A preparation method of fluorine-containing compound and its application

Abstract

The invention discloses a method for preparing a fluorine-containing compound and its application, and relates to the technical field of perovskite material additives. The preparation method is as follows: naphthaleneboric acid, potassium carbonate and bis(triphenylphosphine)palladium chloride are added to a drying container, the container is evacuated to a vacuum state and then filled with nitrogen, phenylacetylene and nine fluoro-4-iodobutane are added to the container, dichloromethane and distilled water are then added to the container, and heated for reaction; the obtained reaction mixture is subjected to extraction and drying, separation and purification, and a fluorine-containing compound is obtained. The fluorine-containing compound prepared by the present invention has good compatibility with the perovskite material, and there will be no heterogeneous phase generation; it is applied as an additive in the perovskite material to suppress the migration and loss of ions, reduce the defect state density at the perovskite grain boundary, extend the carrier lifetime, and improve the charge transfer efficiency; it can also promote the nucleation and growth of perovskite, and improve the quality and morphology of the perovskite film.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite material additives, and in particular to a preparation method and application of a fluorine-containing compound. Background Art

[0002] Organic-inorganic metal halide perovskite materials have broad application prospects in the field of photovoltaic materials due to their characteristics such as adjustable band gap, long carrier diffusion length, long carrier lifetime, and high absorption coefficient. In the past decade, the development of perovskite solar cells (PSCs), their power conversion efficiency (PCE) has jumped from 3.8% to 25.7%. However, perovskite materials still have performance instability problems under light and humid conditions. The A-site organic amine cations in the perovskite easily combine with water molecules, thereby dissociating from the perovskite lattice structure; in addition, the iodide ions in the perovskite film migrate under light, causing I - The tendency toward I2 leads to perovskite degradation. To improve the stability of perovskite performance, additives with various functional groups that can interact with perovskite materials to prevent the migration of cations and anions are currently being studied. To address these issues and enhance the performance of perovskite materials, the present invention provides a method for preparing a fluorine-containing compound and its application. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method and application of a fluorine-containing compound. The prepared fluorine-containing compound has good compatibility with perovskite materials. When used as an additive in perovskite materials, it can improve the performance of perovskite films and devices.

[0004] To achieve the above object, the present invention provides a method for preparing a fluorine-containing compound, comprising the following steps:

[0005] S1. Naphthaleneboric acid, potassium carbonate and bis(triphenylphosphine)palladium chloride were added to a dry container, the container was evacuated to a vacuum state and filled with nitrogen, phenylacetylene and nonafluoro-4-iodobutane were added to the container, and then dichloromethane and distilled water were added to the container, and the reaction was heated for dissolution;

[0006] S2, extracting and drying the obtained reaction mixture, removing the extraction solvent to obtain a crude product, and then separating and purifying the crude product to separate the final product, the fluorine-containing compound;

[0007] The synthetic route is as follows:

[0008]

[0009] Preferably, in step S1, the molar ratio of naphthaleneboric acid, phenylacetylene and nonafluoro-4-iodobutane is 13:10:20.

[0010] Preferably, in step S1, the mixture is heated to 50° C. for dissolution and reacted at this temperature for 12 hours.

[0011] Preferably, the extraction and drying operation in step S2 is: extracting the reaction product with dichloromethane and water, combining the organic layers and drying with anhydrous magnesium sulfate.

[0012] Preferably, in step S2, the extraction solvent is removed by a rotary evaporator to obtain a crude product, and the crude product is purified by column chromatography, wherein the eluent used is a mixed solvent of n-hexane / dichloromethane.

[0013] Application of the fluorine-containing compound prepared by the preparation method in perovskite materials.

[0014] Therefore, the present invention provides a method for preparing a fluorine-containing compound and its application, and the specific beneficial effects are as follows:

[0015] (1) The fluorine-containing compound prepared by the present invention has good compatibility with the perovskite material and no impurity phase is generated;

[0016] (2) Applying fluorine-containing compounds as additives to perovskite materials can inhibit ion migration and loss, reduce the defect state density at the perovskite grain boundary, extend the carrier lifetime, and improve the charge transfer efficiency;

[0017] (3) Applying fluorine-containing compounds as additives to perovskite materials can promote the nucleation and growth of perovskite and improve the quality and morphology of perovskite films.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The fluorine-containing compound prepared by the present invention is dissolved in deuterated chloroform. 1 HNMR spectrum, where the solvent peak is marked with an asterisk *;

[0020] Figure 2 The fluorine-containing compound prepared by the present invention is dissolved in deuterated chloroform. 13 CNMR carbon spectrum, where the solvent peak is marked with an asterisk *;

[0021] Figure 3 It is a high-resolution mass spectrum of the fluorine-containing compound prepared by the present invention;

[0022] Figure 4 is the XRD (X-ray diffraction) pattern of perovskite films doped with different concentrations of fluorine-containing compounds;

[0023] Figure 5is the JV (current density-voltage) curve of the perovskite film doped with different concentrations of fluorine-containing compounds;

[0024] Figure 6 is the PL (photoluminescence) spectrum of perovskite films doped with different concentrations of fluorine-containing compounds;

[0025] Figure 7 is the TRPL (time-resolved photoluminescence) spectra of perovskite films doped with different concentrations of fluorine-containing compounds;

[0026] Figure 8 This is a comparison of SEM (scanning electron microscope) images of perovskite films doped with different concentrations of fluorine-containing compounds. A is an undoped perovskite film; B is a perovskite film doped with 2 mg / mL of fluorine-containing compounds; C is a perovskite film doped with 4 mg / mL of fluorine-containing compounds; and D is a perovskite film doped with 6 mg / mL of fluorine-containing compounds. DETAILED DESCRIPTION

[0027] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0028] Example

[0029] The present invention provides a method for preparing a fluorine-containing compound, comprising the following steps:

[0030] S1. Add 3.9 mmol of naphthaleneboric acid, 6 mmol of potassium carbonate, and 0.12 mmol of bis(triphenylphosphine)palladium chloride to a dry Schlenk tube. Use a vacuum pump to evacuate the Schlenk tube and then fill it with nitrogen. Repeat this operation three times. Then, add 3 mmol of phenylacetylene and 6 mmol of nonafluoro-4-iodobutane to the Schlenk tube. Then, use a syringe to inject 12.5 mL of dichloromethane and 2.5 mL of distilled water into the Schlenk tube in sequence. Heat to 50°C to dissolve, and stir the reaction at this temperature for 12 hours. The reaction is completed.

[0031] S2. The obtained reaction mixture was extracted with dichloromethane and water. The organic layers were combined and dried over anhydrous magnesium sulfate. The extraction solvent was then removed using a rotary evaporator to obtain a crude reaction product. Finally, the crude product was purified by column chromatography using a n-hexane / dichloromethane mixture as eluent to separate the final product, a fluorine-containing compound, with a yield of 88%.

[0032] like Figure 1 、 Figure 2 and Figure 3 As shown, Figure 1 Characterizes the different hydrogen atoms in the structure. Hydrogen atoms at different positions appear in different positions. The peak of hydrogen atoms on the double bond is a characteristic peak, appearing at around 6.2ppm and splitting into three peaks. The remaining hydrogen atoms are all hydrogen atoms on the benzene ring, with peaks appearing at around 7ppm. Figure 2 It characterizes the different carbon atoms in the structure, and the carbon atoms at different positions appear in different locations; Figure 3 It represents the relative molecular mass of the compound. The molecular formula of the compound is C 22 H 13 F9, relative molecular mass 448.09, Figure 3 consistent. Figure 1 、 Figure 2 and Figure 3 This is sufficient to show that the structure of the compound is accurate.

[0033] The fluorine-containing compound prepared in the above example was used as an additive to prepare a solution, which was then spin-coated on the surface of a perovskite substrate to form a thin film. The performance of the perovskite film was then tested. The specific method is as follows:

[0034] 1. Prepare the solution to obtain the electron transport layer

[0035] Tin dioxide hydrogel was diluted 6-fold with deionized water and then doped with 3 mg / mL potassium chloride solution to obtain solution I. Solution I was preheated to 60°C and spin-coated onto a substrate at 5000 rpm for 20 seconds. The substrate was immediately placed on a heating table heated to 160°C for 30 minutes of annealing. After annealing, the solution was cooled in the furnace and ozone-treated for 15 minutes.

[0036] 2. Prepare the solution to obtain the perovskite layer

[0037] A lead iodide solution with a concentration of 0.693 g / mL was prepared using 100 uL of dimethyl sulfoxide and 900 uL of N,N-dimethylformamide as solvents. A formamidine hydroiodide (FAI) solution was prepared by adding 0.009 g / mL of methylammonium chloride, 0.009 g / mL of methylammonium bromide, and fluorinated compounds with concentrations of 0, 2, 4, and 6 mg / mL, respectively, to 1000 uL of isopropanol as solvent.

[0038] The completed substrate and lead iodide solution were placed on a heating table in a glove box and preheated at 70°C for 15 minutes. The lead iodide layer was then spin-coated. The lead iodide solution was added dropwise to the substrate and spun at 2500 rpm for 15 seconds. The substrate was then allowed to stand for 10-20 minutes. The substrate was then placed on a heating table and pre-annealed at 70°C for 15 seconds (the pre-annealed substrate was separated from the unpre-annealed substrate, and the FAI solution could be heated to 50°C during this period).

[0039] After the pre-annealing is completed, the heated FAI solution is added to the substrate, and the substrate is immediately spin-coated at a speed of 5000 rpm for 13 seconds. After the spin coating is completed, it is immediately placed on a heating table at 80°C for pre-annealing. After there is no obvious change in the film layer, it is removed. After all substrates are spin-coated and pre-annealed, a final solvent annealing at 156°C for 16 minutes is performed (solvent is added to the bottle cap every 8 minutes).

[0040] 3. Perform performance tests on the prepared perovskite film.

[0041] Depend on Figure 4 It can be seen that the ratio of the peak intensity of the (011) and (022) interface crystal planes of the perovskite film doped with fluorine-containing compounds, especially when the doping amount is 4 mg / mL, increases significantly, while the peak position relative to lead iodide and other crystal directions is significantly weakened, indicating that the incorporation of fluorine-containing compounds can optimize the crystal orientation of perovskite and inhibit the formation of impurity lead iodide. The (011) and (022) crystal plane orientations are beneficial to charge transport (the higher the peak position, the better the crystal orientation).

[0042] The charge transfer efficiency of perovskite films doped with different concentrations of fluorine-containing compounds is shown in Table 1:

[0043] Table 1

[0044]

[0045] Depend on Figure 5 As shown in Table 1, as the concentration of the doped fluorine-containing compound increases, the photoelectric conversion efficiency (PCE) and current density (Jsc) of the perovskite film both show a trend of first increasing and then decreasing. When the concentration of the doped fluorine-containing compound is 4 mg / mL, it reaches the maximum, and then the current density decreases (the higher the charge transfer efficiency, the better the performance of the perovskite film).

[0046] Depend on Figure 6 It can be seen that the PL intensity of the perovskite film doped with fluorine-containing compounds is greatly enhanced, but with the increase of doping concentration, the PL intensity of the perovskite film shows a process of first increasing and then decreasing. When the doping concentration of the fluorine-containing compound is 4 mg / mL, the peak position reaches the highest. The higher the peak position, the more it indicates that the fluorine-containing compound has a passivating effect on the defects at the perovskite grain boundary and inhibits the generation of defect states in the perovskite, thereby making the non-radiative composite defect states inside the perovskite relatively small.

[0047] Depend on Figure 7 It can be seen that the peak position of the perovskite film increases after doping with fluorine-containing compounds. The higher the peak position in the TRPL spectrum, the fewer non-radiative recombination defect states inside the perovskite, and the longer its service life, which means that the life of the perovskite film is extended after doping with fluorine-containing compounds.

[0048] Depend on Figure 8 It can be seen that the surface of the initial perovskite film is scattered and rough. With the doping of fluorine-containing compounds, the surface of the perovskite film grows smoother and denser, and the crystal particles are significantly larger, indicating that the addition of fluorine-containing compounds is beneficial to promote the crystallization of perovskite and improve the quality of the perovskite film.

[0049] Therefore, the present invention provides a preparation method and application of a fluorine-containing compound. The fluorine-containing compound prepared by the present invention has good compatibility with the perovskite solution and the perovskite material, and no impurity phase is generated. The fluorine-containing compound used as an additive in the perovskite material can inhibit the migration and loss of ions, reduce the defect state density at the perovskite grain boundary, and improve the carrier lifetime and charge transfer efficiency. The fluorine-containing compound also promotes the nucleation and growth of the perovskite, improves the quality and morphology of the perovskite film, and thus improves the device performance.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. Application of a fluorine-containing compound in a perovskite material, characterized in that: The preparation of the fluorine-containing compound comprises the following steps: S1. Naphthaleneboric acid, potassium carbonate and bis(triphenylphosphine)palladium chloride were added to a dry container, the container was evacuated to a vacuum state and filled with nitrogen, phenylacetylene and nonafluoro-4-iodobutane were added to the container, and then dichloromethane and distilled water were added to the container, and the reaction was heated for dissolution; S2, extracting and drying the obtained reaction mixture, removing the extraction solvent to obtain a crude product, and then separating and purifying the crude product to separate the final product, the fluorine-containing compound; The synthetic route is as follows:

2. The use of a fluorine-containing compound in a perovskite material according to claim 1, characterized in that: In step S1, the molar ratio of naphthaleneboric acid, phenylacetylene and nonafluoro-4-iodobutane is 13:10:

20.

3. The use of a fluorine-containing compound in a perovskite material according to claim 1, characterized in that: In step S1, the mixture is heated to 50° C. for dissolution and reacted at this temperature for 12 hours.

4. The use of a fluorine-containing compound in a perovskite material according to claim 1, characterized in that: The extraction and drying operation in step S2 is: extracting the reaction product with dichloromethane and water, combining the organic layers and drying with anhydrous magnesium sulfate.

5. The use of a fluorine-containing compound in a perovskite material according to claim 1, characterized in that: In step S2, the extraction solvent is removed by a rotary evaporator to obtain a crude product, and the crude product is purified by column chromatography, wherein the eluent used is a mixed solvent of n-hexane / dichloromethane.

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