Two-dimensional material doped tin-based perovskite solar cell and preparation method thereof

Abstract

The invention discloses a two-dimensional material doped tin-based perovskite solar cell and a preparation method thereof. The preparation method comprises the following steps: (1) preparing a hole transport layer on an anode substrate; (2) dissolving stannous fluoride, formamidine hydriodate, p-fluorophenylethylamine bromide and stannous iodide in an organic solvent containing 4-(2-aminoethyl) pyridine for reaction, and coating the hole transport layer with an obtained perovskite solution to obtain a perovskite thin film; (3) preparing an electron transport layer on the perovskite thin film; and (4) preparing a hole barrier layer and a cathode electrode on the electron transport layer in sequence to obtain the two-dimensional material doped tin-based perovskite solar cell. According to the tin-based perovskite solar cell, 4-(2-aminoethyl) pyridine is adopted as an additive, the tin-based perovskite crystallization process is delayed, the defect state density of the thin film is effectively reduced, the service life of current carriers is prolonged, and therefore the photoelectric conversion efficiency and the operation stability of the tin-based perovskite solar cell are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic devices, and in particular to a two-dimensional material-doped tin-based perovskite solar cell and a preparation method thereof. Background Art

[0002] Currently, the certified efficiency of perovskite solar cells has significantly increased from an initial 3.81% to 26.95%, gradually approaching the level of multicrystalline silicon cells, demonstrating enormous application potential. However, the lead element, widely used in traditional perovskite solar cell materials, has serious drawbacks. Lead has a strong environmental accumulation property. Once it enters an ecosystem, it accumulates through pathways such as the food chain, causing serious disruption to the ecosystem's balance. It can also cause irreversible damage to human health, such as affecting nervous system development and causing blood and cardiovascular diseases. Therefore, the development of lead-free perovskite materials has become a key research direction in this field.

[0003] Among the many lead-free alternative materials, tin is the most promising candidate due to its low toxicity and similar electronic structure and ionic radius to lead, making it a good substitute for lead in the perovskite structure. Tin-based perovskites possess a range of excellent properties. Their band gap has a wide adjustable range, which can be adjusted according to different application scenarios and needs. At the same time, they have high carrier mobility, which is conducive to the rapid transport of carriers. In addition, through dimensionality control, the stability of the material can be significantly improved, making tin-based perovskites stand out among lead-free perovskite materials and regarded as the most promising research object.

[0004] However, tin-based perovskite materials face many challenges in practical applications. Since tin lacks the lanthanide contraction effect, its electronegativity is lower than that of lead, its atomic energy level is higher, and the splitting energy of s and p orbitals is smaller. These atomic-level characteristics lead to a significant reduction in the ionization energy of tin. In actual material systems, it is manifested as Sn 2+ Pb 2+ It is easier to lose electrons and is easily oxidized to Sn in the environment 4+ . Sn 2+ The oxidation process induces deep-level defects within the material, such as Sn vacancies and interstitial defects. These defect states act as carrier recombination centers, significantly reducing carrier lifetime and exacerbating non-radiative recombination processes. Ultimately, this severely limits the performance of solar cell devices, making it difficult to improve photoelectric conversion efficiency. Furthermore, tin-based perovskites suffer from excessively rapid crystallization during film formation, resulting in porous and uneven films. This undesirable film morphology can hinder carrier transport pathways, affect carrier collection efficiency, and further negatively impact overall device performance.

[0005] Over the years, in order to overcome the above-mentioned problems of tin-based perovskite materials, researchers have actively explored various optimization strategies, such as through the regulation of A-site cations, the use of additive engineering, and the implementation of solvent engineering. These strategies have, to a certain extent, promoted the improvement of the efficiency of tin-based perovskite devices. In the study of the structural dimensions of perovskite materials, two-dimensional perovskites exhibit different properties from three-dimensional perovskites. By introducing a hydrophobic organic layer, two-dimensional perovskites effectively improve the environmental stability of the material and reduce the impact of external environmental factors such as water vapor and oxygen on the material performance. At the same time, the quantum confinement effect gives two-dimensional perovskites adjustable optical properties, making them potentially valuable in specific optical applications. However, due to the existence of interlayer barriers in the two-dimensional structure, the transmission of carriers between layers is greatly restricted, resulting in the efficiency of devices based on two-dimensional perovskites being generally lower than that of three-dimensional perovskite devices, limiting their application in the field of high-efficiency solar cells.

[0006] Therefore, exploring suitable two-dimensional materials to construct two-dimensional / three-dimensional hybrid structure perovskite solar cells with better performance is of great significance for balancing device efficiency and stability. Summary of the Invention

[0007] In order to solve the above technical problems, the purpose of the present invention is to provide a tin-based perovskite solar cell doped with a two-dimensional material and a preparation method thereof, which can delay the crystallization process of the tin-based perovskite, effectively reduce the defect state density of the film, and increase the carrier lifetime, thereby improving the photoelectric conversion efficiency and operational stability of the tin-based perovskite solar cell.

[0008] The present invention is achieved through the following technical solutions:

[0009] A method for preparing a two-dimensional material-doped tin-based perovskite solar cell comprises the following steps:

[0010] (1) preparing a hole transport layer on an anode substrate;

[0011] (2) dissolving stannous fluoride (SnF2), formamidine hydroiodide (FAI), p-fluorophenylethylamine bromide (pF-PEABr) and stannous iodide (SnI2) in an organic solvent containing 4-(2-aminoethyl) pyridine to react to obtain a perovskite solution, and coating the perovskite solution on the hole transport layer described in step (1) to obtain a perovskite film; the concentration of 4-(2-aminoethyl) pyridine in the organic solvent containing 4-(2-aminoethyl) pyridine is 0.4-0.8 mM and the concentration is (90-100):10000;

[0012] (3) preparing an electron transport layer on the perovskite film described in step (2);

[0013] (4) preparing a hole blocking layer and a cathode electrode in sequence on the electron transport layer described in step (3) to obtain a tin-based perovskite solar cell doped with the two-dimensional material.

[0014] The present invention achieves the regulation of thin film crystallization by using 4-(2-aminoethyl)pyridine as an additive. During the annealing stage, the amino group at the end of the long carbon chain in 4-(2-aminoethyl)pyridine can interact with the perovskite, and the pyridine group can also interact with the perovskite. This double-end interaction effectively delays the crystallization process of tin-based perovskite.

[0015] Furthermore, in step (1), the anode substrate includes a fluorine-doped tin oxide (FTO) substrate.

[0016] Furthermore, in step (1), the anode substrate is cleaned, the cleaned anode substrate is dried, and ultraviolet and ozone treatments are performed.

[0017] In a specific embodiment, the FTO substrate is repeatedly ultrasonically cleaned with deionized water, acetone, and ethanol for multiple times, and then baked until the solvent and moisture are completely removed; the treated FTO substrate is treated with ultraviolet light and ozone.

[0018] Furthermore, in step (1), the material of the hole transport layer includes poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS).

[0019] Furthermore, in step (1), the hole transport layer is spin-coated on the anode substrate and then annealed.

[0020] Furthermore, the spin coating method is: first spin coating at a rotation speed of 400-600 rpm for 5-15 s, and then spin coating at a rotation speed of 4000-5000 rpm for 40-60 s.

[0021] Furthermore, the annealing temperature is 130-150° C., and the annealing time is 10-20 minutes.

[0022] Furthermore, in step (2), the mass ratio of SnF2, FAI, pF-PEABr and SnI2 is (10-15):(100-150):(15-20):(280-320), preferably 12.48:137.6:17.6:298.

[0023] Furthermore, in step (2), the usage ratio of SnF2 and organic solvent is (10-15) mg:1 mL.

[0024] Furthermore, in step (2), the organic solvent is dimethylformamide (DMF) and / or dimethyl sulfoxide (DMSO), and when DMF and DMSO are used as a mixed solvent, the volume ratio of DMF to DMSO is 4:1.

[0025] Furthermore, in step (2), the concentration of 4-(2-aminoethyl)pyridine in the organic solvent containing 4-(2-aminoethyl)pyridine is 0.8-4 mM.

[0026] Furthermore, in step (2), the perovskite solution is spin-coated on the hole transport layer, and the perovskite film is obtained after annealing.

[0027] Furthermore, a one-step spin coating method is used, the spin coating speed is 5000-5500 rpm, the anti-solvent is added 20-25 seconds after the start of spin coating, and the substrate is annealed at 90-110° C. for 10-15 minutes after the spin coating is completed.

[0028] Furthermore, the anti-solvent comprises chlorobenzene (CB).

[0029] Furthermore, the volume ratio of the antisolvent to the perovskite solution is (4-6):1.

[0030] Furthermore, in step (3), the material of the electron transport layer includes fullerene and its derivatives, such as ICBA, PCBM, C60, etc.

[0031] Furthermore, in step (3), the electron transport layer is prepared by spin coating, the spin coating speed is 1500-2500 rpm, and the spin coating time is 40-50 s.

[0032] Furthermore, in step (4), a hole blocking layer and a cathode electrode are prepared in sequence by thermal evaporation deposition.

[0033] Furthermore, in step (4), the thermal evaporation deposition method includes vacuum evaporation technology.

[0034] Furthermore, the material of the hole blocking layer includes bathocuproine (BCP).

[0035] Furthermore, the cathode electrode includes a silver (Ag) electrode.

[0036] Furthermore, the thickness of the hole transport layer is 30-40 nm, the thickness of the perovskite layer is 300-400 nm, the thickness of the electron transport layer is 30-40 nm, the thickness of the hole blocking layer is 8-10 nm, and the thickness of the cathode electrode is 100-110 nm.

[0037] The present invention also protects the two-dimensional material-doped tin-based perovskite solar cell prepared by the above method.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The present invention provides a two-dimensional material-doped tin-based perovskite solar cell and a preparation method thereof. 4-(2-aminoethyl)pyridine is used as an additive to achieve regulation of thin film crystallization. During the annealing stage, the amino group at the end of the long carbon chain in 4-(2-aminoethyl)pyridine can interact with the perovskite, and the pyridine group can also interact with the perovskite. This dual-end interaction effectively delays the crystallization process of the tin-based perovskite.

[0040] 2. The present invention not only delays the crystallization process of the perovskite film and improves the quality of the perovskite film, but also prepares a two-dimensional / three-dimensional perovskite hybrid structure, further improving the stability of the perovskite film.

[0041] 3. The tin-based perovskite solar cell doped with two-dimensional materials prepared by the present invention has a high carrier lifetime and low defect state density, which not only reduces the loss of open-circuit voltage but also improves the fill factor, so that its photoelectric conversion efficiency reaches 14.17%. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 1 and 2 are XRD patterns of the perovskite film in Example 1 and the perovskite film in Comparative Example 1.

[0043] Figure 2 Steady-state PL spectra of the perovskite film in Comparative Example 7 and the perovskite film in Comparative Example 1.

[0044] Figure 3 These are the transient photoluminescence spectra of the perovskite film in Example 1 and the perovskite film in Comparative Example 1, as well as the DLCP test spectra of the 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell prepared in Example 1 and the tin-based perovskite solar cell prepared in Comparative Example 1; wherein a is the transient photoluminescence spectrum and b is the DLCP test spectrum.

[0045] Figure 4 Graph showing the JV performance test results of the tin-based perovskite solar cells prepared in Examples 1-2 and Comparative Examples 1-7.

[0046] Figure 5 Graph showing the JV performance test results of the tin-based perovskite solar cells prepared in Example 1 and Comparative Example 1.

[0047] Figure 6 This is a graph showing the operational stability of the tin-based perovskite solar cells prepared in Example 1 and Comparative Example 1 under continuous AM 1.5G sunlight irradiation. DETAILED DESCRIPTION

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0049] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0050] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are all commercially available unless otherwise specified.

[0051] In the following examples and comparative examples, FTO substrates and FAI were purchased from Liaoning Advanced Election Technology Co., Ltd. pF-PEABr was purchased from Xi'an Baolait Co., Ltd. SnI2 was purchased from Libo New Energy Technology Co., Ltd. 4-(2-aminoethyl)pyridine, 4-aminopyridine, 4-methylaminopyridine, 4-pyridylpropylamine, 4-(4-pyridyl)butylamine, 2-(2-aminoethyl)pyridine, and 3-(2-aminoethyl) were purchased from Adamas-beta. SnF2 was purchased from Aldrich. ICBA was purchased from 1-Material. Dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and chlorobenzene (CB) were purchased from Alfa Aesar Ltd. PEDOT:PSS (solid content 1.0-1.3%) was purchased from Heraeus.

[0052] Example 1

[0053] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure comprises the following steps:

[0054] (1) Preparation of a 30 nm PEDOT:PSS layer on an FTO substrate: The FTO substrate was ultrasonically cleaned three times with deionized water, acetone, and ethanol, and then baked for 20 min to completely remove the solvent and moisture. The treated FTO substrate was treated with UV light and ozone for 30 min, and PEDOT:PSS was spin-coated on the FTO substrate, first at 500 rpm for 10 s and then at 4500 rpm for 50 s, and then annealed at 140 °C for 15 min to obtain a PEDOT:PSS layer.

[0055] (2) Preparing a perovskite film on the PEDOT:PSS layer described in step (1): dissolving 12.48 mg SnF2, 137.6 mg FAI, 17.6 mg pF-PEABr and 298 mg SnI2 in 1 mL of a mixed solvent of DMF and DMSO containing 0.95 μL 4-(2-aminoethyl)pyridine, wherein the volume ratio of DMF to DMSO is 4:1 and the concentration of 4-(2-aminoethyl)pyridine is 0.8 mM, and stirring at room temperature overnight to obtain a perovskite solution; statically coating 45 μL of the perovskite solution on the PEDOT:PSS layer at a spin coating speed of 5000 rpm, adding 210 μL of CB dropwise 20 seconds after the start of spin coating, and annealing on a heating table at 100°C for 10 minutes after spin coating to obtain a perovskite film.

[0056] (3) Preparing an ICBA layer on the Perovskite layer described in step (2): dissolving 20 mg of ICBA powder in 1 mL of CB and stirring at room temperature overnight to obtain an ICBA solution; statically coating 45 μL of 20 mg / mL ICBA solution on the Perovskite layer, spin coating at 2000 rpm for 40 seconds, and annealing on a heating plate at 80°C for 5 minutes to obtain an ICBA layer.

[0057] (4) A BCP layer and an Ag electrode were sequentially prepared on the ICBA layer described in step (3): an 8 nm BCP layer and a 100 nm Ag electrode were sequentially deposited using vacuum evaporation technology.

[0058] Example 2

[0059] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 4 mM.

[0060] Comparative Example 1

[0061] A method for preparing a tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that: in step (2), 4-(2-aminoethyl)pyridine is not added.

[0062] Comparative Example 2

[0063] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 0.1 mM.

[0064] Comparative Example 3

[0065] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 0.4 mM.

[0066] Comparative Example 4

[0067] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 8 mM.

[0068] Comparative Example 5

[0069] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 16 mM.

[0070] Comparative Example 6

[0071] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 80 mM.

[0072] Comparative Example 7

[0073] A method for preparing a 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), the concentration of 4-(2-aminoethyl)pyridine is 160 mM.

[0074] Comparative Example 8

[0075] A method for preparing a 4-aminopyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), 4-(2-aminoethyl)pyridine is replaced by 4-aminopyridine.

[0076] Comparative Example 9

[0077] A method for preparing a 4-methylaminopyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), 4-(2-aminoethyl)pyridine is replaced by 4-methylaminopyridine.

[0078] Comparative Example 10

[0079] A method for preparing a 4-pyridinepropylamine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), 4-(2-aminoethyl)pyridine is replaced by 4-pyridinepropylamine.

[0080] Comparative Example 11

[0081] A method for preparing a tin-based perovskite solar cell doped with 4-(4-pyridine)butylamine of an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), 4-(2-aminoethyl)pyridine is replaced by 4-(4-pyridine)butylamine.

[0082] Comparative Example 12

[0083] A method for preparing a 2-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure is basically the same as that in Example 1, except that in step (2), 4-(2-aminoethyl)pyridine is replaced by 2-(2-aminoethyl)pyridine.

[0084] Comparative Example 13

[0085] A method for preparing a tin-based perovskite solar cell with an inverted FTO / PEDOT:PSS / Perovskite / ICBA / BCP / Ag structure and doped with 3-(2-aminoethyl)pyridine is basically the same as that in Example 1, except that in step (2), 4-(2-aminoethyl)pyridine is replaced with 3-(2-aminoethyl)pyridine.

[0086] The concentration of the additives in Comparative Examples 8-13 was all 0.8 mM.

[0087] Figure 1 The X-ray diffraction (XRD) patterns of the perovskite film in Example 1 and the perovskite film in Comparative Example 1 are shown in FIG. Figure 1 It can be seen that the perovskite film in Example 1 exhibits a stronger and sharper diffraction peak at the (100) crystal plane, proving that the addition of 4-(2-aminoethyl)pyridine makes the perovskite film more crystallinity.

[0088] Figure 2 The steady-state photoluminescence (PL) spectra of the perovskite film in Comparative Example 7 and the perovskite film in Comparative Example 1 are shown. To better observe the existence of the two-dimensional phase, the perovskite film in Comparative Example 7 containing a high concentration of additives is selected. Figure 2 It can be seen that the peak value of the main PL peak of the perovskite film after 4-(2-aminoethyl)pyridine doping has a blue shift, and an obvious secondary peak is generated at 540nm to 650nm. The intensity of the secondary peak is much smaller than the intensity of the main peak, indicating that a two-dimensional / three-dimensional perovskite mixed structure is formed in the film, and the three-dimensional perovskite phase is dominant.

[0089] Figure 3 The transient photoluminescence spectra of the perovskite film in Example 1 and the perovskite film in Comparative Example 1, as well as the driving level capacitance analysis (DLCP) test spectra of the 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cell prepared in Example 1 and the tin-based perovskite solar cell prepared in Comparative Example 1, are shown in FIG. Figure 3 As can be seen from a, the carrier lifetime of the perovskite film increases after being doped with 4-(2-aminoethyl)pyridine; Figure 3 As can be seen in Figure b, the defects of the tin-based perovskite solar cell are passivated after being doped with 4-(2-aminoethyl)pyridine, that is, the doping of 4-(2-aminoethyl)pyridine reduces the defect state density of the tin-based perovskite solar cell.

[0090] The tin-based perovskite solar cells prepared in Examples 1-2 and Comparative Examples 1-7 were measured by using a Keithley 2400 source meter under an atmospheric mass (AM) of 1.5G sunlight (100 mW·cm -2) irradiation to conduct short-circuit current density-open circuit voltage (JV) performance test, the test results are as follows Figure 4 and Figure 5 As shown in Figure 2, the most suitable concentration of 4-(2-aminoethyl)pyridine is 0.8 mM. Figure 5 It can be seen that the highest PCE of tin-based perovskite solar cells before and after 4-(2-aminoethyl)pyridine doping reached 12.77% and 14.17%, respectively, and the performance of the optimized tin-based device was significantly improved.

[0091] The tin-based perovskite solar cells prepared in Example 1 and Comparative Example 1 were tested under continuous AM 1.5G sunlight (100 mW·cm -2 ) working stability under irradiation, the test results are as follows Figure 6 As shown in the figure, compared with undoped tin-based perovskite solar cells, 4-(2-aminoethyl)pyridine-doped tin-based perovskite solar cells still maintain 90% of the initial efficiency after 273 hours. The doping of 4-(2-aminoethyl)pyridine greatly improves the stability of tin-based perovskite solar cells.

[0092] The performance tests of the tin-based perovskite solar cells prepared in Example 1 and Comparative Examples 8-13 were carried out as follows: -2 ) irradiation using a programmable Keithley 2400 source meter to test the short-circuit current (J) of tin-based perovskite solar cells sc ), open circuit voltage (V oc ), fill factor (FF) and photoelectric conversion efficiency (PCE).

[0093] The test results are shown in Table 1:

[0094] Table 1 Performance parameters of tin-based perovskite solar cells prepared in Example 1 and Comparative Examples 8-13

[0095] <![CDATA[J sc (mA cm -2 )]]> <![CDATA[V oc (V)]]> FF(%) PCE (%) Example 1 24.04 0.91 65.04 14.17 Comparative Example 8 21.67 0.65 60.08 8.41 Comparative Example 9 25.90 0.80 52.53 10.88 Comparative Example 10 23.86 0.89 62.09 13.16 Comparative Example 11 24.02 0.83 49.61 9.79 Comparative Example 12 24.84 0.82 62.30 12.59 Comparative Example 13 24.66 0.88 63.64 13.67

[0096] The only difference between Example 1 and Comparative Examples 8-11 is the length of the side chains in the additives, while the only difference between Example 1 and Comparative Examples 12 and 13 is the location of the side chains attached to the pyridine ring. As shown in Table 1, the additive 4-(2-aminoethyl)pyridine has the optimal side chain length, and its attachment to the para position of the pyridine ring provides the best improvement in device efficiency.

[0097] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a two-dimensional material-doped tin-based perovskite solar cell, characterized in that: The following steps are involved: (1) preparing a hole transport layer on an anode substrate; (2) dissolving stannous fluoride, formamidine hydroiodide, p-fluorophenethylamine bromide, and stannous iodide in an organic solvent containing 4-(2-aminoethyl)pyridine to react to obtain a perovskite solution, and coating the perovskite solution on the hole transport layer described in step (1) to obtain a perovskite film; the concentration of 4-(2-aminoethyl)pyridine in the organic solvent containing 4-(2-aminoethyl)pyridine is 0.5-6 mM; (3) preparing an electron transport layer on the perovskite film described in step (2); (4) preparing a hole blocking layer and a cathode electrode in sequence on the electron transport layer described in step (3) to obtain a tin-based perovskite solar cell doped with the two-dimensional material.

2. The preparation method according to claim 1, characterized in that In step (1), a hole transport layer is spin-coated on the anode substrate and then annealed.

3. The preparation method according to claim 2, characterized in that The spin coating method is: first spin coating at a rotation speed of 400-600 rpm for 5-15 s, and then spin coating at a rotation speed of 4000-5000 rpm for 40-60 s.

4. The preparation method according to claim 1, characterized in that In step (2), the usage ratio of stannous fluoride and the organic solvent is (10-15) mg:1 mL.

5. The preparation method according to claim 1, characterized in that In step (2), the concentration of 4-(2-aminoethyl)pyridine in the organic solvent containing 4-(2-aminoethyl)pyridine is 0.8-4 mM.

6. The preparation method according to claim 1, characterized in that In step (2), the perovskite solution is spin-coated on the hole transport layer, and the perovskite film is obtained after annealing.

7. The preparation method according to claim 6, characterized in that The spin coating speed is 5000-5500 rpm, the anti-solvent is added 20-25 seconds after the start of spin coating, and the annealing treatment is performed at 90-110° C. for 10-15 minutes after the spin coating is completed.

8. The preparation method according to claim 1, characterized in that In step (3), the electron transport layer is prepared by spin coating, the spin coating speed is 1500-2500 rpm, and the spin coating time is 40-50 s.

9. The preparation method according to claim 1, characterized in that In step (4), a hole blocking layer and a cathode electrode are prepared in sequence by thermal evaporation deposition.

10. A tin-based perovskite solar cell doped with a two-dimensional material prepared by the method according to any one of claims 1 to 9.

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