Method for improving passivation uniformity of large-area perovskite thin film through solution soaking and quenching surface treatment and application

Abstract

The invention relates to the technical field of photovoltaic device manufacturing, in particular to a method for improving passivation uniformity of a large-area perovskite thin film through solution soaking quenching surface treatment and application. According to the invention, the prepared high-temperature perovskite thin film is immersed in the low-temperature quenching liquid to realize uniform surface passivation, and finally the perovskite thin film is prepared into a complete perovskite assembly. According to the solution soaking quenching surface treatment technology, the quenching liquid permeates into the grain boundary in the perovskite film, so that defect repair of the perovskite surface / bulk phase is realized, the defect density of the film is reduced, the contact between the perovskite layer and the electrode is improved, and the service life of the perovskite film is prolonged. The problems of non-uniform distribution of a passivating agent and poor interface contact in the post-treatment process of the large-area perovskite film are solved, and about 20% of high photoelectric conversion efficiency and relatively good stability of the large-area perovskite photovoltaic module are realized.

Description

Technical Field

[0001] The present invention patent relates to the technical field of photovoltaic device manufacturing, and particularly relates to a method for improving the passivation uniformity of large-area perovskite thin films by solution immersion quenching surface treatment, which is applicable to large-area flexible or rigid photovoltaic modules. Background Art

[0002] Perovskite solar cells (PSCs) have attracted much attention due to their high power conversion efficiency (PCE) and low-cost manufacturing process. In recent years, small-area PSCs (<0.1 cm 2 ) at the laboratory scale have achieved an efficiency close to 27%, showing the potential to rival traditional commercial crystalline silicon solar cells. Generally, perovskite components with different bandgaps are applied in different scenarios to meet the requirements of practical applications. Among them, mixed halide wide-bandgap (WBG) perovskite materials (1.6 - 2.0 eV) benefit from their larger bandgaps and theoretically can enable the device to maintain higher transparency and obtain higher V OC , and have played a unique advantage in semi-transparent solar cells and tandem solar cells, and have attracted much attention from researchers in recent years.

[0003] As is well known, WBG perovskite is mainly composed of mixed halogens with a high Br content. Due to the crystallization kinetic differences between different halogens and the phenomena of halogen phase segregation and ion migration under different stresses (such as light, temperature, and humidity), problems such as poor crystallization quality of the thin film, uneven chemical composition, and many bulk and surface defects are caused, resulting in serious interfacial non-radiative recombination and carrier transport losses, which limit the further improvement of efficiency and stability. The blade coating method, as an extensible large-area thin film preparation technology, shows great application potential due to its high ink utilization rate and compatibility with industrial roll-to-roll coating. Due to the crystallization heterogeneity of mixed halogens, the large-area WBG perovskite thin films prepared by the blade coating method further amplify the above-mentioned disadvantages such as uneven crystallization and many interfacial defects, resulting in varying degrees of reduction in each key photovoltaic parameter of the solar photovoltaic module. For example, when attempting to expand these high-efficiency small-area (<1 cm 2 ) cells to large-area modules (>10 cm 2 ), the efficiency will show an efficiency roll-off of >4%, which will seriously hinder the commercialization process and practical application of this type of perovskite solar cell. It should be noted that as the device area increases, compared with the short-circuit current density (J SC ) and open-circuit voltage (V OC ), the reduction of the fill factor (FF) is more obvious. This is mainly attributed to poor interfacial contact on a larger scale, uneven interfacial carrier transport paths, and the aggravated deterioration of other interfacial properties, resulting in a relatively large interfacial series resistance.

[0004] Research findings show that by introducing organic or inorganic small molecules or performing interface modification between the perovskite layer and the electron transport layer, interface contact can be improved, charge extraction efficiency enhanced, thereby increasing the J of perovskite solar cells. SC And FF. However, since most of the currently developed methods for interface modification of solar cells and components mainly rely on spin-coating treatment, some solutions tend to accumulate at the edges of the perovskite film, forming the "coffee ring" effect. As the area increases, the "coffee ring" effect becomes more obvious, and it is difficult to control the uniformity of the distribution of modified ions, easily leading to uneven local chemical composition distribution on the film surface, affecting surface optoelectronic properties such as charge transport performance. Therefore, developing a simple post-treatment method applicable to large-area perovskite films to improve the uniformity of their surface chemical composition, while being able to optimize their interface contact, reduce interface defect states, and improve interface charge transport efficiency is crucial for enhancing the performance of large-area WBG perovskite solar cells. Summary of the Invention

[0005] To solve the above technical problems, the purpose of the present invention is to provide a method for improving the passivation uniformity of large-area perovskite photovoltaic modules. By using a cold quenching liquid, the hot perovskite film is immersed in it for quenching to complete the surface treatment process, realizing the uniformity and high efficiency of surface / interface passivation modification of large-area films. Through thermal shock-induced secondary crystallization of the perovskite film, the crystallinity of the perovskite film is greatly improved. At the same time, dual regulation of gradient doping of passivation ions from the film surface to the deep bulk and halogen stabilization is achieved, relieving the film tensile stress during the crystallization process, optimizing the energy level arrangement, enhancing the surface homogeneity and interface charge transport efficiency of large-area films, thereby preparing uniform and efficient large-area perovskite solar cell modules.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In the first aspect, the present invention provides a method for improving the passivation uniformity of large-area perovskite films by solution immersion quenching surface treatment, including the following steps:

[0008] Immerse the annealed high-temperature perovskite film into a low-temperature quenching liquid for quenching treatment to obtain a perovskite modified film;

[0009] The quenching liquid is a solvent or a solution containing a solute and a solvent. The solution after adding the solute can achieve multiple passivation effects, and the solute is a metal halide or an organic compound.

[0010] Furthermore, the temperature of the high-temperature perovskite film is 80 - 150 °C, the temperature of the low-temperature quenching liquid is 0 - 15 °C, and the quenching immersion time is 1 - 5 minutes.

[0011] Further, the solvent is at least one of chlorobenzene (CB), isopropanol (IPA), isobutanol (IBA), toluene (TOL), m-xylene (ANI), chloroform, tetrafluoroethylene (CF), anisole, ethyl acetate (EA), tetrahydrofuran (THF), cyclohexane (CYH).

[0012] Further, the metal halide includes a compound formed by the ionic bond combination of metal cations (such as Li + , Na + , K + , Rb + , Cs + , Sr 2+ , Cd 2+ , In 2+ , In 3+ , Ga 3+ , Bi 3+ , Eu 2+ , Eu 3+ , Nd 3+ , Nb 5+ ) and halogen anions (F - , Cl - , Br - , I - ), and the organic compound includes at least one of ethylenediamine dihydroiodide (EDADI), ethylenediamine (EDA), benzylammonium halide, phenethylammonium halide, butylammonium halide, guanidinium halide, octylammonium halide.

[0013] Further, the molar concentration of the solute in the solution is 0.1 - 500 mM.

[0014] Further, the structure of the perovskite is ABX3, where A is at least one of La 3+ , Nd 3+ , Ca 2+ , Sr 2+ , Ba 2+ , Na + , Rb + , Cs + , formamidinium (FA + ), methylammonium (MA + ), phenethylamine (PEA + ), trimethylammonium (TMA + ), butylamine (BA + ), hexylamine (HA + ), guanidine (GA + ), and B is at least one of Nb 5+ , Ti 4+ , Fe 3+ , Mn 3+ , Co3+ 、At least one of In 3+ 、Bi 3+ 、Pb 2+ 、Sn 2+ 、Ge 2+ 、Cu 2+ 、Ag + and X is O 2- 、At least one of F - 、Cl - 、Br - 、I - among them.

[0015] Furthermore, the band gap of the perovskite is 1.1 - 2.5 eV, where the narrow band gap value of 1.1 - 1.45 eV is achieved by the gradient design of the Pb / Sn ratio, and the Pb / Sn ratio increases from 0% to 100%. The conventional band gap value of 1.45 - 1.55 eV is achieved by the gradient design of the MA / FA ratio, and the MA / FA ratio increases from 0% to 100%. The wide band gap value of 1.55 eV - 2.5 eV is achieved by the gradient design of the Br / I ratio, and the Br / I ratio increases from 0% to 100%.

[0016] Furthermore, the preparation method of the perovskite thin film includes: dissolving the perovskite raw material in an organic solvent to prepare a perovskite precursor solution, and preparing the perovskite precursor solution into a perovskite thin film by one-step spin coating method or two-step spin coating method or air blowing assisted spin coating method or doctor blade coating method or slot die coating method or spraying method or inkjet printing method or soft cover deposition method or vapor deposition method, and then performing annealing treatment.

[0017] Furthermore, the perovskite thin film is prepared by the doctor blade coating method. The doctor blade coating method uses an inert gas such as nitrogen, argon or helium for air blowing assistance, the doctor blade speed is 1 - 300 mm / s, and the operating temperature range is 15 - 200 °C

[0018] Furthermore, the organic solvent is selected from at least one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), γ-butyrolactone (GBL), N-methylformamide (NMF), acetonitrile (ACN), 2-methoxyethanol (2-ME) and N-methylpyrrolidone (NMP).

[0019] Furthermore, the organic solvent is a mixed solution of DMSO and DMF, and the volume ratio of DMF to DMSO is 9:1 or 4:1 or 7:3 or 3:2.

[0020] Further, the annealing is performed by one-step annealing or two-step annealing. The temperature of the one-step annealing is 80-150°C, and the annealing time is 1-60 minutes. The two-step annealing is to anneal at 50-90°C for 5-30 minutes first, and then anneal at 90-150°C for 5-30 minutes.

[0021] In a second aspect, the present invention provides an application of a large-area perovskite thin film with improved surface passivation uniformity based on solution immersion quenching in the preparation of a solar cell module.

[0022] The present invention realizes dual regulation of gradient doping of passivating ions from the surface to the deep bulk and halogen stabilization in the thin film through the solution immersion quenching method, relieves the tensile stress of the thin film during the crystallization process, optimizes the energy level arrangement, improves the surface homogeneity and interface charge transport efficiency of the large-area thin film, and realizes a large-area perovskite solar cell module with a photoelectric conversion efficiency of ~20% and high stability.

[0023] The present invention also provides a solar cell module prepared from the large-area perovskite thin film passivated by the above method. The solar cell module has a normal device structure including a conductive substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer, and a top electrode in sequence from bottom to top, or an inverted device structure including a conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a hole blocking layer, and a top electrode in sequence from bottom to top. The perovskite thin film is the above large-area perovskite thin film with improved surface passivation uniformity by solution immersion quenching.

[0024] The present invention also provides a preparation method of a semi-transparent large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching. The semi-transparent perovskite solar cell module has a normal device structure including a conductive substrate, an electron transport layer, a perovskite thin film, a hole transport layer, and a transparent top electrode in sequence from bottom to top, or an inverted device structure including a conductive substrate, a hole transport layer, a perovskite thin film, an electron transport layer, a hole blocking layer, and a transparent top electrode in sequence from bottom to top. The perovskite thin film is the above large-area perovskite thin film with improved surface passivation uniformity by solution immersion quenching.

[0025] Further, the hole transport layer material is selected from any one of inorganic types (such as CuI, CuSCN, and NiOx), organic types (such as PTAA, Spiro-OMeTAD, P3HT, PEDOT:PSS, and PolyTPD), or self-assembled monolayer (SAM) types (such as 2PACz, F-2PACz, MeO-2PACz, 4PACz, Me-4PACz, MeO-4PACz, DMACPA, MPA-CPA, and 4PADCB).

[0026] Further, the electron transport layer material is selected from fullerenes and their derivatives (C60 , any one of PCBM, ICBA, etc.) or metal oxides (such as SnO2, TiO2, ZnO, ZrO2, SrTiO3, BaSnO3, etc.).

[0027] Further, the hole blocking layer is selected from any one of BCP, Alq3, PEN, SnO2, TiO2, ZnO, Zr(acac)4, MoO3.

[0028] Further, the conductive substrate can be indium tin oxide (ITO) conductive glass, fluorine-doped tin dioxide (FTO) conductive glass, or flexible conductive substrate (such as ITO-PET, ITO-PEN), etc.

[0029] Further, the top electrode is a metal material with a relatively high work function, including but not limited to gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), molybdenum (Mo), or a conductive carbon material, including but not limited to carbon nanoparticles, carbon nanotubes, graphene, graphyne.

[0030] Further, the transparent top electrode is a light-transmitting ITO or an ultrathin metal material, including but not limited to gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), molybdenum (Mo).

[0031] The beneficial effects that this application can produce are as follows:

[0032] The present invention discloses a method for improving the passivation uniformity of large-area perovskite photovoltaic modules by solution immersion quenching surface treatment. First, the passivation material is dissolved in an organic solvent to prepare a quenching solution, and the annealed high-temperature perovskite thin film is immersed in the low-temperature quenching solution containing passivation ions to complete the quenching interface engineering treatment, and a large-area perovskite thin film with uniformly distributed surface passivation ions is prepared. At the same time, a large-area perovskite thin film based on solution immersion quenching to improve surface passivation uniformity prepared by the above method can be combined with a hole transport layer, an electron transport layer, and a top electrode to prepare a perovskite solar cell module. Through the interface engineering technology of solution immersion quenching, the present invention can reduce the defect density of the thin film, improve the contact between the perovskite layer and the electrode, and is applied to the preparation of large-area solar cell modules with uniform passivation, solving the problems of uneven distribution of the passivation agent and poor interface contact during the post-treatment process of large-area perovskite thin films, and achieving a high photoelectric conversion efficiency of ~20% and good stability for large-area perovskite photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flow chart for solution immersion quenching of the perovskite thin film.

[0034] Figure 2Scanning electron microscope (SEM) images of different perovskite films (a is the perovskite film without solution immersion quenching treatment; b is the perovskite film with solution immersion quenching treatment).

[0035] Figure 3 Atomic force microscope (AFM) images of different perovskite films (a is the perovskite film without solution immersion quenching treatment; b is the perovskite film with solution immersion quenching treatment).

[0036] Figure 4 Photoluminescence (PL) intensity of the perovskite film measured at 13 different positions of a 52 mm × 60 mm perovskite film.

[0037] Figure 5 SEM image of the perovskite film after immersion quenching treatment with a quenching solution containing metal halides.

[0038] Figure 6 SEM image of the perovskite film after immersion quenching treatment with a quenching solution containing organic compounds.

[0039] Figure 7 Schematic diagram of the structure of a large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching.

[0040] Figure 8 J-V curve of a large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching.

[0041] Figure 9 Thermal stability test tracking curve of a large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching.

[0042] Figure 10 J-V curve of a large-area narrow-bandgap perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching.

[0043] Figure 11 J-V curve of a large-area conventional bandgap (about 1.5 eV) perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching.

[0044] Figure 12 Transmission spectrum of a semi-transparent large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching.

[0045] Figure 13 J-V curve of a semi-transparent large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching. Detailed implementation mode

[0046] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0047] Unless otherwise specified, the experimental methods in the following embodiments are all conventional methods. Unless otherwise specified, the test materials used in the following embodiments can all be obtained through conventional commercial channels.

[0048] Example 1

[0049] A method for preparing a large-area perovskite thin film with improved surface passivation uniformity by solution immersion quenching. In this example, the solvent of the quenching solution is IPA and there is no quenching solute. Taking the wide-bandgap component as an example of the perovskite, the specific steps are as follows:

[0050] S1. Select IPA as the quenching solution and cool it to 5 °C for standby;

[0051] S2. Prepare a 1.5 M FAI 0.8 Cs 0.2 Pb(I 0.8 Br 0.2 )3 wide-bandgap perovskite precursor solution, where the molar ratio of FAI, CsI, PbI2, and PbBr2 is 0.8:0.2:0.8:0.2, and the volume ratio of DMF to DMSO is 7:3. After fully mixing the perovskite precursor solution until the solid dissolves and the solution becomes clear, it is reserved for use;

[0052] S3. The perovskite thin film is prepared by the doctor blade method (doctor blade speed 5 mm s -1 ). The operating temperature of the panel is 25 °C. Each coating uses 20 μL of the perovskite precursor solution. During the doctor blade process, nitrogen is applied to assist the evaporation of the solvent and the crystallization of the thin film. Subsequently, the perovskite thin film is transferred to a hot plate and annealed at 105 °C for 10 minutes, and after natural cooling, the perovskite control thin film I is prepared;

[0053] S4. Immerse the 105 °C perovskite thin film described in S3 into the 5 °C quenching solution described in S1 for cooling. The flow chart is as Figure 1 shown, and the perovskite modified thin film is prepared;

[0054] At the same time, after the 105 °C perovskite thin film described in S3 is naturally cooled, a surface passivation layer is prepared by the spin coating method (4000 r, 30 s) using the solution described in S1, and the perovskite control thin film II is prepared;

[0055] The perovskite control film I and the perovskite modified film were characterized by scanning electron microscopy (SEM). As Figure 2 shown in the film morphology, the perovskite control film I presents a typical polycrystalline structure, with uneven grain size distribution and voids and unevenness between grains. The grain boundary defects caused by this non-ideal grain growth (i.e., surface heterogeneity) will form deep energy level defect states, exacerbate carrier loss and reduce its carrier lifetime. In contrast, through the solution immersion quenching process, grain boundary reconstruction was completed, and a high-quality perovskite modified film with a dense surface coverage and increased flatness was obtained, showing a dense interlocking structure between grains.

[0056] The surface roughness information was obtained by the interaction force between the atomic force microscope (AFM) probe and the sample surface. As Figure 3 shown by the measured root mean square (RMS) roughness value, the surface roughness of the perovskite control film I is relatively large, and the measured RMS value is 13.2 nm. In contrast, the surface roughness of the perovskite modified film is reduced by 53%, and this result corresponds to the Figure 2 changes of the perovskite control film I and the perovskite modified film, indicating that the solution immersion quenching method can reduce the surface roughness of the perovskite film, thereby enhancing the interfacial contact between the perovskite film and the electron transport layer.

[0057] The perovskite control film I, the perovskite control film II and the modified film were all divided into 13 different positions for photoluminescence (PL) spectroscopy analysis. As Figure 4 shown by the PL intensity, compared with the perovskite control film I and the perovskite control film II, the PL intensity of the perovskite modified film uniformly shows an enhanced PL intensity at 13 different positions of the film. The coefficient of variation (CV PL ) of the fluorescence intensity at 13 different positions was statistically analyzed. Compared with the perovskite control film II, the coefficient of variation of the fluorescence intensity of the perovskite modified film decreased from 17.16% to 0.67%, indicating that the post-treatment process of solution immersion quenching shows a more uniform advantage in the post-treatment process of large-area films. Through the synergistic optimization of morphology and defect states, the chemical homogeneity of the perovskite film surface during the post-treatment process was realized, which is beneficial to the separation and transport of carriers and realizes the overall improvement of carrier transport performance.

[0058] Example 2

[0059] A method for improving the surface passivation uniformity of a large-area perovskite film by solution immersion quenching. The specific preparation method is the same as that in Example 1, except that in this example, a quenching solution containing metal halide as the solute is selected. Specifically, the quenching solvent is IPA, the quenching solute is metal halide SrI2, and the concentration of this quenching solution is 1 mM. The microscopic morphology of the modified film in this example is as Figure 5As shown, it can be seen that the grain size of the perovskite film prepared in this example is evenly distributed, and the surface is covered densely and has a large flatness.

[0060] Example 3

[0061] A method for preparing a large-area perovskite film with improved surface passivation uniformity by solution immersion quenching. The specific preparation method is the same as that of Example 1, except that in this example, a quenching solution containing an organic compound as a solute is selected. Specifically, the quenching solvent is IPA, the quenching solute is the organic compound EDADI, and the concentration of this quenching solution is 2 mM. The microscopic morphology of the modified film in this example is as Figure 6 As shown, it can be seen that the grain size of the perovskite film prepared in this example is evenly distributed, and the surface is covered densely and has a large flatness.

[0062] Example 4

[0063] An application of a large-area perovskite film with improved surface passivation uniformity based on solution immersion quenching in a perovskite solar cell module. The structure of the solar cell module is as Figure 7 shown, which includes an ITO conductive glass substrate, a hole transport layer (PTAA, 2PACz), a large-area perovskite film prepared by solution immersion quenching with improved surface passivation uniformity in Example 2, an electron transport layer (C 60 , BCP), and an Ag electrode from bottom to top. The specific preparation method includes the following steps:

[0064] S1. Clean the conductive substrate: Ultrasonically clean an ITO conductive substrate with dimensions of 52 mm (length) × 60 mm (width) × 1.1 mm (thickness) successively with deionized water, isopropyl alcohol, and acetone for 20 minutes, and then place it in a drying oven to dry.

[0065] S2. Laser etch P1 (isolate the conductive layer): Use a 532 nm picosecond laser to etch the conductive layer along a preset line width (10 - 100 μm) to the underlying glass substrate to divide the ITO glass substrate into independent units.

[0066] S3. Pretreat the conductive substrate: Treat the processed ITO substrate with an ultraviolet ozone cleaner for 20 minutes.

[0067] S4. Prepare the hole transport layer: Spin-coat 500 μL of a 10 mg / mL NiO X / H2O solution (6000 rpm, 30 s) on the ozone-treated ITO substrate, and anneal at 150 °C for 30 minutes; transfer it to a glove box and cool it to room temperature, then spin-coat 500 μL of a 10 mg / mL 2-PACz / DMF solution (3000 rpm, 30 s), and anneal at 100 °C for 5 minutes.

[0068] S5. Preparation of perovskite light absorption layer: Prepare a 1.5 M FA 0.8 Cs 0.2 Pb(I 0.8 Br 0.2 )3 wide-bandgap perovskite precursor solution, where the molar ratio of FAI, CsI, PbI2, and PbBr2 is 0.8:0.2:0.8:0.2, and the volume ratio of DMF to DMSO is 7:3. After thoroughly mixing the perovskite precursor solution until the solids dissolve and the solution becomes clear, 20 μL of the perovskite precursor solution is spin-coated on the ITO / PTAA / 2PACz substrate by spin-coating (spin speed 5 mm s-1). The operating temperature of the panel is 25 °C, and during the spin-coating process, nitrogen gas at a pressure of 20 psi is applied through an air knife to assist solvent evaporation and film crystallization. Subsequently, the perovskite film is transferred to a hot plate and annealed at 105 °C for 10 minutes;

[0069] S6. Quenching interface engineering to prepare surface passivation layer: Immerse the above-mentioned ITO / PTAA / 2PACz / perovskite film at 105 °C in the quenching solution containing metal halide at 5 °C described in Example 2 for cooling, and the immersion time is 30 seconds;

[0070] S7. Preparation of electron transport layer and hole blocking layer: Under a vacuum condition of 5×10 -4 Pa, 20 nm of C 60 , 7 nm of BCP are sequentially evaporated on the above-prepared ITO / PTAA / 2PACz / perovskite film / quenching passivation layer;

[0071] S8. Laser etching P2 (forming perovskite interconnection channels): Use a 532 nm picosecond laser to etch the electron transport layer, perovskite layer, and hole transport layer along the preset line width (20 - 200 μm) to the underlying conductive layer. The etching line is parallelly offset from the P1 etching line to achieve sub-cell series connection;

[0072] S9. Preparation of top electrode: Under a vacuum condition of 5×10 -4 Pa, 80 nm of Ag is evaporated on the above-prepared ITO / PTAA / 2PACz / perovskite film / quenching passivation layer / C 60 / BCP;

[0073] S10. Laser etching P3 (isolating back electrode): Use a 532 nm picosecond laser to etch through the top electrode layer along the preset line width (20 - 200 μm). The etching line is parallelly offset from the P1 and P2 etching lines to ensure the independence of adjacent sub-cell electrodes, and a large-area perovskite solar cell module based on solution immersion quenching to improve the uniformity of surface passivation is prepared, denoted as Module III.

[0074] Comparative Example 1

[0075] A perovskite solar cell module without surface passivation. The preparation method in this embodiment is the same as that in Example 4, except that the perovskite thin film prepared in S1 - S5 is not subjected to solution immersion quenching treatment (step S6), but directly proceeds to steps S7 - S10, and a large - area perovskite solar cell module without surface passivation is prepared, denoted as Module I.

[0076] Comparative Example 2 A perovskite solar cell module based on spin - coating surface passivation. The preparation method in this embodiment is the same as that in Example 4, except that the perovskite thin film prepared in S1 - S5 is not subjected to quenching treatment (step S6), but a surface passivation layer is prepared by spin - coating: 500 μL of the solution containing metal halide prepared in Example 2 (1 mM) is spin - coated on the prepared ITO / PTAA / 2PACz / perovskite thin film (4000 r, 30 s), and then steps S7 - S10 are carried out to prepare a large - area perovskite solar cell module based on spin - coating surface passivation, denoted as Module II.

[0077] The prepared solar cell modules I, II, and III are subjected to J - V testing. Figure 8 It can be seen that the power conversion efficiency (PCE) of the perovskite solar cell module without surface passivation (Module I) is only 14.03%, and the PCE of the perovskite solar cell module with surface passivation by spin - coating (Module II) is only increased to 16.65%. For the perovskite solar cell module with the post - treatment method of solution immersion quenching, the open - circuit voltage V OC and short - circuit current J SC and fill factor FF are all improved, thus achieving a power conversion efficiency (PCE) of ∼20%, so it can be applied to large - area solar cell modules.

[0078] The prepared solar cell modules I and III are subjected to thermal stability testing. Figure 9 It can be seen that according to the test standard of the protocol (ISOS - D - 2I) formulated by the International Summit on Organic Photovoltaic Stability (ISOS), we evaluated the thermal stability of the unencapsulated perovskite solar cell modules. Modules I and III are heated at a constant temperature of 65 °C ± 5 °C in an inert atmosphere (N2), and the PCE is monitored every 60 hours to evaluate their stability. As Figure 9 shown, Module III retained 87% of its initial efficiency after 540 hours, while Module I only retained 43% of its initial efficiency in the same time, verifying that the solution immersion quenching method can effectively improve the stability of large - area solar cell modules.

[0079] Example 5

[0080] Application of a large-area perovskite thin film with improved surface passivation uniformity based on solution immersion quenching in a perovskite solar cell module. The specific preparation method is the same as that of Example 4, except that in this example, PEDOT:PSS is selected as the hole transport layer in step S4, and a perovskite light absorption layer with a narrow bandgap is selected in step S5. The specific preparation method is as follows:

[0081] S4. Preparation of the hole transport layer: Spin-coat 500 μL of 10 mg / mL PEDOT:PSS / H2O solution (6000 rpm, 30 s) on the ozone-treated ITO substrate, anneal at 150 °C for 30 minutes, and transfer to a glove box for standby after cooling to room temperature;

[0082] S5. Preparation of the perovskite light absorption layer: Prepare a 1.5 M FAI 0.6 MAI 0.3 CsI 0.1 SnI2 0.5 PbI2 0.5 narrow-bandgap perovskite precursor solution, where the molar ratio of FAI, MAI, CsI, PbI2, SnF2, and SnI2 is 0.6:0.3:0.1:0.5:0.25:0.25, and the volume ratio of DMF to DMSO is 3:1. After thoroughly mixing the perovskite precursor solution until the solid dissolves and the solution becomes clear, spin-coat 20 μL of the perovskite precursor solution on the ITO / PEDOT:PSS substrate by spin-coating (spin-coating speed 5 mm s -1 ). The operating temperature of the panel is 25 °C, and nitrogen gas with a pressure of 20 psi is applied through an air knife during spin-coating to assist solvent evaporation and film crystallization. Subsequently, transfer the perovskite thin film to a hot plate and anneal at 120 °C for 10 minutes;

[0083] S6. Quenching interface engineering to prepare the surface passivation layer: Next, immerse the above-mentioned 120 °C ITO / PEDOT:PSS perovskite thin film into the 5 °C quenching solution containing metal halides described in Example 2 for cooling according to step S6 of Example 4, and the immersion time is 30 seconds;

[0084] Perform J-V testing on the prepared narrow-bandgap solar cell module ( Figure 10 ), which verifies the compatibility of this method with different bandgap components of perovskite and is applicable to the application of various different components of perovskite in solar cell modules.

[0085] Example 6

[0086] Application of a large-area perovskite thin film with improved surface passivation uniformity based on solution immersion quenching in a perovskite solar cell module. The specific preparation method is the same as that of Example 4, except that in this example, a perovskite light absorption layer with a conventional bandgap (about 1.5 eV) is selected in step S5. The specific preparation method is as follows:

[0087] S5. Prepare the perovskite light absorption layer: Prepare a 1.5 M FAI 0.6 MA 0.4 PbI3 conventional bandgap perovskite precursor solution, where the molar ratio of FAI, MAI, and PbI2 is 0.6:0.4:1, and the volume ratio of DMF to DMSO is 7:3. After thoroughly mixing the perovskite precursor solution until the solid is dissolved and the solution becomes clear, 20 μL of the perovskite precursor solution is spin-coated (spin speed 5 mm s -1 ) onto the ITO / PTAA / 2PACz substrate. The operating temperature of the panel is 25 °C, and during the spin-coating process, nitrogen gas with a pressure of 20 psi is applied through an air knife to assist solvent evaporation and film crystallization. Subsequently, the perovskite thin film is transferred to a hot plate and annealed at 120 °C for 20 minutes;

[0088] S6. Quenching interface engineering to prepare the surface passivation layer: Next, according to step S6 of Example 4, the ITO / PTAA / 2PACz / perovskite thin film at 120 °C is immersed in the quenching solution containing metal halide at 5 °C described in Example 2 for cooling, and the immersion time is 30 seconds;

[0089] Perform J-V testing on the prepared conventional bandgap solar cell module ( Figure 11 ), which verifies the compatibility of this method with different bandgap components of perovskite and is applicable to the application of various different components of perovskite in solar cell modules.

[0090] Example 7

[0091] Application of a large-area perovskite thin film with improved surface passivation uniformity based on solution immersion quenching in a perovskite semi-transparent solar cell module. The preparation method of this example is the same as that of Example 4, except that the preparation method of the top electrode in step S9 is as follows:

[0092] Under a vacuum condition with a vacuum degree of 5×10 -4 Pa, 100 nm of transparent ITO is evaporated onto the ITO / PTAA / 2PACz / perovskite thin film / quenching passivation layer / C 60 / BCP prepared in S1-S8 of Example 4 to prepare a semi-transparent large-area perovskite solar cell module with improved surface passivation uniformity based on solution immersion quenching;

[0093] Meanwhile, the transmittance of the translucent component was tested by an ultraviolet-visible absorption spectrophotometer. As Figure 12 shown, an average visible transmittance (AVT) of 21% was achieved in the visible light range of 400 nm to 800 nm, indicating that the translucent large-area perovskite solar cell module has excellent light transmittance.

[0094] The J-V test was performed on the prepared translucent solar cell module. As Figure 13 shown, the photovoltaic conversion efficiency (PCE) of the translucent solar cell module achieved a PCE of about 12%, so it can be applied to the translucent large-area solar cell module.

[0095] The present invention provides a method for improving the passivation uniformity of a large-area perovskite photovoltaic module. By using a cold quenching liquid, the hot perovskite film is immersed therein for quenching to complete the surface treatment process, realizing the homogenization and high efficiency of the surface / interface passivation modification of the large-area film. Through thermal shock-induced secondary crystallization of the perovskite film, the crystallinity of the perovskite film is greatly improved. At the same time, dual regulation of gradient doping of passivation ions from the film surface to the deep bulk phase and halogen stabilization is achieved, reducing the defect density of the film and improving the contact between the perovskite layer and the electrode. Applied to the preparation of a large-area solar cell module with uniform passivation, it solves the problems of uneven distribution of the passivation agent and poor interface contact during the post-treatment of the large-area perovskite film, and realizes a high photovoltaic conversion efficiency of ~20% and good stability of the large-area perovskite photovoltaic module.

[0096] The above is a specific description of the preferred embodiment of the present invention. However, the present invention is not limited to the described embodiment. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for improving the passivation uniformity of large-area perovskite thin films by solution immersion quenching surface treatment, characterized in that, It includes the following steps: Immerse the annealed high-temperature perovskite thin film into a low-temperature quenching liquid for quenching treatment to obtain a perovskite modified thin film; The quenching liquid is a solvent or a solution containing a solute and a solvent, and the solute is a metal halide or an organic compound.

2. The method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 1, wherein, The temperature of the high-temperature perovskite thin film is 80-150 °C, the temperature of the low-temperature quenching liquid is 0-15 °C, and the quenching time is 1-5 minutes.

3. The method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 1, wherein, The solvent is at least one of chlorobenzene, isopropyl alcohol, isobutyl alcohol, toluene, m-xylene, chloroform, tetrafluoroethylene, anisole, ethyl acetate, tetrahydrofuran, cyclohexane.

4. The method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 1, characterized in that, The metal halide includes a compound formed by the ionic bond combination of a metal cation and a halogen anion, and the organic compound includes at least one of ethylenediamine dihydroiodide, ethylenediamine, benzyl ammonium halide, phenethyl ammonium halide, butyl ammonium halide, guanidinium halide, octylamine halide.

5. A method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 1, characterized in that, The structure of the perovskite is ABX3, where A is La 3+ , Nd 3+ , Ca 2+ , Sr 2+ , Ba 2+ , Na + , Rb + , Cs + , at least one of formamidine, methylamine, phenethylamine, trimethylammonium, butylamine, hexylamine, guanidine, B is Nb 5+ , Ti 4+ , Fe 3+ , Mn 3 + , Co 3+ , In 3+ , Bi 3+ , Pb 2+ , Sn 2+ , Ge 2+ , Cu 2+ , Ag + , at least one of O 2- , F - , Cl - , Br - , I - .

6. The method for improving the passivation uniformity of a large-area perovskite film by solution immersion quenching surface treatment according to claim 5, characterized in that, The band gap of the perovskite is 1.1-2.5 eV, among which the narrow band gap value of 1.1-1.45 eV is achieved by the gradient design of the Pb / Sn ratio, and the Pb / Sn ratio increases from 0% to 100%. The conventional band gap value of 1.45-1.55 eV is achieved by the gradient design of the MA / FA ratio, and the MA / FA ratio increases from 0% to 100%. The wide band gap value of 1.55 eV-2.5 eV is achieved by the gradient design of the Br / I ratio, and the Br / I ratio increases from 0% to 100%.

7. A method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 1, characterized in that, The preparation method of the perovskite thin film includes: dissolving a perovskite raw material in an organic solvent to prepare a perovskite precursor solution, and preparing the perovskite precursor solution into a perovskite thin film by one-step spin coating method or two-step spin coating method or air-assisted spin coating method or doctor blade coating method or slot die coating method or spraying method or inkjet printing method or soft cover deposition method or vapor deposition method, and then performing annealing treatment.

8. The method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 7, wherein, The organic solvent is selected from at least one of N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, γ-butyrolactone, N-methylformamide, acetonitrile, dimethoxyethanol and N-methylpyrrolidone.

9. The method for improving the passivation uniformity of a large-area perovskite thin film by solution immersion quenching surface treatment according to claim 7, characterized in that, The annealing adopts one-step annealing or two-step annealing. The temperature of the one-step annealing is 80-150 °C, and the annealing time is 1-60 minutes. The two-step annealing is to anneal at 50-90 °C for 5-30 minutes first, and then anneal at 90-150 °C for 5-30 minutes.

10. A solar cell module prepared from a large-area perovskite thin film passivated by the method according to any one of claims 1-9, characterized in that The solar cell device assembly is a normal device structure that sequentially includes a conductive substrate, an electron transport layer, a perovskite thin film, a hole transport layer and a top electrode from bottom to top, or an inverted device structure that sequentially includes a conductive substrate, a hole transport layer, a perovskite thin film, an electron transport layer, a hole blocking layer and a top electrode from bottom to top.

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