Bimolecule co-anchoring-based hydrogen bond network stable perovskite solar cell and preparation method thereof

Abstract

The invention discloses a hydrogen bond network stable perovskite solar cell based on bimolecule co-anchoring and a preparation method thereof, and belongs to the technical field of thin film perovskite cells. According to the invention, combination of HDA and FAI is realized through carbene mediation under a thermal activation condition. -C = N and-COOH groups in GS and uncoordinated Pb < 2 + > form stable bonding, so that lead ion leakage is effectively inhibited. A hydrogen bond network topological structure is constructed at the grain boundary through the synergistic effect of the two, and lattice strain is relieved through molecular flexibility, so that perovskite grains are stabilized, crystallization kinetics are regulated and controlled, the crystallinity is improved, and finally the photo-thermal stability and the phase state stability are enhanced. The power conversion efficiency of the perovskite solar cell optimized through HAD-GS combination reaches 26.07%, and the thermal stability and the light stability are improved.

Description

Technical Field

[0001] This invention belongs to the field of thin-film solar cells and relates to a bimolecular co-anchored hydrogen bond network-stabilized perovskite solar cell and its preparation method. Background Technology

[0002] Perovskite solar cells (PSCs) have attracted much attention due to their superior photoelectric performance. Since their initial reports in 2009 and 2012, the power conversion efficiency (PCE) of PSCs has soared to over 27%. This superior performance is attributed to their extended carrier diffusion length, extended carrier lifetime, tunable bandgap, and high light absorption coefficient, making PSCs and their tandem configurations leading candidates for third-generation photovoltaic technology. In nip structures, the high PCE of formamidinium lead iodide (FAPbI3) is attributed to its ideal bandgap of 1.48 eV, which closely matches the optimal bandgap (1.33 eV) defined by the Shockley-Queisser limit. However, its complex crystallization kinetics and thermodynamic instability pose significant challenges to the preparation of high-quality α-FAPbI3 films. The high formation energy of FAPbI3 leads to thermodynamic instability, readily transforming spontaneously into the d-phase at room temperature, resulting in the loss of photovoltaic performance. Formamide cations (FA...) + Thermal runoff increases lattice defect density, while light stimulation induces lattice expansion and promotes the material's transition from the α phase to the d phase. These technical challenges still constrain the development of perovskite solar cells. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a stable perovskite solar cell based on a bimolecular co-anchored hydrogen bond network and its fabrication method. This addresses the thermodynamic instability of FAPbI3 in existing technologies. This invention utilizes HDA-GS to anchor A / B sites separately and constructs a hydrogen bond network topology at grain boundaries. Molecular flexibility alleviates lattice strain, thereby stabilizing the perovskite, regulating crystallization kinetics, releasing stress accumulation, and improving the photothermal stability of the perovskite solar cell.

[0004] To achieve the above objectives, the present invention employs the following technical solution: A method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network includes the following steps: S1, Pre-treated substrate, electron transport layer is prepared on the substrate; S2, a perovskite precursor solution is spin-coated onto the electron transport layer, with an antisolvent added dropwise during the spin-coating process, and a perovskite layer is formed after annealing; the solutes of the perovskite precursor solution are PbI2, NH2CH=NH2I and CH3NH3Cl, and the solvent is a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide; 4-[3-(trifluoromethyl)-3H-bisacrididin-3-yl]benzoic acid and benzamide-5-guanidinovalerate are added to the perovskite precursor solution as additives; The structural formula of 4-[3-(trifluoromethyl)-3H-bisacryl-3-yl]benzoic acid is shown in Formula (I), and the structural formula of benzamide-5-guanidinovalerate is shown in Formula (II):

[0005] (I) (II) S3, a hole transport layer is prepared on the perovskite layer; S4, fabricating a metal electrode on the hole transport layer.

[0006] A further improvement of the present invention is that: Preferably, in S1, the substrate is FTO glass, and the pretreatment involves ultrasonically cleaning the substrate in a cleaning concentrate, deionized water, and ethanol, followed by ultraviolet ozone treatment.

[0007] Preferably, in S1, the material of the electron transport layer is any one of TiO2, ZnO, or SnO2.

[0008] Preferably, in the perovskite precursor solution of S2, the molar ratio of PbI2, NH2CH=NH2I and CH3NH3Cl is 1.2:1.2:0.42.

[0009] Preferably, in the perovskite precursor solution of S2, the concentration of N,N-dimethylformamide is 0.5 mg / mL and the concentration of benzamide-5-guanidinovalerate is 1 mg / mL.

[0010] Preferably, in S2, the spin-coating process of the perovskite precursor solution is as follows: spin-coating at 3000 rpm for 10 seconds, then spin-coating at 5000 rpm for 30 seconds; and ether is dropped onto the surface 20 seconds before the end of the 5000 rpm spin-coating.

[0011] Preferably, in S2, the annealing temperature is 150°C and the annealing time is 15 minutes.

[0012] Preferably, in S3, the hole transport layer is Spiro-OMeTAD, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], or nickel oxide.

[0013] Preferably, in S4, the metal electrode is a gold electrode.

[0014] A bimolecular co-anchored hydrogen bond network-stabilized perovskite solar cell prepared by any of the above preparation methods includes, from bottom to top, a substrate, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode. The perovskite layer has an FAPbI3 structure. 4-[3-(trifluoromethyl)-3H-bisacrididin-3-yl]benzoic acid and benzamide-5-guanidinovalerate exist in the grain boundaries in a manner that anchors A-site ions and B-site ions. The hydrogen bonding between 4-[3-(trifluoromethyl)-3H-bisacrididin-3-yl]benzoic acid and benzamide-5-guanidinovalerate forms a hydrogen bond network, which encapsulates the perovskite grains.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a composite system of benzamide-5-guanidinovalerate (GS) and 4-[3-(trifluoromethyl)-3H-bisacrylidine-3-yl]benzoic acid (HDA) as dual additives to form a hydrogen bond network, achieving high efficiency and high stability in TiO2-based single-junction perovskite solar cells. HDA contains diazacyclopropane functional groups, which can bind to FAI via carbene-mediated bonding under thermal activation conditions. The -C=N and -COOH groups in GS bind to uncoordinated Pb... 2+ This forms stable bonds, effectively suppressing lead ion leakage. The guanidinyl group in GS has strong N-N hydrogen bonds with FAI, and the hydrogen bonds between HAD and the amino group in GS construct a hydrogen bond network structure, with bilateral FAI bonds forming a strong hydrogen bond network. + An anchoring structure effectively suppresses thermal dissociation. This structure not only blocks the migration path of iodine ions but also significantly reduces internal defects in the thin film. Simultaneously, the dual additives construct a hydrogen-bonded network topology at the grain boundaries, mitigating lattice strain through molecular flexibility, thereby stabilizing perovskite grains, regulating crystallization kinetics, and improving crystallinity, ultimately enhancing photothermal and phase stability. The perovskite solar cell optimized through the HAD-GS combination achieves a power conversion efficiency of 26.07%, and exhibits excellent thermal stability (unencapsulated devices retain 95% of their initial efficiency after 1300 hours of accelerated aging at 85°C under nitrogen) and photothermal stability (maintaining 91% efficiency after 1500 hours of continuous illumination aging). This work aims to effectively improve the power conversion efficiency and photothermal stability of perovskite solar cells using a multi-scale molecular interlocking network strategy. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Figure 1In the figure, (a) shows the reaction of additive 1 with FAI under thermal stimulation; (b) shows the electrostatic potential distribution of additive 2; (c) shows the Fourier transform infrared spectra of additive 1, additive 2, and the mixture of additive 1 and 2; (d) shows the density functional theory calculation results of the adsorption structure and adsorption energy of the lead iodide end surface of the mixture of additive 1 and 2 based on multiple binding sites; (e) shows the planar scanning transmission electron microscope image and fast Fourier transform spectrum of the perovskite thin film of the mixture of additive 1 and 2; and (f) shows the transmission electron microscope image.

[0018] Figure 2 In the figure, (a) shows the in-situ PL of the perovskite film in Comparative Example 1 during the annealing process, (b) shows the in-situ PL of the perovskite film in Example 1 during the annealing process, (c) shows the grazing incidence wide-angle X-ray scattering results of the perovskite film in Comparative Example 1, and (d) shows the grazing incidence wide-angle X-ray scattering results of the perovskite film in Example 1.

[0019] Figure 3 In the figure, (a) is a cross-sectional scanning electron microscope image of the perovskite film of Comparative Example 1, Example 1; control group and target film; (b) is a perovskite film of Comparative Example 1 aged at 85°C for 240 hours; (c) is a perovskite film of Example 1 aged at 85°C for 240 hours.

[0020] Figure 4 The image shows a comparison of the photoelectric performance of the perovskite solar cells prepared in Example 1 and Comparative Example 1.

[0021] Among them, (a) shows the photocurrent-voltage ( JV (a) Figure shows the photoelectric performance evaluation results; (b) Figure shows the IT curve of PSCs under continuous illumination; (c) Figure shows the integral obtained from the external quantum efficiency (EQE) measurement. J SC Value; (e) The figure shows the dark state. JV (f) Figure shows the Mott-Schottky test curve; (g) Figure shows the stability side view; (h) Figure shows the long-term operational stability of the packaged device under continuous sunlight equivalent illumination. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings: To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0025] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0026] The high formation energy of FAPbI3 leads to thermodynamic instability, making it prone to spontaneous transformation into the d-phase at room temperature, resulting in the loss of photovoltaic performance. Formamide cations (FA...) + Thermal expulsion increases lattice defect density, while photostimulation induces lattice expansion and promotes the material's transformation from the α phase to the d phase. These technical challenges still constrain the development of perovskite solar cells, and the synergistic regulation of multiple degradation pathways has not yet been achieved. This paper proposes a dual-additive strategy to anchor the A / B sites of passivated FAPbI3 to delay crystallization and thus improve the stability of the α phase. By constructing a multi-scale molecular interlocking network, it is possible to simultaneously achieve: (i) stabilizing the α phase structure, and (ii) inhibiting FA degradation. + Migration, (iii) blocking Pb 2+ (iv) Improve photothermal stability.

[0027] Based on the above innovative ideas, this application proposes a bimolecular co-anchoring strategy for constructing a hydrogen bond network to stabilize perovskite solar cells, specifically including the following steps: S1. Fluorine-doped tin oxide (FTO) glass was selected as the substrate. The FTO was ultrasonically cleaned sequentially in a cleaning concentrate, deionized water, and ethanol, and then treated in a UV ozone cleaner before an electron transport layer was deposited on the substrate.

[0028] Taking the generation of TiO2 electron transport layer by chemical bath deposition as an example, the specific operation of step S1 is as follows: First, fluorine-doped tin oxide (FTO) glass was selected as the substrate. The FTO was ultrasonically cleaned sequentially in a cleaning concentrate, deionized water, and ethanol for 30 minutes each. Then, the cleaned substrate was dried with a nitrogen stream and treated in a UV ozone cleaner for 15 minutes. Then, the substrate was placed in a 0.2M TiCl4 aqueous solution at 70°C for 60 minutes to deposit, and then washed three times alternately with deionized water and ethanol. Finally, the obtained TiO2 electron transport layer was annealed in air at 200°C for 30 minutes.

[0029] S2. PbI2, NH2CH=NH2I (FAI) and CH3NH3Cl (MACl) were mixed in molar amounts of 1.20 mmol, 1.20 mmol and 0.42 mmol, respectively. HDA and GS were then mixed together with these components at a ratio of 0.5:1 mg / mL and dissolved in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (DMF:DMSO volume ratio of 4:1). After stirring and dissolving, a perovskite precursor solution containing additives was obtained.

[0030] The structural formula of the additive material HDA is shown in formula (1), and the structural formula of GS is shown in formula (2): (1) (2) S3. Approximately 80 μL of perovskite precursor was dropped onto a TiO2 / FTO / glass substrate, and a perovskite thin film was formed using a reverse solution method with diethyl ether as the antisolvent.

[0031] The specific operation of step S3 is as follows: Approximately 80 μL of perovskite precursor is dropped onto a TiO2 / FTO / glass substrate, and a perovskite film is formed using a reverse solution method with diethyl ether as the antisolvent. The solution is spin-coated at 3000 rpm for 10 seconds, and then at 5000 rpm for 30 seconds. 20 seconds before the end of the 5000 rpm step, 600 μL of diethyl ether is rapidly dropped onto the surface. Next, the film is annealed at 150°C for 15 minutes.

[0032] Before spin coating in step S3, the sample is treated in UV ozone for 20 minutes to improve wettability.

[0033] S4. A hole transport layer made of Spiro-OMeTAD, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine or nickel oxide is formed on the perovskite absorber layer of the glass substrate.

[0034] The specific steps for generating the Spiro-OMeTAD hole transport layer in step S4 are as follows: A hole transport layer was formed by spin-coating 50 μL of Spiro-OMeTAD solution at 5000 rpm for 30 seconds.

[0035] S5. An electrode, preferably a gold electrode, is deposited on the hole transport layer of a glass substrate by vapor deposition. The gold electrode has a thickness of 80 nm and an effective area of ​​0.09 cm². 2 Ultimately, perovskite solar cells were obtained.

[0036] A second aspect of this invention discloses a perovskite solar cell fabricated by the above method, comprising, from bottom to top, a substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode; wherein the substrate is FTO glass, the electron transport layer is any one of TiO2, ZnO, or SnO2, the hole transport layer is Spiro-OMeTAD, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], or nickel oxide, and the metal electrode is a gold electrode. The perovskite layer has an FAPbI3 structure, and HDA-GS exists in the grain boundaries in a manner that anchors A / B site ions. The hydrogen bonding between additive molecules promotes the formation of a hydrogen bond network structure that encapsulates the grains.

[0037] This invention provides a bimolecular co-anchored hydrogen-bonded network-stabilized perovskite solar cell and its fabrication method. It utilizes HDA-GS to anchor A / B sites and constructs a hydrogen-bonded network topology at grain boundaries. This molecular flexibility alleviates lattice strain, thereby stabilizing the perovskite, regulating crystallization kinetics, releasing stress accumulation, and improving the photothermal stability of the perovskite solar cell.

[0038] To enable those skilled in the art to further understand the technical solution of the present invention, the technical solution of the present invention will be further described in detail below through specific embodiments and comparative examples.

[0039] Example 1 Step 1: First, fluorine-doped tin oxide (FTO) glass was selected as the substrate. The FTO was ultrasonically cleaned sequentially in a cleaning concentrate, deionized water, and ethanol for 30 minutes each. Then, the cleaned substrate was dried with a nitrogen stream and treated in a UV ozone cleaner for 15 minutes. Next, the substrate was placed in a 0.2M TiCl4 aqueous solution at 70°C for 60 minutes for deposition, followed by three alternating cleanings with deionized water and ethanol. Finally, the obtained TiO2 electron transport layer was annealed in air at 200°C for 30 minutes. Step 2: PbI2, NH2CH=NH2I (FAI) and CH3NH3Cl (MACl) are mixed at molar amounts of 1.20 mmol, 1.20 mmol and 0.42 mmol, respectively. HDA and GS are then mixed with these components at a ratio of 0.5:1 mg / mL and dissolved together in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (DMF:DMSO volume ratio of 4:1). After stirring and dissolving, a perovskite precursor solution containing additives is obtained. Step 3: Approximately 80 μL of perovskite precursor was dropped onto a TiO2 / FTO / glass substrate, and a perovskite film was formed using a reverse solution method with diethyl ether as the antisolvent. The solution was spin-coated at 3000 rpm for 10 seconds, followed by spin-coating at 5000 rpm for 30 seconds. Twenty seconds before the end of the 5000 rpm step, 600 μL of diethyl ether was rapidly dropped onto the surface. Next, the film was annealed at 150°C for 15 minutes.

[0040] Step 4: Spin-coat 50 μL of Spiro-OMeTAD solution at 5000 rpm for 30 seconds to form a hole transport layer.

[0041] Step 5: An electrode, preferably a gold electrode, is formed on the hole transport layer of the glass substrate by vapor deposition. The thickness of the gold electrode is 80 nm, and finally a perovskite solar cell is obtained. Comparative Example 1: Perovskite solar cells fabricated without utilizing HDA-GS to form hydrogen bond networks. Except for step 2, all other steps were the same as in Example 1, except that HDA-GS was not added in step 2 of Comparative Example 1, thus preparing a perovskite precursor solution without HDA-GS. Step 2 was as follows: The perovskite precursor solution was prepared by mixing PbI2, NH2CH=NH2I (FAI), and CH3NH3Cl (MACl) in molar amounts of 1.20 mmol, 1.20 mmol, and 0.42 mmol, respectively, and dissolving them in 1 mL of a mixed solvent (DMF and DMSO volume ratio 4:1).

[0042] The products formed in step 2 of the above embodiments and comparative examples are named perovskite thin films. The inventors characterized the performance of the perovskite thin films prepared in Example 1 and Comparative Example 1. The following describes the beneficial effects of the present invention on the preparation of perovskite thin films based on a bimolecular co-anchored hydrogen bond network to stabilize perovskite solar cells and its preparation method from four aspects: molecular design principles, regulation of crystallization kinetics, thin film performance optimization, and device performance improvement.

[0043] (1) Molecular design principles Organic components (FA) +The loss of iodine ions leads to the formation of structural defects, such as porosity and iodine vacancies, accelerates the δ-phase transformation, and promotes the migration pathway of iodine ions in the perovskite lattice. During thermal annealing at 150°C, the diazacyclopropane group in the HDA molecule undergoes an N2 elimination reaction to generate carbene intermediates, which are subsequently inserted into the -NH2 group of the FAI. Figure 1 As shown in Figure (a). Therefore, HDA anchors FA. + The cation inhibits the thermal escape effect, effectively blocking the migration pathway of iodide ions. This mechanism prevents iodine vacancies and fecal oxidase (FA) from forming. + Vacancy formation. Furthermore, these defect sites can trigger the formation of undercoordinated lead ions (i.e., free Pb). 2+ It is generated and eventually converted into metallic lead (Pb) through a redox reaction. 0 To construct a synergistic passivation system, this invention also introduces GS molecules. A larger molecular dipole moment enhances the interaction with the ligands. GS benefits from its larger dipole moment (μ=4.07 Debye vs HDA μ=1.72 Debye). Figure 1 As shown in Figures (b) and (c), enhanced electrostatic interactions occur between Pb and uncoordinated Pb in the perovskite film. 2+ Metal ions form stable bonds. This mechanism effectively passivates deep-level defects and minimizes carrier trapping. Notably, when these two additives are mixed, they exhibit a synergistic complementary effect through hydrogen bonding. Fourier transform infrared spectroscopy (FTIR) analysis reveals shifts in both the -NH and -COOH groups. Figure 1 As shown in Figure (d), the hydrogen bonding between the two components forms a synergistic passivation network at sites A and B.

[0044] Density functional theory (DFT) calculations confirmed that HDA-GS molecules form intermolecular bonds through carboxylic acid hydrogen bonds. These hydrogen bonds chelate Pb at the -C=N, -NH, and -C=O sites. Figure 1 As shown in Figure (e), exothermic processes are achieved in the perovskite structure. E abs = -3.0355 eV) and a stable adsorption process. These phenomena indicate that the hydrogen bonding interaction between -NH and -COOH, as well as the hydrogen bond pairs formed between -COOH molecules, jointly drive the assembly process of the two molecules. This double hydrogen bond network promotes the formation of the three-dimensional molecular interlocking structure of HAD and GS. Transmission electron microscopy (TEM) analysis shows that the additive promotes the formation of a polymer-like non-perovskite phase at the grain boundaries. Figure 1As shown in Figure (f), this morphological evolution, combined with spectroscopic evidence of hydrogen bonding, indicates the formation of a dynamic hydrogen-bonded cross-linking network at the perovskite grain boundaries, thereby stabilizing the perovskite grain structure.

[0045] (2) Regulation of crystallization kinetics To explore the effect of HDA-GS on crystallization, the following characterization was performed. In-situ photoluminescence (PL) analysis was used to characterize that, compared to Comparative Example 1, the overall photoluminescence signal of HDA-GS appeared later and lasted longer during the annealing process. Figure 2 As shown in Figures (a) and (b), the HDA-GS synergistic passivation requires both spatial matching and electronic coupling between ligands, thus increasing the overall reaction energy barrier. Therefore, a longer time is needed to achieve effective passivation. The longer duration of the photoluminescence signal is due to the HDA diazacyclopropane group anchoring and passivating the FAI, while the guanidinyl and carboxylic acid groups in GS interact with Pb. 2+ After effective passivation is achieved through coordination, the crystallization process is delayed, which in turn promotes stable grain growth and effectively reduces defect formation. (See also...) Figure 2 Figures (c) and (d) in the figure illustrate the effect of HDA-GS on the wet film before annealing, characterized using grazing incidence wide-angle X-ray scattering (GIWAXS). The interplanar spacing d is 2π / q, and the effect is achieved at q = 1.00 Å. -1 At d = 6.3 Å, corresponding to the (001) crystal plane of the α phase. Comparative Example 1 shows a large amount of δ phase in the wet film (q = 0.83 Å). -1 It also contains many impurity peaks in the PbI2 phase (q=0.9Å). -1 The wet film of Example 1 containing HDA-GS significantly reduced the formation of the δ phase and PbI2 phase, indicating that the addition of HDA-GS promoted the formation of the α phase and generated a more stable perovskite film.

[0046] Based on the above theoretical analysis, HDA-GS regulates crystallization kinetics by delaying crystallization and inhibiting the formation of impurity phases, thereby reducing the formation of film defects and improving the stability of perovskite films.

[0047] (3) Thin film performance optimization To verify the effect of HDA-GS as an additive on improving the crystallinity and stability of perovskite by forming a hydrogen bond network and regulating crystallization kinetics, cross-sectional scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to analyze the films. Cross-sectional SEM morphology analysis showed that the films in Comparative Example 1 contained a large number of voids and defects. Figure 3As shown in Figure (a). In contrast, the HDA-GS dual passivation treatment of the film in Example 1 effectively improved the carrier transport efficiency to the electrode by promoting vertically oriented grain growth and maintaining structural integrity. It is the synergistic passivation mechanism of the HDA-GS combination that significantly enhances the photothermal stability of the material. The long-term thermal stability of the material was evaluated by continuously monitoring X-ray diffraction data under thermal aging conditions at 85°C for 200 hours. Experiments showed that the perovskite film in Comparative Example 1 almost completely decomposed into the PbI2 phase after 96 hours. Figure 3 As shown in Figure (b), the film of Example 1 maintained its structural integrity after 240 hours, with only trace amounts of PbI2 phase appearing. Figure 3 As shown in Figure (c), the above analysis demonstrates that the HDA-GS combination effectively improves the thermal stability of the film by suppressing the generation of internal defects through hydrogen bonding network and crystallization kinetics regulation.

[0048] (4) Improved device performance Finally, TiO2-based single-junction ni-pPSCs were fabricated using an FTO / TiO2 / FAPbI3 / Spiro-OMeTAD / Au structure, and their photovoltaic performance was evaluated. The photocurrent-voltage ratio of the device was optimized. JV (The curve is as follows) Figure 4 As shown in Figure (a), detailed photovoltaic parameters are shown in Table 1. Comparative Example 1 has a PCE of 24.24%, an open-circuit voltage of 1.16 V, and a fill factor of 80.97%. Example 1 has an improved PCE of 26.07%, an open-circuit voltage of 1.19 V, and a fill factor of 84.11%. The photovoltaic performance of 50 independent devices was independently evaluated, as shown in... Figure 4 As shown in Figure (b), the average PCE increased significantly. Figure 4 Figure (c) shows the IT curves of PSCs under continuous illumination at the maximum power point; the change after 600 seconds is negligible, indicating good stability. The integral obtained from external quantum efficiency (EQE) measurements... J SC value( Figure 4 (d diagram in the middle) and JV Measured current density results ( Figure 4 The results (Figure a) show a high degree of agreement. This indicates that HDA-GS, as a perovskite layer additive, exhibits excellent stability and reproducibility in nip-structured perovskite solar cell materials. Dark state JV Curve test Figure 4 Figure (e) shows that the device of Example 1 significantly improved the perovskite crystal quality and effectively reduced leakage current. The built-in voltage of the HDA-GS modified device was measured using a Mott-Schottky experiment. V biThe value reached 1.18 V, significantly higher than the 1.12 V of the control group. Figure 4 Figure (f) shows this numerical improvement. This improvement confirms the optimization of carrier separation and transport paths, thus contributing to achieving higher efficiency. V OC To evaluate device stability, unpackaged perovskite devices were continuously heated at 85°C under N2 conditions. Figure 4 In Figure (g), the device of Example 1 maintained 95% of its initial efficiency after 1300 hours, while Comparative Example 1 only maintained 65%. Furthermore, the long-term operational stability of the packaged devices was evaluated using maximum power point tracking (MPP) under continuous sunlight equivalent illumination. Notably, the device of Example 1 maintained a power conversion efficiency (PCE) of 91% after 1500 hours of MPP tracking, significantly higher than the 42% of Comparative Example 1. Figure 4 Figure (h) shows the results of these stability tests, which confirm that the HDA-GS modified Example 1 device exhibits excellent long-term operational stability under photothermal conditions.

[0049] Table 1. Performance test results of solar cells prepared in Example 1 and Comparative Example 1

[0050] The above research results fully demonstrate that the perovskite solar cell based on bimolecular co-anchored hydrogen bond network and its preparation method proposed in this invention can utilize intermolecular interaction forces to form a hydrogen bond network during the perovskite cell preparation process, thereby changing the crystallization kinetics to delay perovskite crystallization and improve the quality of the perovskite thin film.

[0051] In summary, the present invention proposes a bimolecular co-anchored hydrogen bond network-stabilized perovskite solar cell and its fabrication method, which not only improves the device efficiency of perovskite solar cells but also enhances their stability.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network, characterized in that, Includes the following steps: S1, Pre-treated substrate, electron transport layer is prepared on the substrate; S2, a perovskite precursor solution is spin-coated onto the electron transport layer, with an antisolvent added dropwise during the spin-coating process, and a perovskite layer is formed after annealing; the solutes of the perovskite precursor solution are PbI2, NH2CH=NH2I and CH3NH3Cl, and the solvent is a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide; 4-[3-(trifluoromethyl)-3H-bisacrididin-3-yl]benzoic acid and benzamide-5-guanidinovalerate are added to the perovskite precursor solution as additives; The structural formula of 4-[3-(trifluoromethyl)-3H-bisacryl-3-yl]benzoic acid is shown in Formula (I), and the structural formula of benzamide-5-guanidinovalerate is shown in Formula (II): (I) (II) S3, a hole transport layer is prepared on the perovskite layer; S4, fabricating a metal electrode on the hole transport layer.

2. The method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In S1, the substrate is FTO glass, and the pretreatment involves ultrasonically cleaning the substrate in a cleaning concentrate, deionized water, and ethanol, followed by ultraviolet ozone treatment.

3. The perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In S1, the material of the electron transport layer is any one of TiO2, ZnO or SnO2.

4. The method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In the perovskite precursor solution of S2, the molar ratio of PbI2, NH2CH=NH2I and CH3NH3Cl is 1.2:1.2:0.

42.

5. The method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In the perovskite precursor solution of S2, the concentration of N,N-dimethylformamide is 0.5 mg / mL and the concentration of benzamide-5-guanidinovalerate is 1 mg / mL.

6. The perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In S2, the spin-coating process of the perovskite precursor solution is as follows: spin-coat at 3000 rpm for 10 seconds, then spin-coat at 5000 rpm for 30 seconds; ether is dropped onto the surface 20 seconds before the end of 5000 rpm.

7. The method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In S2, the annealing temperature is 150°C and the annealing time is 15 minutes.

8. The method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In S3, the hole transport layer is Spiro-OMeTAD, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], or nickel oxide.

9. The method for fabricating a perovskite solar cell based on a bimolecularly co-anchored hydrogen bond network according to claim 1, characterized in that, In S4, the metal electrode is a gold electrode.

10. A bimolecularly co-anchored hydrogen bond network-stabilized perovskite solar cell prepared by any one of claims 1-9, characterized in that, It includes, from bottom to top, a substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode; The perovskite layer has an FAPbI3 structure. 4-[3-(trifluoromethyl)-3H-bisacrididin-3-yl]benzoic acid and benzamide-5-guanidinovalerate exist in the grain boundaries in a manner that anchors A-site ions and B-site ions. The hydrogen bonding between 4-[3-(trifluoromethyl)-3H-bisacrididin-3-yl]benzoic acid and benzamide-5-guanidinovalerate forms a hydrogen bond network, which encapsulates the perovskite grains.

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