Low-dimensional structure in-situ passivation perovskite solar cell and preparation method thereof

Abstract

The invention discloses a low-dimensional structure in-situ passivation perovskite solar cell and a preparation method thereof, and the perovskite solar cell comprises a conductive substrate, a hole transport layer, a molecular modified perovskite light absorption layer, an electron transport layer, an electron blocking layer, and a back electrode layer. The bulk phase additive and the interface modifier are used for modifying the perovskite light absorption layer, the bulk phase additive is added into the perovskite light absorption layer, and / or the interface modifier is coated on the upper interface of the perovskite light absorption layer; each of the bulk phase additive and the interface modifier contains pyridazine hydrochloride; according to the invention, the pyridazine hydrochloride is utilized to improve perovskite crystallization, passivate perovskite defects and reduce non-radiative recombination on the surface of perovskite through bulk phase addition and interface modification, the prepared perovskite solar cell has more excellent surface appearance and crystallinity, and the photoelectric conversion efficiency and working condition stability of a device are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a low-dimensional in-situ passivated perovskite solar cell and its preparation method. Background Technology

[0002] Organic-inorganic hybrid perovskite solar cells have seen rapid development in recent years due to their excellent photoelectric properties, with the highest certified efficiency reaching 27%. Despite these advantages, the crystallization rate of perovskite thin films prepared by solution methods is difficult to control. This leads to uneven grain size and the accumulation of numerous defects at grain boundaries and surfaces, resulting in ion migration and easy reaction with oxygen and moisture in the air, which damages the crystal structure.

[0003] Additive strategies and interface engineering work synergistically to precisely control the crystallization and passivation defects of perovskites. Additive strategies involve doping various small organic molecules into perovskite films to regulate the crystallization process and passivate perovskite defects. Interface engineering strategies, on the other hand, optimize the interfacial energy level arrangement and reduce nonradiative recombination losses by introducing a functional interlayer between the perovskite film and the charge transport layer. Common molecules include functionalized functional groups such as carboxyl groups, sulfonic acid groups, amines, and halides. Among these, amine groups can induce residual lead iodide to transform into a two-dimensional perovskite structure to passivate three-dimensional perovskite films. The low-dimensional phase can effectively passivate surface defects in three-dimensional perovskites and suppress nonradiative recombination. More importantly, the band structure formed by the low-dimensional phase and the three-dimensional layer helps promote interfacial charge extraction and reduce energy loss, thereby simultaneously improving the open-circuit voltage and fill factor of the cell. This provides a key strategy for achieving high-efficiency and stable perovskite solar cells.

[0004] However, in existing strategies, small molecules themselves have poor stability and cannot meet the requirements for long-term stable operation of devices. Traditional two-dimensional perovskite structures can form mixed-dimensional perovskites with three-dimensional perovskites under photothermal stimulation, reducing the efficiency and stability of devices. Therefore, there is an urgent need to develop a reliable technology for stable low-dimensional in-situ passivation of perovskite thin films. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention, based on traditional spin-coating techniques, utilizes pyridazine hydrochlorides (including 3-hydrazine hydrochloride, 3-aminopyridazine hydrochloride, and 6-methoxypyridazine-3-ammonium hydrochloride) to optimize the performance of perovskite solar cell devices. These hydrochlorides are used for bulk addition and interface modification to improve the crystallization of perovskite solar cells and enhance device efficiency.

[0006] The present invention provides a low-dimensional structure in-situ passivated perovskite solar cell, the perovskite solar cell comprising: a conductive substrate, a hole transport layer, a molecularly modified perovskite light-absorbing layer, an electron transport layer, an electron blocking layer, a back electrode layer, and bulk additives and interface modifiers for modifying the perovskite light-absorbing layer. The perovskite light-absorbing layer contains a bulk additive, and / or the perovskite light-absorbing layer is coated with an interface modifier. Both the bulk additive and the interface modifier contain pyridazine hydrochloride.

[0007] Preferably, the pyridazine hydrochloride is one or more of 3-hydrazinopyridazine hydrochloride, 3-aminopyridazine hydrochloride, and 6-methoxypyridazine-3-ammonium hydrochloride.

[0008] As a further explanation of the present invention, the molecular additives used in the present invention may also be 4-aminomethylpyridazine hydrochloride, 3,6-diaminopyridazine hydrochloride, or 2-aminomethylpyrazine hydrochloride.

[0009] Preferably, the bulk additive further comprises a first organic solvent, which is one or more of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0010] As a further explanation of the present invention, in the process of preparing the bulk additive, pyridazine hydrochloride is dissolved in a first organic solvent. When the first organic solvent is a mixture of N,N-dimethylformamide and dimethyl sulfoxide, the volume ratio of the mixed solvent is 5:1 to 1:1, and a bulk additive solution with a concentration of 0.01 to 5 mg / mL is obtained.

[0011] Preferably, the interface modifier further comprises a second organic solvent, which is one or more of acetonitrile, isopropanol, chlorobenzene, dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone.

[0012] As a further illustration of the present invention, in the process of preparing the interface modifier, pyridazine hydrochloride is dissolved in a second organic solvent, wherein the concentration of the second organic solvent in the interface modifier is 0.1 mg / mL to 5 mg / mL, and when there are multiple second organic solvents, the volume ratio of the mixed solvents is 5:1 to 1:1.

[0013] A second aspect of this invention provides a method for fabricating a low-dimensional in-situ passivated perovskite solar cell, the method comprising the following steps: S1. Pre-treat the conductive substrate; perform ultraviolet-ozone treatment or oxygen plasma treatment on the conductive substrate. S2. Spin-coat the hole transport layer solution onto the pretreated conductive substrate and anneal it to obtain the hole transport layer; wherein, the spin-coating speed of the hole transport layer solution on the pretreated conductive substrate is 2000~4000 rpm / min, the spin-coating time is 20~50 s, the annealing temperature is 100~150℃, and the time is 5~20 min. S3. Prepare a perovskite light-absorbing layer with molecular modification on the hole transport layer to obtain a perovskite light-absorbing layer-upper interface modification layer, and / or a perovskite light-absorbing layer with added bulk additives. S4. An electron transport layer and an electron blocking layer are sequentially thermally deposited on the molecularly modified perovskite light-absorbing layer, and a metal electrode is thermally deposited on top of the electron blocking layer to obtain the low-dimensional structure in-situ passivated perovskite solar cell.

[0014] Preferably, in step S3, during the preparation of the perovskite light-absorbing layer with added bulk additive, the perovskite precursor solution is mixed with the bulk additive, then spin-coated onto the hole transport layer, and subjected to annealing heat treatment to obtain the perovskite light-absorbing layer with added bulk additive.

[0015] Preferably, in step S3, during the preparation of the perovskite light-absorbing layer-upper interface modification layer, the perovskite precursor solution is spin-coated onto the hole transport layer, annealed and heat-treated to form the perovskite light-absorbing layer, and then the interface modifier is spin-coated onto the perovskite light-absorbing layer, annealed and heat-treated to obtain the perovskite light-absorbing layer-upper interface modification layer.

[0016] Preferably, in step S3, during the preparation of the perovskite light-absorbing layer-upper interface modification layer and the addition of the bulk additive to the perovskite light-absorbing layer, the perovskite precursor solution is mixed with the bulk additive, spin-coated onto the hole transport layer, and subjected to annealing heat treatment to obtain the perovskite light-absorbing layer with added bulk additive. Then, the interface modifier is spin-coated onto the perovskite light-absorbing layer with added bulk additive, and subjected to annealing heat treatment to obtain the perovskite light-absorbing layer-upper interface modification layer with added bulk additive.

[0017] As a further explanation of the present invention, the spin coating speed of the perovskite precursor solution on the hole transport layer is 3000~6000 rpm / min, the amount of perovskite precursor solution added is 30~100μL, the spin coating time is 20~60 s, the annealing heat treatment temperature is 100~160℃, and the treatment time is 10~40 min.

[0018] Preferably, when the perovskite precursor solution is mixed with the bulk additive, the amount of bulk additive added is 2.5 μL to 15 μL, the concentration of the perovskite precursor solution is 1.2 to 1.8 M, and the concentration of the bulk additive is 0.01 to 5 mg / mL.

[0019] As a further explanation of the present invention, the preparation process of the perovskite precursor solution is as follows: in an anhydrous and oxygen-free nitrogen glove box, the perovskite precursor is dissolved in an organic solvent. The organic solvent for dissolving the perovskite precursor is at least one selected from N,N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone. When multiple solvents are selected, the volume ratio of the mixed solvent is 6:1 to 2:1. The mixture is heated and stirred at 15 to 80°C for 2 to 24 hours.

[0020] Preferably, in step S3, the chemical formula of the perovskite light-absorbing layer is ABX. n A + Selected from FA + (CH(NH2)2) + MA + (CH3NH3) + ), Cs + 、Rb + One or more of the following; B is selected from Pb 2+ Sn 2+ One or more of the following; X is selected from Cl - , Br - I - One or more of them.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The 3-hydrazine hydrochloride bulk phase of the present invention is incorporated into the perovskite precursor solution to regulate the crystallization of perovskite during annealing, thereby improving the film quality, facilitating carrier transport, and enhancing photoelectric conversion efficiency and stability. The hydrazine group in this molecule can interact with defects on the surface of the perovskite film, thereby suppressing nonradiative recombination of carriers. The resulting low-dimensional perovskite structure can stabilize grain boundaries. At the same time, the structure of hydrazine group + pyridazine ring + hydrochloride enables it to passivate both lead and iodine defects simultaneously, and through multidentate coordination, it forms a more stable passivation effect, further improving photoelectric conversion efficiency and stability.

[0022] (2) This invention utilizes 3-aminopyridazine hydrochloride and 6-methoxypyridazine-3-ammonium hydrochloride as interface modifiers applied to the perovskite surface. After annealing, a low-dimensional perovskite structure is formed, which can stabilize the interface and effectively inhibit the decomposition of the perovskite material, thereby significantly improving the stability of the light-absorbing layer. Among them, the methoxy group enhances the electron cloud density of the pyridazine ring through the inductive effect, enhances the ability of the pyridazine nitrogen atom as a hydrogen bond acceptor, makes the intermolecular hydrogen bonds stronger, and the structure more stable. The electronic properties of the formed low-dimensional phase change, which helps to form a more matched energy level structure with the three-dimensional layer, promotes the extraction of interface charge, not only reduces the hysteresis effect of the device, but also improves the working efficiency of the device. In addition, the formed low-dimensional perovskite can passivate defects on the surface of the perovskite film, inhibit the nonradiative recombination of charge carriers, and improve the device performance.

[0023] (3) The pyrazine and pyrazine derivatives of the present invention can be used as modifiers on the upper interface of the perovskite light-absorbing layer, or as bulk additives directly incorporated into the interior of the perovskite light-absorbing layer. The bulk-added molecules regulate grain growth and passivate grain boundary defects during the perovskite crystallization process; the interface-modified molecules form a coordination-type low-dimensional interface layer on the surface and optimize energy level matching. The two work together to achieve comprehensive defect passivation from the bulk phase to the interface. This dual modification strategy from interface passivation to bulk doping can simultaneously suppress non-radiative recombination and optimize the crystallization kinetics of perovskite, thereby significantly improving the efficiency of charge extraction and transport. This synergistic effect ultimately achieves an overall improvement in device performance. In addition, this technical solution has good compatibility with other existing perovskite surface passivation technologies, and the preparation process is stable, showing excellent reproducibility. Attached Figure Description

[0024] Figure 1 This is a structural diagram of a perovskite solar cell with interface modification and bulk addition provided by the present invention.

[0025] Figure 2 The present invention provides molecular structural formulas for 3-hydrazinopyridazine hydrochloride, 3-aminopyridazine hydrochloride, and 6-methoxypyridazine-3-ammonium hydrochloride, wherein (a) is the molecular structural formula for 3-hydrazinopyridazine hydrochloride, (b) is the molecular structural formula for 3-aminopyridazine hydrochloride, and (c) is the molecular structural formula for 6-methoxypyridazine-3-ammonium hydrochloride.

[0026] Figure 3 This is a current-voltage curve of a perovskite solar cell with bulk addition of 3-hydrazine hydrochloride prepared in Example 1 of this invention.

[0027] Figure 4 These are the current-voltage curves and SEM images of the perovskite solar cell with bulk 3-hydrazine hydrochloride added prepared in Example 2 of this invention; wherein, (a) is the current-voltage curve and (b) is the SEM image of the perovskite layer.

[0028] Figure 5 This is a current-voltage curve of a perovskite solar cell with bulk addition of 3-hydrazine hydrochloride prepared in Example 3 of this invention.

[0029] Figure 6 This is the current-voltage curve of the perovskite solar cell with interface modification of 3-aminopyridazine hydrochloride prepared in Example 4 of this invention.

[0030] Figure 7These are the current-voltage curves and SEM images of the perovskite solar cells with interface modification on the 3-aminopyridazine hydrochloride prepared in Example 5 of this invention, wherein (a) is the current-voltage curve and (b) is the SEM image of the perovskite layer.

[0031] Figure 8 This is the current-voltage curve of the perovskite solar cell with interface modification of 3-aminopyridazine hydrochloride prepared in Example 6 of this invention.

[0032] Figure 9 This is the current-voltage curve of the perovskite solar cell with interface modification on the 6-methoxypyridazine-3-ammonium hydrochloride molecule prepared in Example 7 of the present invention.

[0033] Figure 10 These are the current-voltage curves and SEM images of the perovskite solar cells with interface modification on the 6-methoxypyridazine-3-ammonium hydrochloride molecule prepared in Example 8 of this invention, wherein (a) is the current-voltage curve and (b) is the SEM image of the perovskite layer. Figure 11 This is the current-voltage curve of the perovskite solar cell with interface modification on the 6-methoxypyridazine-3-ammonium hydrochloride molecule prepared in Example 9 of this invention. Figure 12 These are the current-voltage curves and SEM images of the perovskite solar cells prepared in Example 10 of this invention, which exhibit synergistic effects of bulk addition of 3-hydrazine hydrochloride and interfacial modification on the molecule of 6-methoxypyridazine-3-ammonium hydrochloride. (a) is the current-voltage curve, and (b) is the SEM image of the perovskite layer. Figure 13 These are the current-voltage curves and SEM images of the perovskite solar cells prepared in Comparative Example 1 of this invention, wherein (a) is the current-voltage curve and (b) is the SEM image. Figure 14 These are X-ray diffraction patterns of the perovskite thin films prepared in Examples 2, 5, 8 and Comparative Example 1 of this invention; Figure 15 This is a single-crystal simulated XRD pattern of PyAPbI3 formed by the reaction of 3-aminopyridazine hydrochloride with PbI2 in Example 6 of this invention; Figure 16 This is a comparison of the stability curves of the perovskite solar cells prepared in Examples 10, 8 and Comparative Example 1 of this invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are also within the scope of protection of this disclosure.

[0035] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the specification and in the relevant art, and shall not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein.

[0036] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] This invention provides a method for preparing a perovskite solar cell, wherein the perovskite solar cell is configured by sequentially stacking a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, a charge buffer layer, and a back electrode layer, and further includes pyridazine hydrochloride (3-hydrazidopyridazine hydrochloride, 3-aminopyridazine hydrochloride, 6-methoxypyridazine-3-ammonium hydrochloride) as a bulk additive and interface modifier.

[0038] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments: Example 1 3-hydrazinopyridazine hydrochloride was incorporated into the perovskite precursor solution to prepare perovskite solar cells. The solvents for the bulk additive solution were N,N-dimethylformamide and dimethyl sulfoxide, with a solution concentration of 0.01 mg / mL.

[0039] S1: Preparation of bulk additive solution: In a nitrogen glove box environment, N,N-dimethylformamide and dimethyl sulfoxide are mixed at a volume ratio of 4:1, and an appropriate amount of 3-hydrazine hydrochloride molecules are dissolved to obtain a bulk additive solution with a concentration of 0.01 mg / mL. S2: Preparation of the bulk additive-perovskite precursor solution: In a nitrogen-filled environment, N,N-dimethylformamide and dimethyl sulfoxide were first mixed in a 4:1 volume ratio. Then, CsI, MAI, FAI, and PbI2 were dissolved in the mixture in a molar ratio of 0.025:0.025:0.95:1. Subsequently, an appropriate amount of the bulk additive solution prepared in S1 was added dropwise to the perovskite precursor solution. The mixture was then stirred at 20°C for 6 h. Finally, after filtration, a 1.5 M perovskite precursor solution (CsI, MAI, FAI, PbI2) was obtained. 0.025 MA 0.025 FA 0.95 PbI3; S3: Preparation of the hole transport layer: ITO conductive glass was placed in a UV cleaner for 20 min, and NiO at a concentration of 10 mg / mL was placed in air. x The suspension was spin-coated at 4000 rpm / min for 30 s, then coated onto a pre-treated substrate and annealed at 120 °C for 10 minutes at room temperature. It was then transferred to a dry nitrogen glove box. A hole transport layer solution was prepared by dissolving 4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid (Me-4PACz) in dimethoxyethanol. 50 μL of the hole transport layer solution was dropped onto the center of an ITO glass substrate, spin-coated for 40 s, and then heat-treated at 110 °C to obtain the hole transport layer substrate. S4: Preparation of bulk-added perovskite light-absorbing layer: 50 μL of bulk-added perovskite precursor solution was dropped onto the center of the hole transport layer substrate and rotated at 4000 rpm / min for 50 s. After annealing at 140℃ for 30 min, a perovskite film was formed and placed in a dry place for cooling.

[0040] S5: Preparation of electron transport layer: Fullerene C60 with a thickness of 30 nm was deposited on top of the perovskite layer using thermal evaporation.

[0041] S6: Preparation of electron blocking layer: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) with a wavelength of 5 nm was deposited above the electron transport layer using thermal evaporation.

[0042] S7: Preparation of metal electrode layer: Using thermal evaporation, 120 nm of silver is deposited on top of the electron blocking layer.

[0043] like Figure 3 As shown, the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 23.55% and an effective area of ​​0.054 cm². 2 .

[0044] Example 2 3-Hydroxypyridazine hydrochloride was incorporated into the perovskite precursor solution to prepare perovskite solar cells. The solvent for the bulk additive solution was N,N-dimethylformamide and dimethyl sulfoxide, with a concentration of 0.1 mg / mL. The remaining steps were the same as in Example 1.

[0045] like Figure 4 As shown in (a), the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 24.2% and an effective area of ​​0.054 cm². 2 .

[0046] Example 3 3-Hydroxypyridazine hydrochloride was incorporated into the perovskite precursor solution to prepare perovskite solar cells. The solvent for the bulk additive solution was N,N-dimethylformamide and dimethyl sulfoxide, with a concentration of 0.5 mg / mL. The remaining steps were the same as in Example 1.

[0047] like Figure 5 As shown, the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 23.34% and an effective area of ​​0.054 cm². 2 .

[0048] Example 4 3-Aminopyridazine hydrochloride was used as an interface modifier to prepare perovskite solar cells. Isopropanol was used as a solvent to dissolve the interface modifier, and the concentration of the prepared interface modifier was 0.1 mg / mL.

[0049] S1: Preparation of interface modifier solution: In a nitrogen glove box environment, 3-aminopyridazine hydrochloride was dissolved in isopropanol as solvent to obtain a bulk additive solution with a concentration of 0.1 mg / mL. S2: Preparation of perovskite precursor solution: In a nitrogen-filled environment, N,N-dimethylformamide and dimethyl sulfoxide were first mixed in a 4:1 volume ratio. Then, CsI, MAI, FAI, and PbI2 were dissolved in the mixture in a molar ratio of 0.025:0.025:0.95:1. The mixture was stirred at 40°C for 6 h. Finally, after filtration, a 1.6 M perovskite precursor solution was obtained. 0.025 MA 0.025 FA 0.95 PbI3; S3: Preparation of the hole transport layer: ITO conductive glass was placed in a UV cleaner for 20 min, and NiO at a concentration of 10 mg / mL was placed in air. xThe suspension was spin-coated at 4000 rpm / min for 30 s, then coated onto a pre-treated substrate and annealed at 120 °C for 10 minutes at room temperature. It was then transferred to a dry nitrogen glove box. A hole transport layer solution was prepared by dissolving 4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid (Me-4PACz) in dimethoxyethanol. 50 μL of the hole transport layer solution was dropped onto the center of an ITO glass substrate, spin-coated for 40 s, and then heat-treated at 110 °C to obtain the hole transport layer substrate. S4: Preparation of perovskite light-absorbing layer: 50 μL of bulk-added perovskite precursor solution was dropped onto the center of the hole transport layer substrate and rotated at 4000 rpm / min for 50s. After annealing at 140℃ for 30min, a perovskite film was formed and placed in a dry place for cooling.

[0050] S5: Preparation of the upper interface modification layer: Take 50 μL of the interface modifier solution prepared in S1 and drop it onto the perovskite light-absorbing layer. Rotate at a speed of 2000-6000 rpm / min for 30 s, and then heat treat at 100℃ for 10 min to obtain the upper interface modification layer. S6: Preparation of electron transport layer: Fullerene C60 with a thickness of 30 nm was deposited on top of the perovskite layer using thermal evaporation.

[0051] S7: Preparation of electron blocking layer: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) with a wavelength of 5 nm was deposited above the electron transport layer using a thermal evaporation method.

[0052] S8: Preparation of metal electrode layer: 120 nm of silver is deposited on top of the electron blocking layer using thermal evaporation.

[0053] like Figure 6 As shown, the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 23.81% and an effective area of ​​0.054 cm². 2 .

[0054] Example 5 3-Aminopyridazine hydrochloride was used as an interface modifier to prepare perovskite solar cells. Isopropanol was used as a solvent for dissolution, and the concentration of the prepared interface modifier was 1 mg / mL.

[0055] The remaining steps are the same as in Example 4.

[0056] like Figure 7 As shown in (a), the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 24.23% and an effective area of ​​0.054 cm².2 .

[0057] Example 6 3-Aminopyridazine hydrochloride was used as an interface modifier to prepare perovskite solar cells. Isopropanol was used as a solvent to dissolve the interface modifier, and the concentration of the prepared interface modifier was 2 mg / mL.

[0058] The remaining steps are the same as in Example 4.

[0059] like Figure 8 As shown, the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 23.73% and an effective area of ​​0.054 cm². 2 .

[0060] Example 7 6-Methoxypyridazine-3-ammonium hydrochloride was used as an interface modifier to prepare perovskite solar cells. Isopropanol was used as a solvent for dissolution, and the concentration of the prepared interface modifier was 0.1 mg / mL.

[0061] The remaining steps are the same as in Example 4.

[0062] like Figure 9 As shown, the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 23.84% and an effective area of ​​0.054 cm². 2 .

[0063] Example 8 6-Methoxypyridazine-3-ammonium hydrochloride was used as an interface modifier to prepare perovskite solar cells. Isopropanol was used as a solvent for dissolution, and the concentration of the prepared interface modifier was 1 mg / mL.

[0064] The remaining steps are the same as in Example 4.

[0065] like Figure 10 As shown in (a), the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 24.49% and an effective area of ​​0.054 cm². 2 .

[0066] Example 9 6-Methoxypyridazine-3-ammonium hydrochloride was used as an interface modifier for the preparation of perovskite solar cells. Isopropanol was used as a solvent for dissolution, and the concentration of the prepared interface modifier was 2 mg / mL.

[0067] The remaining steps are the same as in Example 4.

[0068] like Figure 11As shown, the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 24.16% and an effective area of ​​0.054 cm². 2 .

[0069] Example 10 3-Hydroxypyridazine hydrochloride was incorporated into the perovskite precursor solution to prepare perovskite solar cells. The solvents for the bulk additive solution were N,N-dimethylformamide and dimethyl sulfoxide, with a solution concentration of 0.1 mg / mL.

[0070] 6-Methoxypyridazine-3-ammonium hydrochloride was used as an interface modifier to prepare perovskite solar cells. Isopropanol was used as a solvent for dissolution, and the concentration of the prepared interface modifier was 1 mg / mL.

[0071] S1: Preparation of bulk additive solution: In a nitrogen glove box environment, N,N-dimethylformamide and dimethyl sulfoxide are mixed at a volume ratio of 4:1, and an appropriate amount of 3-hydrazine hydrochloride molecules are dissolved to obtain a bulk additive solution with a concentration of 0.1 mg / mL. S2: Preparation of interface modifier solution: In a nitrogen glove box environment, 6-methoxypyridazine-3-ammonium hydrochloride was dissolved in isopropanol as solvent to obtain a bulk additive solution with a concentration of 1 mg / mL. S3: Preparation of bulk additive-perovskite precursor solution: In a nitrogen-filled environment, N,N-dimethylformamide and dimethyl sulfoxide were first mixed in a 4:1 volume ratio. Then, CsI, MAI, FAI, and PbI2 were dissolved in the mixture in a molar ratio of 0.025:0.025:0.95:1. Subsequently, an appropriate amount of the bulk additive solution prepared in S1 was added dropwise to the perovskite precursor solution. The mixture was then stirred at 20°C for 6 h. Finally, after filtration, a 1.5 M perovskite precursor solution (CsI, MAI, FAI, PbI2) was obtained. 0.025 MA 0.025 FA 0.95 PbI3; S4: Preparation of the hole transport layer: ITO conductive glass was placed in a UV cleaner for 20 min, and NiO at a concentration of 10 mg / mL was placed in air. xThe suspension was spin-coated at 4000 rpm for 30 s, then coated onto a pre-treated substrate and annealed at 120°C for 10 minutes at room temperature. It was then transferred to a dry nitrogen glove box. A hole transport layer solution was prepared by dissolving 4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid (Me-4PACz) in dimethoxyethanol. 50 μL of the hole transport layer solution was dropped onto the center of an ITO glass substrate, spin-coated for 40 s, and then heat-treated at 110°C to obtain the hole transport layer substrate. S5: Preparation of perovskite light-absorbing layer: 50 μL of bulk-added perovskite precursor solution was dropped onto the center of the hole transport layer substrate and rotated at 4000 rpm / min for 50s. After annealing at 140℃ for 30min, a perovskite film was formed and placed in a dry place for cooling.

[0072] S6: Preparation of the upper interface modification layer: Take 50 μL of the interface modifier solution prepared in S2 and drop it onto the perovskite light-absorbing layer. Rotate at a speed of 2000-4000 rpm / min for 30 s, and then heat treat at 100℃ for 10 min to obtain the upper interface modification layer. S7: Preparation of electron transport layer: Fullerene C60 with a thickness of 30 nm was deposited on top of the perovskite layer using thermal evaporation.

[0073] S8: Preparation of electron blocking layer: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) with a wavelength of 5 nm was deposited above the electron transport layer using a thermal evaporation method.

[0074] S9: Preparation of metal electrode layer: 120 nm of silver is deposited on top of the electron blocking layer using thermal evaporation.

[0075] like Figure 12 As shown in (a), the perovskite solar cell prepared in this embodiment has a photoelectric conversion efficiency of 25.04% and an effective area of ​​0.054 cm². 2 .

[0076] Comparative Example 1 Perovskite solar cells were prepared without the addition of 3-hydrazinopyridazine hydrochloride, 3-aminopyridazine hydrochloride, or 6-methoxypyridazine-3-ammonium hydrochloride as bulk additives and interface modifiers.

[0077] S1: Preparation of perovskite precursor solution: In a nitrogen-filled environment, N,N-dimethylformamide and dimethyl sulfoxide were first mixed in a 4:1 volume ratio. Then, CsI, MAI, FAI, and PbI2 were dissolved in the mixture in a molar ratio of 0.025:0.025:0.95:1. The mixture was stirred at 40°C for 6 h. Finally, after filtration, a 1.6 M perovskite precursor solution (CsI, MAI, FAI, and PbI2) was obtained. 0.025 MA 0.025 FA 0.95 PbI3; S2: Preparation of the hole transport layer: ITO conductive glass was placed in a UV cleaner for 20 min, and NiO at a concentration of 10 mg / mL was placed in air. x The suspension was spin-coated at 4000 rpm for 30 s, then coated onto a pre-treated substrate and annealed at 120°C for 10 minutes at room temperature. It was then transferred to a dry nitrogen glove box. A hole transport layer solution was prepared by dissolving 4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid (Me-4PACz) in dimethoxyethanol. 50 μL of the hole transport layer solution was dropped onto the center of an ITO glass substrate, spin-coated for 40 s, and then heat-treated at 110°C to obtain the hole transport layer substrate. S3: Preparation of perovskite light-absorbing layer: 50 μL of bulk-added perovskite precursor solution was dropped onto the center of the hole transport layer substrate and rotated at 4000 rpm / min for 50s. After annealing at 140℃ for 30min, a perovskite film was formed and placed in a dry place for cooling.

[0078] S4: Preparation of electron transport layer: Fullerene C60 with a thickness of 30 nm was deposited on top of the perovskite layer using thermal evaporation.

[0079] S5: Preparation of electron blocking layer: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) with a wavelength of 5 nm was deposited above the electron transport layer using a thermal evaporation method.

[0080] S6: Preparation of metal electrode layer: Using thermal evaporation, 120 nm of silver is deposited on top of the electron blocking layer.

[0081] like Figure 13 As shown, the perovskite solar cell prepared in this comparative example has a photoelectric conversion efficiency of 21.46% and an effective area of ​​0.054 cm². 2 .

[0082] Comparative Example 1 and Figure 3-12Comparing the data, it can be found that the open-circuit voltage and fill factor of the device are improved after molecular modification. This indicates that the addition of 3-hydrazidopyridazine hydrochloride in the bulk phase and the interface modification of 3-aminopyridazine hydrochloride and 6-methoxypyridazine-3-ammonium hydrochloride can improve the crystallization of perovskite thin films, passivate surface defects, and thus effectively improve the photoelectric conversion efficiency of perovskite solar cells.

[0083] like Figure 14 As shown, compared with perovskite devices modified with bulk 3-hydrazidopyrazine hydrochloride, interface modifications with 3-aminopyrazine hydrochloride, and 6-methoxypyrazine-3-ammonium hydrochloride, Comparative Example 1 exhibits lower characteristic peak intensities and no low-dimensional phase diffraction peaks. In contrast, the perovskite surface modified with larger pyrazine ring molecules undergoes structural reconstruction, resulting in the in-situ growth of a low-dimensional capping layer on the three-dimensional layer. The aromatic pyrazine rings of the molecules, through π-π stacking interactions, ultimately tend to self-assemble into a stable two-dimensional layered structure.

[0084] like Figure 15 As shown, the single-crystal XRD of PyAPbI3 formed by the reaction of 3-aminopyridazine hydrochloride with PbI2 further illustrates the structure of the low-dimensional phase and confirms the formation of the low-dimensional phase.

[0085] like Figure 16 As shown, the perovskite device with the synergistic effect of bulk addition of 3-hydrazidopyridazine hydrochloride and interface modification of 6-methoxypyridazine-3-ammonium hydrochloride maintained an efficiency of 90% of its initial efficiency after heating at 85℃ in a nitrogen atmosphere for 800 h, which is better than the 84% efficiency of the device treated with only 6-methoxypyridazine-3-ammonium hydrochloride interface modification. The stability of Comparative Example 1 was worse compared to both. Figure 4 (b) Figure 7 (b) Figure 10 (b) Figure 12 (b) Figure 13 (b) shows a comparison of microstructure images. Compared with the perovskite film with bulk doping, the perovskite film modified with pyridazine hydrochloride molecules has improved quality, larger grains, and a smoother film surface. This indicates that 3-hydrazinopyridazine hydrochloride, 3-aminopyridazine hydrochloride, and 6-methoxypyridazine-3-ammonium hydrochloride molecules can optimize perovskite crystallization and passivation defects, thereby improving film quality.

[0086] The above results indicate that the pyridazine hydrochloride (3-hydrazinopyridazine hydrochloride, 3-aminopyridazine hydrochloride, 6-methoxypyridazine-3-ammonium hydrochloride) molecules of the present invention can effectively improve the device performance of perovskite solar cells and have high commercial application potential.

Claims

1. A low-dimensional in-situ passivated perovskite solar cell, characterized in that, The perovskite solar cell includes: a conductive substrate, a hole transport layer, a molecularly modified perovskite light-absorbing layer, an electron transport layer, an electron blocking layer, a back electrode layer, and bulk additives and interface modifiers for modifying the perovskite light-absorbing layer. The perovskite light-absorbing layer contains a bulk additive, and / or the perovskite light-absorbing layer is coated with an interface modifier. Both the bulk additive and the interface modifier contain pyridazine hydrochloride.

2. The low-dimensional in-situ passivated perovskite solar cell according to claim 1, characterized in that, The pyridazine hydrochloride is one or more of 3-hydrazinopyridazine hydrochloride, 3-aminopyridazine hydrochloride, and 6-methoxypyridazine-3-ammonium hydrochloride.

3. The low-dimensional in-situ passivated perovskite solar cell according to claim 1, characterized in that, The bulk additive further comprises a first organic solvent, which is one or more of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

4. The low-dimensional in-situ passivated perovskite solar cell according to claim 1, characterized in that, The interface modifier further comprises a second organic solvent, which is one or more of acetonitrile, isopropanol, chlorobenzene, dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone.

5. The method for fabricating a low-dimensional in-situ passivated perovskite solar cell according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: S1. Pre-treat the conductive substrate; S2. Spin-coat the hole transport layer solution onto the pretreated conductive substrate and anneal it to obtain the hole transport layer. S3. Prepare a perovskite light-absorbing layer with molecular modification on the hole transport layer to obtain a perovskite light-absorbing layer-upper interface modification layer, and / or a perovskite light-absorbing layer with added bulk additives. S4. An electron transport layer and an electron blocking layer are sequentially thermally deposited on the molecularly modified perovskite light-absorbing layer, and a metal electrode is thermally deposited on top of the electron blocking layer to obtain the low-dimensional structure in-situ passivated perovskite solar cell.

6. The method for fabricating a low-dimensional in-situ passivated perovskite solar cell according to claim 5, characterized in that, In step S3, during the preparation of the perovskite light-absorbing layer with added bulk additive, the perovskite precursor solution is mixed with the bulk additive, then spin-coated onto the hole transport layer, and subjected to annealing heat treatment to obtain the perovskite light-absorbing layer with added bulk additive.

7. The method for fabricating a low-dimensional in-situ passivated perovskite solar cell according to claim 5, characterized in that, In step S3, during the preparation of the perovskite light-absorbing layer-upper interface modification layer, the perovskite precursor solution is spin-coated onto the hole transport layer, annealed and heat-treated to form the perovskite light-absorbing layer, and then the interface modifier is spin-coated onto the perovskite light-absorbing layer, annealed and heat-treated to obtain the perovskite light-absorbing layer-upper interface modification layer.

8. The method for fabricating a low-dimensional in-situ passivated perovskite solar cell according to claim 5, characterized in that, In step S3, during the preparation of the perovskite light-absorbing layer-upper interface modification layer and the addition of bulk additives to the perovskite light-absorbing layer, the perovskite precursor solution is mixed with the bulk additives, spin-coated onto the hole transport layer, and then subjected to annealing heat treatment to obtain the perovskite light-absorbing layer with added bulk additives. Then, the interface modifier is spin-coated onto the perovskite light-absorbing layer with added bulk additives, and subjected to annealing heat treatment to obtain the perovskite light-absorbing layer-upper interface modification layer with added bulk additives.

9. A method for fabricating a low-dimensional in-situ passivated perovskite solar cell according to claim 6 or 8, characterized in that, When the perovskite precursor solution is mixed with the bulk additive, the amount of the bulk additive added is 2.5 μL to 15 μL, the concentration of the perovskite precursor solution is 1.2 to 1.8 M, and the concentration of the bulk additive is 0.01 to 5 mg / mL.

10. The method for fabricating a low-dimensional in-situ passivated perovskite solar cell according to claim 5, characterized in that, In step S3, the general chemical formula of the perovskite light-absorbing layer is ABX. n A + Selected from FA + (CH(NH2)2) + MA + (CH3NH3) + ), Cs + 、Rb + One or more of the following; B is selected from Pb 2+ Sn 2+ One or more of the following; X is selected from Cl - , Br - I - One or more of them.

Images