Antimony-doped manganese-based organic-inorganic metal chloride luminescent material and synthesis and application thereof

Abstract

The application discloses preparation and application of antimony-doped manganese-based organic-inorganic metal chloride luminescent material. The preparation method is an anti-solvent method, and the chemical formula of the obtained crystal material is (TTPhP)2MnCl4:Sb 3+ (TTPhP + =C 24 H 20 P + , which is a tetraphenylphosphonium cation), wherein 0.00028 The application has the advantages of low cost, simple and environment-friendly method, enriched luminescent properties of manganese-based organic-inorganic metal halide through antimony doping, improved fluorescence quantum yield, solved single-component organic-inorganic metal halide luminescence single problem, and good application prospect in luminescent information anti-counterfeiting and self-referencing calorimeter preparation. The material can also emit green light under X-rays excitation and has good temperature thermal stability, which widens the application field of organic-inorganic metal luminescent halide, and makes the material also have good application in scintillators.

Description

Technical Field

[0001] This invention belongs to the field of single-component multimode luminescence technology, specifically relating to the synthesis and application of a novel excitation wavelength-dependent and thermochromic luminescent material. Background Technology

[0002] Scintillator luminescent materials, capable of absorbing high-energy X-ray / γ-ray photons and converting the absorbed energy into low-energy visible light, have wide applications in medical diagnostics and environmental monitoring. However, most commercially available scintillator materials are inorganic materials containing rare-earth metals, and their preparation generally requires very high temperatures. Organic-inorganic hybrid metal halides, due to their high luminous efficiency and tunable emission color, can be used to fabricate light-emitting diodes, solar cells, and anti-counterfeiting devices. However, current single-component materials generally emit only one color of light, limiting their multifunctional applications. Moreover, only a small number of organic-inorganic metal halides have been used in scintillator luminescence. Therefore, single-component luminescent materials with multiple emission modes have attracted widespread attention from researchers worldwide.

[0003] Therefore, to broaden the application range of materials, the synthesis of single-component materials with multi-mode luminescence is a potential trend in the development of luminescent materials. In organic-inorganic hybrid metal halides, the dielectric difference between the organic and inorganic parts gives them unique photoelectric properties. Currently, antimony-doped manganese-based organic-inorganic metal chloride multi-mode luminescent materials with high luminescence thermal stability and X-ray excitation capabilities have not been reported. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing antimony-doped manganese-based organic-inorganic metal chloride luminescent materials and their optical applications. The materials are simple to prepare, environmentally friendly and non-toxic, have excellent photoelectric properties, and good luminescence thermal stability. They are expected to be used in information anti-counterfeiting and temperature sensing devices. Furthermore, the materials can be excited by high-energy X-rays and emit green light, and are expected to be used as scintillators in fields such as high-temperature environmental monitoring and high-temperature medical flaw detection.

[0005] Antimony-doped manganese-based organic-inorganic metal chloride luminescent material, characterized in that the chemical formula of the antimony-doped manganese-based organic-inorganic metal chloride luminescent material is (TTPhP)2MnCl4:Sb 3+ (TTPhP + =C 24 H 20 P + [SbCl5] is a tetraphenylphosphine cation. This antimony-doped organic-inorganic manganese-based metal chloride luminescent material is made from [SbCl5]. 2- Ion-substituted portion [MnCl4] 2-The crystal structure of (TTPhP)2MnCl4 is not destroyed by doping ions, and the crystal structure of (TTPhP)2MnCl4 is not destroyed, wherein 0.00028 < Sb / Mn < 0.0003, the crystal material belongs to a monoclinic crystal system, belongs to a C2 / c group, and the longest side length of the obtained crystal can reach 1 cm.

[0006] The preparation method of the antimony-doped organic-inorganic manganese metal chloride luminescent material is as follows:

[0007] (1) A sample bottle is added with tetraphenylphosphonium chloride, manganese dichloride and antimony trichloride according to a molar ratio, and then N,N-dimethylformamide (DMF) is added, and the solution is stirred and dissolved at room temperature; the sample bottle containing the solution is placed in a container containing anhydrous ether with an open mouth, and the container is sealed with a cover, and the anhydrous ether is volatilized into the solution in the sample bottle.

[0008] (2) After 1-3 days, crystals grow in the sample bottle, and the crystals are taken out and dried in air.

[0009] The synthesis method of the antimony-doped organic-inorganic manganese metal chloride luminescent material is characterized in that the ratio of the molar amount of tetraphenylphosphonium chloride to the total molar amount of manganese dichloride and antimony trichloride is 1.9-2.1:1 in the preparation process, and the molar ratio of antimony trichloride to manganese dichloride is about 0.95-1.05. The corresponding composition of the obtained crystal is 0.00028 < Sb / Mn < 0.0003.

[0010] The synthesis method of the antimony-doped organic-inorganic manganese metal chloride luminescent material is characterized in that anhydrous ether is volatilized into the DMF solution of the reactants at room temperature, so that the crystals are precipitated, 1 mmol of tetraphenylphosphonium chloride, and the amount of DMF is 1-3 mL; the volume of the ether is 2-10 times that of the N,N-dimethylformamide (DMF).

[0011] The material is not decomposed until 380°C, and exhibits good thermal stability.

[0012] The antimony-doped organic-inorganic manganese metal chloride luminescent material has two different luminescent centers, has two different luminescent peaks of 518 nm and 640 nm, and the luminescent color gradually changes from green to orange and then back to green under irradiation of different wavelengths of ultraviolet light (250-450 nm), and the highest fluorescence quantum yield can reach 98%, and can be used as a photoluminescent material for information anti-counterfeiting or directly used as a fluorescent powder.

[0013] The application of the antimony-doped organic-inorganic manganese-based metal chloride luminescent material, which has two different luminescent centers and two different luminescent peaks of 518 nm and 640 nm, and the two different luminescent centers have different responses to temperature; under excitation of 360-370 nm ultraviolet light, when the temperature is increased from 30 DEG C to 120 DEG C, the crystal luminescence gradually changes from orange-yellow light to green light, and the process is reversible; when the temperature is decreased from 120 DEG C to 30 DEG C, the crystal luminescence gradually changes from green light to orange-yellow light. The material can be used as a temperature-sensitive photo-induced light material for information anti-counterfeiting or directly used as a fluorescent powder.

[0014] The application of the antimony-doped organic-inorganic manganese-based metal chloride luminescent material, which has two different luminescent centers and two different luminescent peaks of 518 nm and 640 nm, and the two different luminescent centers have different responses to temperature; under excitation of 360-370 nm ultraviolet light, when the temperature is increased from 30 DEG C to 120 DEG C, the crystal luminescence gradually changes from orange-yellow light to green light, and the process is reversible; when the temperature is decreased from 120 DEG C to 30 DEG C, the crystal luminescence gradually changes from green light to orange-yellow light. The material can be used as a temperature-sensitive photo-induced light material for information anti-counterfeiting or directly used as a fluorescent powder.

[0015] The application of the antimony-doped organic-inorganic manganese-based metal chloride luminescent material, which can be excited by X-rays to emit green light and has a high photon yield (59000 photon MeV -1 ), and can be applied to X-rays imaging.

[0016] The application of the antimony-doped organic-inorganic manganese-based metal chloride luminescent material, which has a good X-rays luminescence thermal stability and can still maintain a strong X-rays luminescence at a temperature of 200 DEG C, and has a photon yield of 37000 photon MeV -1 . The material can be applied to X-rays imaging at a temperature of 0-200 DEG C

[0017] Beneficial effects: the present application provides a kind of antimony doped organic-inorganic manganese-based metal chloride luminescent material.Antimony doped organic-inorganic manganese-based metal chloride luminescent material is by antimony ion substitution part manganese ion, under the condition of not destroying (TTPhP) 2MnCl4 Crystal structure, increase the luminescent center of material, make the material have different color luminescence under different excitation wavelength and temperature, combine the excellent thermal stability of the material, can be applied to information anti-counterfeiting and self-reference calorimeter etc. As a kind of multifunctional luminescent material.In addition, the material can absorb high-energy X-rays energy and convert the absorbed energy into visible green light emission, and has high temperature stability, can still maintain high intensity luminescence at high temperature.Can be applied to high temperature environment monitoring and high temperature medical radiation etc. As an environmentally friendly scintillator material.

[0018] The present application is low in preparation cost, simple in method and environmental protection, the luminescent properties of manganese-based organic-inorganic metal halide are enriched by antimony doping, the fluorescence quantum yield is improved, the problem of single component organic-inorganic metal halide luminescence is solved, and the application prospect is good in the preparation of luminescent information anti-counterfeiting and self-reference calorimeter.The material can also emit green light under X-rays excitation, and has good temperature thermal stability, which widens the application field of organic-inorganic metal luminescent halide, so that the material also has good application in scintillator. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 For the antimony doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP) 2MnCl4:Sb of the present application 3+ The crystal structure diagram of the undoped manganese-based organic-inorganic metal chloride material.

[0020] Figure 2 For the antimony doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP) 2MnCl4:Sb of the present application 3+ The powder XRD diffraction spectrum of the undoped manganese-based organic-inorganic metal chloride material.

[0021] Figure 3 For the antimony doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP) 2MnCl4:Sb of the present application 3+ Normalized room temperature steady-state fluorescence spectrum and crystal luminescence photo under different wavelength excitation.

[0022] Figure 4 For the antimony doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP) 2MnCl4:Sb of the present application 3+ Crystal luminescence photo under different temperature excitation of 365nm ultraviolet light.

[0023] Figure 5 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Pseudo-color plot of variable-temperature steady-state fluorescence spectra under 365 nm UV excitation.

[0024] Figure 6 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Ratio of fluorescence intensity of two emission peaks at different temperatures under 365 nm UV excitation.

[0025] Figure 7 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Absolute and relative temperature sensitivity at different temperatures.

[0026] Figure 8 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Ratio of fluorescence intensity of two emission peaks under 365 nm UV excitation, cycled between room temperature and 130 °C for 10 times.

[0027] Figure 9 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Application in information anti-counterfeiting.

[0028] Figure 10 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Dosimetry dependence of the luminescence intensity of the Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb compared to the standard reference scintillator LuAG:Ce.

[0029] Figure 11 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Variable-temperature X-rays spectrum pseudo-color plot.

[0030] Figure 12 Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb 3+ Ratio of the integrated intensity of the luminescence of the Sb-doped organic-inorganic manganese metal halide luminescent material (TTPhP)2MnCl4:Sb to the commercial scintillator at different temperatures compared to room temperature.

[0031] Figure 13 Picture of the electronic component used for X-rays imaging.

[0032] Figure 14Sb-doped (TTPhP)2MnCl4 3+ The imaging photos at different temperatures for different electronic components X-rays imaging. DETAILED DESCRIPTION

[0033] The application will be further described below in conjunction with the drawings and specific examples:

[0034] Example 1

[0035] 1 mmol of tetraphenylphosphonium chloride and 0.5 mmol of manganese dichloride were added to a sample bottle (20 ml), and then 2 mL of DMF was added, and the mixture was stirred and dissolved at room temperature. The sample bottle containing the solution was placed in a blue cap reagent bottle (250 mL) containing 4 mL of anhydrous ether, sealed with a cap, and the anhydrous ether was slowly evaporated into the solution in the sample bottle. After 3 days, crystals grew in the sample bottle. The crystals were taken out and dried in the air.

[0036] The single crystal XRD diffraction test and crystal analysis showed that the obtained undoped manganese-based organic-inorganic metal chloride luminescent material (TTPhP)2MnCl4 had high crystallinity, belonged to a monoclinic system, and had a C2 / c space group. Figure 1

[0037] Example 2

[0038] 2 mmol of tetraphenylphosphonium chloride, 0.5 mmol of manganese dichloride, and 0.5 mmol of antimony trichloride were added to a sample bottle, and then 3 mL of DMF was added, and the mixture was stirred and dissolved at room temperature. The sample bottle containing the solution was placed in a container containing 10 mL of anhydrous ether, and the container was sealed, and the anhydrous ether was slowly evaporated into the solution in the sample bottle. After 3 days, crystals grew in the sample bottle. The crystals were taken out and dried in the air.

[0039] The powder XRD diffraction test showed that the obtained Sb-doped organic-inorganic manganese metal chloride luminescent material (TTPhP)2MnCl4:Sb Figure 2 3+ The powder XRD thereof was basically the same as that of the undoped one, indicating that the Sb doping did not destroy the crystal structure of (TTPhP)2MnCl4, but because of the substitution of Mn 3+ by a small amount of Sb 2+ with a large ionic radius, the diffraction peak shifted to a small angle.

[0040] The ICP-OES test analysis showed that the corresponding composition of the finally obtained crystal was Sb / Mn = 0.00029.

[0041] The Sb-doped organic-inorganic manganese metal chloride luminescent material (TTPhP)2MnCl4:Sb obtained in Example 2​​3+ Steady-state fluorescence test, such as Figure 3 The material has two emission peaks, one at 518 nm, originating from Mn. 2+ dd 4 T1- 6 A1 transition; another emission peak is at 640 nm, originating from [SbCl5]. 2- Radiative recombination of self-limiting excitons. Furthermore, the relative intensity of these two emission peaks varies with the excitation wavelength from 280 nm to 450 nm, resulting in different luminescent colors from the crystal.

[0042] Example 2 yielded an antimony-doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP) 2MnCl4:Sb 3+ When excited by a 365nm ultraviolet lamp, it emits different colors of light under different temperature conditions. For example... Figure 4 When the temperature rises from 30℃ to 120℃, the crystal's light emission gradually changes from orange-yellow to green, and this process is reversible. When the temperature drops back from 120℃ to 30℃, the crystal's light emission will gradually change from green to orange-yellow again.

[0043] Example 2 yielded an antimony-doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP) 2MnCl4:Sb 3+ After temperature-dependent fluorescence testing, such as Figure 5 , Figure 6 With an excitation wavelength of 365 nm, the crystalline material exhibits two emission peaks in its emission spectrum, one at 518 nm, originating from Mn. 2+ dd 4 T1- 6 A1 transition; another emission peak is at 640 nm, originating from [SbCl5]. 2- Radiative recombination of self-limiting excitons. And the relative intensities I of the two emission peaks. 518 / I 640 It changes with temperature. When the temperature gradually increases from 27℃ to 127℃, I... 518 / I 640 The temperature gradually increases, and this process is reversible; as the temperature gradually decreases from 127°C back to 27°C, I... 518 / I 640 The corresponding decrease is gradual. For example... Figure 7 Within the tested temperature range of 27℃ to 127℃, its absolute temperature sensitivity Sa gradually increases, reaching a maximum value of 0.18K at 127℃. -1 The relative temperature sensitivity of Sr first increases and then decreases, reaching a maximum of 3.6 K at 67℃. -1 And it has good reversible stability, such as... Figure 8Under 365 nm UV excitation, the temperature was cycled between 30 and 130 °C for 10 times, I 518 / I 640 The values are basically consistent. Based on this property, a self-referencing calorimeter with better performance can be prepared.

[0044] Example 3

[0045] The antimony-doped organic-inorganic manganese-based metal chloride luminescent material (TTPhP)2MnCl4:Sb obtained in Example 2 was used as a luminescent material. 3+ It can be used for information anti-counterfeiting. For example, Figure 9 The pattern and the letter "DICP" prepared by the screen printing method are irradiated with 254 nm ultraviolet light, the pattern and the letter emit green light, and under 365 nm ultraviolet excitation, the pattern and the letter emit orange-yellow light, which is different from the fluorescent powder which can only emit light of one color. When the excitation light is fixed as 365 nm ultraviolet light, the prepared pattern and letter exhibit different colors at different temperatures. When the temperature is increased from room temperature (about 22 °C) to 100 °C, the luminescence of the pattern and the letter gradually changes from orange-yellow light to green light, and this process is reversible. When the temperature is decreased from 100 °C to room temperature, the luminescence of the crystal gradually changes from green light to orange-yellow light. The dual luminescence property that the luminescence color changes with the excitation wavelength and the temperature can enhance the level of information anti-counterfeiting.

[0046] Example 4

[0047] 2 mmol of tetraphenylphosphonium chloride, 0.7 mmol of manganese dichloride and 0.3 mmol of antimony trichloride were added to a sample bottle, and 3 mL of DMF was added. The mixture was stirred and dissolved at room temperature. The sample bottle containing the solution was placed in a container containing 10 mL of anhydrous ether, and the container was sealed. The anhydrous ether was slowly evaporated into the solution in the sample bottle. After 3 days, crystals grew in the sample bottle. The crystals were taken out and dried in air.

[0048] The crystals obtained in Example 4 were analyzed by ICP-OES. The composition of the final crystals was: Sb / Mn = 0.00019. Under excitation of 365 nm and 254 nm ultraviolet light, the crystals emitted green light, which was basically consistent with the luminescence color of (TTPhP)2MnCl4. The crystals could not play a good role in information anti-counterfeiting.

[0049] Example 5

[0050] 2 mmol of tetraphenylphosphonium chloride, 0.7 mmol of manganese dichloride and 0.3 mmol of antimony trichloride were added to a sample bottle, and 3 mL of DMF was added. The mixture was stirred and dissolved at room temperature. The sample bottle containing the solution was placed in a container containing 10 mL of anhydrous ether, and the container was sealed. The anhydrous ether was slowly evaporated into the solution in the sample bottle. After 3 days, crystals grew in the sample bottle. The crystals were taken out and dried in air.

[0051] The crystal obtained in Example 5 was tested by ICP-OES analysis, and the final composition of the obtained crystal was Sb / Mn = 0.0015. The crystal emitted orange light under excitation of ultraviolet light at 365 nm and 254 nm, and the light emission color was consistent with (TTPhP)2SbCl5, which could not play a good information anti-counterfeiting role.

[0052] Example 6

[0053] The manganese-based organic-inorganic metal chloride scintillator luminescent material (TTPhP)2MnCl4: Sb obtained in Example 2 3+ X-rays related tests were performed, and the specific steps were as follows:

[0054] 1. The applied voltage of the X-rays was kept unchanged, the intensity of the X-rays was changed by changing the applied current of the X-rays, and the luminescent intensity of the material under different X-rays intensity radiation was measured by a spectrometer. The obtained spectral intensity was integrated and fitted, as shown in Figure 10 The intensity of the material under X-rays excitation had a good linear relationship with the intensity of the X-rays, and could be effectively applied to scintillator imaging.

[0055] 2. The intensity (45.8 μGy s -1 ) of the X-rays was kept unchanged, the ambient temperature of the material (i.e. 30℃, 40℃, 60℃, 80℃, 100℃, 120℃, 140℃, 160℃, 180℃, 200℃) was changed, and the luminescent intensity of the material at different temperatures was measured by a spectrometer. The integrated luminescent intensity at different temperatures was compared with that at room temperature, as shown in Figure 11 and Figure 12 The material had high thermal stability under X-rays excitation, and the stability was close to that of a commercial LuAG(Ce) scintillator, and was much higher than that of a perovskite Cs3Cu2I5 and CsPbBr3 nanocrystal material. It could be used for X-rays scintillator imaging under high temperature conditions.

[0056] Example 7

[0057] The manganese-based organic-inorganic metal chloride scintillator luminescent material (TTPhP)2MnCl4: Sb obtained in Example 2 3+The tablet is pressed and then applied to the X-rays imaging of the electronic component. The electronic component is placed between the X-rays source and the material tablet. When the X-rays of a certain intensity pass through the electronic component, the X-rays of different intensity are transmitted through the electronic component due to the different materials and thickness at different positions of the electronic component, so that the light intensity at the corresponding positions of the material tablet is different. The imaging diagram on the material tablet can finally show that there is a larger gap in the example electronic component, as shown in Figure 14 and a clearer X-rays imaging diagram can be obtained even when the temperature is as high as 200°C, which shows that the material can be used for X-rays imaging at high temperature and can be used for medical high-temperature flaw detection.

[0058] The above-described embodiments are only preferred schemes of the present application and are used for illustrating the present application but not for limiting the scope of the present application. Any technical scheme obtained by using equivalent substitution or equivalent transformation falls within the protection scope of the present application.

Claims

1. An antimony-doped manganese-based organic-inorganic metal chloride luminescent material, characterized in that, This is an antimony-doped manganese-based organic-inorganic metal chloride luminescent material, the chemical formula of which is (TTPhP)2MnCl4:Sb 3+ , TTPhP + = C 24 H 20 P + [SbCl5] is a tetraphenylphosphine cation, and this antimony-doped manganese-based organic-inorganic metal chloride multimode luminescent material is composed of [SbCl5]. 2- Ionic substitution moiety [MnCl4] 2- The ions are extracted without disrupting the crystal structure of (TTPhP)₂MnCl₄, wherein the molar ratio is 0.00028 < Sb / Mn < 0.0003; The crystal system of this material is monoclinic, and its space group is C2 / c.

2. A method for synthesizing the luminescent material according to claim 1, characterized in that, Follow these steps: (a) Add tetraphenylphosphine chloride, manganese dichloride, and antimony trichloride to the sample vial by molar ratio, then add N,N-dimethylformamide (DMF), and stir at room temperature to dissolve to obtain a solution; place the sample vial containing the solution open in a container containing anhydrous diethyl ether, seal the container, and wait for the anhydrous diethyl ether to evaporate into the solution in the sample vial; After 1-3 days, crystals will grow in the sample vial. Remove the crystals and let them air dry. The molar ratio of tetraphenylphosphine chloride to the sum of the molar amounts of manganese dichloride and antimony trichloride used in the preparation process is 1.9~2.1:1, and the molar ratio of antimony trichloride to manganese dichloride is in the range of 0.95~1.

05. The corresponding composition of the final crystal is: 0.00028 < Sb / Mn < 0.0003.

3. The method for synthesizing the luminescent material according to claim 2, characterized in that: At room temperature, anhydrous diethyl ether evaporates into the DMF solution of the reactants, causing crystals to precipitate. For 1 mmol of tetraphenylphosphine chloride, the amount of DMF used is 1-3 mL; the volume of diethyl ether used is 2-10 times that of N,N-dimethylformamide (DMF).

4. An application of the luminescent material according to claim 1, characterized in that: It can be used as a luminescent material for information anti-counterfeiting or directly as a fluorescent powder.

5. The application according to claim 4, characterized in that, This material has two different luminescent centers with two different luminescent peaks at 518 nm and 640 nm. Under ultraviolet light of different wavelengths from 250 to 450 nm, the luminescent color gradually changes from green to orange and then back to green. The fluorescence quantum yield can reach up to 98%. It can be used as a photoluminescent material for information anti-counterfeiting or directly as a phosphor. Alternatively, the material has two distinct luminescent centers with two different emission peaks at 518 nm and 640 nm, and these two centers respond differently to temperature: under 360-370 nm ultraviolet light excitation, when the temperature rises from 30°C to 120°C, the crystal emission gradually changes from orange-yellow to green light, and this process is reversible. When the temperature drops from 120°C back to 30°C, the crystal emission gradually changes from green to orange-yellow again. It can be used as a temperature-sensitive photoluminescent material for information anti-counterfeiting or directly as a phosphor.

6. An application of the luminescent material according to claim 1, characterized in that: It can be used as a luminescent material in the preparation of calorimeters.

7. The application according to claim 6, characterized in that, This material has two distinct luminescent centers with two different emission peaks at 518 nm and 640 nm, and these two centers respond differently to temperature. Under 360–370 nm ultraviolet light excitation, as the temperature increases from 27 °C to 127 °C, the intensity ratio of the 518 nm and 640 nm fluorescence peaks gradually increases, and this process is reversible. As the temperature decreases from 127 °C back to 27 °C, the intensity ratio of the 518 nm and 640 nm fluorescence peaks gradually decreases. It can be used as a luminescent material for the preparation of calorimeters.

8. An application of the luminescent material according to claim 1, characterized in that, This luminescent material is used as a scintillator in X-ray imaging.

9. The application according to claim 8, characterized in that: X-ray imaging applications can be performed at temperatures ranging from 0 to 200°C.

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