Preparation method and application of amino acid-based perovskite fluorescent powder with high fluorescence quantum yield

Abstract

The invention discloses a preparation method and application of high-fluorescence quantum yield perovskite fluorescent powder based on amino acid, and belongs to the technical field of luminescent materials and display, the preparation method is used for preparing the perovskite fluorescent powder, and the preparation method comprises the following steps: dissolving potassium bromide in deionized water, then adding lead bromide, and carrying out ultrasonic dissolution to obtain a first solution; dissolving cesium bromide in another deionized water to obtain a second solution; mixing the first solution and the second solution, and standing to obtain a mixed solution; dropwise adding the mixed solution into absolute ethyl alcohol, and stirring to obtain a precursor solution; adding amino acid into the precursor solution, and stirring to obtain a precursor reaction suspension; and centrifuging the suspension, collecting the precipitate, centrifugally washing the precipitate with absolute ethyl alcohol, and drying the washed precipitate to obtain the perovskite fluorescent powder. The invention provides a green synthesis method of a water-ethanol system, which is combined with an amino acid synergistic passivation effect to realize low-cost preparation and improvement of luminous efficiency.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials and display technology, specifically relating to a method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids and its application. Background Technology

[0002] With the continuous development of display technology, LCD backlight display devices using white LEDs as backlights have captured a large market share, opening a new chapter in the display field. White LED devices mainly consist of LED chips and phosphor conversion materials, therefore, LED backlight displays place high demands on the performance of these phosphor conversion materials. Developing highly stable, efficient, narrow-band emission phosphor conversion materials for use in backlights has become crucial for improving display performance.

[0003] Metal halide perovskite materials, especially cesium lead bromide (CsPbBr3), are widely recognized as next-generation high-performance luminescent materials due to their superior optical properties, such as narrow emission lines (typically less than 25 nm full width at half maximum), high color purity, photoluminescence quantum yield (PLQY) approaching the theoretical limit, and tunable emission wavelength. They show great potential in wide color gamut displays, solid-state lighting, and fluorescent labeling. However, the practical application of perovskite fluorescent materials is limited. Traditional synthesis methods mainly include hot-injection and solid-state methods. Hot-injection methods are currently limited by the solubility of PbX2, and are currently only prepared using a few organic solvents such as dimethyl sulfoxide (DMSO). Solid-state methods, due to high sublimation and reaction temperatures, have high energy consumption, complex synthesis processes, and high costs. These methods are not only environmentally unfriendly but also complex, making it difficult to meet the needs of large-scale, green industrial production.

[0004] Existing technologies include the co-precipitation method for synthesizing perovskite phosphors in a water-ethanol system. While this method explores the use of green solvents, the PLQY of the products is generally low, and it does not fundamentally solve the long-term stability problem of perovskite materials in an aqueous environment, making them unsuitable for direct use as high-performance phosphors. On the other hand, to improve luminescence efficiency, some studies have focused on surface passivation technology, but this is usually achieved in organic solvent systems. The passivation mechanism is not combined with a truly green and safe aqueous synthesis route, failing to solve the solvent toxicity problem in the phosphor preparation process. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing perovskite phosphors with high photoluminescence quantum yield based on amino acids and their applications, so as to solve the problems of low synthesis efficiency, poor stability and dependence on toxic organic solvents in the existing technology of perovskite phosphors.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids, comprising the following steps: S1. Dissolve potassium bromide in deionized water, then add lead bromide and sonicate to dissolve, thus obtaining the first solution; S2. Dissolve cesium bromide in another deionized water solution to obtain a second solution; S3. Mix the first solution and the second solution and let stand to obtain a mixture containing a silver precipitate; S4. Add the mixture containing the silver precipitate obtained in S3 dropwise to anhydrous ethanol, stir, and then obtain the precursor solution; S5. Add amino acids to the precursor solution obtained in S4 and stir continuously to obtain a precursor reaction suspension. S6. Centrifuge the precursor reaction suspension obtained in S5, collect the precipitate, and wash the precipitate multiple times with anhydrous ethanol by centrifugation. Discard the supernatant, and repeat the washing with anhydrous ethanol three times. Dry the washed precipitate at 50°C to obtain perovskite phosphor. Furthermore, in S1, the molar ratio of potassium bromide to lead bromide is 40:1, and the molar volume ratio of potassium bromide to deionized water is 4:1.

[0007] Furthermore, the molar ratio of potassium bromide to cesium bromide is 40:1.

[0008] Furthermore, in S2, the molar volume ratio of cesium bromide to deionized water is 1:10.

[0009] Furthermore, in S3, the settling time is 5 minutes.

[0010] Furthermore, in step S4, the volume of anhydrous ethanol is 15 mL, and the stirring time is 15 min.

[0011] Furthermore, in step S5, the amino acid is any one of L-arginine, L-tryptophan, and L-lysine, and the stirring time is 24 hours.

[0012] Furthermore, the molar ratio of potassium bromide to amino acids is 200:19.

[0013] Furthermore, in S6, centrifugation is performed at 5000 rpm for 5 minutes.

[0014] The present invention also provides a method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids and the application of the perovskite phosphor in white LEDs. The perovskite phosphor is mixed with a nitride-based red phosphor and a photocurable photoresist. The mixture is heated at 40°C for 0.5 h. Subsequently, the mixture is deposited on a 460 nm blue LED chip and cured with ultraviolet light.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The synthesis process of this invention employs a water-ethanol green solvent system, eliminating the need for toxic organic solvents and complex organic ligands. Furthermore, the reaction does not require the participation of precious metals, making the preparation process environmentally friendly and significantly reducing production costs. Utilizing the water solubility of lead bromide and cesium bromide, the preparation process avoids the use of costly and polluting organic solvents and ligands, achieving the synthesis of highly efficient perovskite phosphors. The amino acids used, such as L-arginine (L-Arg), L-tryptophan (L-Trp), and L-lysine (L-Lys), act as passivating agents, overcoming the drawbacks of traditional perovskite phosphor synthesis which relies on organic solvents and high temperatures, resulting in high costs and easy agglomeration. The resulting perovskite phosphor exhibits good stability in air and even at high temperatures, precisely repairing perovskite lattice surface defects and significantly improving the material's stability in air, water, and high-temperature environments. This solves the problem of poor stability in traditional perovskite materials, providing a feasible path for the industrial production and commercial application of perovskite materials, and possessing significant practical and economic value. Attached Figure Description

[0016] Figure 1 The images show the XRD patterns of the perovskite phosphors prepared in Example 1 and Comparative Example 1.

[0017] Figure 2 The images show the XRD patterns of the perovskite phosphor intermediates prepared in Example 1 and Comparative Example 1.

[0018] Figure 3 The fluorescence lifetime spectra of the perovskite phosphors prepared in Example 1 and Comparative Example 1 are shown.

[0019] Figure 4 The images show the fluorescence emission-absorption spectra of the perovskite phosphors prepared in Example 1 and Comparative Example 1.

[0020] Figure 5 This is a scanning electron microscope (SEM) image of the green fluorescent perovskite powder (L-Arg CPB) prepared in Example 1.

[0021] Figure 6 This is a high-resolution transmission electron microscope (HRTEM) image of the L-Arg CPB prepared in Example 1.

[0022] Figure 7 This is a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) image of the L-Arg CPB prepared in Example 1.

[0023] Figure 8 The image shows the energy dispersive spectroscopy (EDS) spectra of Br in L-Arg CPB prepared in Example 1.

[0024] Figure 9 The image shows the energy dispersive spectroscopy (EDS) spectra of N in the L-Arg CPB prepared in Example 1.

[0025] Figure 10 The image shows the energy dispersive spectroscopy (EDS) spectra of Pb in the L-Arg CPB prepared in Example 1.

[0026] Figure 11 The image shows the energy dispersive spectroscopy (EDS) spectra of Cs in the L-Arg CPB prepared in Example 1.

[0027] Figure 12 The graph shows the stability of L-Arg CPB prepared in Example 1 at different temperatures.

[0028] Figure 13 The image shows the electroluminescence spectrum of the white perovskite LED prepared in Example 2.

[0029] Figure 14 The image shows the chromaticity coordinates of the white perovskite LED prepared in Example 2 on the CIE 1931 chromaticity diagram.

[0030] Figure 15 The image shows the electroluminescence spectrum of the white perovskite LED prepared in Example 2 at 20-100mA.

[0031] Figure 16 The graph shows the chromaticity coordinate changes of the white perovskite LED prepared in Example 2 on the CIE 1931 chromaticity diagram at 20-100mA.

[0032] Figure 17 The fluorescence spectra of the perovskite phosphors prepared in Example 3 and Comparative Example 1 are shown.

[0033] Figure 18 The fluorescence spectra of the perovskite phosphors prepared in Example 4 and Comparative Example 1 are shown. Detailed Implementation

[0034] The present invention will be further illustrated below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the invention in any way. It should be understood that the described embodiments are merely some, not all, of the embodiments described in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0035] The raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods.

[0036] Example 1 First, 0.476 g KBr (4 mmol) was dissolved in 1 mL of deionized water, and then 0.0367 g PbBr2 (0.1 mmol) was added and sonicated for 20 min to obtain the first solution; Dissolve 0.0213 g CsBr (0.1 mmol) in another 1 mL of deionized water to obtain a second solution; After thoroughly mixing the first and second solutions, let stand for 5 minutes to obtain a mixture containing a silver precipitate. Then, add the mixture containing the silver precipitate dropwise to 15 mL of anhydrous ethanol and stir for 15 minutes to form a precursor solution. Then, 0.38 mmol of L-Arg powder was added to the precursor solution and stirred continuously for 24 h to obtain the precursor reaction suspension. Centrifuge the precursor reaction suspension at 5000 rpm for 5 min, discard the supernatant, and collect the solid precipitate. Anhydrous ethanol was added to the solid precipitate, and after it was dispersed evenly, it was centrifuged again and the supernatant was discarded. This was one anhydrous ethanol washing operation. The anhydrous ethanol washing operation was repeated 3 times. The washed precipitate was dried at 50°C to obtain perovskite phosphor (L-Arg CPB).

[0037] Example 2 White perovskite LED 10 mg of the perovskite phosphor prepared in Example 1, 1-2 mg of nitride-based red phosphor (ZYP630H), and 200 mg of photocurable adhesive (Norland-61) were mixed. To remove air bubbles from the optical adhesive, the mixture was heated at 40°C for 0.5 h. Finally, the mixture was deposited onto a 460 nm blue LED chip and then UV-cured for 50 s (365 nm, 80 W / cm²). −2 ).

[0038] Example 3 First, 0.476 g KBr (4 mmol) was dissolved in 1 mL of deionized water, and then 0.0367 g PbBr2 (0.1 mmol) was added and sonicated for 20 min to obtain the first solution; Dissolve 0.0213 g CsBr (0.1 mmol) in another 1 mL of deionized water to obtain a second solution; After thoroughly mixing the first and second solutions, let stand for 5 minutes to obtain a mixture containing a silver precipitate. Then, add the mixture containing the silver precipitate dropwise to 15 mL of anhydrous ethanol and stir for 15 minutes to form a precursor solution. Then, 0.38 mmol of L-Trp powder was added to the precursor solution and stirred continuously for 24 h to obtain the precursor reaction suspension. Centrifuge the precursor reaction suspension at 5000 rpm for 5 min, discard the supernatant, and collect the solid precipitate. Anhydrous ethanol was added to the solid precipitate, and after it was dispersed evenly, it was centrifuged again and the supernatant was discarded. This was one anhydrous ethanol washing operation. The anhydrous ethanol washing operation was repeated 3 times. The washed precipitate was dried at 50°C to obtain perovskite phosphor (L-Trp CPB).

[0039] Example 4 First, 0.476 g KBr (4 mmol) was dissolved in 1 mL of deionized water, and then 0.0367 g PbBr2 (0.1 mmol) was added and sonicated for 20 min to obtain the first solution; Dissolve 0.0213 g CsBr (0.1 mmol) in another 1 mL of deionized water to obtain a second solution; After thoroughly mixing the first and second solutions, let stand for 5 minutes to obtain a mixture containing a silver precipitate. Then, add the mixture containing the silver precipitate dropwise to 15 mL of anhydrous ethanol and stir for 15 minutes to form a precursor solution. Then, 0.38 mmol of L-Lys powder was added to the precursor solution and stirred continuously for 24 h to obtain the precursor reaction suspension. Centrifuge the precursor reaction suspension at 5000 rpm for 5 min, discard the supernatant, and collect the solid precipitate. Anhydrous ethanol was added to the solid precipitate, and after it was dispersed evenly, it was centrifuged again and the supernatant was discarded. This was one anhydrous ethanol washing operation. The anhydrous ethanol washing operation was repeated 3 times. The washed precipitate was dried at 50°C to obtain perovskite phosphor (L-Lys CPB).

[0040] Comparative Example 1 Dissolve 0.476 g KBr (4 mmol) in 1 mL of deionized water, then add 0.0367 g PbBr2 (0.1 mmol) and sonicate for 20 min to obtain the first solution; Meanwhile, 0.0213 g CsBr (0.1 mmol) was dissolved in another 1 mL of deionized water. The two solutions were mixed and allowed to stand for 5 min to obtain a mixture containing a silver precipitate. The mixture containing the silver precipitate was then added dropwise to 15 mL of anhydrous ethanol and stirred for 15 min to form a precursor solution. Centrifuge the precursor solution at 5000 rpm for 5 min, discard the supernatant, and collect the solid precipitate. Anhydrous ethanol was added to the solid precipitate, and after it was dispersed evenly, it was centrifuged again and the supernatant was discarded. This was one anhydrous ethanol washing operation. The anhydrous ethanol washing operation was repeated 3 times. The washed precipitate was dried at 50°C to obtain perovskite phosphor (CPB).

[0041] Figure 1 The images show the XRD patterns of the perovskite phosphors prepared in Example 1 and Comparative Example 1. Figure 1 As can be seen, the XRD patterns of CPB prepared in Comparative Example 1 without the addition of L-Arg, the mixture containing silver precipitate during the synthesis of Comparative Example 1 (Intermediate, intermediate product), and the L-Arg CPB prepared in Example 1 are shown.

[0042] The standard PDF card (PDF#97-009-7851) for the orthorhombic crystal system CsPbBr3 shows that the XRD pattern of CPB is basically consistent with the characteristic diffraction peaks of the standard PDF card for orthorhombic CsPbBr3, proving that the final product CPB in Comparative Example 1 is orthorhombic CsPbBr3. The XRD pattern of L-Arg CPB is basically consistent with that of CPB, indicating that L-Arg modification did not change the orthorhombic phase of CsPbBr3, but acted on the material surface or defects. However, the XRD pattern of Intermediate is significantly different from that of orthorhombic CsPbBr3, indicating that Intermediate is an incompletely crystallized transitional product and has not formed a stable orthorhombic CsPbBr3. The XRD patterns of the CsPb2Br5 standard PDF card (PDF#00-025-0211) were compared with those of CPB and L-Arg CPB, proving that both CPB and L-Arg CPB are orthorhombic CsPbBr3. The L-Arg CPB of Example 1 and the CPB of Comparative Example 1 are both CsPbBr3 phases, without CsPb2Br5, indicating that the preparation process successfully avoided the formation of the byproduct CsPb2Br5, and there were no characteristic diffraction peaks of KBr (PDF#04-008-1876).

[0043] Figure 2 The images show the XRD patterns of the perovskite phosphor intermediates prepared in Example 1 and Comparative Example 1. Figure 2 It can be seen that, The CPB prepared in Comparative Example 1 exhibits the characteristic diffraction peaks of orthorhombic CsPbBr3; while the L-Arg CPB prepared in Example 1 has diffraction peaks that are basically consistent with the standard peaks of orthorhombic CsPbBr3, indicating that L-Arg modification promotes the transformation of CsPb2Br5 to the luminescent phase structure of CsPbBr3. The silver precipitate obtained in the intermediate steps of Example 1 and Comparative Example 1, the CPB prepared in Comparative Example 1, the supernatant in the mixed solution containing the silver precipitate obtained in the intermediate steps of Comparative Example 1, the supernatant in the mixed solution containing the silver precipitate obtained in the intermediate steps of Example 1 with added L-Arg (L-ArgSupernatant, L-Arg Supernatant), the L-Arg CPB prepared in Example 1, the L-Arg CPB of Example 1 is a CsPbBr3 phase, and the CPB of Comparative Example 1 is a CsPb2Br5 phase, indicating that the preparation process successfully avoided the formation of the byproduct CsPb2Br5. The absence of the characteristic diffraction peak of KBr (PDF#04-008-1876) in the spectrum indicates that the product is encapsulated in KBr.

[0044] Figure 3 The images show the fluorescence lifetime spectra of the perovskite phosphors prepared in Example 1 and Comparative Example 1. Figure 3 As can be seen, the fluorescence lifetime of the L-Arg CPB prepared by adding L-Arg in Example 1 is 200.2 ns, which is longer than that of the CPB prepared without adding L-Arg in Comparative Example 1.

[0045] Figure 4 The images show the fluorescence emission-absorption spectra of the perovskite phosphors prepared in Example 1 and Comparative Example 1. Figure 4 As can be seen from the fluorescence emission spectrum (solid line) and absorption spectrum (dashed line), the blue curve corresponds to CPB and the red curve corresponds to L-ArgCPB. The absorption peaks of CPB and L-ArgCPB are concentrated in the wavelength range of 460nm-500nm, indicating that the light energy in this range is effectively absorbed by the two perovskite phosphors, providing energy for subsequent fluorescence emission. Furthermore, the emission peaks of CPB and L-ArgCPB are concentrated near 520nm, indicating that the L-Arg modification did not change the emission wavelength of the perovskite, which remains green fluorescence. The emission intensity of L-ArgCPB is higher than that of CPB, indicating that the L-Arg modification improves the luminescence efficiency of the perovskite. The full width at half maximum (FWHM) of L-ArgCPB is narrower, indicating that the L-ArgCPB modified with L-Arg has better luminescence monochromaticity and improved luminescence efficiency.

[0046] Figure 5 This is a scanning electron microscope (SEM) image of the L-Arg CPB prepared in Example 1. Figure 5It can be seen that the L-Arg CPB prepared in Example 1 exhibits a cubic structure. Figure 6 This is a high-resolution transmission electron microscope (HRTEM) image of L-Arg CPB obtained in Example 1. Figure 6 It can be seen that L-Arg CPB has lattice stripes with a lattice spacing of 0.291 nm corresponding to its (200) lattice.

[0047] Figure 7 This is a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) image of the L-Arg CPB obtained in Example 1. According to... Figure 7 As can be seen, the L-Arg CPB prepared in Example 1 exhibits a plate-like / quasi-spherical aggregated particle structure with obvious differences in brightness. The bright areas correspond to the enriched regions of elements with higher atomic numbers (Pb, Cs), while the dark areas correspond to the regions of elements with lower atomic numbers (Br) or the pores and defects of the material. The overall structure shows that the perovskite particles exhibit agglomeration, but still maintain nanoscale dispersion characteristics.

[0048] Figure 8 The image shows the energy dispersive spectroscopy (EDS) spectra of Br in L-Arg CPB prepared in Example 1. Figure 9 The image shows the energy dispersive spectroscopy (EDS) spectra of N in the L-Arg CPB prepared in Example 1. Figure 10 The image shows the energy dispersive spectroscopy (EDS) spectra of Pb in the L-Arg CPB prepared in Example 1. Figure 11 The image shows the energy dispersive spectroscopy (EDS) spectra of Cs in the L-Arg CPB prepared in Example 1. According to... Figure 8 , Figure 9 , Figure 10 as well as Figure 11 It can be seen that the Br, N, Pb, and Cs elements are evenly distributed in the cubic structure of the perovskite phosphor. Combined with the XRD pattern, it can be confirmed that the phosphor prepared in Example 1 is CsPbBr3. The presence of N indicates that L-Arg participated in the synthesis of the perovskite phosphor. Figure 12 The graph shows the stability of L-Arg CPB prepared in Example 1 at different temperatures. According to... Figure 12 It can be seen that the L-Arg CPB prepared in Example 1 did not drop sharply at 120℃, proving that it has good stability between 80℃ and 120℃.

[0049] Figure 13 The image shows the electroluminescence spectrum of the white perovskite LED prepared in Example 2. According to... Figure 13 It can be seen that the spectrum covers the entire visible light range of 400~750nm (blue, green and red bands), indicating that white light emission has been achieved. Figure 14This is the chromaticity coordinate diagram of the white perovskite LED prepared in Example 2 on the CIE 1931 chromaticity diagram. According to... Figure 14 It can be seen that the CIE coordinates of the white perovskite LED prepared in Example 2 are (0.332, 0.336). Figure 15 The image shows the electroluminescence spectrum of the white perovskite LED prepared in Example 2 at 20-100 mA. Figure 15 It can be seen that the amount of phosphor required for the light-emitting diode varies under different currents, thus resulting in different intensity of the emitted emission peak. Figure 16 This is a graph showing the chromaticity coordinate changes of the white perovskite LED prepared in Example 2 on the CIE 1931 chromaticity diagram at 20-100mA. According to... Figure 16 It can be seen that as the current increases from 20mA to 100mA, the position of the chromaticity point shifts, indicating that the luminous color of the white perovskite LED changes with the operating current.

[0050] Figure 17 The images show the fluorescence spectra of the perovskite phosphors prepared in Example 3 and Comparative Example 1. According to... Figure 17 It can be seen that the luminescence intensity of L-Trp CPB is higher than that of CPB, indicating that L-tryptophan modification improves the luminescence efficiency of perovskite. Figure 18 The images show the fluorescence spectra of the perovskite phosphors prepared in Example 4 and Comparative Example 1. According to... Figure 18 It can be seen that the luminescence intensity of L-Lys CPB is higher than that of CPB, indicating that the modification of L-lysine improves the luminescence efficiency of perovskite.

[0051] Combination Figure 4 , Figure 17 and Figure 18 As can be seen, compared with L-TrpCPB prepared in Example 3 and L-LysCPB prepared in Example 4, L-Arg CPB prepared in Example 1 not only has higher luminescence intensity, but also a narrower half-width at half maximum (WHM) of the fluorescence emission peak, resulting in superior overall optical performance.

[0052] The L-Arg CPB prepared in Example 1 of this invention exhibits a high PLQY of 96.1% and demonstrates high stability in air, water, and high temperatures, making it suitable for fabricating perovskite light-emitting diodes (LEDs). Furthermore, by encapsulating red and green perovskite phosphors in silicone, a white perovskite LED with a wide color gamut (134% NTSC) and an external quantum efficiency (EQE) of 34.3% was obtained, with color coordinates of (0.332, 0.336). Additionally, the use of low-cost passivating agents and solvents as raw materials for the perovskite phosphors reduces material synthesis costs, potentially enabling commercialization.

[0053] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids, characterized in that, Includes the following steps: S1. Dissolve potassium bromide in deionized water, then add lead bromide and sonicate to dissolve, thus obtaining the first solution; S2. Dissolve cesium bromide in another deionized water solution to obtain a second solution; S3. Mix the first solution and the second solution and let stand to obtain a mixture containing a silver precipitate; S4. Add the mixture containing the silver precipitate obtained in S3 dropwise to anhydrous ethanol, stir, and then obtain the precursor solution; S5. Add amino acids to the precursor solution obtained in S4 and stir continuously to obtain a precursor reaction suspension. S6. Centrifuge the precursor reaction suspension obtained in S5, collect the precipitate, and wash the precipitate with anhydrous ethanol multiple times by centrifugation. Discard the supernatant, and wash the precipitate three times with anhydrous ethanol. Dry the washed precipitate at 50°C to obtain perovskite phosphor.

2. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, In S1, the molar ratio of potassium bromide to lead bromide is 40:1, and the molar volume ratio of potassium bromide to deionized water is 4:

1.

3. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, The molar ratio of potassium bromide to cesium bromide is 40:

1.

4. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, In S2, the molar volume ratio of cesium bromide to deionized water is 1:

10.

5. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, In step S3, the settling time is 5 minutes.

6. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, In step S4, the volume of anhydrous ethanol is 15 mL, and the stirring time is 15 min.

7. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, In step S5, the amino acid is any one of L-arginine, L-tryptophan, and L-lysine, and the stirring time is 24 hours.

8. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, The molar ratio of potassium bromide to amino acids is 200:

19.

9. The method for preparing a high photoluminescence quantum yield perovskite phosphor based on amino acids according to claim 1, characterized in that, In S6, centrifugation is performed at 5000 rpm for 5 minutes.

10. The application of a perovskite phosphor prepared by any one of claims 1-9 in a white LED, characterized in that, Perovskite phosphor was mixed with nitrided red phosphor and photocurable photoresist. The mixture was heated at 40°C for 0.5 h. Subsequently, the mixture was deposited on a 460 nm blue LED chip and cured with ultraviolet light.

Images