Preparation method and application of phosphorus diethyl phosphate-containing silane passivator

Abstract

The application discloses a preparation method and application of a silane passivator containing diethyl phosphate groups. The preparation method comprises the following steps: heating and stirring allyl diethyl phosphate and hydrogen-containing silicone oil under an argon atmosphere; adding hydrogen-containing silicone oil, toluene and a catalyst chloroplatinic acid into the system in sequence, and heating and reacting under the Ar atmosphere; performing reduced pressure distillation until no distillate is evaporated; adding ethyl acetate into the reaction liquid for washing, and then evaporating the ethyl acetate under reduced pressure; finally, washing the reaction liquid for several times, pouring out the organic phase, and then performing reduced pressure distillation until no distillate is evaporated, so that the silane passivator containing diethyl phosphate groups is obtained. The silane passivator is stable in chemical properties and convenient to store. After the passivator is used to passivate perovskite, the ethoxy group of the passivator can endow the passivator with certain electronic transport capacity, and a phosphorus oxygen (P=O) double bond can be combined with uncoordinated lead ions (Pb 2+ ) to coordinate, so that the crystal structure is perfected, non-radiation recombination is inhibited, and the optical properties and stability of the perovskite material are effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of passivation of perovskite, and relates to a preparation method and application of a silane passivation agent containing a diethyl phosphate group. BACKGROUND

[0002] A passivation agent is a common means for modifying existing materials to improve their moisture resistance, oxidation resistance, thermal stability, and other properties. When synthesizing perovskite quantum dots, the fast crystal growth rate leads to disordered crystal structures and defects. Perovskite quantum dots are extremely sensitive to environmental factors such as oxygen, water vapor, and temperature. Therefore, an effective passivation agent is very valuable for improving the environmental stability of perovskite. In recent years, there have been many studies on the passivation of perovskite. For example, n-butylamine, n-octylamine, octanoic acid, and didodecyldimethylammonium bromide can passivate the surface defects of perovskite, form coordination bonds, and improve the thermal stability and oxidation resistance of perovskite materials. However, it is difficult to completely remove these substances from the perovskite system, which inhibits the ability of perovskite materials to transport electrons and affects the photoelectric properties of perovskite materials. Patent CN201810588390.7 discloses a method for preparing CH3NH3PbBr3 by introducing a thiocyanate group in situ, which introduces lead thiocyanate as a lead source into the precursor solution to significantly improve the stability and fluorescence quantum yield of perovskite. However, the luminescence intensity is not significantly improved. Patent CN202011446848.9 discloses a preparation method for modifying perovskite solar cells based on a maleimide-based undecanoic acid. The carboxylic acid can bind to uncoordinated Pb 2+ After the annealing process, the passivation agent is expelled to the surface of the perovskite to form a hydrophobic layer, which improves the stability of the solar cell. However, the photoelectric conversion efficiency of the device is not high, and long-chain alkyl passivation agents can significantly improve the stability of perovskite, but have some impact on the photoelectric conversion efficiency of perovskite.

[0003] The silane passivation agent of the present application can significantly improve the moisture resistance, oxidation resistance, and thermal stability of perovskite, and can improve the photoelectric properties of perovskite materials. Perovskite passivation agents are usually organic compounds without photoelectric properties, but the P=O double bond in the silane passivation agent containing a diethyl phosphate group can bind to the uncoordinated Pb 2+ The P=O double bond in the silane passivation agent containing a diethyl phosphate group can bind to the uncoordinated Pb SUMMARY

[0004] The purpose of the present application is to provide a preparation method and application of a silane passivation agent containing a diethyl phosphate group to overcome the shortcomings of the prior art.

[0005] To achieve the above object, the technical scheme of the present application is: as a first aspect, a preparation method of a silane passivator containing diethyl phosphate groups is provided, comprising the following steps:

[0006] 100 parts by weight of allyl diethyl phosphate and 50-200 parts by weight of hydrogen-containing silicone oil are mixed in a reactor and stirred at 40-60°C under Ar atmosphere for 4-6h;

[0007] 500 parts by weight of toluene and 1-10 parts by weight of chloroplatinic acid are added to the above reaction solution, and the reaction is carried out at 30-50°C under Ar atmosphere for 6-8h, and then distilled at 60-80°C under reduced pressure until no distillate is distilled out;

[0008] The product of the above step is washed with ethyl acetate, and the ethyl acetate is removed by vacuum filtration; then 100 parts by weight of deionized water and 100-300 parts by weight of ethyl acetate are added to form a mixed solvent, which is then added to a separatory funnel and shaken thoroughly, and then allowed to stand and separate into two layers, and the water phase is discharged from the bottom, and the organic phase is poured out from the top, and the organic phase is distilled at 60-80°C under reduced pressure to remove the ethyl acetate until no distillate is distilled out, thereby obtaining a silane passivator containing diethyl phosphate groups.

[0009] Further, the hydrogen-containing silicone oil is any one of polymethyl hydrogen-containing silicone oil with a hydrogen content of 0.3-1.6% by mass, hydrogen-containing silicone oil with a hydrogen content of 0.3-1.6% by mass, or hydrogen-containing double-seal head.

[0010] As a second aspect, the present application provides a silane passivator containing diethyl phosphate groups prepared by the above preparation method.

[0011] As a third aspect, the present application provides an application of the above silane passivator containing diethyl phosphate groups in the passivation of perovskite.

[0012] Further, the application specifically refers to: dissolving 0.02mmol CsBr and 0.02mmol PbBr2 in a mixed solvent of 3.5mL N,N-dimethylformamide and 1.5mL dimethyl sulfoxide, adding 0.5mL oleylamine and 1mL oleic acid ligand, stirring at room temperature for 24h, to obtain a precursor solution; taking 0.2mL of the precursor solution and dropping it into 5mL of anti-solvent under continuous stirring (stirring at 2600r / min for 20s) to obtain perovskite nanocrystals; adding the silane passivator containing diethyl phosphate groups to the precursor solution or the solution after the synthesis of perovskite nanocrystals for passivation, and the addition concentration of the silane passivator is 5mg / mL-30mg / mL; and the anti-solvent is selected from toluene and chlorobenzene.

[0013] Preferably, the passivation method is in-situ passivation or post-passivation; the in-situ passivation is adding the silane passivation agent in the precursor solution, and the adding concentration is 10 mg / mL-20 mg / mL, calculated by the volume of the precursor solution; the post-passivation is adding the silane passivation agent in the solution after synthesizing the perovskite nanocrystals, stirring at room temperature (10 minutes), and the adding concentration is 5 mg / mL-10 mg / mL, calculated by the volume of the solution after synthesizing the perovskite nanocrystals.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] (1) The present application first synthesizes a silane compound containing diethyl phosphate groups as a passivation agent for perovskite. The P=O double bond in the molecule can combine with the uncoordinated Pb 2+ in the perovskite crystal to form a coordination bond, thereby perfecting the crystal structure defects; the existence of the ethyl group provides certain electron transport ability without affecting the photoelectric properties of the perovskite material; the existence of Si-O-Si provides a guarantee for the stability of the perovskite material. It is suitable for passivation of perovskite materials.

[0016] (2) After the silane passivation agent of the present application passivates the perovskite material, it can improve the thermal stability and humidity stability of the perovskite material, improve the environmental stability and photoelectric performance of the perovskite material, and inhibit non-radiative recombination.

[0017] (3) The present application uses diethyl allyl phosphate and hydrogen-containing double seal as raw materials, the reaction is simple and feasible, the reaction conditions are easy to control, the generation of by-products is effectively avoided, the product has small molecular weight and symmetrical structure, and the passivation effect is remarkable. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The H-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 1-3 is shown in Figure 1. 1 The H-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 1-3 is shown in Figure 1.

[0019] Figure 2 The C-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 1-3 is shown in Figure 2. 13 The C-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 1-3 is shown in Figure 2.

[0020] Figure 3 The P-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 1-3 is shown in Figure 3. 31 The P-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 1-3 is shown in Figure 3.

[0021] Figure 4 The H-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 4-7 is shown in Figure 4. 1 The H-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 4-7 is shown in Figure 4.

[0022] Figure 5 The C-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 4-7 is shown in Figure 5. 13 The C-NMR spectrum of the diethyl phosphate group-containing silane passivation agent obtained in Examples 4-7 is shown in Figure 5.

[0023] Figure 6 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7 31 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7

[0024] Figure 7 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7 1 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7

[0025] Figure 8 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7 13 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7

[0026] Figure 9 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7 31 P-NMR spectrum of the phosphodiethyl ester group-containing silane passivator obtained in Example 4-7

[0027] Figure 10 PL spectrum of the perovskite material of Example 1 perovskite passivated by the passivator

[0028] Figure 11 PL spectrum of the perovskite material of Example 2 perovskite passivated by the passivator

[0029] Figure 12 PL spectrum of the perovskite material of Example 3 perovskite passivated by the passivator. DETAILED DESCRIPTION

[0030] The application will be further explained in connection with the following examples. The following examples are only used to illustrate the application, but not to limit the scope of the application. The parts in the following examples are all parts by mass; the allyl phosphodiethyl ester is prepared by reacting 30-100 parts by weight of 3-halopropene with 100 parts by weight of triethyl phosphite at 40-60°C under Ar atmosphere for 2-4 hours, followed by distillation under reduced pressure, or commercially available; wherein the 3-halopropene is one or more of 3-chloropropene, 3-bromopropene, 3-iodopropene, or a mixture of them in any ratio.

[0031] Example 1

[0032] Into a reactor, 100 parts of allyl phosphonate diethyl ester and 50 parts of 0.3% polymethyl hydrogen-containing silicone oil (mass ratio, the same below) were added, stirred at 40°C under Ar atmosphere for 4h; into the above reaction solution, 200 parts of 0.3% hydrogen-containing polymethyl hydrogen-containing silicone oil, 500 parts of toluene and 10 parts of chloroplatinic acid were added, reacted at 30°C under Ar atmosphere for 6h, then distilled at 70°C under reduced pressure until no distillate was evaporated; the above product was washed with ethyl acetate for several times, removed ethyl acetate by vacuum filtration, then mixed with 100 parts of deionized water and 300 parts of ethyl acetate mixed solvent, added into a separatory funnel, fully shaken, stood to separate, the water phase was discharged from the bottom, the organic phase was poured out from the top, then distilled at 70°C under reduced pressure to remove ethyl acetate, thus a silane passivator containing phosphonate diethyl ester group was obtained.

[0033] Example 2

[0034] Into a reactor, 100 parts of allyl phosphonate diethyl ester and 100 parts of 1% polymethyl hydrogen-containing silicone oil were added, stirred at 60°C under Ar atmosphere for 5h; into the above reaction solution, 100 parts of 1% hydrogen-containing polymethyl hydrogen-containing silicone oil, 500 parts of toluene and 5 parts of chloroplatinic acid were added, reacted at 40°C under Ar atmosphere for 6h, then distilled at 70°C under reduced pressure until no distillate was evaporated; the above product was washed with ethyl acetate for several times, removed ethyl acetate by vacuum filtration, then mixed with 100 parts of deionized water and 300 parts of ethyl acetate mixed solvent, added into a separatory funnel, fully shaken, stood to separate, the water phase was discharged from the bottom, the organic phase was poured out from the top, then distilled at 70°C under reduced pressure to remove ethyl acetate, thus a silane passivator containing phosphonate diethyl ester group was obtained.

[0035] Example 3

[0036] Into a reactor, 100 parts of allyl phosphonate diethyl ester and 100 parts of 1.6% polymethyl hydrogen-containing silicone oil were added, stirred at 50°C under Ar atmosphere for 5h; into the above reaction solution, 200 parts of 1.6% hydrogen-containing polymethyl hydrogen-containing silicone oil, 500 parts of toluene and 1 part of chloroplatinic acid were added, reacted at 50°C under Ar atmosphere for 8h, then distilled at 70°C under reduced pressure until no distillate was evaporated; the above product was washed with ethyl acetate for several times, removed ethyl acetate by vacuum filtration, then mixed with 100 parts of deionized water and 300 parts of ethyl acetate mixed solvent, added into a separatory funnel, fully shaken, stood to separate, the water phase was discharged from the bottom, the organic phase was poured out from the top, then distilled at 70°C under reduced pressure to remove ethyl acetate, thus a silane passivator containing phosphonate diethyl ester group was obtained.

[0037] Product 1 H nuclear magnetic resonance spectrum, 13 C nuclear magnetic resonance spectrum and 31 P nuclear magnetic resonance spectrum respectively as Figures 1-3 The nuclear magnetic resonance spectrum data are as follows: 1HNMR (400 MHz, CDC13) δ 3.76 (dh, J = 14.9, 7.8 Hz, 8H), 1.43 (dt, J = 16.1, 7.8 Hz, 4H), 1.38 - 1.22 (m, 4H), 0.99 (dt, J = 14.1, 7.2 Hz, 12H), 0.32 (q, J = 8.0 Hz, 3H), -0.26 (dt, J = 14.8, 7.9 Hz, 34H). 13 C NMR (101 MHz, CDC13) δ 61.30, 28.66, 19.74, 16.73, 16.50, 0.56. 31 P NMR (162 MHz, CDC13) δ 32.31.

[0038] Example 4

[0039] 100 parts of allyl phosphonate diethyl ester and 200 parts of 0.3% end hydrogen containing hydrogen silicone oil (mass ratio, the same below) were added to a reactor, stirred at 60°C under Ar atmosphere for 6h; 50 parts of 0.3% end hydrogen containing hydrogen silicone oil, 500 parts of toluene and 5 parts of chloroplatinic acid were added to the above reaction liquid, reacted at 50°C under Ar atmosphere for 8h, then distilled at 80°C under reduced pressure until no fraction was distilled out; the above product was washed with ethyl acetate several times, removed by vacuum filtration, then mixed with 100 parts of deionized water and 200 parts of ethyl acetate mixed solvent, added to a separatory funnel, fully shaken, and then separated; the water phase was discharged from the bottom, and the organic phase was poured out from the top, distilled under reduced pressure at 80°C to remove ethyl acetate, and a phosphonate diethyl ester containing silane passivator was obtained.

[0040] Example 5

[0041] 100 parts of allyl phosphonate diethyl ester and 200 parts of 0.8% end hydrogen containing hydrogen silicone oil were added to a reactor, stirred at 50°C under Ar atmosphere for 5h; 100 parts of 0.8% end hydrogen containing hydrogen silicone oil, 500 parts of toluene and 5 parts of chloroplatinic acid were added to the above reaction liquid, reacted at 30°C under Ar atmosphere for 8h, then distilled at 80°C under reduced pressure until no fraction was distilled out; the above product was washed with ethyl acetate several times, removed by vacuum filtration, then mixed with 100 parts of deionized water and 200 parts of ethyl acetate mixed solvent, added to a separatory funnel, fully shaken, and then separated; the water phase was discharged from the bottom, and the organic phase was poured out from the top, distilled under reduced pressure at 80°C to remove ethyl acetate, and a phosphonate diethyl ester containing silane passivator was obtained.

[0042] Example 6

[0043] Into a reactor, 100 parts of allyl phosphonate diethyl ester and 200 parts of 1.2% end hydrogen containing hydrogen silicone oil were added, stirred at 40°C, Ar atmosphere for 4h; 50 parts of hydrogen containing hydrogen silicone oil with hydrogen content of 1.2%, 500 parts of toluene and 10 parts of chloroplatinic acid were added to the above reaction liquid, reacted at 50°C, Ar atmosphere for 7h, then distilled at 80°C under reduced pressure until no distillate was evaporated; the above product was washed with ethyl acetate several times, removed by vacuum filtration, then mixed with 100 parts of deionized water and 200 parts of ethyl acetate mixed solvent, added to the separatory funnel, fully shaken, and then separated; the water phase was discharged from the bottom, and the organic phase was poured out from the top, and then distilled under reduced pressure at 80°C to remove ethyl acetate, to obtain a silane passivator containing phosphonate diethyl ester group.

[0044] Example 7

[0045] Into a reactor, 100 parts of allyl phosphonate diethyl ester and 100 parts of 1.6% end hydrogen containing hydrogen silicone oil were added, stirred at 40°C, Ar atmosphere for 6h; 50 parts of hydrogen containing hydrogen silicone oil with hydrogen content of 1.6%, 500 parts of toluene and 10 parts of chloroplatinic acid were added to the above reaction liquid, reacted at 50°C, Ar atmosphere for 7h, then distilled at 80°C under reduced pressure until no distillate was evaporated; the above product was washed with ethyl acetate several times, removed by vacuum filtration, then mixed with 100 parts of deionized water and 200 parts of ethyl acetate mixed solvent, added to the separatory funnel, fully shaken, and then separated; the water phase was discharged from the bottom, and the organic phase was poured out from the top, and then distilled under reduced pressure at 80°C to remove ethyl acetate, to obtain a silane passivator containing phosphonate diethyl ester group.

[0046] Product 1 H nuclear magnetic resonance spectrum, 13 C nuclear magnetic resonance spectrum and 31 P nuclear magnetic resonance spectrum respectively as Figures 4-6 , the nuclear magnetic resonance spectrum data are: 1 HNMR (400 MHz, CDCI3) δ 3.95 (hept, J = 7.1 Hz, 8H), 1.63 (dt, J = 16.8, 7.8 Hz, 4H), 1.56 - 1.47 (m, 4H), 1.17 (t, J = 7.0 Hz, 13H), 0.58 - 0.48 (m, 4H), -0.07 (t, J = 5.4 Hz, 20H). 13 C NMR (101 MHz, CDCI3) δ 61.25, 28.61, 19.70, 16.70, 16.46, 0.12. 31 P NMR (162 MHz, CDCI3) δ 32.34.

[0047] Example 8

[0048] Into a reactor were added 100 parts of allyl phosphinic acid diethyl ester and 200 parts of hydrogen-containing double-seal head, and the mixture was stirred at 50°C under Ar atmosphere for 5 hours. Then, 100 parts of hydrogen-containing double-seal head, 500 parts of toluene and 1 part of chloroplatinic acid were added to the above reaction solution, and the mixture was reacted at 30°C under Ar atmosphere for 6 hours. After that, the mixture was distilled at 60°C under reduced pressure until no distillate was obtained. The above product was washed with ethyl acetate several times, and then filtered under reduced pressure to remove ethyl acetate. Then, 100 parts of deionized water and 100 parts of ethyl acetate mixed solvent were added to the product in a separatory funnel, and the mixture was shaken well. After standing, the water phase was removed from the bottom, and the organic phase was poured out from the top. The organic phase was distilled under reduced pressure at 60°C to remove ethyl acetate, thereby obtaining a silane passivator containing phosphinic acid diethyl ester group.

[0049] Example 9

[0050] Into a reactor were added 100 parts of allyl phosphinic acid diethyl ester and 50 parts of hydrogen-containing double-seal head, and the mixture was stirred at 60°C under Ar atmosphere for 4 hours. Then, 200 parts of hydrogen-containing double-seal head, 500 parts of toluene and 1 part of chloroplatinic acid were added to the above reaction solution, and the mixture was reacted at 50°C under Ar atmosphere for 8 hours. After that, the mixture was distilled at 60°C under reduced pressure until no distillate was obtained. The above product was washed with ethyl acetate several times, and then filtered under reduced pressure to remove ethyl acetate. Then, 100 parts of deionized water and 100 parts of ethyl acetate mixed solvent were added to the product in a separatory funnel, and the mixture was shaken well. After standing, the water phase was removed from the bottom, and the organic phase was poured out from the top. The organic phase was distilled under reduced pressure at 60°C to remove ethyl acetate, thereby obtaining a silane passivator containing phosphinic acid diethyl ester group.

[0051] Example 10

[0052] Into a reactor were added 100 parts of allyl phosphinic acid diethyl ester and 200 parts of hydrogen-containing double-seal head, and the mixture was stirred at 60°C under Ar atmosphere for 6 hours. Then, 50 parts of hydrogen-containing double-seal head, 500 parts of toluene and 10 parts of chloroplatinic acid were added to the above reaction solution, and the mixture was reacted at 50°C under Ar atmosphere for 8 hours. After that, the mixture was distilled at 60°C under reduced pressure until no distillate was obtained. The above product was washed with ethyl acetate several times, and then filtered under reduced pressure to remove ethyl acetate. Then, 100 parts of deionized water and 100 parts of ethyl acetate mixed solvent were added to the product in a separatory funnel, and the mixture was shaken well. After standing, the water phase was removed from the bottom, and the organic phase was poured out from the top. The organic phase was distilled under reduced pressure at 60°C to remove ethyl acetate, thereby obtaining a silane passivator containing phosphinic acid diethyl ester group.

[0053] Product 1 H nuclear magnetic resonance spectrum, 13 C nuclear magnetic resonance spectrum and 31 P nuclear magnetic resonance spectrum are respectively as shown in Figures 7-9 The nuclear magnetic resonance spectrum data are as follows: 1HNMR (400 MHz, CDC13) δ 4.06 - 3.89 (m, 8H), 1.72 - 1.59 (m, 4H), 1.59 - 1.45 (m, 4H), 1.20 (td, J = 7.0, 2.3 Hz, 12H), 0.59 - 0.47 (m, 4H), -0.02 - -0.08 (m, 16H). 13 C NMR (101 MHz, CDC13) δ 61.31, 28.58, 19.82, 16.68, 16.45, 0.91. 31 PNMR (162 MHz, CDC13) δ 32.37.

[0054] Perovskite passivation research was carried out using the passivation agent synthesized in the above examples. The synthesis method of perovskite used room temperature ligand reprecipitation method: 0.02 mmol CsBr and 0.02 mmol PbBr2 were dissolved in 3.5 mL of N, N-dimethylformamide (DMF) and 1.5 mL of dimethyl sulfoxide (DMSO) mixed solvent, 0.5 mL of oleylamine and 1 mL of oleic acid ligand were added, and it was stirred at room temperature for 24 h to obtain a precursor solution; 5 mL of anti-solvent (toluene, chlorobenzene) was measured, and 0.2 mL of the precursor solution was quickly dropped into the anti-solvent stirred at high speed (magnetic stirring was used in this example, 2600 r / min, stirring for 20 s) to obtain perovskite nanocrystals. The passivation agent was directly introduced into the precursor solution, and the perovskite nanocrystals were synthesized using chlorobenzene as the anti-solvent, that is, in-situ passivation; the passivation agent was not introduced into the precursor solution, and the perovskite nanocrystals were synthesized using chlorobenzene as the anti-solvent, and then the passivation agent was introduced after the perovskite nanocrystals were synthesized, and it was stirred at room temperature for 10 min, that is, post-passivation. The photoluminescence spectrum (PL) was measured using a 405 nm light source as the excitation light source, and the larger the PL value, the better the luminescent performance of the material.

[0055] Thermal stability test: the perovskite solution synthesized above was heated and stirred at 80°C for 10 min, and the effect of temperature on the change of photoluminescence spectrum (PL) of perovskite was investigated, wherein the PL ratio was the PL value of the perovskite after heating and stirring to the PL value of the perovskite without heating and stirring.

[0056] Humidity stability test: the perovskite solution synthesized above was centrifuged at 8000 rpm for 3 min in a centrifuge, and the centrifuged perovskite was coated on a single crystal silicon wafer and placed in a humidity of 84%, 75% and 43% for 16 h, and the effect of humidity on the change of photoluminescence spectrum (PL) of perovskite was investigated, wherein the PL ratio was the PL value of the perovskite placed in the corresponding humidity for 16 h to the PL value of the perovskite before placed in the corresponding humidity. The supersaturated potassium chloride aqueous solution, sodium chloride aqueous solution and potassium carbonate aqueous solution were used to control the humidity.

[0057] Passivation of perovskite by passivation agent example 1

[0058] The perovskite passivated by the passivation agent synthesized in selected embodiment 3 was subjected to experiments according to the above-mentioned ligand re-precipitation method at room temperature. The perovskite was precipitated from the precursor solution without introducing the passivation agent and chlorobenzene as the anti-solvent to obtain M0; 20 mg / mL of the passivation agent was introduced into the precursor solution, and the perovskite was precipitated from chlorobenzene as the anti-solvent to obtain M1; 30 mg / mL of the passivation agent was introduced into the precursor solution, and the perovskite was precipitated from chlorobenzene as the anti-solvent to obtain M2. The changes in properties were studied according to the above-mentioned method, and the PL spectrum results are shown in Figure 10 Table 1 and Table 2, respectively.

[0059] Table 1. Thermal stability test results of perovskite materials before and after passivation

[0060] Number Perovskite Passivating agent (mg / mL) PL ratio (%) 1 M0 0 25.59 2 M1 20 43.56 3 M2 30 40.27

[0061] Table 2. Humidity stability test results of perovskite materials before and after passivation

[0062]

[0063] It can be seen from Figure 10 that the PL value of the perovskite M0 directly synthesized without passivation by the silane passivation agent is only 4216, while the PL value of the perovskite passivated by the silane passivation agent provided by the present application containing diethyl phosphate groups is increased to 5281, and the PL value is increased by 25.26%, and the PL intensity is significantly enhanced. This shows that the P=O double bond in the passivation agent combines with the uncoordinated Pb 2+ , perfects the crystal structure, and inhibits non-radiative recombination, thereby improving the photoelectric properties of the material. As can be seen from Table 1, the thermal stability test result is increased from 25.59% to 43.56%, and the thermal stability of the passivated perovskite is increased by 17.97%. As can be seen from Table 2, the humidity test result is increased from 80.12% to 88.06% under 84% humidity, and the stability of the passivated perovskite under 84% humidity is increased by 7.94%. The excellent thermal stability and humidity stability effectively prolong the service life of the perovskite material. When the amount of the silane passivation agent introduced in the present application exceeds 20 mg / mL, the PL value will decrease, and the humidity stability and thermal stability will have a downward trend, indicating that the introduction of the passivation agent of the present application needs to be controlled at an appropriate concentration, and it is not the case that the greater the introduction amount, the better.

[0064] Example 2 of passivation of perovskite by passivation agent

[0065] The passivation agent synthesized in Example 7 was selected to passivate the perovskite, and the experiment was carried out according to the above-mentioned room temperature ligand reprecipitation method. No passivation agent was introduced into the precursor solution, and chlorobenzene was used as the antisolvent to precipitate the perovskite to obtain M0; 10 mg / mL passivation agent (based on the volume of the precursor solution) was introduced into the precursor solution, and chlorobenzene was used as the antisolvent to precipitate the perovskite to obtain M1; 20 mg / mL passivation agent was introduced into the precursor solution, and chlorobenzene was used as the antisolvent to precipitate the perovskite to obtain M2. The property changes were studied according to the above method, and the PL spectrum results are shown as follows: Figure 11 The results of thermal stability test and humidity stability test are shown in Tables 3 and 4 respectively:

[0066] Table 3 Thermal stability test results of perovskite materials before and after passivation

[0067] Number Perovskite Passivating agent (mg / mL) PL ratio (%) 1 M0 0 26.54 2 M1 10 43.26 3 M2 20 45.58

[0068] Table 4 Humidity stability test results of perovskite materials before and after passivation

[0069]

[0070] Depend on Figure 11 It can be seen that the PL value of the perovskite M0 synthesized directly without the use of a silane passivator is 4309. When the amount of the silane passivator introduced is 10 mg / mL, the PL value of M1 is the best at 6433. When the amount of the silane passivator introduced is further increased (20 mg / mL), the PL value of M2 decreases to 5546. This indicates that the P=O double bond in the passivator is bound to the uncoordinated Pb 2+ The coordination improves the crystal structure and inhibits non-radiative recombination, thereby enhancing the photoelectric properties of the material. Table 3 shows that the thermal stability of the perovskite material increased from 26.54% to 43.26% and then to 45.58%. Table 4 shows that the humidity stability under 84% humidity conditions increased from 78.19% to 80.96% and then to 82.22%. At this point, as the amount of passivator introduced increases, the PL value first increases and then decreases, while the thermal stability and humidity stability continue to increase. This indicates that the relationship between the amount of passivator introduced and the PL, thermal stability, and humidity stability of the present invention is not a simple linear relationship. The amount of silane passivator introduced can be adjusted according to actual needs to achieve optimal use. Therefore, when using in-situ passivation to passivate perovskite, the optimal amount of silane passivator introduced is 10 mg / mL to 20 mg / mL.

[0071] Example 3 of passivation of perovskite by passivation agent

[0072] The passivator synthesized in Example 10 was selected to passivate the perovskite, and the experiment was carried out according to the above-mentioned room temperature ligand reprecipitation method. In the following experiments, no passivator was introduced into the precursor solution, and chlorobenzene was used as the anti-solvent to precipitate the perovskite to obtain M0; 5 mg / mL of passivator (based on the volume of the solution after the synthesis of the perovskite nanocrystal) was introduced into the perovskite nanocrystal precipitated with chlorobenzene, and stirred at room temperature for 10 minutes to obtain M1; 10 mg / mL of passivator was introduced into the perovskite nanocrystal precipitated with chlorobenzene, and stirred at room temperature for 10 minutes to obtain M2. The property changes were studied according to the method described above, and the PL spectrum results are shown as follows: Figure 12 The results of thermal stability test and humidity stability test are shown in Tables 5 and 6 respectively:

[0073] Table 5 Thermal stability test results of perovskite materials before and after passivation

[0074] Number Perovskite Passivating agent (mg / mL) PL ratio (%) 1 M0 0 26.04 2 M1 5 37.62 3 M2 10 39.18

[0075] Table 6 Humidity stability test results of perovskite materials before and after passivation

[0076]

[0077] Depend on Figure 12 It can be seen that when the perovskite is passivated by post-passivation, the PL value of the unpassivated perovskite M0 is the lowest at 3564; when the passivator addition amount is 5 mg / mL, the M1 PL value increases to 4252; when the passivator addition amount is 10 mg / mL, the M2 PL value continues to increase to 4976. The introduction of the passivator of the present invention can significantly improve the PL value of the perovskite material. The P=O double bond and the uncoordinated Pb 2+ Combined with coordination, its crystal structure is improved, non-radiative recombination is suppressed, and its luminescence performance is improved. As can be seen from Table 5, as the amount of passivator introduced increases, the thermal stability also increases by 26.04%, 37.62% and 39.18%. As can be seen from Table 6, the same is true for humidity stability. As the amount of passivator added increases, the humidity stability (84%) also increases linearly by 79.56%, 80.81% and 81.06%. Therefore, the silane passivator of the present invention is used and the perovskite is passivated by post-passivation, which significantly enhances the luminescence performance of the perovskite material and the excellent thermal stability and humidity stability, prolongs the service life, and expands the application scenarios. Therefore, when the perovskite is passivated by post-passivation, the optimal introduction amount of the silane passivator is 5 mg / mL to 10 mg / mL.

[0078] The specific description of the present invention in the above embodiments is only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technical engineers in this field may make some non-essential improvements and adjustments to the present invention based on the contents of the above invention, which fall within the scope of protection of the present invention.

Claims

1. A method for preparing a diethyl phosphate-containing silane passivating agent, characterized in that: The following steps are involved: Mix 100 parts by weight of allyl diethyl phosphate with 50-200 parts by weight of hydrogenated silicone oil, and stir at 40-60° C. under Ar atmosphere for 4-6 hours; Add 50-200 parts by weight of hydrogenated silicone oil, 500 parts by weight of toluene and 1-10 parts by weight of chloroplatinic acid, react at 30-50° C. under Ar atmosphere for 6-8 hours, and then distill under reduced pressure at 60-80° C. until no fraction is distilled out; Ethyl acetate is added for washing, and the ethyl acetate is removed by filtration under reduced pressure; then a mixed solvent of 100 parts by weight of deionized water and 100 to 300 parts by weight of ethyl acetate is added, mixed and fully shaken, allowed to stand and separate into layers, and the organic phase is poured out, and the ethyl acetate is removed by distillation under reduced pressure at 60 to 80° C. until no fraction is distilled out, thereby obtaining a silane passivator containing a diethyl phosphate group.

2. The preparation method according to claim 1, characterized in that The hydrogen-containing silicone oil is any one of polymethyl hydrogen-containing silicone oil with a hydrogen content of 0.3-1.6% by mass, terminal hydrogen-containing silicone oil with a hydrogen content of 0.3-1.6% by mass, and hydrogen-containing double-end seal oil.

3. A silane passivating agent containing diethyl phosphate prepared by the preparation method according to claim 1 or 2.

4. Use of the diethyl phosphate-containing silane passivator according to claim 3 in perovskite passivation.

5. The use according to claim 4, characterized in that 0.02 mmol CsBr and 0.02 mmol PbBr2 were dissolved in a mixed solvent of 3.5 mL N,N-dimethylformamide and 1.5 mL dimethyl sulfoxide, 0.5 mL oleylamine and 1 mL oleic acid ligand were added, and the mixture was stirred at room temperature for 24 h to obtain a precursor solution; 0.2 mL of the precursor solution was dropped into 5 mL of anti-solvent which was constantly stirred to obtain perovskite nanocrystals; the diethyl phosphate-containing silane passivator was added to the precursor solution or the solution after synthesizing the perovskite nanocrystals for passivation, and the added concentration of the silane passivator was 5 mg / mL to 30 mg / mL; the anti-solvent was selected from toluene and chlorobenzene.

6. The use according to claim 5, characterized in that The passivation method is in-situ passivation or post-passivation; the in-situ passivation is to add the silane passivator to the precursor solution, and the added concentration is 10 mg / mL to 20 mg / mL based on the volume of the precursor solution; the post-passivation is to add the silane passivator to the solution after synthesizing the perovskite nanocrystals, stir at room temperature, and the added concentration is 5 mg / mL to 10 mg / mL based on the volume of the solution after synthesizing the perovskite nanocrystals.

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