin oxide as a substrate; 3) Hot air treatment The precursor solution is dropped onto the substrate in step 2), the temperature is adjusted, and hot air is injected to prepare a two-dimensional perovskite film.
5. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 4, characterized in that: The stoichiometric ratio is 2:n-1:n, where n=1-5.
6. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 4, characterized in that: The raw material containing A is selected from one of butylammonium iodide, tetrapentylammonium iodide, tetrabutylammonium iodide, and phenethylammonium iodide; the raw material containing B is selected from one of formamidine iodide, tetramethylammonium iodide, and methylammonium iodide.
7. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 4, characterized in that: The volume ratio of dimethyl sulfoxide and N,N-dimethylformamide in the mixed solvent is 7:3; the Pb 2+ The concentration is 0.9M.
8. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 4, characterized in that: The heating and stirring temperature is 70° C. and the time is ≥8 h.
9. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 4, characterized in that: The dropping step is to drop 2 μL of the precursor solution onto the substrate having a size of 1.5 cm×1.5 cm.
10. The method for preparing a two-dimensional perovskite / crystalline silicon tandem solar cell according to claim 4, characterized in that: The range of the adjustment temperature is from room temperature to 200°C; The hot air was injected at a distance of 5 cm between the hot air gun and the substrate, with an injection angle of 20° and an air flow rate of 350 L / min.