Efficient stable white light Cs2NaYCl6 nanocrystal regulated and controlled by multifunctional carboxylic acid and preparation method of efficient stable white light Cs2NaYCl6 nanocrystal

Abstract

The invention is suitable for the technical field of nano luminescent materials, and provides a multifunctional carboxylic acid regulated efficient stable white light Cs2NaYCl6 nanocrystal and a preparation method thereof.The preparation method comprises the following steps that octadecene, oleic acid, cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate, manganese acetate, dichlorobenzoic acid and oleylamine are heated and stirred in an inert atmosphere, and a mixture is obtained; a clear and transparent solution is obtained; heating the solution, and injecting TMSCl into the solution; and carrying out heat preservation on the solution, rapidly cooling to room temperature, and centrifugally dispersing into a non-polar solvent to obtain the Cs2NaYCl6 nanocrystal. The surface state structure of the Cs2NaYCl6 perovskite is controlled by adjusting the amount of the multifunctional carboxylic acid, regulation and control of luminous intensity and surface energy are realized, and the prepared sample has excellent room temperature stability, wide spectrum color gamut, high luminous intensity, low surface energy and good stability, and can be used in the fields of light emitting diodes, solar cells, photoelectric detectors and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of nano-luminescent materials, and in particular relates to highly efficient and stable white-light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acids and a preparation method thereof. Background Art

[0002] Lead halide perovskite is a new semiconductor light-emitting material with excellent photoelectric properties. It is widely used in photodetectors, solar cells, light-emitting diodes and other fields. However, the lead toxicity and spectral regulation of lead halide are difficult to solve. In order to explore lead-free metal halide perovskites with efficient photoelectric performance, people have made many attempts and finally discovered rare earth-based double perovskites, such as CsNaYCl6. Rare earth-based double perovskites not only retain the three-dimensional perovskite structure similar to lead halide perovskites, but also have rich energy level structures and can flexibly adjust the spectrum; however, the wide band gap and ion migration of rare earth-based double perovskites limit the preparation of efficient and stable white light rare earth-based double perovskites, while carboxyl groups can produce strong coordination effects with metal ions in rare earth-based double perovskites, thereby regulating the surface state structure of rare earth-based double perovskites. Therefore, exploring the regulation of the photoelectric properties and stability of CsNaYCl6 by multifunctional carboxylic acids is of great significance for the preparation of efficient and stable white light CsNaYCl6.

[0003] At present, there is no report on the synthesis of white-light CsNaYCl6, and there is no report on the preparation of efficient and stable white-light CsNaYCl6 regulated by multifunctional carboxylic acids. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a method for preparing efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acids, aiming to solve the problems raised in the above-mentioned background technology.

[0005] The embodiment of the present invention is achieved by a method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid, comprising the following steps: Step 1: heating and stirring octadecene, oleic acid, cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate, manganese acetate, dichlorobenzoic acid and oleylamine under an inert atmosphere to obtain a clear and transparent solution; Step 2, heating the solution of step 1, and then injecting TMSCl therein; Step 3: Keep the solution of step 2 warm, then quickly cool it to room temperature, and then disperse it into a non-polar solvent by centrifugation to obtain Cs2NaYCl6 nanocrystals.

[0006] Preferably, in step 1, the volume ratio of octadecene, oleic acid and oleylamine is 12:6:1, the molar ratio of cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate and manganese acetate is 75:40:65:0-3:0-3:0-0.9, and the molar ratio of yttrium acetylacetonate and dichlorobenzoic acid is 65:0-1.

[0007] Preferably, in step 1, the inert atmosphere is N2.

[0008] Preferably, in step 1, the stirring speed is 600 rad and the stirring time is 40 min.

[0009] Preferably, in step 2, the temperature of the solution in step 1 is raised to 160°C.

[0010] Preferably, in step 2, the volume ratio of TMSCl to the solution in step 1 is 1:24.

[0011] Preferably, in step three, the insulation time is 3 minutes.

[0012] Preferably, in step three, the rotation speed of the centrifugal dispersion is 8500-10000 rad, and the non-polar solvent is n-hexane.

[0013] Another object of an embodiment of the present invention is to provide a highly efficient and stable white light Cs2NaYCl6 nanocrystal regulated by a multifunctional carboxylic acid, which is prepared by the above-mentioned preparation method.

[0014] Another object of an embodiment of the present invention is to provide an application of the above-mentioned Cs2NaYCl6 nanocrystals in the preparation of light-emitting devices.

[0015] The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid provided in an embodiment of the present invention adopts a modified hot injection method, wherein cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate, manganese acetate and multifunctional carboxylic acid are fully dissolved in an octadecene solvent mixed with surfactant oleic acid and oleylamine under the protection of an inert gas, so that a variety of metal atoms are fully in contact with the surfactant and the multifunctional carboxylic acid, and after reacting for a period of time at a certain temperature, TMSCl is injected, and then TMSCl gradually nucleates with cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate, manganese acetate and multifunctional carboxylic acid solution in the process, and the surface state structure of Cs2NaYCl6 perovskite is controlled by adjusting the amount of multifunctional carboxylic acid to achieve regulation of luminescence intensity and surface energy, and the prepared sample has excellent room temperature stability, and the color rendering index hardly changes after being placed for 60 days, and the spectral color gamut is wide, the luminescence intensity is high, the surface energy is low and the stability is good, and it can be used in light-emitting diodes, solar cells, photodetectors and other fields; The preparation method is simple to operate, takes little time, consumes little energy, and has high development value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 TEM images of samples prepared in Examples 1-2 and Comparative Example 1 of the present invention; Figure 2 XRD images of samples prepared in Example 1 and Comparative Example 1 of the present invention; Figure 3 Photoluminescence (PL) spectra of samples prepared in Examples 1-2 and Comparative Example 1 of the present invention; Figure 4 The PLQY results of the samples prepared in Examples 1-2 and Comparative Example 1 of the present invention are shown.

[0017] Figure 5 These are the stability results of the samples prepared in Examples 1-2 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0020] Example 1: A method for preparing highly efficient and stable white light-emitting Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid comprises the following steps: Step 1: add 6 mL of octadecene, 3 mL of oleic acid, 0.75 mmol of cesium acetate, 0.4 mmol of sodium acetate, 0.65 mmol of yttrium acetylacetonate, 0.02 mmol of antimony acetate, 0.03 mmol of terbium acetate, 0.02 mmol of manganese acetate, 0.007 mmol (0.004 g) of dichlorobenzoic acid and 0.5 mL of oleylamine into a 50 mL three-necked flask, evacuate the air, then introduce inert gas N2, heat to 120°C under N2 atmosphere, and stir the solution at a speed of 600 rad for 40 min until it becomes clear and transparent; Step 2: Heat to 160°C and inject 0.4 mL of TMSCl into the transparent solution of step 1; Step 3: Maintain at 160°C for 3 min, and quickly cool to room temperature using an ice-water bath, then disperse into 2 mL of n-hexane by centrifugation to obtain Cs2NaYCl6 nanocrystals.

[0021] Example 2: The preparation method of highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid is compared with that of Example 1, except that the dichlorobenzoic acid in step 1 is changed to 0.002 g, and other conditions remain the same.

[0022] Example 3: The preparation method of highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid is the same as that of Example 1, except that the temperature in step 2 is raised to 155°C, and other conditions remain the same.

[0023] Example 4: The preparation method of highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid is the same as that of Example 1, except that the temperature in step 2 is raised to 165°C, and other conditions remain the same.

[0024] Example 5: The preparation method of highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid is the same as that of Example 1, except that the temperature in step 2 is raised to 170°C, and other conditions remain the same.

[0025] Comparative Example 1, compared with Example 1, the only difference is that dichlorobenzoic acid is not added in step 1, and other conditions remain the same.

[0026] Performance Test: The samples prepared in Example 1, Example 2 and Comparative Example 1 were analyzed using a transmission electron microscope, and the TEM images were as follows: Figure 1 As shown, according to Figure 1 It can be seen that the addition of dichlorobenzoic acid has no significant effect on the morphology of Cs2NaYCl6 nanocrystals; The samples prepared in Example 1 and Comparative Example 1 were analyzed by X-ray diffractometer, and the XRD patterns were as follows: Figure 2 As shown, according to Figure 2 It can be seen that the addition of dichlorobenzoic acid has no significant effect on the lattice structure of the nanocrystals; The samples prepared in Examples 1-2 and Comparative Example 1 were analyzed using a spectrometer to obtain photoluminescence (PL) spectra as shown in Figure 3 As shown, according to Figure 3 It can be seen that after adding dichlorobenzoic acid, the emission peak undergoes an obvious blue shift; The quantum efficiency (PLQY) results of the samples prepared in Examples 1-2 and Comparative Example 1 were obtained by using a photoluminescence quantum efficiency measurement system. Figure 4 As shown, according to Figure 4 It can be seen that the quantum efficiency increases after adding dichlorobenzoic acid; The stability of the samples prepared in Examples 1-2 and Comparative Example 1 was tested, and the results were as follows: Figure 5 As shown, according to Figure 5 It can be seen that after adding dichlorobenzoic acid, the stability of nanocrystals can be extended from 2 days to 60 days.

[0027] In summary, by adjusting the amount of added dichlorobenzoic acid, it can be seen that a certain amount of dichlorobenzoic acid can promote the formation of efficient and stable white light Cs2NaYCl6 nanocrystals, but too little dichlorobenzoic acid is not conducive to obtaining efficient and stable Cs2NaYCl6 nanocrystals.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid, characterized in that: The following steps are involved: Step 1: heating and stirring octadecene, oleic acid, cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate, manganese acetate, dichlorobenzoic acid and oleylamine under an inert atmosphere to obtain a clear and transparent solution; Step 2, heating the solution of step 1, and then injecting TMSCl therein; Step 3: Keep the solution of step 2 warm, then quickly cool it to room temperature, and then disperse it into a non-polar solvent by centrifugation to obtain Cs2NaYCl6 nanocrystals.

2. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 1, the volume ratio of octadecene, oleic acid and oleylamine is 12:6:1, the molar ratio of cesium acetate, sodium acetate, yttrium acetylacetonate, antimony acetate, terbium acetate and manganese acetate is 75:40:65:0-3:0-3:0-0.9, and the molar ratio of yttrium acetylacetonate and dichlorobenzoic acid is 65:0-1.

3. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 1, the inert atmosphere used is N2.

4. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 1, the stirring speed is 600 rad and the stirring time is 40 min.

5. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 2, the temperature of the solution in step 1 is raised to 160°C.

6. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 2, the volume ratio of the TMSCl to the solution in step 1 is 1:

24.

7. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 3, the insulation time is 3 minutes.

8. The method for preparing highly efficient and stable white light Cs2NaYCl6 nanocrystals regulated by multifunctional carboxylic acid according to claim 1, characterized in that: In step 3, the rotation speed of the centrifugal dispersion is 8500-10000 rad, and the non-polar solvent is n-hexane.

9. A highly efficient and stable white light Cs2NaYCl6 nanocrystal regulated by a multifunctional carboxylic acid, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the Cs2NaYCl6 nanocrystal as claimed in claim 9 in preparing a light-emitting device.

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