Preparation method and application of pure-phase 2D perovskite passivation layer

Abstract

The application discloses a preparation method of a pure-phase 2D perovskite passivation layer and application thereof. The method for preparing the single-n-value two-dimensional perovskite passivation layer is characterized in that: a passivation molecule is directly reacted on the surface of a perovskite absorption layer by a hot-pressing method to generate a single-n-value two-dimensional perovskite, which can effectively passivate defects on the surface and at the grain boundary of the perovskite, reduce non-complex radiation centers of the perovskite thin film, adjust the energy level of a solar cell, and further improve the photoelectric conversion efficiency of the solar cell; on the other hand, the perovskite thin film after passivation can inhibit ion migration, thereby effectively improving the stability of the solar cell. The perovskite thin film passivation method is simple in operation, can be produced on a large scale, and can effectively avoid the disadvantages caused by a solvent method. The method can also process large-area perovskite thin films, thereby providing a new strategy for preparation of a perovskite module.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology and relates to a method for preparing a pure-phase 2D perovskite passivation layer and its application. Background Technology

[0002] Two-dimensional (2D) perovskite passivation layers can suppress ion migration, thus improving the efficiency and stability of organic-inorganic metal hybrid perovskite solar cells. However, the high exciton binding energy of 2D perovskites with mixed quantum wells limits carrier generation and collection. Currently, highly reactive passivation molecules can penetrate into the interior of 3D perovskite films through solvents, forming mixed-dimensional 2D perovskites. Furthermore, solvents used in solution methods can remodel the surface of 3D perovskites, causing chemical degradation of the 3D perovskite film, thereby further hindering the improvement of perovskite solar cell performance. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a method for preparing a pure-phase 2D perovskite passivation layer. By using a hot-pressing method, the preparation temperature and applied pressure are controlled to directly induce a reaction between passivation molecules and the three-dimensional perovskite, forming a two-dimensional perovskite passivation layer at the single quantum well scale. This method not only effectively avoids the continuous phase transition problem inherent in solution-based methods but also yields a perovskite thin film with a more suitable energy level. Solar cells incorporating this perovskite thin film exhibit improved charge transport, thereby effectively enhancing the photoelectric conversion efficiency and stability of the solar cell.

[0004] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0005] A method for preparing a pure-phase 2D perovskite passivation layer includes reacting passivation molecules directly on the surface of a perovskite absorber layer by hot pressing to generate a two-dimensional perovskite passivation layer with a single n value.

[0006] According to an embodiment of the present invention, the thickness of the passivation layer is 5-10 nm.

[0007] According to an embodiment of the present invention, the passivation layer is a pure-phase 2D perovskite passivation layer.

[0008] According to embodiments of the present invention, the passivating molecule is selected from at least one of RP-type organic cationic salts, phenylethylamine salts, butylammonium salts, octylammonium salts, bisphenylethylammonium salts, and 4-methoxyphenylethylammonium iodide. For example, the phenylethylamine salt, butylammonium salt, octylammonium salt, and bisphenylethylammonium salt can be their iodide salts, bromides, or chloride salts. In this invention, phenylethylamine, butylammonium, octylammonium, and bisphenylethylammonium are named PEA, BA, OA, and BPEA, respectively.

[0009] According to an embodiment of the present invention, the hot-pressing method includes modifying a passivating molecular solution onto a substrate, and then applying it to the surface of the perovskite absorber layer by hot pressing. Preferably, the modification method can be spin coating. For example, the spin coating speed is 1000-5000 rpm / s, exemplarily 1000, 2000, 3000, 4000 or 5000 rpm / s; the spin coating time is 1-60 s, exemplarily 1, 10, 20, 30, 40, 50 or 60 s.

[0010] According to an embodiment of the present invention, the passivation molecule solution is obtained by dissolving the passivation molecules in an alcohol solvent (such as isopropanol).

[0011] According to an embodiment of the present invention, the concentration of the passivating molecular solution is 1-10 mg / mL, exemplarily 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 mg / mL.

[0012] According to an embodiment of the present invention, the pressure of the hot pressing method is 20-200 MPa, exemplarily 20, 40, 60, 80, 100, 150 or 200 MPa; the heating temperature of the hot pressing method is 40-200°C, exemplarily 40, 80, 120, 160 or 200°C; and the heating time of the hot pressing method is 1-10 min, exemplarily 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 min.

[0013] According to an embodiment of the present invention, the perovskite absorber layer is in the form of a thin film, preferably a three-dimensional perovskite thin film. Preferably, the thickness of the perovskite absorber layer is 200-900 nm.

[0014] The present invention also provides a perovskite thin film comprising a perovskite absorber layer and a two-dimensional perovskite passivation layer with the aforementioned single n value modified on the perovskite absorber layer.

[0015] The present invention also provides the use of the above-described method and / or the above-described perovskite thin film in the fabrication of perovskite solar cells.

[0016] The present invention also provides a perovskite solar cell containing the above-described perovskite thin film.

[0017] According to an embodiment of the present invention, the perovskite solar cell further includes an electron transport layer. Preferably, the electron transport material used in the electron transport layer can be an n-type inorganic semiconductor or an n-type organic semiconductor. For example, the n-type inorganic semiconductor or n-type organic semiconductor includes, but is not limited to, one of: TiO2, mesoporous TiO2, SnO2, and ZnO-ZnS. Exemplarily, the electron transport layer is preferably one of SnO2, TiO2 / SnO2, ZnO-ZnS / mesoporous TiO2, and TiO2 / mesoporous TiO2. Preferably, the thickness of the electron transport layer is 10-120 nm.

[0018] For example, the electron transport layer can be prepared by spin coating, spray pyrolysis or chemical bath method, etc., of electron transport materials.

[0019] According to an embodiment of the present invention, the perovskite solar cell further includes a hole transport layer. Preferably, the hole transport layer comprises a hole transport material and an additive. For example, the hole transport material is one of Spiro-OMeTAD, PTAA, P3HT, or CuSCN; preferably Spiro-OMeTAD; the additive is tert-butylpyridine (tBP), Li salt (LiTFSI), or Co salt (FK2O9).

[0020] For example, the hole transport layer is prepared by spin coating or vacuum evaporation of a hole transport layer solution; for example, the hole transport layer solution contains hole transport materials and additives.

[0021] According to an embodiment of the present invention, the perovskite solar cell further includes a metal electrode. For example, the metal electrode is one of gold, silver, copper, or aluminum; or, for example, the thickness of the metal electrode is 30-200 nm. For example, the metal electrode is prepared by vacuum evaporation.

[0022] According to an embodiment of the present invention, the perovskite solar cell further includes a transparent conductive substrate. Preferably, the transparent conductive substrate is one of ITO conductive glass and FTO conductive glass.

[0023] According to an embodiment of the present invention, the perovskite material used in the perovskite thin film has the chemical formula A. a M b X c A includes CH3NH3 + HC(NH2)2 + Cs + and Rb + At least one of them; M is Pb 2+ Sn 2+ One of them; X is I -,Br - Or I - ,Br - There are a total of ; a, b, and c are the stoichiometric proportions of A, M, and X, respectively, where a = 1, b = 1, and c = 3.

[0024] According to an embodiment of the present invention, the perovskite solar cell includes, from top to bottom, a transparent conductive substrate, an electron transport layer, the perovskite thin film described above, a hole transport layer, and a metal electrode.

[0025] According to an embodiment of the present invention, the perovskite solar cell includes, from top to bottom, a transparent conductive substrate, a hole transport layer, the perovskite thin film described above, an electron transport layer, and a metal electrode.

[0026] The present invention also provides a method for preparing the above-mentioned perovskite solar cell, which includes a method for preparing the above-mentioned pure phase 2D perovskite passivation layer.

[0027] According to an embodiment of the present invention, the preparation method further includes a pretreatment of the transparent conductive substrate. For example, the transparent conductive substrate is cut into fixed sizes and etched, the prepared conductive substrate is ultrasonically cleaned in a solvent, dried, and then subjected to ultraviolet ozone sterilization treatment.

[0028] According to an embodiment of the present invention, the preparation method further includes preparing an electron transport layer and / or a hole transport layer on a pretreated transparent conductive substrate.

[0029] According to an embodiment of the present invention, the preparation method further includes subjecting the transparent conductive substrate coated with an electron transport layer and / or a hole transport layer to ultraviolet ozone sterilization treatment again, and after the treatment is completed, transferring the conductive substrate to a glove box.

[0030] According to an embodiment of the present invention, the preparation method further includes preparing a perovskite absorber layer on the electron transport layer and / or the hole transport layer. For example, the perovskite absorber layer can be prepared by spin coating, blade coating, etc. Exemplarily, a perovskite precursor solution is coated onto the electron transport layer by spin coating to form a perovskite absorber layer; the chemical formula of the perovskite absorber layer is A. a M b X c A includes CH3NH3 + HC(NH2)2 + Cs + and Rb + At least one of them; M is Pb 2+ Sn 2 + One of them; X is I - ,Br - Or I- ,Br - There are a total of ; a, b, and c are the stoichiometric proportions of A, M, and X, respectively, where a = 1, b = 1, and c = 3.

[0031] In one embodiment of the present invention, the method for preparing the perovskite precursor solution includes dissolving a metal iodide (PbI2 or SnI2), a cationic iodide (FAI, MAI, RbI or CsI), lead bromide (PbBr2), methyl ammonium chloride (MACl), and methyl ammonium bromide (MABr) in a specific molar ratio in an organic solvent and stirring; wherein the organic solvent is one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), and 2-methoxyethanol (2-Me); wherein the stirring temperature is 25-70°C and the stirring time is 30-300 min.

[0032] According to an embodiment of the present invention, the preparation method further includes modifying a passivating molecule (e.g., 4-methoxyphenylethylammonium iodide) onto a substrate using a solution method, and then pressing it onto the surface of the perovskite absorber layer using a hot-pressing method to obtain a perovskite film with a single n-value two-dimensional perovskite passivation. Preferably, the concentration of the passivating molecule solution used in the solution method is 1-10 mg / mL; the pressure of the hot-pressing method is 20-200 MPa; the heating temperature of the hot-pressing method is 40-200 °C; and the heating time of the hot-pressing method is 1-10 min.

[0033] According to an embodiment of the present invention, the preparation method further includes preparing a hole transport layer and / or an electron transport layer on a perovskite thin film with single n-value two-dimensional perovskite passivation.

[0034] According to an embodiment of the present invention, the preparation method further includes preparing a metal electrode on a hole transport layer and / or an electron transport layer.

[0035] According to an embodiment of the present invention, the method for preparing the perovskite solar cell includes the following steps:

[0036] (1) Cut the transparent conductive substrate into a fixed size and perform etching (scribing the P1 channel of the module with a laser). Clean the prepared conductive substrate with ultrasonic in different solvents, dry it and then perform ultraviolet ozone sterilization.

[0037] (2) Prepare an electron transport layer and / or a hole transport layer on the transparent conductive substrate processed in step (1);

[0038] (3) The transparent conductive substrate coated with the electron transport layer and / or hole transport layer is subjected to ultraviolet ozone sterilization treatment again. After the treatment is completed, the conductive substrate is transferred to the glove box, and the perovskite precursor solution is coated onto the electron transport layer and / or hole transport layer by spin coating to form a perovskite absorption layer.

[0039] (4) 4-methoxyphenylethyl ammonium iodide was modified onto the substrate by solution method and then pressed onto the surface of the perovskite absorber layer by hot pressing method to obtain a perovskite film with single n-value two-dimensional perovskite passivation.

[0040] (5) Prepare hole transport layer and / or electron transport layer on a perovskite thin film with single n-value two-dimensional perovskite passivation.

[0041] (6) Deposit metal electrodes onto the hole transport layer and / or electron transport layer by vacuum evaporation (by laser scribing the P3 channel of the module).

[0042] The beneficial effects of this invention are:

[0043] (1) The method for preparing a two-dimensional perovskite passivation layer with a single n value provided by the present invention can effectively passivate defects on the surface and at the grain boundaries of the perovskite, reduce non-composite radiation centers of the perovskite film, adjust the energy level of the solar cell, and thus improve the photoelectric conversion efficiency of the solar cell. On the other hand, the perovskite film after passivation can suppress ion migration, thereby effectively improving the stability of the solar cell.

[0044] (2) The perovskite thin film passivation method of the present invention is simple to operate, can be mass-produced, and can effectively avoid the drawbacks of solvent methods. The method of the present invention can also process large-area perovskite thin films, thus providing a new strategy for the preparation of perovskite modules. Attached Figure Description

[0045] Figure 1 The X-ray diffraction patterns are of the two-dimensional perovskite passivated perovskite film with a single n-value prepared in Example 1 and the two-dimensional perovskite passivated perovskite film with a mixed n-value prepared in Comparative Example 1.

[0046] Figure 2 The image shows a steady-state fluorescence comparison between the two-dimensional perovskite passivated film with a single n-value prepared in Example 1 and the two-dimensional perovskite passivated film with a mixed n-value prepared in Comparative Example 1.

[0047] Figure 3 This is a comparison chart of the photoelectric conversion efficiency of the two-dimensional perovskite passivated perovskite film with a single n-value prepared in Example 1 and the two-dimensional perovskite passivated perovskite film with a mixed n-value prepared in Comparative Example 1.

[0048] Figure 4The graph shows the photoelectric conversion efficiency of the two-dimensional perovskite passivated perovskite thin film solar module with a single n value prepared in Example 1.

[0049] Figure 5 This is a comparison chart of the stability tests of solar cells (modules) of the two-dimensional perovskite passivated perovskite film with a single n-value prepared in Example 1 and the two-dimensional perovskite passivated perovskite film with a mixed n-value prepared in Comparative Example 1. Detailed Implementation

[0050] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0051] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0052] Example 1

[0053] (1) Cut FTO (fluorine-doped tin dioxide) conductive glass into glass substrates of 15mm x 15mm size. Clean the cut glass substrates ultrasonically in deionized water, acetone and ethanol for 15min respectively, and then treat them in an ultraviolet ozone generator for 15min.

[0054] (2) SnO2 colloid (concentration of 15wt%, purchased from Alfa Aesar) was diluted with water to 2.67wt% and then spin-coated onto the prepared FTO glass at a speed of 3000rpm / s. After spin-coating for 30s, it was annealed at 150℃ in air for 30 minutes.

[0055] (3) PbI2 and FAI were dissolved in a mixed solvent of DMF and DMSO with a volume ratio of 8:1 at a molar ratio of 1.09:1. The mixture was stirred continuously at room temperature for 3 hours to completely dissolve the PbI2 and FAI to obtain a 1.4 M FAPbI3 perovskite precursor solution. The perovskite precursor solution was spin-coated onto an FTO / SnO2 substrate at a spin speed of 5000 rpm / s for 30 s. The resulting mesophase film was heated at 100 °C for 60 minutes to generate a black perovskite phase FAPbI3 film.

[0056] (4) Spin-coat a 4 mg / mL solution of 4-methoxyphenylethyl ammonium iodide passivation molecules in isopropanol onto the blank FTO glass substrate prepared in step (1) at a spin-coating speed of 5000 rpm / s and a spin-coating time of 30 s. Then place it on the black perovskite phase FAPbI3 film generated in step (3), apply a pressure of 40 MPa, and heat at 160 °C for 5 minutes. After heating, remove the glass slide with 4-methoxyphenylethyl ammonium iodide passivation molecules spin-coated to obtain a black perovskite phase FAPbI3 film with single n-value two-dimensional perovskite passivation.

[0057] (5) The hole transport layer solution (72.3 mg Spiro-OMeTAD, 28.8 μL tBP and 17.5 μL LiTFSI dissolved in 1 mL chlorobenzene) was spin-coated onto the surface of the perovskite phase FAPbI3 film obtained in step (4) by spin-coating, with the rotation speed controlled at 4000 rpm / s and the spin-coating time at 30 s;

[0058] (6) Finally, Au was deposited onto the hole transport layer by vacuum evaporation (with a deposition thickness of 100 nm), and the deposition area of ​​Au was made to be 80 mm² using a specific mold. 2 ;

[0059] Steps (3), (5) and (6) are all completed in the glove box.

[0060] Comparative Example 1

[0061] Compared with Example 1, the only difference is that: in step (4), a two-dimensional perovskite passivated perovskite film with mixed n values ​​is prepared by solution method. The specific method is as follows: 4 mg / mL of 4-methoxyphenylethyl ammonium iodide passivation molecular isopropanol solution is spin-coated onto the surface of the black perovskite phase FAPbI3 film prepared in step (3). The spin-coating speed is 5000 rpm and the spin-coating time is 30 s. After spin-coating, the obtained film is heat-treated on a hot stage. The annealing temperature is 100 ℃ and the annealing time is 10 min.

[0062] Figure 1 The images show X-ray diffraction patterns of the two-dimensional perovskite passivated film with a single n-value prepared in Example 1 and the two-dimensional perovskite passivated film with a mixed n-value prepared in Comparative Example 1. The figures show that the two-dimensional perovskite passivation layer prepared by the solution method is mixed-dimensional, while the two-dimensional perovskite passivation layer with a single n-value prepared by the solid-state method in this invention is single-dimensional. Furthermore, the three-dimensional perovskite passivated by the solid-state method exhibits better crystallinity compared to that prepared by the solution method.

[0063] Figure 2The image shows a steady-state fluorescence comparison between the single-n-value two-dimensional perovskite passivated perovskite film prepared in Example 1 and the mixed-n-value two-dimensional perovskite passivated perovskite film prepared in Comparative Example 1. The image shows that the two-dimensional perovskite passivation layer prepared by the solution method is mixed-dimensional, while the two-dimensional perovskite passivation layer prepared by the solid-state method in this invention is single-dimensional. Furthermore, the emission peak at 800 nm of the single-n-value two-dimensional perovskite passivated perovskite film prepared by the solid-state method in this invention is much higher than that of the perovskite film prepared by the solution method. This indicates that the two-dimensional perovskite passivation layer prepared by the solid-state method in this invention has better passivation defect capability than that prepared by the solution method.

[0064] Figure 3 This figure compares the photoelectric conversion efficiency of the two-dimensional perovskite passivated film with a single n-value prepared in Example 1 with that of the two-dimensional perovskite passivated film with mixed n-values ​​prepared in Comparative Example 1. As can be seen from the figure, the perovskite solar cell prepared using the single n-value two-dimensional perovskite passivation layer obtained by the solid-state method of this invention has a higher open-circuit voltage and short-circuit current compared to the cell prepared using mixed n-values; this indicates that the single n-value two-dimensional perovskite passivated film prepared by the solid-state method of this invention has better charge extraction capability.

[0065] Figure 4 The graph shows the photoelectric conversion efficiency of the perovskite thin-film solar module with single-n-value two-dimensional perovskite passivation prepared in Example 1. As can be seen from the graph, the perovskite solar cell module (14cm²) based on the black perovskite phase FAPbI3 thin film with single-n-value two-dimensional perovskite passivation prepared by the solid-state method of this invention is a perovskite solar cell module. 2 It has an open-circuit voltage of 6.69V and a current of 4.2mA / cm. 2 The short-circuit current has a fill factor of 80.07% and an efficiency of 22.49%.

[0066] Figure 5 This is a comparison of the stability tests of solar cells (modules) using a single-n-value two-dimensional perovskite passivated perovskite film prepared in Example 1 and a mixed-n-value two-dimensional perovskite passivated perovskite film prepared in Comparative Example 1. As can be seen from the figure, after continuous illumination stability testing of the encapsulated perovskite module under sunlight, the perovskite module based on the single-n-value two-dimensional perovskite passivated black perovskite phase FAPbI3 film prepared by the solid-state method of this invention showed a lower stability (T1). 80 The time is 520h, while the T of the perovskite module based on the mixed n-value two-dimensional perovskite passivated perovskite thin film prepared by solution method is 520h. 80The duration is 40 hours. This indicates that the perovskite module of the black perovskite phase FAPbI3 film with single n-value two-dimensional perovskite passivation prepared by the solid-state method has better continuous illumination stability compared with the perovskite module of the mixed n-value two-dimensional perovskite passivation perovskite film prepared by the solution method.

[0067] Example 2

[0068] (1) Cut FTO (fluorine-doped tin dioxide) conductive glass into glass substrates of 15mm x 15mm size. Clean the cut glass substrates ultrasonically in deionized water, acetone and ethanol for 15min respectively, and then treat them in an ultraviolet ozone generator for 15min.

[0069] (2) Tetraisopropoxy titanium (purchased from Greatcell Solar) was dissolved in water to obtain a 0.2M tetraisopropoxy titanium aqueous solution, which was then spin-coated onto the washed FTO layer at a spin speed of 3000 rpm / s and a spin time of 30 s. The substrate composed of FTO / dense mesoporous TiO2 layer was annealed in air at 550°C for 30 minutes. After the temperature dropped to room temperature, the substrate was transferred to a glove box.

[0070] (3) PbI2 and FAI were dissolved in a mixed solvent of DMF and DMSO at a molar ratio of 1.09:1 and stirred continuously at room temperature for 3 hours to completely dissolve them, resulting in a 1.4M FAPbI3 perovskite precursor solution. The perovskite precursor solution was spin-coated onto a substrate of FTO / dense mesoporous TiO2 layer at a speed of 5000 rpm / s for 30 s. The resulting mesophase film was heated at 100℃ for 60 minutes to generate a black perovskite phase FAPbI3 film.

[0071] (4) Spin-coat a 4 mg / mL solution of 4-methoxyphenylethyl ammonium iodide passivation molecules in isopropanol onto the blank FTO glass substrate prepared in step (1) at a spin-coating speed of 5000 rpm / s and a spin-coating time of 30 s. Then place it on the black perovskite phase FAPbI3 film generated in step (3), apply a pressure of 40 MPa, and heat at 160 °C for 5 minutes. After heating, remove the glass slide with 4-methoxyphenylethyl ammonium iodide passivation molecules spin-coated to obtain a black perovskite phase FAPbI3 film with single n-value two-dimensional perovskite passivation.

[0072] (5) The hole transport layer solution (72.3 mg Spiro-OMeTAD, 28.8 μL tBP and 17.5 μL LiTFSI dissolved in 1 mL chlorobenzene) was spin-coated onto the surface of the perovskite phase FAPbI3 film obtained in step (4) by spin-coating, with the rotation speed controlled at 4000 rpm / s and the spin-coating time at 30 s;

[0073] (6) Finally, Au was deposited onto the hole transport layer by vacuum evaporation (with a deposition thickness of 100 nm), and the deposition area of ​​Au was made to be 80 mm² using a specific mold. 2 ;

[0074] Steps (3), (5) and (6) are all completed in the glove box.

[0075] Example 3

[0076] (1) Cut FTO (fluorine-doped tin dioxide) conductive glass into glass substrates of 15mm x 15mm size. Clean the cut glass substrates by ultrasonic cleaning in deionized water, acetone and ethanol for 15min respectively, and then place them in an ultraviolet ozone generator for 15min.

[0077] (2) SnO2 colloid (concentration of 15wt%, purchased from Alfa Aesar) was diluted with water to 2.67wt% and then spin-coated onto the prepared FTO glass at a speed of 3000rpm / s. After spin-coating for 30s, it was annealed at 150℃ in air for 30 minutes.

[0078] (3) PbI2 and FAI were dissolved in a mixed solvent of DMF and DMSO with a volume ratio of 8:1 at a molar ratio of 1.09:1. The mixture was stirred continuously at room temperature for 3 hours to completely dissolve the PbI2 and FAI to obtain a 1.4 M FAPbI3 perovskite precursor solution. The perovskite precursor solution was then coated onto an FTO / SnO2 substrate with a scraper height of 100 μm and a scraping speed of 8 mm / s. The resulting mesophase film was heated at 100 °C for 60 minutes to generate a black perovskite phase FAPbI3 film.

[0079] (4) Spin-coat a 4 mg / mL solution of 4-methoxyphenylethyl ammonium iodide passivation molecules in isopropanol onto the blank FTO glass substrate prepared in step (1) at a spin-coating speed of 5000 rpm / s and a spin-coating time of 30 s. Then place it on the black perovskite phase FAPbI3 film generated in step (3), apply a pressure of 40 MPa, and heat at 160 °C for 5 minutes. After heating, remove the glass slide with 4-methoxyphenylethyl ammonium iodide passivation molecules spin-coated to obtain a black perovskite phase FAPbI3 film with single n-value two-dimensional perovskite passivation.

[0080] (5) The hole transport layer solution (72.3 mg Spiro-OMeTAD, 28.8 μL tBP and 17.5 μL LiTFSI dissolved in 1 mL chlorobenzene) was spin-coated onto the surface of the perovskite phase FAPbI3 film obtained in step (4) by spin-coating, with the rotation speed controlled at 4000 rpm / s and the spin-coating time at 30 s;

[0081] (6) Finally, Au was deposited onto the hole transport layer by vacuum evaporation (with a deposition thickness of 100 nm), and the deposition area of ​​Au was made to be 80 mm² using a specific mold. 2 ;

[0082] Steps (3), (5) and (6) are all completed in the glove box.

[0083] Example 4

[0084] (1) FTO (fluorine-doped tin dioxide) conductive glass was cut into 50mm x 50mm glass substrates and etched using a laser (the P1 channel of the module was etched using a green laser with a power of 30% and a frequency of 200kHz). The etched glass substrates were ultrasonically cleaned in deionized water, acetone and ethanol for 15 minutes, and then placed in an ultraviolet ozone generator for 15 minutes.

[0085] (2) SnO2 colloid (concentration of 15wt%, purchased from Alfa Aesar) was diluted with water to 2.67wt% and then spin-coated onto the prepared FTO glass at a speed of 3000rpm / s. After spin-coating for 30s, it was annealed at 150℃ in air for 30 minutes.

[0086] (3) PbI2 and FAI were dissolved in a mixed solvent of DMF and DMSO with a volume ratio of 8:1 at a molar ratio of 1.09:1. The mixture was stirred continuously at room temperature for 3 hours to completely dissolve the PbI2 and FAI to obtain a 1.4 M FAPbI3 perovskite precursor solution. The perovskite precursor solution was spin-coated onto an FTO / SnO2 substrate at a speed of 5000 rpm / s for 30 s. The resulting mesophase film was heated at 100 °C for 60 minutes to generate a black perovskite phase FAPbI3 film.

[0087] (4) Spin-coat a 4 mg / mL solution of 4-methoxyphenylethyl ammonium iodide passivation molecules in isopropanol onto the blank FTO glass substrate prepared in step (1) at a spin-coating speed of 5000 rpm / s and a spin-coating time of 30 s. Then place it on the black perovskite phase FAPbI3 film generated in step (3), apply a pressure of 40 MPa, and heat at 160 °C for 5 minutes. After heating, remove the glass slide with 4-methoxyphenylethyl ammonium iodide passivation molecules spin-coated to obtain a black perovskite phase FAPbI3 film with single n-value two-dimensional perovskite passivation.

[0088] (5) The hole transport layer solution (72.3 mg Spiro-OMeTAD, 28.8 μL tBP, and 17.5 μL LiTFSI dissolved in 1 mL chlorobenzene) was spin-coated onto the surface of the perovskite phase FAPbI3 film obtained in step (4) by spin-coating. The spin-coating speed was controlled at 4000 rpm / s and the spin-coating time was 30 s. The P2 channel of the module was scribed with a laser with a power of 25% and a frequency of 200 kHz.

[0089] (6) Finally, Au was deposited onto the hole transport layer by vacuum evaporation (with a deposition thickness of 100 nm), and the deposition area of ​​Au was made to be 80 mm² using a specific mold. 2 The P3 channel of the module was laser-scribed, with a power of 27.5% and a frequency of 200kHz.

[0090] Steps (3), (5) and (6) are all completed in the glove box.

[0091] Example 5

[0092] (1) Cut FTO (fluorine-doped tin dioxide) conductive glass into glass substrates of 15mm x 15mm size. Clean the cut glass substrates by ultrasonic cleaning in deionized water, acetone and ethanol for 15min respectively, and then place them in an ultraviolet ozone generator for 15min.

[0093] (2) SnO2 colloid (concentration of 15wt%, purchased from Alfa Aesar) was diluted with water to 2.67wt% and then spin-coated onto the prepared FTO glass at a speed of 3000rpm / s. After spin-coating for 30s, it was annealed at 150℃ in air for 30 minutes.

[0094] (3) PbI2 and MAI were dissolved in a mixed solvent of DMF and DMSO with a volume ratio of 8:1 at a molar ratio of 1.09:1. The mixture was stirred continuously at room temperature for 3 hours to completely dissolve the PbI2 and MAI to obtain a 1.4 M MAPbI3 perovskite precursor solution. The perovskite precursor solution was spin-coated onto an FTO / SnO2 substrate at a speed of 5000 rpm / s for 30 s. The resulting mesophase film was heated at 100 °C for 60 minutes to generate a black perovskite phase MAPbI3 film.

[0095] (4) Dissolve 4 mg / mL of 4-methoxyphenylethyl ammonium iodide passivation molecules in isopropanol and spin-coat it onto the blank FTO glass substrate prepared in step (1) at a spin-coating speed of 5000 rpm / s and a spin-coating time of 30 s. Then place it on the black perovskite phase MAPbI3 film generated in step (3), apply a pressure of 40 MPa, and heat it at 160 °C for 5 minutes. After heating, remove the glass slide with 4-methoxyphenylethyl ammonium iodide passivation molecules spin-coated to obtain a black perovskite phase MAPbI3 film with single n-value two-dimensional perovskite passivation.

[0096] (5) The hole transport layer solution (72.3 mg Spiro-OMeTAD, 28.8 μL tBP, 17.5 μL LiTFSI dissolved in 1 mL chlorobenzene) was spin-coated onto the surface of the perovskite phase MAPbI3 film obtained in step (4) by spin-coating, with the rotation speed controlled at 4000 rpm / s and the spin-coating time at 30 s;

[0097] (6) Finally, Au was deposited onto the hole transport layer by vacuum evaporation (with a deposition thickness of 100 nm), and the deposition area of ​​Au was made to be 80 mm² using a specific mold. 2 ;

[0098] Steps (3), (4), (5) and (6) are all completed in the glove box.

[0099] Example 6

[0100] The preparation steps and material selection in this embodiment are the same as in Embodiment 1. The only difference is that the electron transport layer material in step (2) is a TiO2 / mesoporous TiO2 layer (the TiO2 / mesoporous TiO2 layer material was purchased from Youxuan Technology Company). The rest of the preparation steps and material selection are the same as in Embodiment 1.

[0101] Example 7

[0102] The preparation steps and material selection in this embodiment are the same as in Example 1. The only difference is that in step (3), PbI2 and FAI are dissolved in 2-ME (2-methoxyethanol) at a molar ratio of 1.09:1 and stirred continuously for 1 hour under heating at 70°C to completely dissolve them, so as to obtain a FAPbI3 perovskite precursor solution with a concentration of 1.2M. The remaining preparation steps and material selection are the same as in Example 1.

[0103] Example 8

[0104] The preparation steps and material selection in this embodiment are the same as in Example 1. The only difference is that in step (5), the hole transport layer material is PTAA layer. The hole transport layer solution (30mg PTAA, 10μL tBP, 5μL LiTFSI dissolved in 1mL chlorobenzene) is spin-coated onto the surface of the perovskite phase FAPbI3 film obtained in step (4) by spin coating. The rotation speed is controlled at 2000rpm / s and the spin coating time is 30s. The remaining preparation steps and material selection are the same as in Example 1.

[0105] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a pure-phase 2D perovskite passivation layer, characterized in that, This includes reacting passivation molecules directly on the surface of the perovskite absorber layer to generate a two-dimensional perovskite passivation layer with a single n value through a hot-pressing method; The passivating molecule is selected from 4-methoxyphenylethylammonium iodide; The hot-pressing method includes modifying a passivation molecular solution onto a substrate, and then applying pressure to the surface of the perovskite absorber layer by hot-pressing. The modification method is spin coating, the spin coating speed is 1000-5000 rpm / s, and the spin coating time is 1-60s; The pressure of the hot pressing method is 20-200 MPa; the heating temperature of the hot pressing method is 40-200 ℃; and the heating time of the hot pressing method is 1-10 min.

2. A perovskite thin film, characterized in that, It includes a perovskite absorber layer and a two-dimensional perovskite passivation layer with a single n value prepared by the method of claim 1 modified on the perovskite absorber layer.

3. Use of the method of claim 1 and / or the perovskite thin film of claim 2 in the fabrication of perovskite solar cells.

4. A perovskite solar cell, characterized in that, It contains the perovskite thin film as described in claim 3.

5. The battery as described in claim 4, characterized in that, The perovskite solar cell also includes an electron transport layer.

6. The battery as described in claim 5, characterized in that, The electron transport layer uses an n-type inorganic semiconductor or an n-type organic semiconductor as its electron transport material. The n-type inorganic semiconductor or n-type organic semiconductor includes, but is not limited to, one of TiO2, SnO2, and ZnO-ZnS. The thickness of the electron transport layer is 10-120 nm.

7. The battery as described in claim 4, characterized in that, The perovskite solar cell also includes a hole transport layer; The hole transport layer comprises a hole transport material and an additive, wherein the hole transport material is one of Spiro-OMeTAD, PTAA, P3HT or CuSCN.

8. The battery according to any one of claims 4-7, characterized in that, The perovskite solar cell further includes a metal electrode, which is one of gold, silver, copper or aluminum; the thickness of the metal electrode is 30-200 nm.

9. The battery according to any one of claims 4-7, characterized in that, The perovskite solar cell also includes a transparent conductive substrate.

10. The battery according to any one of claims 4-7, characterized in that, The chemical formula of the perovskite material used in the perovskite thin film is A. a M b X c A includes CH3NH3 + HC(NH2)2 + Cs + and Rb + At least one of them; M is Pb 2+ Sn 2+ One of them; X is I - ,Br - Or I - ,Br - There are a total of ; a, b, and c are the stoichiometric proportions of A, M, and X, respectively, with a=1, b=1, and c=3.

11. The method for preparing a perovskite solar cell according to any one of claims 4-10, characterized in that, The preparation method includes the preparation method of the pure phase 2D perovskite passivation layer as described in claim 1.

12. The method for preparing a perovskite solar cell as described in claim 11, characterized in that, The preparation method further includes preparing an electron transport layer and / or a hole transport layer on a pretreated transparent conductive substrate.

13. The method for preparing a perovskite solar cell as described in claim 12, characterized in that, The preparation method further includes preparing a perovskite absorber layer on the electron transport layer and / or hole transport layer.

14. The method for preparing a perovskite solar cell as described in claim 13, characterized in that, The chemical formula of the perovskite absorber layer is A. a M b X c A includes CH3NH3 + HC(NH2)2 + Cs + and Rb + At least one of them; M is Pb 2+ Sn 2+ One of them; X is I - ,Br - Or I - ,Br - There are a total of ; a, b, and c are the stoichiometric proportions of A, M, and X, respectively, with a=1, b=1, and c=3.

15. The method for preparing a perovskite solar cell as described in claim 14, characterized in that, The preparation method further includes preparing a hole transport layer and / or an electron transport layer on a perovskite thin film with single n-value two-dimensional perovskite passivation.

16. The method for preparing a perovskite solar cell as described in claim 15, characterized in that, The preparation method further includes preparing a metal electrode on a hole transport layer and / or an electron transport layer.

17. The method for preparing a perovskite solar cell according to any one of claims 11-16, characterized in that, Includes the following steps: (1) Cut the transparent conductive substrate into a fixed size and perform etching. Clean the prepared conductive substrate in different solvents by ultrasonication, and then perform ultraviolet ozone sterilization after drying. (2) Prepare an electron transport layer and / or a hole transport layer on the transparent conductive substrate processed in step (1); (3) The transparent conductive substrate coated with the electron transport layer and / or hole transport layer is subjected to ultraviolet ozone sterilization treatment again. After the treatment is completed, the conductive substrate is transferred to the glove box, and the perovskite precursor solution is coated onto the electron transport layer and / or hole transport layer by spin coating to form a perovskite absorption layer. (4) 4-methoxyphenylethyl ammonium iodide was modified onto the substrate by solution method and then pressed onto the surface of the perovskite absorber layer by hot pressing method to obtain a perovskite film with single n-value two-dimensional perovskite passivation. (5) Prepare hole transport layer and / or electron transport layer on a perovskite thin film with single n-value two-dimensional perovskite passivation. (6) Deposit metal electrodes onto the hole transport layer and / or electron transport layer by vacuum evaporation.

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