Perovskite solar cell with cysteine-silver cluster target implanted perovskite active layer

Abstract

The invention belongs to the technical field of solar cells, and particularly relates to a perovskite solar cell with cysteine-silver clusters implanted into a perovskite active layer in a targeted mode, a cysteine-silver cluster colloidal solution is prepared by adopting a liquid-phase pulse laser irradiation technology, the cysteine-silver clusters serve as an additive and are implanted into the perovskite solution, and the perovskite active layer is prepared. And sequentially spin-coating a hole transport layer, a perovskite layer and an electron transport layer, and finally evaporating a metal electrode to prepare the perovskite solar cell with the cysteine-silver cluster target implanted perovskite active layer. The cysteine-silver cluster is implanted into the perovskite solution, and the smaller critical dimension of the cysteine-silver cluster can be used as a nucleation site, so that the growth of perovskite crystals is regulated and controlled, the defects of the perovskite thin film are passivated, the residual stress of the thin film is released, the formation of gradient energy levels of the perovskite layer and the electron transport layer is promoted, and the extraction and transmission of electrons are improved; the perovskite solar cell with higher efficiency is obtained, the implantation mode is convenient, and the preparation process is simple.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cell preparation, and in particular relates to a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into a perovskite active layer. Background Art

[0002] Solution-processed organic-inorganic halide perovskite solar cells have broad application prospects as the next generation of photovoltaic technology and are expected to make significant contributions to the development of sustainable energy. However, uncontrolled crystallization processes often lead to high-density defects such as multiple grain boundaries and insufficient coordination in perovskite films, which greatly affect the overall performance and stability of perovskite solar cells. Currently, molecular / ionic additives with coordination groups coordinate with lead ions or hydrogen bond with iodine ions to anchor PbI6 in FAPbI3. 2- The octahedral skeleton stabilizes the film; functional nanocrystal / quantum dot additives are implanted on the surface and grain boundaries of the formamidinium-based perovskite film, potentially enabling lattice anchoring of α-FAPbI3 or modulation of carrier dynamics, thereby simultaneously improving the efficiency and stability of formamidinium-based perovskite solar cells. These results demonstrate that molecular / ionic and nanocrystal / quantum dot-based perovskite solar cells exhibit relatively limited functionality. Therefore, developing methods to simultaneously passivate perovskite defects and promote charge transfer by assembling organic molecules with functional groups on metal clusters is crucial for improving the photoelectric conversion efficiency and operational stability of perovskite solar cells.

[0003] However, in the existing technology, some organic molecules have functional groups such as (cyano and thiol) with strong coordination ability with Pb in perovskite. 2+ The formation of a stable Pb-CN / Pb-S complex leads to the 2+ Overconsumption interferes with the formation of the perovskite lattice, causing lattice distortion and increasing the defect state density. At the same time, these organic molecules with polar functional groups will self-aggregate on the surface of the perovskite layer or at the grain boundaries, forming insulating regions that hinder charge transport and accelerate the aging of perovskite solar cells. Summary of the Invention

[0004] In response to the technical deficiencies of the above-mentioned prior art, the present invention provides a perovskite solar cell with cysteine-silver clusters targeted for implantation into the perovskite active layer. The present invention uses liquid-phase laser irradiation technology to obtain a cysteine-silver cluster colloidal solution with uniform particle size and uniform dispersion in a solvent. The solute of the cysteine-silver cluster colloidal solution is cysteine-silver clusters, and its stable silver nanoclusters have good electrical conductivity. Furthermore, based on the advantages of the synergistic assembly of silver nanoclusters and cysteine ​​multifunctional groups, the application of single organic molecules and nanocrystals in perovskite solar cells is improved. Furthermore, the cysteine-silver clusters are used as crystal seeds to regulate the implantation of additives into the perovskite layer, thereby preparing a perovskite solar cell with cysteine-silver clusters targeted for implantation into the perovskite active layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0005] Compared with the prior art, the technical solution of the present invention is: The present invention provides a method for preparing a cysteine-silver cluster colloidal solution, comprising the following steps: In an anhydrous and oxygen-free environment, a silver target is placed in a solvent selected from N,N-dimethylformamide, and then the silver target is irradiated using liquid phase pulsed laser irradiation technology. The supernatant is taken to obtain a silver nanocrystal colloidal solution. The silver nanocrystals have good conductivity and do not have self-catalytic ability, thus avoiding the problem of perovskite layer destruction caused by self-catalysis.

[0006] The silver nanocrystal colloidal solution was frozen with liquid nitrogen to fix the dispersed position of the silver nanocrystals. Then, the pre-prepared cysteine ​​solution was added to it, and pulsed laser irradiation was performed again to obtain a 1mg / mL~2mg / mL cysteine-silver cluster colloidal solution. Since the position of the silver nanocrystals was fixed, the size of the cysteine-silver clusters was made smaller when laser irradiation was performed again.

[0007] Preferably, the conditions for the two pulsed laser irradiation treatments are: irradiation is carried out under the conditions of laser emission wavelength of 1064nm, laser irradiation range of 1.2cm, pulse frequency of 1Hz~10Hz, pulse width of 6ns~8ns, spot size of 8mm~12mm, laser energy of 0.7J~1.0J, and irradiation time of 1min~2min.

[0008] Preferably, the concentration of the cysteine ​​solution is 2 mg / mL to 5 mg / mL; and the volume ratio of the silver nanocrystal colloid solution to the cysteine ​​solution is 1 to 2.5:1.

[0009] The present invention also protects a cysteine-silver cluster colloid solution, which is prepared by the above preparation method. The solute in the cysteine-silver cluster colloid solution is cysteine-silver clusters with an average particle size of 1.1 nm.

[0010] The present invention also protects a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into a perovskite active layer. The perovskite solar cell consists of a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer and a metal electrode layer stacked in sequence from bottom to top, and the perovskite layer is doped with cysteine-silver clusters.

[0011] The present invention also provides a method for preparing a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into a perovskite active layer, comprising the following steps: The hole transport layer solution MeO-2PACz solution was spin-coated on the conductive substrate to obtain a hole transport layer.

[0012] First, a cysteine-silver cluster colloidal solution is implanted into a perovskite layer solution and dropped onto a hole transport layer. Then, an antisolvent is added under rotating conditions, followed by heat treatment, so that the cysteine-silver clusters are embedded in the composite layer at the perovskite grain boundary to obtain a perovskite layer.

[0013] An electron transport layer solution and a hole blocking layer solution are sequentially spin-coated on the perovskite layer to obtain an electron transport layer.

[0014] A metal electrode is evaporated on the electron transport layer to form a metal electrode layer, and a perovskite solar cell with cysteine-silver clusters targetedly implanted into the perovskite active layer is prepared.

[0015] Preferably, the thickness of the perovskite layer is 500 nm to 600 nm.

[0016] Preferably, the solvent volume ratio of the cysteine-silver cluster colloid solution to the perovskite layer solution is 0.5-1.0:1.

[0017] Preferably, the metal electrode layer (5) is a gold electrode layer or a silver electrode layer.

[0018] Preferably, the perovskite layer is an ABX3 type compound, wherein A is CH3NH3 + 、HC(=NH)NH2 + or Cs + , B is Pb 2+ , X is a halogen ion, and the concentration of the perovskite layer solution is 1.40mol / L~1.60mol / L; Specifically, the perovskite layer solution is selected from cationic (FAPbI3 abbreviated as FA), double cationic (FA 0.95 MA 0.05 Pb(I 0.95 Br 0.05 )3 abbreviated as FAMA) or triple positive (Cs 0.05 FA 0.85 MA 0.10 Pb(I 0.97 Br 0.03 )3abbreviated as CsFAMA) ion solution.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses a liquid-phase laser irradiation method to quickly and easily prepare size-controlled, monodisperse, and stable cysteine-silver clusters, allowing direct use without requiring complex processes such as solvent / ligand exchange and centrifugal drying. The structure of the cysteine-silver clusters is as follows: cysteine-coated silver clusters, with cysteine ​​as the organic ligand, possessing excellent biocompatibility, multifunctionality, and multiple chemically reactive groups; and silver nanoclusters possessing unique optical and electrochemical properties, as well as size-tunable physicochemical properties. The present invention synthesizes silver nanoclusters protected by cysteine ​​ligands through pulsed laser irradiation technology. The unique functional groups of cysteine ​​can passivate iodine defects and lead defects in the perovskite layer, giving the cysteine-silver clusters the ability of targeted regulation. The silver clusters have good electrical conductivity, overcoming the insulation problem after cysteine ​​passivation. Then, they are in situ implanted into the perovskite film, which not only plays the "conducting" role of the silver nanoclusters in carrier transport, but also plays the "passive" role of cysteine ​​in passivating perovskite defects. This provides an important way to effectively improve the efficiency and stability of perovskite solar cells with cysteine-silver clusters targetedly implanted into the perovskite active layer.

[0020] The present invention implants cysteine-silver clusters into the perovskite layer and utilizes carboxyl and ammonium groups as anchoring functional groups to exhibit anchoring and chemical bonding with lead iodide in the perovskite component, thereby realizing a thorough multi-site defect targeted anchoring mechanism; the silver clusters with a smaller critical size reduce the energy loss between the perovskite and PCBM, while realizing the regulation of perovskite crystallization and the rapid extraction and transmission of photogenerated carriers. Compared with the preparation technology of introducing ligand molecules cysteine ​​or silver clusters alone, the present invention obtains a highly efficient and stable perovskite solar cell with cysteine-silver clusters targetedly implanted into the perovskite active layer in one step.

[0021] 2. The present invention uses cysteine-silver clusters to implant into the perovskite solution, which is simple to operate and can effectively improve the energy levels of the perovskite layer and the electron transport layer.

[0022] 3. The present invention implants cysteine-silver clusters into the perovskite solution, greatly improving the efficiency of perovskite solar cells in which cysteine-silver clusters are targetedly implanted into the perovskite active layer. The photoelectric conversion efficiency is increased from the basic 23% to 25%, which promotes the development of perovskite solar cells and has extremely high application prospects.

[0023] 4. The present invention implants cysteine-silver clusters into the perovskite layer and prepares a perovskite solar cell with cysteine-silver clusters targeted for implantation into the perovskite active layer. The perovskite solar cell with cysteine-silver clusters targeted for implantation into the perovskite active layer is composed of a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode layer stacked in sequence from bottom to top. The perovskite layer is a composite layer formed after the cysteine-silver clusters are embedded in the perovskite grain boundaries. The present invention uses liquid-phase pulsed laser irradiation technology to prepare a cysteine-silver cluster colloidal solution, and implants the cysteine-silver clusters as additives into the perovskite solution. The hole transport layer, the perovskite layer, and the electron transport layer are spin-coated in sequence. Finally, a metal electrode is evaporated to obtain a perovskite solar cell with cysteine-silver clusters targeted for implantation into the perovskite active layer. Cysteine-silver clusters are implanted into perovskite solutions. Their smaller critical size can serve as nucleation sites, regulating perovskite crystal growth and passivating perovskite film defects, releasing residual stress in the perovskite film, and promoting the formation of gradient energy levels between the perovskite layer and the electron transport layer. This improves the extraction and transmission of electrons, resulting in a more efficient perovskite solar cell with cysteine-silver clusters targeted for implantation into the perovskite active layer. The implantation method is convenient and the preparation process is simple. The cysteine-silver clusters of the present invention combine the passivation properties of organic molecules with the excellent electrical conductivity of metal clusters. Their dual effect not only targets and passivates the defects of the perovskite layer, but also enhances carrier extraction and transmission in the perovskite layer, thereby achieving improved stability and photoelectric conversion efficiency of the perovskite solar cell, and have extremely high application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer in Examples 1 to 3.

[0025] Figure 2 These are characterization images of the cysteine-silver cluster (AMPH-AgNCs) colloidal solution of Example 1, where Figure a is a TEM image of the cysteine-silver cluster colloidal solution; and Figure b is a full XPS spectrum of the cysteine-silver cluster.

[0026] Figure 3 This is an XPS graph of the interaction between the cysteine-silver cluster colloidal solution and lead iodide in Example 1.

[0027] Figure 4 are SEM images; wherein, Figure a is an SEM image of the FA perovskite film without cysteine-silver cluster implantation in Comparative Example 1, and Figure b is an SEM image of the FA perovskite film with cysteine-silver cluster implantation in Example 1.

[0028] Figure 5are SEM images; wherein, Figure a is an SEM image of the FAMA perovskite film without cysteine-silver cluster implantation in Comparative Example 2, and Figure b is an SEM image of the FAMA perovskite film with cysteine-silver cluster implantation in Example 2.

[0029] Figure 6 are SEM images; wherein, Figure a is an SEM image of the CsFAMA perovskite film without cysteine-silver cluster implantation in Comparative Example 3, and Figure b is an SEM image of the CsFAMA perovskite film with cysteine-silver cluster implantation in Example 3.

[0030] Figure 7 This is a current-voltage curve of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer, prepared by implanting cysteine-silver clusters into the FA perovskite film in Example 1.

[0031] Figure 8 This is a current-voltage curve of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer of the FA perovskite film prepared in Comparative Example 1 without implanting cysteine-silver clusters.

[0032] Figure 9 This is a current-voltage curve of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer, prepared by implanting cysteine-silver clusters into the FAMA perovskite film in Example 2.

[0033] Figure 10 This is a current-voltage curve of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer, prepared in Comparative Example 2, without implanting cysteine-silver clusters into the FAMA perovskite film.

[0034] Figure 11 This is a current-voltage curve of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer, prepared by implanting cysteine-silver clusters into the CsFAMA perovskite film in Example 3.

[0035] Figure 12 This is a current-voltage curve of a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer, prepared in Comparative Example 3, without implanting cysteine-silver clusters into the CsFAMA perovskite film.

[0036] Figure 13 This is a physical comparison picture of PbI2-cysteine-silver cluster film, PbI2-silver cluster film and PbI2 film.

[0037] Figure 1 Description of the reference numerals: 1. Conductive substrate; 2. Hole transport layer; 3. Perovskite layer; 4. Electron transport layer; 5. Metal electrode layer. DETAILED DESCRIPTION

[0038] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0039] The present invention aims to solve the problem that the strong coordination group in the prior art is not coordinated to Pb on the surface of the passivation perovskite layer. 2+ When it is also combined with Pb 2+ The key problem is that the coordination reaction occurs, which leads to the destruction of the perovskite structure. Cysteine ​​is innovatively used as a selective passivating agent. Cysteine ​​molecules can specifically recognize and bind only to the uncoordinated Pb 2+ The combination achieves precise passivation of defect sites while avoiding damage to the intrinsic structure of the perovskite lattice. Furthermore, by constructing cysteine-silver nanocluster sub-nanomaterials, the excellent conductive properties of the silver nanoclusters effectively compensate for the grain boundary insulation problem caused by single cysteine ​​passivation, thereby maintaining the integrity of the perovskite structure while ensuring the efficient charge transfer performance of perovskite solar cells.

[0040] The technical solution of this application is further explained using examples and comparative examples, as shown below: Example 1 A method for preparing a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into a perovskite active layer comprises the following steps: S1. In an anhydrous and oxygen-free environment, place a silver block in 3 mL of N,N-dimethylformamide and mix well. Under the assistance of ultrasound and cryogenics, use an Nd:YAG pulsed laser (wavelength 1064 nm, irradiation range 1.2 cm, pulse frequency 10 Hz, pulse width 8 ns, spot size 12 mm, laser energy 1.0 J) to irradiate the silver block for 1 min at -2°C. After irradiation, remove the silver block to obtain a silver nanocrystal colloidal solution.

[0041] S2. Freeze the silver nanocrystal colloidal solution with liquid nitrogen for 1 minute, then mix the prepared 4 mg / mL cysteine ​​solution with the silver nanocrystal colloidal solution to obtain a mixed solution; irradiate the mixed solution again with a pulsed laser under the same conditions as step S1 for a second time for 1 minute, and after the irradiation, a 1 mg / mL, well-dispersed cysteine-silver cluster colloidal solution is obtained. In the cysteine-silver cluster colloidal solution, the size of the cysteine-silver clusters is 1.1 nm.

[0042] S3. Preparation of MeO-2PACz hole transport layer: Spin coat 50 μL of 0.75 mg / mL MeO-2PACz hole transport layer solution onto the FTO conductive substrate at 3000 rpm for 30 seconds, and then heat treat on a hot plate at 100°C for 10 minutes to obtain the MeO-2PACz hole transport layer.

[0043] S4. A FA perovskite precursor solution with a concentration of 1.4 mol / L was prepared in a nitrogen glove box. The preparation method was as follows: 240.75 mg of HC(=NH)NH3I, 703.50 mg of PbI2 and 32.77 mg of CH3NH3Cl were mixed in a small reagent bottle, and then 800 μL of the cysteine-silver cluster colloidal solution of step S2 and 200 μL of dimethyl sulfoxide solvent were added to obtain a mixed solution; the mixed solution was stirred at 50°C for 2 h, and filtered through a 0.22 μm organic filter head to obtain 1 mL of a 1.4 mol / L cysteine-silver cluster-implanted FA perovskite precursor solution for the experiment. In the FA perovskite precursor solution implanted with cysteine-silver clusters, except for the cysteine-silver cluster colloidal solution, the rest was FA perovskite solution, and the solvent volume ratio of the cysteine-silver cluster colloidal solution to the FA perovskite solution was 0.64:1.

[0044] S5. Preparation of FA perovskite layer: Take 30 μL of the FA perovskite precursor solution implanted with cysteine-silver clusters in step S4 and spin-coat it onto the MeO-2PACz hole transport layer in step S3. First, spin-coat it at a low speed (2000 rpm) for 10 seconds, then spin-coat it at a high speed (5000 rpm) for 30 seconds. When there are 10 seconds left in the high-speed spin coating, immediately add 100 μL of ethyl acetate solution. After the addition is completed, heat treat it at 100°C for 40 minutes to prepare a FA perovskite film with a thickness of 500 nm and cysteine-silver clusters embedded in the perovskite grain boundaries.

[0045] S6. Preparation of PCBM electron transport layer: prepare a PCBM electron transport layer solution with a concentration of 20 mg / mL and a BCP hole blocking layer solution with a concentration of 0.75 mg / mL in a nitrogen glove box, add them to a rotor and stir for 12 hours, and filter them with a 0.22 μm organic filter head before use; take 50 μL of the PCBM electron transport layer solution and spin coat it on the FA perovskite film in step S5, spin coat it at a low speed of 2000 rpm for 30 seconds to prepare a PCBM film with a uniform and flat surface; then take 150 μL of the BCP hole blocking layer solution and spin coat it on the PCBM film, spin coat it at a high speed of 4000 rpm for 30 seconds, and then anneal it at 70°C for 5 minutes to remove the residual solvent to obtain the electron transport layer.

[0046] S7, evaporating a layer with an effective area of ​​0.05 cm on the electron transport layer in step S62 , a silver electrode with a thickness of 100 nm, thus obtaining a FA perovskite solar cell with targeted regulation of cysteine-silver clusters.

[0047] Example 2 The method for preparing a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer is the same as steps S1 to S3 and S6 of Example 1, except that: S4. Prepare a 1.5 mol / L FAMA perovskite precursor solution in a nitrogen glove box by mixing 245.05 mg of HC(=NH)NH3I, 35.92 mg of CH3NH3PbBr3, 753.75 mg of PbI2, and 34.35 mg of CH3NH3Cl in a small reagent bottle, then add 800 μL of cysteine-silver cluster colloid solution and 200 μL of dimethyl sulfoxide solvent to obtain a mixed solution. The mixed solution was stirred at 50°C for 2h and filtered through a 0.22μm organic filter to obtain 1mL of a 1.5mol / L cysteine-silver cluster-implanted FAMA perovskite precursor solution for the experiment. In the cysteine-silver cluster-implanted FAMA perovskite precursor solution, except for the cysteine-silver cluster colloidal solution, the rest was a FAMA perovskite solution. The solvent volume ratio of the cysteine-silver cluster colloidal solution to the FAMA perovskite solution was 0.64:1.

[0048] S5. Preparation of FAMA perovskite layer: Take 30 μL of the FAMA perovskite precursor solution implanted with cysteine-silver clusters in step S4 and spin-coat it onto the MeO-2PACz hole transport layer. First, spin-coat it at a low speed (1000 rpm) for 10 seconds, then spin-coat it at a high speed (5000 rpm) for 30 seconds. When there are 10 seconds left in the high-speed spin coating, immediately add 150 μL of ethyl acetate solution. After the addition is completed, heat treat it at 100°C for 30 minutes to prepare a FAMA perovskite film with a thickness of 530 nm and cysteine-silver clusters embedded in the perovskite grain boundaries.

[0049] S7, evaporate a layer on the electron transport layer with an effective area of ​​0.05cm 2 , a silver electrode with a thickness of 100 nm, thus obtaining a FAMA perovskite solar cell with targeted regulation of cysteine-silver clusters.

[0050] Example 3 The method for preparing a perovskite solar cell in which cysteine-silver clusters are targetedly implanted into the perovskite active layer is the same as steps S1 to S3 and S6 of Example 1, except that: S4. Prepare a 1.5 mol / L CsFAMA perovskite precursor solution in a nitrogen glove box by mixing 232.80 mg of HC(=NH)NH3I, 41.29 mg of PbBr2, 676.81 mg of PbI2, 35.19 mg of CH3NH3Cl, and 19.49 mg of CsI in a small reagent bottle, then add 800 μL of cysteine-silver cluster colloid solution and 200 μL of dimethyl sulfoxide solvent to obtain a mixed solution. The mixed solution was stirred at 50°C for 2h and filtered through a 0.22μm organic filter to obtain 1mL of 1.5mol / L cysteine-silver cluster-implanted CsFAMA perovskite precursor solution for the experiment. In the cysteine-silver cluster-implanted CsFAMA perovskite precursor solution, except for the cysteine-silver cluster colloidal solution, the rest was CsFAMA perovskite solution. The solvent volume ratio of the cysteine-silver cluster colloidal solution to the CsFAMA perovskite solution was 0.64:1.

[0051] S5. Preparation of CsFAMA perovskite layer: Take 30 μL of the CsFAMA perovskite precursor solution implanted with cysteine-silver clusters in step S4 and spin-coat it onto the MeO-2PACz hole transport layer. Spin-coat it at 3000 rpm for 40 seconds. When there are 15 seconds left in the high-speed spin-coating, immediately add 250 μL of ethyl acetate solution. After the addition is complete, heat-treat it at 120°C for 20 minutes to prepare a CsFAMA perovskite film with a thickness of 600 nm and cysteine-silver clusters embedded in the perovskite grain boundaries.

[0052] S7, evaporate a layer on the electron transport layer with an effective area of ​​0.05cm 2 , a silver electrode with a thickness of 100 nm, thus obtaining a CsFAMA perovskite solar cell with targeted regulation of cysteine-silver clusters.

[0053] Comparative Example 1 A perovskite solar cell, prepared in the same manner as in Example 1, except that no cysteine-silver clusters are implanted into the FA perovskite active layer, comprises the following steps: S1. Preparation of MeO-2PACz hole transport layer: Spin coat 50 μL of 0.75 mg / mL MeO-2PACz hole transport layer solution onto the FTO conductive substrate at 3000 rpm for 30 seconds, and then heat treat on a hot plate at 100°C for 10 minutes to obtain a MeO-2PACz hole transport layer.

[0054] S2. Prepare a 1.4 mol / L FA perovskite precursor solution in a nitrogen glove box by mixing 240.75 mg of HC(=NH)NH3I, 703.50 mg of PbI2, and 32.77 mg of CH3NH3Cl in a small reagent bottle, then add 800 μL of N,N-dimethylformamide and 200 μL of dimethyl sulfoxide solvent to obtain a mixed solution; stir the mixed solution at 50°C for 2 h, filter it with a 0.22 μm organic filter head, and obtain 1 mL of 1.4 mol / L FA perovskite precursor solution for the experiment.

[0055] S3. Preparation of FA perovskite layer: Take 30 μL of the FA perovskite precursor solution of step S2 and spin-coat it onto the MeO-2PACz hole transport layer of step S1. First, spin-coat it at a low speed (2000 rpm) for 10 seconds, then spin-coat it at a high speed (5000 rpm) for 30 seconds. When there is 10 seconds left in the high-speed spin coating, immediately add 100 μL of ethyl acetate solution. After the addition is completed, heat treat it at 100°C for 40 minutes to prepare a FA perovskite film with a thickness of 500 nm.

[0056] S4. Preparation of PCBM electron transport layer: prepare a PCBM electron transport layer solution with a concentration of 20 mg / mL and a BCP hole blocking layer solution with a concentration of 0.75 mg / mL in a nitrogen glove box, add them to a rotor and stir for 12 hours, and filter them with a 0.22 μm organic filter head before use; take 50 μL of the PCBM electron transport layer solution and spin coat it on the FA perovskite film in step S3, spin coat it at a low speed of 2000 rpm for 30 seconds to prepare a PCBM film with a uniform and flat surface; then take 150 μL of the BCP hole blocking layer solution and spin coat it on the PCBM film, spin coat it at a high speed of 4000 rpm for 30 seconds, and then anneal it at 70°C for 5 minutes to remove the residual solvent to obtain the electron transport layer.

[0057] S5, evaporating a layer with an effective area of ​​0.05 cm on the electron transport layer in step S4 2 , a silver electrode with a thickness of 100nm, and a perovskite solar cell is obtained.

[0058] Comparative Example 2 A perovskite solar cell, prepared in the same manner as in Example 2, except that no cysteine-silver clusters are implanted into the FAMA perovskite active layer, comprises the following steps: S1. Preparation of MeO-2PACz hole transport layer: Spin coat 50 μL of 0.75 mg / mL MeO-2PACz hole transport layer solution onto the FTO conductive substrate at 3000 rpm for 30 seconds, and then heat treat on a hot plate at 100°C for 10 minutes to obtain a MeO-2PACz hole transport layer.

[0059] S2. Prepare a 1.5 mol / L FAMA perovskite precursor solution in a nitrogen glove box by mixing 245.05 mg of HC(=NH)NH3I, 35.92 mg of CH3NH3PbBr3, 753.75 mg of PbI2, and 34.35 mg of CH3NH3Cl in a small reagent bottle, then add 800 μL of N,N-dimethylformamide and 200 μL of dimethyl sulfoxide solvent to obtain a mixed solution; stir the mixed solution at 50°C for 2 h, filter it with a 0.22 μm organic filter head, and obtain 1 mL of 1.5 mol / L FAMA perovskite precursor solution for the experiment.

[0060] S3. Preparation of FAMA perovskite layer: Take 30 μL of the FAMA perovskite precursor solution of step S2 and spin-coat it onto the MeO-2PACz hole transport layer of step S1. First, spin-coat it at a low speed (1000 rpm) for 10 seconds, then spin-coat it at a high speed (5000 rpm) for 30 seconds. When there are 10 seconds left in the high-speed spin coating, immediately add 150 μL of ethyl acetate solution. After the addition is completed, heat treat it at 100°C for 30 minutes to prepare a FAMA perovskite film with a thickness of 530 nm.

[0061] S4. Preparation of PCBM electron transport layer: prepare a PCBM electron transport layer solution with a concentration of 20 mg / mL and a BCP hole blocking layer solution with a concentration of 0.75 mg / mL in a nitrogen glove box, add them to the rotor and stir for 12 hours, and filter them with a 0.22 μm organic filter head before use; take 50 μL of the PCBM electron transport layer solution and spin coat it on the FAMA perovskite film in step S3, spin coat it at a low speed of 2000 rpm for 30 seconds to prepare a PCBM film with a uniform and flat surface; then take 150 μL of the BCP hole blocking layer solution and spin coat it on the PCBM film, spin coat it at a high speed of 4000 rpm for 30 seconds, and then anneal it at 70°C for 5 minutes to remove the residual solvent to obtain the electron transport layer.

[0062] S5, evaporating a layer with an effective area of ​​0.05 cm on the electron transport layer in step S4 2 , a silver electrode with a thickness of 100nm, and a perovskite solar cell is obtained.

[0063] Comparative Example 3 A perovskite solar cell, prepared in the same manner as in Example 3, except that no cysteine-silver clusters are implanted into the CsFAMA perovskite active layer, comprises the following steps: S1. Preparation of MeO-2PACz hole transport layer: Spin coat 50 μL of 0.75 mg / mL MeO-2PACz hole transport layer solution onto the FTO conductive substrate at 3000 rpm for 30 seconds, and then heat treat on a hot plate at 100°C for 10 minutes to obtain a MeO-2PACz hole transport layer.

[0064] S2. Prepare a CsFAMA perovskite precursor solution with a concentration of 1.5 mol / L in a nitrogen glove box. The preparation method is as follows: mix 232.80 mg of HC(=NH)NH3I, 41.29 mg of PbBr2, 676.81 mg of PbI2, 35.19 mg of CH3NH3Cl and 19.49 mg of CsI in a small reagent bottle, and then add 800 μL of N,N-dimethylformamide and 200 μL of dimethyl sulfoxide solvent to obtain a mixed solution; stir the mixed solution at 50°C for 2 h, filter it with an organic filter head of 0.22 μm, and obtain 1 mL of 1.5 mol / L CsFAMA perovskite precursor solution for the experiment.

[0065] S3. Preparation of CsFAMA perovskite layer: Take 30 μL of the CsFAMA perovskite precursor solution of step S2 and spin-coat it onto the MeO-2PACz hole transport layer of step S1. Spin-coat at 3000 rpm for 40 seconds, then spin-coat at 5000 rpm for 30 seconds. When there are 15 seconds left in the high-speed spin coating, immediately add 250 μL of ethyl acetate solution. After the addition is complete, heat treat at 120°C for 20 minutes to prepare a CsFAMA perovskite film with a thickness of 600 nm.

[0066] S4. Preparation of PCBM electron transport layer: prepare a PCBM electron transport layer solution with a concentration of 20 mg / mL and a BCP hole blocking layer solution with a concentration of 0.75 mg / mL in a nitrogen glove box, add them to the rotor and stir for 12 hours, and filter them with a 0.22 μm organic filter head before use; take 50 μL of the PCBM electron transport layer solution and spin coat it on the CsFAMA perovskite film in step S3, spin coat it at a low speed of 2000 rpm for 30 seconds to prepare a PCBM film with a uniform and flat surface; then take 150 μL of the BCP hole blocking layer solution and spin coat it on the PCBM film, spin coat it at a high speed of 4000 rpm for 30 seconds, and then anneal it at 70°C for 5 minutes to remove the residual solvent to obtain the electron transport layer.

[0067] S5, evaporating a layer with an effective area of ​​0.05 cm on the electron transport layer in step S4 2 , a silver electrode with a thickness of 100nm, and a perovskite solar cell is obtained.

[0068] Figure 1Schematic diagram of the structure of the perovskite solar cell with cysteine-silver clusters targetedly implanted into the perovskite active layer in Examples 1 to 3 of the present invention; in order to verify the performance of the perovskite solar cell with cysteine-silver clusters targetedly implanted into the perovskite active layer after the cysteine-silver clusters are implanted into the perovskite active layer of the present invention, the perovskite solar cells with cysteine-silver clusters targetedly implanted into the perovskite active layer in Examples 1 to 3 and the perovskite solar cells in Comparative Examples 1 to 3 are studied as examples, and the specific research methods and results are shown below: from Figure 2 The TEM image of a shows that after pulsed laser treatment, the cysteine-silver cluster colloidal solution has good monodispersity and the average particle size of the cysteine-silver clusters is 1.1 nm. Figure 2 The XPS pattern in b shows C, O, N, S, and Ag elements, providing further evidence for the successful preparation of cysteine-silver clusters.

[0069] like Figure 3 The figure shows the XPS graph of the interaction between cysteine-silver clusters and lead iodide. The functional groups of the cysteine-silver clusters are effectively chemically anchored and bonded with the components of the perovskite. The carboxyl group of cysteine ​​can react with Pb 2+ Forming a coordination bond, the amino group of cysteine ​​can bind to I - The formation of hydrogen bonds helps to reduce ion migration and the generation of vacancies, achieving the simultaneous passivation of multiple defects, which is expected to slow down the improvement of the morphology and crystal quality of perovskite films, thereby promoting the comprehensive regulation of perovskites.

[0070] from Figure 4 a and Figure 4 The SEM image of the single-cation FA perovskite film in b shows that the FA perovskite film with cysteine-silver clusters implanted has larger grain size and smoother film than the perovskite film without cysteine-silver clusters implanted.

[0071] The method of the present invention has been verified to be universal by similar experiments. Cysteine-silver clusters were implanted into dicationic FAMA perovskite films and tricationic CsFAMA perovskite films, and similar film lifting phenomena were observed. Figure 5 and Figure 6 The SEM images show that the perovskite film with cysteine-silver clusters implanted has larger grains and smoother films than the perovskite film without cysteine-silver clusters implanted, indicating that cysteine-silver clusters facilitate the growth of perovskite films.

[0072] from Figures 7 to 12It can be seen that after cysteine-silver clusters are implanted into FA perovskite film, FAMA perovskite film and CsFAMA perovskite film, the photoelectric conversion efficiency of the perovskite solar cells with cysteine-silver clusters targetedly implanted into the perovskite active layer prepared is improved compared with the efficiency of the perovskite solar cells without cysteine-silver clusters implanted. After the implantation of cysteine-silver clusters, the highest efficiencies achieved by the perovskite solar cells with cysteine-silver clusters targetedly implanted into the perovskite active layer are 24.63%, 25.02% and 25.06% respectively; the efficiencies of the perovskite solar cells without cysteine-silver clusters implanted are 23.39%, 23.75% and 23.86% respectively.

[0073] The following are the preparations of three samples: PbI2 film, PbI2-silver cluster film and PbI2-cysteine-silver cluster film: 676.81 mg of PbI2 was dissolved in N,N-dimethylformamide, poured into a mold, and annealed at 70 °C for 5 min to obtain a PbI2 film.

[0074] 676.81 mg of PbI2 was dissolved in N,N-dimethylformamide, and then silver nanocrystal colloidal solution was added. The film was poured into a mold with a volume ratio of silver nanocrystal colloidal solution to N,N-dimethylformamide of 0.64:1. The film was annealed at 70°C for 5 minutes to obtain a PbI2-silver cluster film.

[0075] 676.81 mg of PbI2 was dissolved in N,N-dimethylformamide, and then the cysteine-silver cluster colloid solution was added. The mixture was poured into a mold with a volume ratio of cysteine-silver cluster colloid solution to N,N-dimethylformamide of 0.64:1. The mixture was annealed at 70°C for 5 minutes to obtain a PbI2-cysteine-silver cluster film.

[0076] Figure 13 In the figure, from left to right are PbI2-cysteine-silver cluster film, PbI2-silver cluster film and PbI2 film. PbI2 is yellow in color. Silver clusters without cysteine ​​coordination will affect the crystallization of PbI2 due to surface defects. Cysteine-silver clusters isolate the silver clusters from direct contact with PbI2, but instead interact with Pb through carboxyl groups. 2+ Forming a coordination bond through the ammonium group and I - Hydrogen bond interactions are formed, effectively inhibiting the crystallization of PbI2; ultimately, the color of the PbI2-cysteine-silver cluster film changes from the yellow of the PbI2 film to transparent.

[0077] In summary, the present invention introduces cysteine-silver clusters into the perovskite layer, passivates different perovskite grain boundary defects, facilitates the growth of perovskite films, regulates the extraction and transmission of photogenerated carriers, and achieves higher photoelectric conversion efficiency than the initial perovskite solar cell.

[0078] The above description is merely a list of preferred embodiments for purposes of illustration only, and the scope of protection of the present invention is not limited thereto. Anyone skilled in the art, once understanding the basic inventive concepts, can readily make additional changes and modifications to these embodiments. Therefore, the appended claims are intended to fall within the scope of protection of the present invention.

Claims

1. A method for preparing a cysteine-silver cluster colloidal solution, characterized in that: The steps include: In an anhydrous and oxygen-free environment, a silver target is placed in a solvent and then irradiated using a liquid-phase pulsed laser irradiation technique to obtain a silver nanocrystal colloidal solution; After the silver nanocrystal colloidal solution is frozen with liquid nitrogen, a cysteine ​​solution is added and pulsed laser irradiation is performed again to obtain a cysteine-silver cluster colloidal solution.

2. The method for preparing the cysteine-silver cluster colloidal solution according to claim 1, wherein The conditions for the two pulsed laser irradiation treatments were: laser emission wavelength of 1064 nm, laser irradiation range of 1.2 cm, pulse frequency of 1 Hz to 10 Hz, pulse width of 6 ns to 8 ns, spot size of 8 mm to 12 mm, laser energy of 0.7 J to 1.0 J, and irradiation time of 1 min to 2 min.

3. The method for preparing the cysteine-silver cluster colloidal solution according to claim 2, wherein: The pulse laser irradiation treatment is performed simultaneously with ultrasound and cryogenic assisted treatment, the ultrasound frequency is 90 Hz to 100 Hz, and the temperature of the cryogenic assisted treatment is -2°C to 0°C.

4. The method for preparing the cysteine-silver cluster colloidal solution according to claim 1, wherein The concentration of the cysteine ​​solution is 2 mg / mL to 5 mg / mL; the volume ratio of the silver nanocrystal colloid solution to the cysteine ​​solution is 1 to 2.5:

1.

5. A cysteine-silver cluster colloidal solution, characterized in that: The cysteine-silver cluster colloidal solution is prepared by the preparation method according to any one of claims 1 to 4, wherein the solute in the cysteine-silver cluster colloidal solution is cysteine-silver clusters with an average particle size of 1.1 nm.

6. A perovskite solar cell with cysteine-silver clusters targetedly implanted into a perovskite active layer, comprising a conductive substrate (1), a hole transport layer (2), a perovskite layer (3), an electron transport layer (4) and a metal electrode layer (5) stacked in sequence from bottom to top, characterized in that: The perovskite layer (3) is doped with the cysteine-silver cluster according to claim 5.

7. A method for preparing a perovskite solar cell with cysteine-silver clusters targetedly implanted into a perovskite active layer according to claim 6, characterized in that: The steps include: Spin coating a hole transport layer solution on a conductive substrate (1) to obtain a hole transport layer (2); First, a cysteine-silver cluster colloidal solution is implanted into a perovskite layer solution and dripped onto the hole transport layer (2), and then an antisolvent is dripped under a rotating condition, and then heat-treated, so that the cysteine-silver clusters are embedded in the composite layer of the perovskite grain boundary, thereby obtaining a perovskite layer (3); Sequentially spin-coating an electron transport layer solution and a hole blocking layer solution on the perovskite layer (3) to obtain the electron transport layer (4); A metal electrode is evaporated on the electron transport layer (4) to form a metal electrode layer (5), and a perovskite solar cell is prepared in which cysteine-silver clusters are targetedly implanted into the perovskite active layer.

8. The method for preparing a perovskite solar cell with cysteine-silver clusters targetedly implanted into a perovskite active layer according to claim 7, characterized in that: The solvent volume ratio of the cysteine-silver cluster colloid solution to the perovskite layer solution is 0.5~1.0:

1.

9. The method for preparing a perovskite solar cell with cysteine-silver clusters targetedly implanted into a perovskite active layer according to claim 7, characterized in that: The metal electrode layer (5) is a gold electrode layer or a silver electrode layer.

10. The method for preparing a perovskite solar cell comprising organic metal clusters implanted into a perovskite active layer and cysteine-silver clusters targetedly implanted into the perovskite active layer according to claim 7, characterized in that: The perovskite layer (3) is an ABX3 type compound, wherein A is CH3NH3 + 、HC(=NH)NH2 + or Cs + , B is Pb 2+ , X is a halogen ion, and the concentration of the perovskite layer solution is 1.40 mol / L~1.60 mol / L.

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