A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, its preparation method and application

Abstract

The present invention belongs to the field of luminescent materials, and particularly relates to a CsPbBr<subgt;3< / subgt> / Cs<subgt;4< / subgt;PbBr<subgt;6< / subgt> quantum dot glass-ceramic composite luminescent material, a preparation method thereof and an application thereof. The luminescent material comprises perovskite quantum dots and lithium disilicate glass-ceramics, wherein the concentration of the perovskite quantum dots is 5-70 wt%; the chemical formula of the perovskite quantum dots is CsPbBr<subgt;3< / subgt>@Cs<subgt;4< / subgt>PbBr<subgt;6< / subgt>; the molar percentage composition of the luminescent material is as follows: SiO<subgt;2: 58-70%, Li<subgt;2O: 20-35%, Al<subgt;2O<subgt;3: 1-5%, K<subgt;2O: 1-5%, P<subgt;2O<subgt;5: 1-5%, La<subgt;2O<subgt;3: 1-5%, CsBr: 0.4-5.6%, PbBr<subgt;2: 0.4-5.6%. The preparation method of the present invention has simple process, high photoluminescence intensity, low equipment requirements, narrow full width at half maximum, is environmentally friendly, and has good industrialization and application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of luminescent materials, and specifically relates to a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, a preparation method and an application thereof. Background Art

[0002] Zero-dimensional quantum dots Cs4PbX6 and CsPbX3 (X=I, Br and Cl) are a new generation of optoelectronic functional materials that have emerged in recent years. In recent years, all-inorganic perovskite cesium halide (CsPbX3, CsPb2X5 and Cs4PbX6 (X=I, Br and Cl) quantum dots have attracted widespread attention due to their excellent optical properties such as the effect of size on emission wavelength, narrow-band emission spectrum and high luminescence quantum yield. These properties make perovskite quantum dots considered to be high-quality candidate materials for the next generation of solar cells, light-emitting diodes (LEDs), backlight displays and biodiagnostics. In addition, due to their wide absorption range, perovskite quantum dots can also be used in short-wave shielding applications. However, despite the excellent photoluminescence and radiation-induced photoluminescence of perovskite quantum dots, the perovskite quantum dots have a wide absorption range and can be used in short-wave shielding applications. However, despite the excellent photoluminescence and radiation-induced photoluminescence of perovskite quantum dots, the perovskite quantum dots have a wide absorption range and can be used in short-wave shielding applications. Luminescence performance: Due to their colloidal properties and variable crystallization, perovskite quantum dots have poor stability to air, temperature, polar solvents, and light irradiation, which limits their applications in many areas. Currently, there are reports on embedding perovskite quantum dots into a glass matrix. Because the oxide glass matrix effectively prevents the degradation of metal halide quantum dots, the stability of these glass-embedded quantum dots is significantly improved, and they still exhibit good optical properties within the glass. However, there are currently few reports on Cs4PbBr6 quantum dots embedded in glass, and they have only been synthesized in borosilicate glass and tellurite glass.

[0003] This study synthesized stable, highly luminescent CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramics at high temperatures. The effects of calcination temperature, calcination time, and varying concentrations on the reaction process, crystal structure, micromorphology, and optical properties of the perovskite quantum dots were investigated. The successful encapsulation of the perovskite quantum dots within the glass matrix not only significantly improved their chemical stability and luminescence intensity, but also maintained excellent optical properties in nonpolar solutions, significantly enhancing their stability. Summary of the Invention

[0004] The purpose of the present invention is to provide a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material and its preparation method and application.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] On one hand, the present invention provides a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the luminescent material comprises perovskite quantum dots and lithium disilicate glass-ceramic, wherein the concentration of the perovskite quantum dots is 5 to 70 wt %; the chemical formula of the perovskite quantum dots is CsPbBr3 / Cs4PbBr6;

[0007] The molar percentage composition of the luminescent material is as follows: SiO2: 58-70%, Li2O: 20-35%, Al2O3: 1-5%, K2O: 1-5%, P2O5: 1-5%, La2O3: 1-5%, CsBr: 0.4-5.6%, and PbBr2: 0.4-5.6%.

[0008] In the above technical solution, further, the particle size of the perovskite quantum dots is 2 to 5 nm.

[0009] In the above technical solution, further, the concentration of the perovskite quantum dots is 5 to 20 wt%.

[0010] In the above technical solution, further, when excited at 365-400 nm, green light with a peak wavelength at 518 nm is emitted.

[0011] Another aspect of the present invention provides a method for preparing the composite luminescent material, the method comprising the following steps:

[0012] (1) According to the molar percentage composition of the CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, the molar percentage composition of the glass-ceramic is selected and the mass of each corresponding glass-ceramic component is calculated and each raw material is accurately weighed, wherein the Li2O is introduced by Li2CO3, the K2O is introduced by K2CO3, the P2O5 is introduced by NH4H2PO4, the Al2O3 is introduced by Al2O3, the SiO2 is introduced by SiO2, and the La2O3 is introduced by La2O3. The weighed glass raw materials are ground in an agate mortar and mixed uniformly to form a glass-ceramic raw material;

[0013] (2) placing the glass ceramic raw material obtained in step (1) into a corundum crucible and melting it in a muffle furnace for the first time, taking out the crucible after it is completely melted, pouring the clarified glass liquid into a preheated stainless steel mold to obtain transparent glass, then quenching and grinding it, placing the evenly ground glass powder into a muffle furnace again for melting it for the second time, taking out the crucible after the glass is completely melted again, pouring the clarified glass liquid into a preheated stainless steel mold to obtain a transparent glass block;

[0014] (3) annealing the glass block obtained in step (2), cooling it in a furnace, and then grinding it to obtain glass powder;

[0015] (4) The glass powder obtained in step (3) is weighed, mixed with CsBr and PbBr2, and ground evenly, and heat-treated in a muffle furnace to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material.

[0016] In the above technical solution, further, in step (2), the temperature of the first melting is 1450° C., and the temperature is kept warm for 30 minutes; the temperature of the second melting is 1450° C., and the temperature is kept warm for 60 minutes.

[0017] In the above technical solution, further, in step (3), the annealing temperature is 30 to 50° C. lower than Tg, and the temperature is kept for 1 to 3 hours, where Tg is the glass transition temperature.

[0018] In the above technical solution, further, in step (4), the heat treatment temperature is 500-650° C., and the heat treatment time is 30-240 min.

[0019] On the other hand, the present invention provides an application of the above-mentioned CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material in lighting devices, fingerprint recognition, and biological cell imaging.

[0020] In the above technical solution, further, in the lighting device, it is used to prepare LED lamp beads; in fingerprint recognition, when the ultraviolet light chip is excited at 365-400nm, bright green light can be obtained to realize the acquisition and recognition of fingerprints that are difficult to find in dark environments.

[0021] The beneficial effects of the present invention are:

[0022] 1. The preparation method of the present invention has simple process, high photoluminescence intensity, low equipment requirements, narrow half-peak width, is environmentally friendly, and has good industrialization and application prospects.

[0023] 2. The CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material obtained in the present invention can be used in display lighting devices and fingerprint recognition. Under near-ultraviolet light excitation, it can achieve single green light emission with a peak value at 520nm. The peak width of the green light emission peak is relatively narrow (the half-peak width is only 20 to 35nm), and it has good monochromaticity, which is conducive to its application in the field of display lighting.

[0024] 3. The present invention improves the stability of quantum dots by coating with lithium disilicate glass ceramics, so that the quantum dots can maintain a certain strength even in non-polar solvents. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 Transmission electron microscope image of the sample prepared in Example 5;

[0027] Figure 2 X-ray diffraction patterns of the samples prepared in Example 3, Example 4, and Example 5;

[0028] Figure 3 X-ray diffraction patterns of the samples prepared in Example 4, Example 6, and Example 7;

[0029] Figure 4 Emission spectra of the samples prepared in Example 2, Example 3, Example 4, and Example 5 under excitation at a wavelength of 365 nm;

[0030] Figure 5 Emission spectra of the samples prepared in Example 8, Example 9, Example 10, and Example 11 under excitation at a near-ultraviolet light wavelength of 365 nm. Detailed implementation manners

[0031] The following further illustrates the present invention in conjunction with the embodiments, but the protection scope of the invention is not limited thereto.

[0032] Unless otherwise specified, the materials used in the embodiments of the present invention can be obtained through commercial channels or prepared according to the conventional methods well-known to those skilled in the art.

[0033] Example 1

[0034] Table 1

[0035] raw material Weight (g) <![CDATA[SiO2]]> 19 <![CDATA[Li2CO3]]> 10 <![CDATA[Al2O3]]> 1.0 <![CDATA[Potassium carbonate]]> 1.3 <![CDATA[NH4H2PO4]]> 1.1 <![CDATA[La2O3]]> 3.1

[0036] The above-mentioned amounts of silicon dioxide, lithium carbonate, aluminum oxide, potassium carbonate, diammonium hydrogen phosphate and lanthanum oxide were weighed according to the stoichiometric ratio, transferred to an agate mortar and ground to fully mix the raw materials. The mixed raw materials were transferred to a corundum crucible and kept warm in a muffle furnace at 1450°C for 30 minutes. After the holding time, the glass liquid was water quenched, and the glass block obtained by water quenching was dried in an oven at 80°C for 30 minutes, and then ground evenly in an agate mortar to obtain a glass powder for the first heat treatment. The glass powder for the first heat treatment was then transferred to a corundum crucible and kept warm in a muffle furnace at 1450°C for 60 minutes. After the holding time, the clarified glass liquid was poured into a preheated stainless steel mold to obtain a transparent glass block. The glass block was then transferred to a muffle furnace and annealed at 500°C for 120 minutes. After cooling with the furnace, it was ground to obtain lithium disilicate glass powder.

[0037] Example 2

[0038] Table 2

[0039] raw material Weight (g) CbD 0.009 <![CDATA[PbBr2]]> 0.016 Lithium disilicate glass powder 0.5

[0040] A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material was prepared by a high-temperature solid-phase method, comprising the following steps: uniformly mixing the above-mentioned amounts of cesium bromide and lead bromide in an agate mortar, adding 0.5 g of the lithium disilicate glass powder obtained in Example 1, grinding the powder evenly and transferring the powder to a glass slide, placing the powder in a muffle furnace and sintering the powder at 600°C for 3 h to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the concentration of the perovskite quantum dots was 5 wt%.

[0041] The green emission peak of the sample of Example 2 is narrow, with a peak value at 520 nm and a half-peak width of only 20 to 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light of a certain intensity, which can still maintain a certain intensity in non-polar solvents.

[0042] Example 3

[0043] Table 3

[0044] raw material Weight (g) CbD 0.055 <![CDATA[PbBr2]]> 0.095 Lithium disilicate glass powder 0.5

[0045] A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material was prepared by a high-temperature solid-phase method, comprising the following steps: uniformly mixing the above-mentioned amounts of cesium bromide and lead bromide in an agate mortar, adding 0.5 g of the lithium disilicate glass powder obtained in Example 1, grinding the powder evenly and transferring the powder to a glass slide, placing the powder in a muffle furnace and sintering the powder at 600°C for 3 h to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the concentration of the perovskite quantum dots was 30 wt%.

[0046] The green emission peak of the sample of Example 3 is narrow, with a peak value at 518 nm and a half-peak width of only 20 to 35 nm; the excitation peak covers the near-ultraviolet region, emitting relatively bright green light, and can still maintain a certain intensity in non-polar solvents.

[0047] Example 4

[0048] Table 4

[0049] raw material Weight (g) CbD 0.092 <![CDATA[PbBr2]]> 0.158 Lithium disilicate glass powder 0.5

[0050] A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material was prepared by a high-temperature solid-phase method, comprising the following steps: uniformly mixing the above-mentioned amounts of cesium bromide and lead bromide in an agate mortar, adding 0.5 g of the lithium disilicate glass powder obtained in Example 1, grinding the powder evenly and transferring the powder to a glass slide, placing the powder in a muffle furnace and sintering the powder at 600°C for 3 h to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the concentration of the perovskite quantum dots was 50 wt%.

[0051] The green emission peak of the sample of Example 3 is narrow, with a peak value at 518 nm and a half-peak width of only 20 to 35 nm; the excitation peak covers the near-ultraviolet region, emitting extremely bright green light, and still having a high luminous intensity in non-polar solvents.

[0052] Example 5

[0053] Table 5

[0054] raw material Weight (g) CbD 0.128 <![CDATA[PbBr2]]> 0.222 Lithium disilicate glass powder 0.5

[0055] A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material was prepared by a high-temperature solid-phase method, comprising the following steps: uniformly mixing the above-mentioned amounts of cesium bromide and lead bromide in an agate mortar, adding 0.5 g of the lithium disilicate glass powder obtained in Example 1, grinding the powder evenly and transferring the powder to a glass slide, placing the powder in a muffle furnace and sintering the powder at 600°C for 3 h to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the concentration of the perovskite quantum dots was 70 wt%.

[0056] The green emission peak of the sample of Example 5 is narrow, with a peak value at 520 nm and a half-peak width of only 20 to 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light of a certain intensity, which can still maintain a certain intensity in non-polar solvents.

[0057] Example 6

[0058] Table 6

[0059] raw material Weight (g) CbD 0.092 <![CDATA[PbBr2]]> 0.158 Lithium disilicate glass powder 0.5

[0060] A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material was prepared by a high-temperature solid-phase method, comprising the following steps: uniformly mixing the above-mentioned amounts of cesium bromide and lead bromide in an agate mortar, adding 0.5 g of the lithium disilicate glass powder obtained in Example 1, grinding the powder evenly and transferring the powder to a glass slide, placing the powder in a muffle furnace and sintering the powder at 500°C for 180 min to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the concentration of the perovskite quantum dots is 50 wt%.

[0061] The green emission peak of the sample of Example 6 is narrow, with a peak value at 521 nm and a half-peak width of only 20 to 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light of a certain intensity, which can still maintain a certain intensity in non-polar solvents.

[0062] Example 7

[0063] Table 7

[0064] raw material Weight (g) CbD 0.092 <![CDATA[PbBr2]]> 0.158 Lithium disilicate glass powder 0.5

[0065] A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material was prepared by a high-temperature solid-phase method, comprising the following steps: uniformly mixing the above-mentioned amounts of cesium bromide and lead bromide in an agate mortar, adding 0.5 g of the lithium disilicate glass powder obtained in Example 1, grinding the powder evenly and transferring the powder to a glass slide, placing the powder in a muffle furnace and sintering at 550°C for 180 min to obtain a CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, wherein the concentration of the perovskite quantum dots is 50 wt%.

[0066] The green emission peak of the sample of Example 7 is narrow, with a peak value at 521 nm and a half-peak width of only 20 to 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light of a certain intensity, which can still maintain a certain intensity in non-polar solvents.

[0067] Example 8

[0068] Table 8

[0069] raw material Weight (g) CbD 0.092 <![CDATA[PbBr2]]> 0.158 Lithium disilicate glass powder 0.5

[0070] The CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material is prepared by a high-temperature solid-phase method, including the following steps: Mix the above-mentioned amounts of cesium bromide and lead bromide drugs evenly in an agate mortar, then add 0.5 g of the lithium disilicate glass powder obtained in Example 1, transfer it to a glass slide after grinding evenly, and put it into a muffle furnace for high-temperature sintering at 500 °C for 30 min to obtain the CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, where the perovskite quantum dot concentration is 30 wt%.

[0071] The green emission peak of the sample in Example 8 is relatively narrow, with the peak value located at 521 nm and the full width at half maximum being only 20 - 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light with a relatively low intensity, and still maintaining a certain intensity in non-polar solvents.

[0072] Example 9

[0073] Table 9

[0074] raw material Weight (g) CbD 0.092 <![CDATA[PbBr2]]> 0.158 Lithium disilicate glass powder 0.5

[0075] The CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material is prepared by a high-temperature solid-phase method, including the following steps: Mix the above-mentioned amounts of cesium bromide and lead bromide drugs evenly in an agate mortar, then add 0.5 g of the lithium disilicate glass powder obtained in Example 1, transfer it to a glass slide after grinding evenly, and put it into a muffle furnace for high-temperature sintering at 550 °C for 30 min to obtain the CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, where the perovskite quantum dot concentration is 30 wt%.

[0076] The green emission peak of the sample in Example 9 is relatively narrow, with the peak value located at 525 nm and the full width at half maximum being only 20 - 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light with a certain intensity, and still maintaining a certain intensity in non-polar solvents.

[0077] Example 10

[0078] Table 10

[0079] raw material Weight (g) CbD 0.092 <![CDATA[PbBr2]]> 0.158 Lithium disilicate glass powder 0.5

[0080] The CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material is prepared by a high-temperature solid-phase method, including the following steps: Mix the above-mentioned amounts of cesium bromide and lead bromide drugs evenly in an agate mortar, then add 0.5 g of the lithium disilicate glass powder obtained in Example 1, transfer it to a glass slide after grinding evenly, and put it into a muffle furnace for high-temperature sintering at 600 °C for 30 min to obtain the CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, where the perovskite quantum dot concentration is 30 wt%.

[0081] The green emission peak of the sample of Example 10 is narrow, with the peak value located at 525 nm and the full width at half maximum being only 20 - 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light with a certain intensity and still maintaining a certain intensity in non-polar solvents.

[0082] Example 11

[0083] Table 11

[0084]

[0085]

[0086] The CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material is prepared by the high-temperature solid-phase method, including the following steps: Mix the above-mentioned amounts of cesium bromide and lead bromide drugs evenly in an agate mortar, then add 0.5 g of the lithium disilicate glass powder obtained in Example 1, transfer it to a glass slide after grinding evenly, and sinter it at 650 °C in a muffle furnace for 30 min to obtain the CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, where the perovskite quantum dot concentration is 30 wt%.

[0087] The green emission peak of the sample of Example 11 is narrow, with the peak value located at 521 nm and the full width at half maximum being only 20 - 35 nm; the excitation peak covers the near-ultraviolet region, emitting green light with a certain intensity and still maintaining a certain intensity in non-polar solvents.

[0088] Figure 1 It is the transmission electron microscope (HRTEM) image of the sample prepared in Example 5. From Figure 1 it can be seen that the glass matrix has a good coating effect, and the spherical quantum dots are clearly visible in the glass matrix.

[0089] Figure 2 It is the X-ray diffraction pattern of the samples prepared in Example 3, Example 4 and Example 5. From Figure 2 it can be seen that the diffraction peaks of the X-ray diffraction patterns of perovskite quantum dots with different concentrations correspond to CsPbBr3 and Cs4PbBr6.

[0090] Figure 3 It is the X-ray diffraction pattern of the samples prepared in Example 4, Example 6 and Example 7. From Figure 3 it can be seen that for the samples obtained at different preparation temperatures, their diffraction peaks correspond to CsPbBr3 and Cs4PbBr6.

[0091] Figure 4 It is the emission spectrum of the samples prepared in Example 2, Example 3, Example 4 and Example 5 under the excitation of 365 nm wavelength. From Figure 4 It can be seen that when samples of perovskite quantum dots with different concentrations are excited by 365nm near-ultraviolet light, the peak value is around 518nm, and the half-peak width is 20-35nm.

[0092] Figure 5 The emission spectra of the samples prepared in Example 8, Example 9, Example 10 and Example 11 under the excitation of 365nm near-ultraviolet light are as follows: Figure 5 It can be seen that the samples obtained by heat treatment at 500℃, 550℃, 600℃, and 650℃ have a peak value of about 518nm under excitation of 365nm near-ultraviolet light, and its half-peak width is 20-35nm.

[0093] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Other variations or modifications may be made based on the above description. Obvious variations or modifications derived therefrom shall remain within the scope of protection of the present invention.

Claims

1. A CsPbBr3 / Cs4PbBr6 quantum dot glass-ceramic composite luminescent material, characterized by: The luminescent material includes perovskite quantum dots and lithium disilicate glass ceramics, wherein the concentration of the perovskite quantum dots is 5-70 wt%; the chemical formula of the perovskite quantum dots is CsPbBr3 / Cs4PbBr6; The molar percentage composition of the luminescent material is as follows: SiO2: 58-70%, Li2O: 20-35%, Al2O3: 1-5%, K2O: 1-5%, P2O5: 1-5%, La2O3: 1-5%, CsBr: 0.4-5.6%, PbBr2: 0.4-5.6%.

2. The composite luminescent material according to claim 1, wherein The particle size of the perovskite quantum dots is 2-5 nm.

3. The composite luminescent material according to claim 1, wherein The concentration of the perovskite quantum dots is 5-20 wt%.

4. The composite luminescent material according to claim 1, characterized in that, When excited at 365-400 nm, green light with a peak wavelength located at 518 nm is emitted.

5. A method for preparing the composite luminescent material according to any one of claims 1-4, characterized in that, The method includes the following steps: (1) According to the molar percentage composition of the CsPbBr3 / Cs4PbBr6 quantum dot glass ceramic composite luminescent material, select the molar percentage composition of the glass ceramic and calculate the mass of each corresponding glass ceramic composition, and accurately weigh each raw material. The Li2O is introduced by Li2CO3, the K2O is introduced by K2CO3, the P2O5 is introduced by NH4H2PO4, the Al2O3 is introduced by Al2O3, the SiO2 is introduced by SiO2, and the La2O3 is introduced by La2O3. Grind the weighed glass raw materials and mix them evenly to form glass ceramic raw materials; (2) First melt the glass ceramic raw materials obtained in step (1) in a muffle furnace. After complete melting, pour them onto a preheated stainless steel mold, then water quench and grind. Put the evenly ground glass powder into the muffle furnace again for a second melting. After the glass is completely melted again, pour it onto a preheated stainless steel mold to obtain a glass block; (3) Anneal the glass block obtained in step (2), cool it in the furnace, and then grind it to obtain glass powder; (4) Weigh and mix the glass powder obtained in step (3) with CsBr and PbBr2 and grind them evenly, and perform heat treatment in a muffle furnace to obtain the CsPbBr3 / Cs4PbBr6 quantum dot glass ceramic composite luminescent material.

6. The preparation method according to claim 5, wherein In step (2), the temperature of the first melting is 1450 °C and the holding time is 30 min; the temperature of the second melting is 1450 °C and the holding time is 60 min.

7. The preparation method according to claim 5, characterized in that, In step (3), the annealing temperature is 30-50 °C lower than the glass transition temperature, and the holding time is 1-3 hours.

8. The preparation method according to claim 5, characterized in that, In step (4), the heat treatment temperature is 500-650 °C, and the heat treatment time is 30-240 min.

9. Application of the composite luminescent material according to any one of claims 1-4 in lighting devices, fingerprint recognition, and biological cell imaging.

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