Preparation method of organic perovskite nanocrystal and organic perovskite nanocrystal

Abstract

The application belongs to the technical field of nanocrystal material preparation, and particularly relates to a preparation method of organic perovskite nanocrystal and the organic perovskite nanocrystal. The method comprises the steps of obtaining a precursor solution and performing high-temperature vacuum extraction on the precursor solution. The step of obtaining the precursor solution at least comprises: heating and complexing organic precursor salt and a ligand to form an organic salt complex; the structure of the ligand is R1-R-SO3H, wherein R is selected from C6-C18 arylene, R1 is selected from C n H 2n+1 , H, and n is an integer from 1 to 18. The method can completely remove impurities in the synthesis of the organic perovskite nanocrystal during the high-temperature vacuum extraction operation by pre-synthesizing the organic salt complex, which has a higher melting point and binding stability, while avoiding the escape of small organic molecules caused by high-temperature vacuum extraction. The synthesized nanocrystal has adjustable wavelength, uniform size, high quantum efficiency and high stability.

Description

Technical Field

[0001] This invention belongs to the field of nanocrystalline material preparation technology, specifically relating to a method for preparing organic perovskite nanocrystals and the organic perovskite nanocrystals themselves. Background Technology

[0002] In recent years, halide perovskite ABX3 (A=MA) + FA + Cs + B = Pb 2+ Cu 2+ Sn 2+ Cs-based inorganic perovskite nanocrystals (CsPbBr3) have attracted widespread attention due to their excellent photoelectric properties and have great application potential. Pure Cs-based inorganic perovskite nanocrystals have an inherent disadvantage in wavelength. Current technologies can generally adjust the wavelength to around 520 nm through size adjustment and surface modification, but this is often accompanied by a decrease in luminescence performance due to nanocrystal aggregation. Doping with iodine can adjust the wavelength, but this easily leads to halogen segregation and phase separation, making stability difficult to guarantee. Formamidinium / methylamine bromide (FAPbBr3 / MAPbBr3) organic perovskite nanocrystals emit light in the 520–540 nm range, giving them a unique advantage as display luminescent materials. They offer a purer green color, a wider color gamut, and do not require halogen doping, thus avoiding phase separation problems.

[0003] Typically, in the synthesis of organoperovskite nanocrystals, inexpensive and readily available materials such as formamidine acetate, methylamine acetate, and lead acetate trihydrate are inevitably used. The acetate and water of crystallization in these materials need to be removed under vacuum at a high temperature of around 120°C; otherwise, the properties of the prepared nanocrystals will be affected. However, this high-temperature vacuum process removes small organic molecules such as formamidine and methylamine simultaneously, leading to reduced yield, low batch reproducibility, and low quantum efficiency, hindering industrial-scale production. Furthermore, the poor stability of organoperovskite nanocrystals also restricts their development and application.

[0004] To address the issues of small organic molecules escaping during high-temperature vacuum impurity removal and the poor stability of organic perovskite nanocrystals, existing technologies involve adding organic ligands, such as oleic acid and oleylamine, during the synthesis of organic perovskite nanocrystals. These organic ligands bind with formamidin to form organic salts. However, the binding between the ligands and small organic molecules is not strong, and they gradually separate during high-temperature vacuum heating, causing most of the small organic molecules to escape. This approach has minimal effect on solving the problem of small organic molecule escape. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low quantum efficiency and poor stability of organic perovskite nanocrystals caused by the escape of small organic molecules during high-temperature vacuum extraction in the synthesis process of organic perovskite nanocrystals in the prior art. Thus, the present invention provides a method for preparing organic perovskite nanocrystals and organic perovskite nanocrystals that solves the above technical problems.

[0006] The technical solution of the present invention:

[0007] A method for preparing organic perovskite nanocrystals includes the following steps: obtaining a precursor solution and subjecting the precursor solution to high-temperature vacuum, characterized in that the step of obtaining the precursor solution includes at least: heating and complexing an organic precursor salt with a ligand to form an organic salt complex.

[0008] The ligand has the structure R1-R-SO3H, where R is selected from C6-C18 aryl groups, and R1 is selected from C6-C18 aryl groups. n H 2n+1 It can be any one of H, where n is an integer from 1 to 18.

[0009] R is selected from C6-C12 arylene groups; R1 is selected from C n H 2n+1 It can be any one of H, where n is an integer from 1 to 12.

[0010] The heating complexation temperature is above 40°C, preferably 50–70°C;

[0011] The complexation reaction time is 10 min or more, preferably 10 to 40 min.

[0012] The molar ratio of the organic precursor salt to the organic ligand is less than or equal to 1; preferably, the molar ratio of the organic precursor salt to the ligand is 1:(1-10), more preferably 1:(2-4).

[0013] The organic precursor salt is selected from formamidine acetate, methylamine acetate, or a combination of both; preferably formamidine acetate.

[0014] The heating and complexation process is carried out in an inert gas atmosphere.

[0015] The step of obtaining the precursor solution is as follows: the metal precursor salt is mixed with the organic precursor salt, ligand and solvent, and heated to form a complex, thereby obtaining the precursor solution.

[0016] Alternatively, the step of obtaining the precursor solution is as follows: mixing the organic precursor salt, ligand and solvent, heating and complexing to obtain a first precursor solution, and adding the metal precursor salt to the first precursor solution to obtain a second precursor solution.

[0017] The first precursor solution and / or the second precursor solution are subjected to high-temperature vacuuming.

[0018] The metal precursor salt is selected from one or a combination of lead acetate, tin acetate, bismuth acetate, and germanium acetate; preferably lead acetate.

[0019] The molar ratio of the organic precursor salt to the metal precursor salt is (0.1–5):1.

[0020] The solvent is any one or a combination of octadecene, trimethylbenzene, xylene, and toluene.

[0021] The temperature for high-temperature vacuuming is greater than 100℃, preferably 100~140℃.

[0022] The high-temperature vacuuming time is greater than 10 minutes, preferably 10 to 60 minutes.

[0023] The high-temperature vacuum heating process is carried out in an inert gas atmosphere.

[0024] It also includes the step of injecting a halogen source solution into the precursor solution after high-temperature vacuuming to react and synthesize an organic perovskite nanocrystal solution.

[0025] The synthesis reaction temperature is 25–200℃.

[0026] The halogen source solution is heated to 25–130°C before injection.

[0027] The process of synthesizing the organic perovskite nanocrystal solution is carried out under an inert gas atmosphere.

[0028] The halogen source in the halogen source solution is selected from one or a combination of several of quaternary ammonium halides, oleylamine halides, and benzoyl bromide; more preferably, the quaternary ammonium halide is selected from either dioctadecyldimethylammonium bromide or didodecyldimethylammonium bromide; and the oleylamine halide is oleylamine bromide.

[0029] The molar ratio of the metal precursor salt to the halogen source is 1:(2-5).

[0030] An organic perovskite nanocrystal was synthesized using the preparation method described above.

[0031] The technical solution of this invention has the following advantages:

[0032] This invention provides a method for preparing organic perovskite nanocrystals. It utilizes a ligand with a sulfonic acid functional group (possessing strong acidity, close to sulfuric acid) to pre-form an organic salt complex with small organic molecules in an organic precursor salt. Because the ligand can continuously ionize hydrogen ions, the electrostatic interaction with the small organic molecules is stronger, resulting in higher and more stable ionic bonds. Therefore, the organic salt complex formed by the ligand with the stronger binding force has a higher melting and boiling point, which helps to effectively prevent the escape of small organic molecules during high-temperature vacuum impurity removal. This not only improves the purity of the precursor salt reacting with the halogen source and ensures the stability of the small organic molecule content, but also improves the crystallinity and uniformity of the nanocrystals. The synthesized nanocrystals have tunable wavelengths, uniform size, excellent optical properties (high quantum efficiency), high stability, and high yield, while also improving batch repeatability. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 The aging test results are based on the FAPbBr3 perovskite nanocrystals prepared in Example 1 of this invention.

[0035] Figure 2 The results are based on the aging test results of the optical film prepared using the FAPbBr3 perovskite nanocrystals prepared in Comparative Example 3 of this invention. Detailed Implementation

[0036] The specific testing methods for the luminescence quantum efficiency of the nanocrystalline solution in the examples and comparative examples are as follows: The luminescence peak position testing method is as follows: First, adjust the optical path so that the xenon lamp light illuminates the center of the sample. Then, use excitation light with continuously varying wavelengths to illuminate the sample and record the signal intensity to obtain the steady-state spectrum. Finally, record the highest peak position in the steady-state spectrum, which is the luminescence peak position. The quantum efficiency (PLQY) testing method is as follows: Before testing, the integrating sphere has been calibrated with the standard luminescent sample Rhodamine B. The emission spectra of the blank control and the sample under 420nm excitation light conditions were tested respectively. The quantum efficiency of the sample can be measured by calculating the ratio of the number of photons emitted to the number of photons absorbed by the sample using software.

[0037] Preparation method of optical film in the examples and comparative examples: Take 1 ml of nanocrystalline solution in a centrifuge tube, add 3 ml of ethyl acetate, centrifuge at 8000 rpm for 5 min, discard the supernatant, add 0.5 g of isobornyl acrylate (IBOA), 1.5 g of polyurethane acrylate, and 20 μL of 1173 initiator to the precipitate, mix evenly using a degassing and stirring device, coat to form a liquid film, and then UV cure. Optical film stability test method: Place the optical film between the probe and the blue light backplane, ensuring that the brightness of the blue light backplane remains constant at 315 nits, and test the change in brightness of the optical film. Aging conditions: room temperature, placed at room temperature under room light; dry heat, placed in an 85℃ oven; blue light, directly placed on a blue light backplane with a brightness of 800 nits and a wavelength of 450 nm for continuous irradiation.

[0038] Example 1

[0039] A method for preparing FAPbBr3 perovskite nanocrystals includes the following steps:

[0040] Weigh 0.54 mmol of formamidine acetate, 0.27 mmol of lead acetate trihydrate, and 1.89 mmol of dodecylbenzenesulfonic acid (DBSA) separately using a balance, and place them in a 100 ml three-necked flask. Add 10 ml of octadecene (ODE), remove air by vacuum at room temperature, and then introduce N2. Heat to 60 °C and stir for 30 min to induce a complexation reaction, obtaining a precursor solution. Heat to 120 °C, vacuum for 30 min, and after the temperature stabilizes, introduce N2 and quickly inject a pre-prepared solution of dioctadecyl dimethyl ammonium bromide (DDOAB) in thallium (0.675 mmol of DDOAB dissolved in 1 ml of thallium, heated to 120 °C on a hot plate). After reacting for 5 s, place in an ice-water bath. Add 3 times the volume of ethyl acetate to the crude solution, centrifuge at 8000 rpm for 5 min, collect the precipitate, add the original volume of n-hexane, centrifuge at 4000 rpm for 5 min, and collect the supernatant to obtain a nanocrystalline solution.

[0041] The quantum efficiency of the nanocrystalline solution is 95%, the emission peak is at 530 nm, and the full width at half maximum (FWHM) is 22 nm. The aging stability data of the optical film are as follows: Figure 1 As shown, it exhibits excellent stability, with virtually no brightness decay when placed at room temperature; after 300 hours of exposure to 800nit blue light, the brightness is 76% of the initial brightness; after 300 hours of high-temperature aging at 85℃, the brightness is 83% of the initial brightness.

[0042] Example 2

[0043] This embodiment describes a method for preparing MAPbBr3 perovskite nanocrystals. In Example 1, formamidine acetate is replaced with an equimolar amount of methylamine acetate. The remaining operations are consistent with Example 1. The resulting nanocrystal solution exhibits a quantum efficiency of 90%, a emission peak position of 525 nm, and a full width at half maximum (FWHM) of 23 nm. The optical film demonstrates excellent aging stability; its brightness shows virtually no decay at room temperature; after 300 hours of 800 nits blue light irradiation, the brightness is 73% of the initial brightness; after 300 hours of high-temperature aging at 85°C, the brightness is 75% of the initial brightness.

[0044] Example 3

[0045] This embodiment describes a method for preparing FAPbBr3 perovskite nanocrystals, in which the trimethylbenzene solution of DDOAB in Example 1 is replaced with an equal volume and equimolar amount of toluene solution of OAmBr (0.675 mmol of OAmBr is dissolved in 1 ml of toluene and heated to 120°C on a hot plate), and the remaining operations are the same as in Example 1.

[0046] Its nanocrystalline solution has a quantum efficiency of 97%, an emission peak of 531 nm, and a full width at half maximum (FWHM) of 20 nm. The optical film exhibits excellent aging stability, with virtually no brightness decay at room temperature; after 300 hours of 800 nit blue light irradiation, the brightness is 78% of the initial brightness; after 300 hours of high-temperature aging at 85℃, the brightness is 82% of the initial brightness.

[0047] Example 4

[0048] The method for preparing FAPbBr3 perovskite nanocrystals in this embodiment differs from that in Example 1 in that the stirring time at 60°C is 60 min, while the rest of the operation is the same as in Example 1.

[0049] Due to the extended stirring time, the reaction between DBSA and formamidin was complete, thus having no adverse effects under the high-temperature vacuum process. The quantum efficiency of the nanocrystalline solution was 97%, with a emission peak at 532 nm and a full width at half maximum (FWHM) of 21 nm. The optical film exhibited excellent aging stability, with virtually no brightness decay at room temperature; after 300 hours of 800 nits of blue light irradiation, the brightness was 79% of the initial brightness; after 300 hours of high-temperature aging at 85°C, the brightness was 81% of the initial brightness.

[0050] Example 5

[0051] The method for preparing FAPbBr3 perovskite nanocrystals in this embodiment differs from that in Example 1 in that the complexation reaction temperature is 40°C, while the remaining operations are the same as in Example 1.

[0052] The reaction temperature was relatively low, resulting in incomplete reaction between formamidin and DBSA. This led to the removal of a small amount of formamidin during subsequent vacuuming, causing a slight decrease in performance. The quantum efficiency of the nanocrystalline solution was 85%, the emission peak was 533 nm, and the full width at half maximum (FWHM) was 22 nm. The optical film exhibited moderate aging stability; brightness showed virtually no decay at room temperature; after 300 hours of 800 nit blue light irradiation, the brightness was 69% of the initial brightness; after 300 hours of high-temperature aging at 85°C, the brightness was 65% of the initial brightness.

[0053] Example 6

[0054] The method for preparing FAPbBr3 perovskite nanocrystals in this embodiment differs from that in Example 1 in that the heating temperature for high-temperature vacuuming is 140°C, while the remaining operations are the same as in Example 1.

[0055] Because formamidin binds completely to DBSA, raising the vacuum temperature to 140℃ has little effect. The quantum efficiency of the nanocrystalline solution is 95%, the emission peak is 530nm, and the full width at half maximum (FWHM) is 21nm. The optical film exhibits excellent aging stability; its brightness shows virtually no decay at room temperature; after 300 hours of 800nit blue light irradiation, the brightness is 80% of the initial brightness; after 300 hours of high-temperature aging at 85℃, the brightness is 79% of the initial brightness.

[0056] Example 7

[0057] The method for preparing FAPbBr3 perovskite nanocrystals in this embodiment differs from that in Example 1 in that the high-temperature vacuuming time is 60 minutes, while the rest of the operation is the same as in Example 1.

[0058] Since formamidin binds completely to DBSA, extending the vacuuming time by 30 minutes has little impact. The quantum efficiency of the nanocrystalline solution is 96%, the emission peak is 529 nm, and the full width at half maximum (FWHM) is 21.5 nm. The optical film exhibits excellent aging stability; its brightness shows virtually no decay at room temperature; after 300 hours of 800 nits of blue light irradiation, the brightness is 81% of the initial brightness; after 300 hours of high-temperature aging at 85°C, the brightness is 76% of the initial brightness.

[0059] Example 8

[0060] This embodiment describes a method for preparing FAPbBr3 perovskite nanocrystals, in which DBSA in Example 1 is replaced with an equimolar amount of benzenesulfonic acid, and the remaining operations are the same as in Example 1.

[0061] Its nanocrystalline solution has a quantum efficiency of 94.3%, an emission peak of 531 nm, and a full width at half maximum (FWHM) of 22 nm. The optical film exhibits excellent aging stability, with virtually no brightness decay at room temperature; after 300 hours of 800 nit blue light irradiation, the brightness is 82% of the initial brightness; after 300 hours of high-temperature aging at 85℃, the brightness is 83% of the initial brightness.

[0062] Example 9

[0063] This embodiment describes a method for preparing FAPbBr3 perovskite nanocrystals, in which DBSA in Example 1 is replaced with an equimolar amount of naphthalenesulfonic acid, and the remaining operations are completely consistent with those in Example 1.

[0064] Its nanocrystalline solution has a quantum efficiency of 95.6%, an emission peak of 532 nm, and a full width at half maximum (FWHM) of 21 nm. The optical film exhibits excellent aging stability, with virtually no brightness decay at room temperature; after 300 hours of 800 nit blue light irradiation, the brightness is 78% of the initial brightness; after 300 hours of high-temperature aging at 85℃, the brightness is 81% of the initial brightness.

[0065] Example 10

[0066] The method for preparing FAPbBr3 perovskite nanocrystals in this embodiment differs from that in Example 1 in that the molar amount of DBSA is 0.54 mmol, the molar ratio of FA to DBSA is 1:1, and the remaining operations are the same as in Example 1.

[0067] Since the DBSA ligand was sufficient to coordinate with FA and successfully complex, nanocrystals could be synthesized. However, due to insufficient DBSA, the binding was incomplete, resulting in a decrease in the performance of the nanocrystals. The quantum efficiency of the nanocrystal solution was 90.5%, the emission peak was 531 nm, and the full width at half maximum (FWHM) was 22 nm. The optical film exhibited moderate aging stability; at room temperature, the brightness showed almost no decrease; after 300 hours of 800 nits of blue light irradiation, the brightness was 65% of the initial brightness; after 300 hours of high-temperature aging at 85°C, the brightness was 68% of the initial brightness.

[0068] Example 11

[0069] The method for preparing FAPbBr3 perovskite nanocrystals in this embodiment differs from that in Example 1 in that the molar amount of DBSA is 2.7 mmol, the molar ratio of FA to DBSA is 1:5, and the remaining operations are the same as in Example 1.

[0070] Its nanocrystalline solution has a quantum efficiency of 94.8%, an emission peak of 533 nm, and a full width at half maximum (FWHM) of 22.5 nm. The optical film exhibits excellent aging stability, with virtually no brightness decay at room temperature; after 300 hours of 800 nit blue light irradiation, the brightness is 77% of the initial brightness; after 300 hours of high-temperature aging at 85℃, the brightness is 75% of the initial brightness.

[0071] Example 12

[0072] This embodiment describes a method for preparing FAPbBr3 perovskite nanocrystals, comprising the following steps:

[0073] Weigh 0.54 mmol of formamidine acetate and 1.89 mmol of dodecylbenzenesulfonic acid (DBSA) using a balance, place them in a 100 ml three-necked flask, add 10 ml of octadecene (ODE), remove air by vacuum at room temperature, then introduce N2, heat to 60 °C, and stir for 30 min to induce a complexation reaction, obtaining the first precursor solution. Then, allow it to cool naturally to room temperature, add 0.27 mmol of lead acetate trihydrate, and obtain the second precursor solution. Heat the second precursor solution to 120 °C, vacuum for 30 min, and after the temperature stabilizes, introduce N2, and quickly inject a pre-prepared trimethylammonium bromide (DDOAB) solution in thallium (0.675 mmol of DDOAB dissolved in 1 ml of thallium, heated to 120 °C on a hot plate). After reacting for 5 s, place in an ice-water bath. Add 3 times the volume of ethyl acetate to the crude solution, centrifuge at 8000 rpm for 5 min to collect the precipitate, add the original volume of n-hexane, centrifuge at 4000 rpm for 5 min to collect the supernatant, and obtain the nanocrystalline solution.

[0074] The nanocrystalline solution exhibits a quantum efficiency of 96%, a emission peak at 532 nm, and a full width at half maximum (FWHM) of 21 nm. The optical film demonstrates excellent aging stability, with virtually no brightness decay at room temperature; after 300 hours of 800 nit blue light irradiation, the brightness reaches 80% of the initial brightness; and after 300 hours of high-temperature aging at 85°C, the brightness reaches 85% of the initial brightness.

[0075] Comparative Example 1

[0076] This comparative example describes a method for preparing FAPbBr3 perovskite nanocrystals, in which the heating complexation step of heating to 60°C and stirring for 30 min in Example 1 is removed, while the remaining operations are the same as in Example 1.

[0077] DBSA and formamidin did not react completely to form a complex, resulting in a large amount of small organic formamidin being removed after the high-temperature vacuum process. After the bromine source was injected, the solution was turbid and white-green, and the luminescence was very weak under ultraviolet flashlight irradiation.

[0078] Comparative Example 2

[0079] This comparative example describes a method for preparing FAPbBr3 perovskite nanocrystals, in which DBSA in Example 1 is replaced with an equimolar amount of oleic acid, and the remaining operations are consistent with those in Example 1.

[0080] Because the combination of oleic acid and formamidin is unstable, a large amount of small organic formamidin molecules are removed after the high-temperature vacuum process, making it impossible to generate nanocrystals.

[0081] Comparative Example 3

[0082] The preparation method of FAPbBr3 perovskite nanocrystals in this comparative example differs from that in Example 1 in that DBSA in Example 1 is replaced with an equimolar amount of oleic acid, the vacuuming time at 120°C is 5 min, and the remaining operations are the same as in Example 1.

[0083] Although shortening the high-temperature vacuuming time can ensure that formamidin is not completely removed, it cannot completely remove water, oxygen, and acetic acid from the system, resulting in a decrease in optical properties and stability (especially dry heat stability). Its nanocrystalline solution has a quantum efficiency of 75%, a emission peak position of 535 nm, and a full width at half maximum (FWHM) of 25 nm. For example... Figure 2 As shown, the optical film exhibits poor aging stability. When placed at room temperature, the brightness decreases slightly and not significantly. After 300 hours of exposure to 800 nits of blue light, the brightness is 74% of the initial brightness. After 300 hours of aging at 85℃, the brightness is 44% of the initial brightness.

[0084] Comparative Example 4

[0085] The preparation method of FAPbBr3 perovskite nanocrystals in this comparative example differs from that in Example 5 in that DBSA is replaced with an equimolar amount of oleic acid.

[0086] Its nanocrystalline solution has a quantum efficiency of 60%, an emission peak of 534 nm, and a full width at half maximum (FWHM) of 24 nm. The optical film exhibits moderate aging stability; at room temperature, its brightness decreases slightly and insignificantly; after 300 hours of irradiation with 800 nits of blue light, its brightness is 51% of the initial brightness; after 300 hours of aging at 85°C, its brightness is 21% of the initial brightness.

[0087] Comparative Example 5

[0088] The method for preparing FAPbBr3 perovskite nanocrystals in this comparative example differs from that in Example 10 in that DBSA is replaced with an equimolar amount of oleic acid.

[0089] Its nanocrystalline solution has a quantum efficiency of 62%, an emission peak of 533 nm, and a full width at half maximum (FWHM) of 25 nm. The optical film exhibits moderate aging stability; at room temperature, its brightness decreases slightly and insignificantly; after 300 hours of irradiation with 800 nits of blue light, its brightness is 52% of the initial brightness; after 300 hours of aging at 85°C, its brightness is 19% of the initial brightness.

[0090] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing an organic perovskite nanocrystal, characterized by, The method comprises the following steps: obtaining a precursor solution, and performing high-temperature vacuum extraction on the precursor solution, after the high-temperature vacuum extraction is completed, injecting a halogen source solution into the precursor solution to react and synthesize an organic perovskite nanocrystal solution; the step of obtaining the precursor solution is: mixing an organic precursor salt, a ligand and a solvent, heating and complexing to obtain a first precursor solution, and adding a metal precursor salt to the first precursor solution to obtain a second precursor solution; performing high-temperature vacuum extraction on the first precursor solution and / or the second precursor solution; alternatively, the step of obtaining the precursor solution is: mixing a metal precursor salt with an organic precursor salt, a ligand and a solvent, heating and complexing to obtain a precursor solution; performing high-temperature vacuum extraction on the precursor solution; the temperature of the high-temperature vacuum extraction is greater than 100℃; The structure of the ligand is R1-R-SO3H, wherein R is selected from the group consisting of C6-C18 arylene, R1is selected from the group consisting of C1-C18 alkyl, and n is an integer from 1 to 18. n H 2n+1 , any one of H, n is an integer from 1 to 18. the organic precursor salt is selected from any one or a combination of the two of formamidinium acetate and methylamine acetate; the molar ratio of the organic precursor salt to the ligand is less than or equal to 1; the metal precursor salt is selected from any one or a combination of several of lead acetate trihydrate, lead acetate, tin acetate, bismuth acetate and germanium acetate.

2. The production method according to claim 1, characterized by, R is selected from C6-C12 arylene; R1is selected from C n H 2n+1 , H, n is an integer from 1 to 12.

3. The preparation method according to claim 1, characterized in that, The heating and complexing temperature is 40℃ or higher. And / or, the complexing reaction time is 10 minutes or longer.

4. The production method according to claim 3, characterized by, The heating and complexing temperature is 50-70℃. And / or, the complexing reaction time is 10-40 minutes.

5. The preparation method according to claim 1, characterized in that, The heating and complexing process is performed in an inert gas atmosphere.

6. The production method according to claim 5, wherein The molar ratio of the organic precursor salt to the ligand is 1:(1-10).

7. The production method according to claim 6, wherein The molar ratio of the organic precursor salt to the ligand is 1:(2-4).

8. The method of claim 1, wherein, The molar ratio of the organic precursor salt to the metal precursor salt is (0.1-5):

1. And / or, the solvent is any one or a combination of several of octadecene, trimethylbenzene, dimethylbenzene and toluene.

9. The production method according to claim 8, characterized by, The metal precursor salt is lead acetate.

10. The production method according to any one of claims 1 to 5, characterized by, The high-temperature vacuum extraction time is greater than 10 minutes. And / or, the heating process of the high-temperature vacuum extraction is performed in an inert gas atmosphere.

11. The method of claim 10, wherein, The temperature of the high-temperature vacuum extraction is 100-140℃. And / or, the high-temperature vacuum extraction time is 10-60 minutes.

12. The method of claim 1, wherein, Further comprising: after the high-temperature vacuum extraction is completed, injecting a halogen source solution into the precursor solution to react and synthesize an organic perovskite nanocrystal solution.

13. The preparation method according to claim 12, characterized in that, the synthesis reaction temperature is 25-200℃; the halogen source solution is heated to 25-130℃ before being injected; the process of synthesizing the organic perovskite nanocrystal solution is performed in an inert gas atmosphere; the halogen source in the halogen source solution is selected from any one or a combination of several of a quaternary ammonium halide salt, an oleylamine halide salt and benzoyl bromide; the molar ratio of the metal precursor salt to the halogen source is 1:(2-5).

14. The preparation method according to claim 13, characterized in that, the quaternary ammonium halide salt is selected from any one of dioctadecyldimethylammonium bromide and didodecyldimethylammonium bromide; the oleylamine halide salt is oleylamine bromide.

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