High-heat-resistant red light-emitting material, preparation and application thereof

Abstract

The application relates to a high-heat-resistance red light-emitting material and a preparation method and application thereof, and the chemical general formula of the material is CaLaTiTaO7: x Eu 3+ , and 0 < x <= 0.8; the material is synthesized by a high-temperature solid-phase method, CaCO3, La2O3, TiO2, Ta2O5 and Eu2O3 are weighed according to the stoichiometric ratio, are ground and are calcined, the sintered product is cooled and is finely ground to obtain the material; the CaLaTiTaO7 material is first selected as a matrix to synthesize a CaLaTiTaO7: x Eu 3+ series red fluorescent powder, under 393 nm near-ultraviolet light excitation, the material presents characteristic red light emission of Eu 3+ ions at 613 nm. The CLTT:0.6Eu 3+ / PDMS flexible composite thin film constructed by the material can maintain structural integrity and light emission stability in an acid-base environment, and an LED device prepared by using the material has good white light emission characteristics.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials technology, specifically relating to a high heat-resistant red luminescent material, its preparation method, and its application. Background Technology

[0002] Luminescent materials play a vital role in many key fields, including information display, solid-state lighting, defense technology, and anti-counterfeiting technology. Among them, white LEDs, with their high luminous efficiency and energy-saving and environmentally friendly advantages, have become the next generation of mainstream lighting sources, widely used in indoor and outdoor lighting, bio-imaging, and plant lighting. However, currently, mainstream white LEDs use blue LED chips to excite YAG:Ce... 3+ Yellow phosphor solutions generally suffer from high color temperature and low color rendering index due to the lack of red light components, necessitating the introduction of highly efficient and stable red phosphors for improvement. Meanwhile, LED devices generate high temperatures of around 420 K during operation, and most phosphor materials are prone to thermal quenching at high temperatures, severely limiting their use in practical environments. Furthermore, in the high-end anti-counterfeiting field, traditional fluorescent anti-counterfeiting materials often face problems such as poor weather resistance, easy signal attenuation, or low barriers to counterfeiting. Therefore, developing novel fluorescent materials that combine high thermal stability and good environmental tolerance is crucial for promoting the upgrading of white LED technology and building a highly secure anti-counterfeiting system. Summary of the Invention

[0003] The purpose of this invention is to provide a high heat-resistant red luminescent material, its preparation method and application. The high heat-resistant red luminescent material is a novel fluorescent material that combines high thermal stability and good environmental tolerance.

[0004] The objective of this invention is achieved through the following technical solution: A highly heat-resistant red luminescent material with the general chemical formula CaLaTiTaO7: x Eu 3+ , and 0 <x≤0.8。

[0005] Furthermore, the aforementioned high heat-resistant red luminescent material has the general chemical formula CaLaTiTaO7: x Eu 3+ Where x = 0.1, 0.2, 0.4, 0.6, or 0.8. The CaLaTiTaO7: x Eu 3+ (x = 0.1, 0.2, 0.4, 0.6, 0.8) series of red phosphors, abbreviated as: CLTT: x Eu 3+ .

[0006] Preferably, the high heat-resistant red luminescent material has the general chemical formula CaLaTiTaO7: x Eu 3+ , where x = 0.6.

[0007] The preparation method of the high heat-resistant red luminescent material adopts a high-temperature solid-state synthesis method, which includes the following steps: Weighing CaCO3, La2O3, TiO2, Ta2O5, and Eu2O3 according to the stoichiometric ratio and grinding them thoroughly in an agate mortar for 20 min; then, placing the thoroughly ground sample into a crucible and calcining it twice. The first calcination is carried out in a muffle furnace at 850℃ for 8 h; the sample is then removed and ground a second time (approximately 20 min), followed by calcination in air at 1200℃ for 8 h; finally, the sintered product is cooled and ground again to obtain the target sample, which is the high heat-resistant red luminescent material with the general chemical formula CaLaTiTaO7. x Eu 3+ , of which 0 <x≤0.8; The relevant reaction formulas are as follows: .

[0008] The preparation method includes the following specific steps: Weigh 1 mol CaCO3 (0.1897 g), 0.2 mol La2O3 (0.1235 g), 1 mol TiO2 (0.1513 g), 0.5 mol Ta2O5 (0.4188 g), and 0.3 mol Eu2O3 (0.2002 g) according to the stoichiometric ratio and grind them thoroughly in an agate mortar for 20 min; then, place the thoroughly ground sample into a crucible and calcine it twice. The first calcination is carried out in a muffle furnace at 850℃ for 8 h; after a second grinding (approximately 20 min), it is calcined again in air at 1200℃ for 8 h; finally, after cooling the sintered product, it is ground again to obtain the target sample, which is the high heat-resistant red luminescent material with the chemical formula CaLaTiTaO7. x Eu 3+ , where x = 0.6.

[0009] The application of the aforementioned high heat-resistant red luminescent material in the preparation of composite films.

[0010] A composite film is prepared using the aforementioned high heat-resistant red luminescent material.

[0011] The composite film is prepared by mixing the high heat-resistant red luminescent material with PDMS; the PDMS is obtained by mixing polydimethylsiloxane prepolymer and a curing agent; the chemical formula of the high heat-resistant red luminescent material is CaLaTiTaO7. x Eu 3+ Where x = 0.6, abbreviated as CLTT: 0.6Eu 3+ .

[0012] The curing agent is an organosilicon curing agent, which may be an organosilicon curing agent produced by DOW SILICONE SCORPORATION.

[0013] The method for preparing the composite film includes the following steps: First, polydimethylsiloxane prepolymer and curing agent are uniformly mixed to obtain PDMS; then, a high heat-resistant red luminescent material is weighed and added to PDMS, and magnetically stirred at 500 r / min for 2 h to obtain an emulsion; the mixed emulsion is injected into a petri dish, placed in a vacuum drying oven, and heated and cured at 150℃ for 15 min; after the sample cools to room temperature, it is demolded to obtain a flexible composite film.

[0014] The high heat-resistant red luminescent material has the general chemical formula CaLaTiTaO7: x Eu 3+ Where x = 0.6; the composite film is named CLTT:0.6Eu 3+ / PDMS composite film.

[0015] The CLTT: 0.6Eu 3+ Application of PDMS composite films in the fabrication of flexible devices.

[0016] The application of the aforementioned high heat-resistant red luminescent material in the fabrication of white LED devices.

[0017] A white LED device is made using the aforementioned high heat-resistant red luminescent material.

[0018] The white LED device is composed of the aforementioned high heat-resistant red luminescent material and blue phosphor (BAM:Eu). 2+ ), Green Powder (BSS: Eu) 2+ The high-heat-resistant red luminescent material was obtained by encapsulating it on a 395 nm chip at a mass ratio of 1:0.5:6; the chemical formula of the material is CaLaTiTaO7. x Eu 3+ And x = 0.6.

[0019] Compared with the prior art, the advantages of this invention are: this invention is the first to use CaLaTiTaO7 material as a matrix and synthesizes CaLaTiTaO7 using a high-temperature solid-state method. x Eu 3+ A series of red phosphors, when excited by near-ultraviolet light at 393 nm, exhibit Eu at 613 nm. 3+ Characteristic red light emission of ions; the designed CaLaTiTaO7:0.6Eu 3+ Within the temperature range of 300–510K, its red light emission intensity is exceptionally stable and even exhibits a unique phenomenon of "negative thermal quenching," and it has extremely small color coordinate shift, demonstrating excellent thermal stability and color retention capabilities.

[0020] The optimal sample is CaLaTiTaO7:0.6Eu. 3+ It exhibits remarkable anomalous thermal stability; at 360 K, the luminescence intensity remains 109.8% of that at 300 K; even at 420 K, the intensity still maintains 108.4%, with minimal change in color coordinates, demonstrating excellent negative thermal quenching properties and color retention. A CLTT:0.6Eu phosphor was constructed based on this phosphor. 3+ The PDMS flexible composite film maintains structural integrity and stable luminescence even in acidic and alkaline environments. Furthermore, based on this material, white LED devices encapsulated with commercially available blue and green phosphors and 395 nm chips exhibit excellent white light emission characteristics, with a color temperature of 5827 K and CIE color coordinates (0.3253, 0.3374), close to the ideal white light point, indicating good white light quality. Considering these characteristics, CaLaTiTaO7:0.6Eu 3+ It has shown promising application prospects in both anti-counterfeiting and white LED lighting fields. Attached Figure Description

[0021] Figure 1 This invention is CLTT: x Eu 3+ XRD pattern.

[0022] Figure 2 This invention is CLTT:0.6Eu 3+ Microscopic morphology images obtained from SEM testing.

[0023] Figure 3 This invention is CLTT:0.6Eu 3+ EDS plot.

[0024] Figure 4 This invention relates to CLTT and CLTT:0.6Eu. 3+ The DRS diagram.

[0025] Figure 5This invention relates to CLTT and CLTT:0.6Eu. 3+ The band gap diagram.

[0026] Figure 6 This invention is CLTT:0.6Eu 3+ The excitation spectrum.

[0027] Figure 7 This invention is CLTT: x Eu 3+ The emission spectrum.

[0028] Figure 8 This invention is CLTT:0.6Eu 3+ Temperature-dependent fluorescence spectra.

[0029] Figure 9 This invention is CLTT:0.6Eu 3+ The relationship between luminescence intensity and temperature.

[0030] Figure 10 This invention is CLTT:0.6Eu 3+ The color coordinate diagram.

[0031] Figure 11 This invention is CLTT:0.6Eu 3+ / PDMS composite film (A) under sunlight; (B) under ultraviolet light.

[0032] Figure 12 This invention is CLTT:0.6Eu 3+ / Photos of PDMS composite membranes immersed in solutions with different pH values.

[0033] Figure 13 These are the emission spectra of the composite membrane of this invention before and after immersion in acid and alkali solutions.

[0034] Figure 14 This is the electroluminescence spectrum of the white LED device of the present invention. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and embodiments: Example 1: Preparation and Product Analysis of High Heat Resistance Red Luminescent Material 1.1 Preparation of high heat-resistant red luminescent materials Synthesis of CaLaTiTaO7 using a high-temperature solid-state method: x Eu 3+ (x = 0.1, 0.2, 0.4, 0.6, 0.8) series of red phosphors (abbreviated as: CLTT: x Eu 3+Taking x = 0.6 as an example, according to the stoichiometric ratio, 1 mol CaCO3 (0.1897 g), 0.2 mol La2O3 (0.1235 g), 1 mol TiO2 (0.1513 g), 0.5 mol Ta2O5 (0.4188 g), and 0.3 mol Eu2O3 (0.2002 g) were weighed and placed in an agate mortar and ground thoroughly for 20 min. Next, the thoroughly ground sample was placed in a crucible and calcined twice. The first calcination was carried out in a muffle furnace at 850℃ for 8 h. After a second grinding (approximately 20 min), it was calcined again at 1200℃ in air for 8 h. Finally, the sintered product was cooled and ground again to obtain the target sample, which was then loaded and labeled. The relevant reaction formula is as follows:

[0036] 1.2 Results and Discussion 1.2.1 XRD Analysis Figure 1 The product shown is CaLaTiTaO7: x Eu 3+ XRD patterns of powdered samples. Different concentrations of Eu... 3+ Comparison of the diffraction data of the doped sample with the standard card (04-008-0438) of cubic CaLaTiTaO7 revealed that all major diffraction peaks showed good agreement with the standard spectrum, with only two weak impurity peaks appearing near 33.0 ° and 47.2 ° (indicated by...). The markers (which can be attributed to the formation of the orthorhombic CLTT) indicate the successful synthesis of CLTT predominantly composed of a cubic phase. x Eu 3+ Sample. With Eu 3+ As the doping concentration increases, the intensity of these two weak peaks gradually weakens, indicating that an appropriate amount of Eu... 3+ Doping promotes the formation of cubic phase structures. Furthermore, the positions of the characteristic diffraction peaks in samples with different doping concentrations did not shift significantly, further confirming the presence of Eu. 3+ The ions have entered the lattice of the CLTT matrix.

[0037] 1.2.2 SEM and EDS Analysis For CLTT: 0.6Eu 3+ The sample was subjected to SEM testing, and its microstructure was as follows: Figure 2 As shown. The sample particles have irregular morphology and a wide particle size distribution. The particle surface has no obvious pores, but some agglomeration occurs due to the high-temperature sintering process. To further analyze the elemental composition of the sample, CLTT:0.6Eu was analyzed. 3+ The sample was subjected to EDS energy dispersive spectroscopy analysis, and the results are as follows: Figure 3 As shown, characteristic peaks of Ca, La, Ti, Ta, O, and Eu were clearly detected in the energy dispersive spectroscopy (EDS). The types of each element are consistent with those of the target compound CaLaTiTaO7:Eu. 3+ Completely consistent, confirming Eu 3+ It has been successfully incorporated into the CLTT matrix.

[0038] 1.2.3 DRS Analysis For CLTT matrix and CLTT:0.6Eu 3+ DRS spectral analysis of the phosphor yielded the following results: Figure 4 As shown. In the ultraviolet region below 300 nm, both samples exhibit strong broad-band absorption, which is attributed to the absorption of the matrix itself. Compared with the CLTT matrix, CLTT: 0.6Eu 3+ The sample exhibits distinct characteristic absorption peaks near 464 nm and 534 nm, corresponding to Eu, respectively. 3+ Ionic 7 F0→ 5 D2 and 7 F0→ 5 D1 transition, proving Eu 3+ It has been successfully incorporated into the CLTT matrix lattice.

[0039] To further explore the impact of rare earth doping on the matrix material from the perspective of electronic structure, band gap calculations were performed on these two samples. Figure 5 As shown, the calculation results indicate that the band gap of the CLTT matrix is ​​3.78 eV. However, when Eu... 3+ After ions are introduced into the crystal lattice, CLTT: 0.6Eu 3+ The band gap value decreased to 3.75 eV. This change indicates that Eu 3+ The introduction of dopant ions can regulate the band structure of materials to a certain extent. This effect may be due to the perturbation of the original band structure by the local electronic states introduced by the dopant ions.

[0040] 1.2.4 Fluorescence Spectroscopy Analysis Figure 6 CLTT at a monitoring wavelength of 613 nm: 0.6Eu 3+ The excitation spectrum of [the spectrum] exhibits a strong and broad excitation band centered at 315 nm in the near-ultraviolet region, which is attributed to O [the spectrum]. 2- To Eu 3+ The charge transfer band (CTB) is also observed. Furthermore, a series of sharp peaks are present at 361, 380, 393, 412, and 461 nm, corresponding to Eu... 3+ The 4f-4f transition of ions is specifically as follows: 7 F0→ 5 D4、7 F0→ 5 L7 7 F0→ 5 L6 7 F0→ 5 D3 and 7 F0→ 5 D2. Among these narrow-band peaks, the strongest excitation peak appears at 393 nm, which means that the phosphor can be effectively excited by near-ultraviolet light and is suitable for optical applications that match near-ultraviolet LED chips.

[0041] Under near-ultraviolet light excitation at 393 nm Figure 7 Presenting different Eu 3+ CLTT of doping concentration: x Eu 3+ Emission spectra of phosphors. All samples exhibit Eu. 3+ The characteristic emission of Eu shows that the position and shape of each emission peak do not change with the doping concentration, indicating that Eu... 3+ It occupies fixed crystallographic sites in the CLTT matrix. Specifically, the emission peaks located near 581, 598, 613, 660, and 707 nm are attributed to Eu. 3+ Ions from excited state 5 D0 to ground state 7 F J The ff transitions (J = 0, 1, 2, 3, 4) are shown. Among them, the transition at 613 nm... 5 D0→ 7 The emission intensity of the F2 electric dipole transition is significantly higher than that at 592 nm. 5 D0→ 7 F1 magnetic dipole transition indicates that Eu 3+ Ions occupy non-centrosymmetric lattice sites in the matrix lattice. Additionally, Eu... 3+ The doping concentration has a significant impact on its luminescence intensity. With x As the concentration increased from 0.1 to 0.6, the intensity of all characteristic emission peaks continuously increased, reaching a maximum at x = 0.6. However, when the concentration was further increased to 0.8, the emission intensity decreased, exhibiting typical concentration quenching behavior. This phenomenon is mainly due to the high concentration of Eu... 3+ The shortened interion distance enhances non-radiative energy transfer processes such as cross-relaxation between ions, thereby reducing luminescence efficiency.

[0042] Figure 8 CLTT: 0.6Eu 3+Temperature-varying emission spectra were obtained in the range of 300 K to 510 K. It can be seen that under near-ultraviolet excitation at 393 nm, the shape and position of all emission peaks remained stable with increasing temperature, without significant shift or change, indicating that CLTT: 0.6Eu 3+ It exhibits good thermal stability and its structure does not change due to temperature variations. Figure 9 The relationship between the integrated luminescence intensity and temperature in the 550–650 nm range shows that this phosphor exhibits unconventional thermal response behavior. Specifically, as the temperature increases from 300 K to 360 K, its normalized luminescence intensity does not decrease but increases, reaching 109.8% of the intensity at 300 K. Even when the temperature is further increased to 420 K, the intensity remains at 108.4% of that at 300 K. No conventional thermal quenching was observed in the 300–480 K temperature range; instead, it exhibits "negative thermal quenching" characteristics, further demonstrating the material's excellent thermal stability.

[0043] Figure 10 Table 1 shows CLTT: 0.6Eu 3+ The chromatic coordinates change under different temperature conditions. As the temperature gradually increases from 300 K to 510 K, the chromatic coordinates only slightly shift from (0.5966, 0.4028) to (0.5891, 0.4103), with all coordinate points stably distributed in the red light region. This extremely small color shift indicates that the material has excellent chromatic stability over a wide temperature range, and the emitted color hardly changes significantly with temperature fluctuations. CLTT: 0.6Eu 3+ The high thermal stability and color retention of phosphors at high temperatures provide a key advantage for their practical application in the field of anti-counterfeiting labels. In real-world scenarios such as warehousing and logistics where temperature changes are possible, anti-counterfeiting labels based on this material can maintain the consistency and reliability of fluorescent signals, effectively overcoming the identification stability problems caused by thermal quenching or color drift of traditional fluorescent materials.

[0044] Table 1 CLTT: 0.6Eu 3+ (λ ex Color coordinates of (392 nm)

[0045] Example 2 CLTT: 0.6Eu 3+ Preparation and performance analysis of PDMS composite films 2.1 CLTT: 0.6Eu 3+ Preparation of PDMS composite films First, 5 g of polydimethylsiloxane prepolymer was uniformly mixed with 0.5 g of curing agent to obtain PDMS. Then, 0.1 g of CLTT:0.6Eu was weighed out. 3+ Phosphor was added to PDMS and magnetically stirred at 500 r / min for 2 h. The mixed emulsion was poured into petri dishes and placed in a vacuum drying oven for curing at 150 °C for 15 min. After the sample cooled to room temperature, it was demolded to obtain flexible CLTT:0.6Eu. 3+ / PDMS composite film.

[0046] For comparison, blank PDMS films without phosphors were prepared under the same conditions.

[0047] The curing agent is an organosilicon curing agent, which may be an organosilicon curing agent produced by DOW SILICONE SCORPORATIONO.

[0048] 2.2 CLTT: 0.6Eu 3+ Performance Analysis of PDMS Composite Thin Film Figure 11 (A) and (B) show the states of the corresponding films under natural light and 365 nm ultraviolet light excitation, respectively. Under natural light, the PDMS blank film is a colorless and transparent film, while the CLTT:0.6Eu film... 3+ The PDMS composite film appears milky white, and neither film emits light. However, when placed under ultraviolet light, the composite film emits bright red light, while the blank PDMS film shows no luminescence. This experiment visually demonstrates that Eu... 3+ Its efficient light-emitting properties were successfully maintained in the composite film, which makes its application in flexible devices possible.

[0049] CLTT prepared for system evaluation: 0.6Eu 3+ To assess the stability of the PDMS composite film in practical applications, the inventors cut it into equal portions and immersed them in solutions of different pH values ​​for 48 hours each. Figure 12 As shown in the figure, no significant morphological changes were observed on the surface of any composite membrane samples after immersion treatment, preliminarily indicating that they possess good chemical stability. Figure 13 The emission spectra of the composite membrane before and after immersion in acid and alkali solutions are shown. Compared with the sample before immersion, the fluorescence intensity of the sample after immersion in acid and alkali solutions only decreased slightly, indicating that CLTT: 0.6Eu 3+ The PDMS composite film has good acid and alkali resistance, which makes it a promising candidate for anti-counterfeiting applications in complex real-world environments.

[0050] Example 3: Fabrication and Performance Analysis of White LED Devices 3.1 Applications of White LED Devices To evaluate CLTT:0.6Eu 3+ The practicality of phosphors in white LED lighting is demonstrated by the prepared CLTT:0.6Eu 3+ Red fluorescent powder and commercial blue powder (BAM:Eu) 2+ ), Green Powder (BSS:Eu) 2+ The components were packaged on a 395 nm chip at a mass ratio of 1:0.5:6. The electroluminescence spectrum of the device was measured under a driving voltage of 3 V and a current of 80 mA as follows: Figure 14 As shown, its emission covers the entire visible light spectrum. The illustration shows that the device emits bright white light when powered on. The color temperature (CCT) of this white LED device is 5827 K, significantly lower than that of commercially available YAG:Ce LEDs. 3+ The CCT value when combined with the blue light chip is approximately 7746 K. Furthermore, its CIE chromaticity coordinates are (0.3253, 0.3374), very close to the ideal white light point (0.333, 0.333). These results indicate that CLTT: 0.6Eu 3+ Red phosphors have good potential for white LED applications.

[0051] in conclusion CaLaTiTaO7:xEu was successfully synthesized using a high-temperature solid-state method. 3+ A series of red phosphors. Under near-ultraviolet light excitation at 393 nm, the material exhibits Eu at 613 nm. 3+ Characteristic red light emission of ions. Optimal sample: CaLaTiTaO7:0.6Eu 3+ It exhibits remarkable anomalous thermal stability; at 360 K, the luminescence intensity remains 109.8% of that at 300 K; even at 420 K, the intensity still maintains 108.4%, with minimal change in color coordinates, demonstrating excellent negative thermal quenching characteristics and color retention ability. Based on this phosphor, CaLaTiTaO7:0.6Eu was prepared. 3+ The PDMS composite film maintains structural integrity and stable red light emission even in acidic and alkaline environments. Further integration with commercially available blue and green phosphors and a 395 nm chip resulted in a white LED device with a color temperature of 5827 K and CIE color coordinates of (0.3253, 0.3374), close to the ideal white light point, indicating good white light quality. Considering these characteristics, CaLaTiTaO7:0.6Eu... 3+ It has shown promising application prospects in both anti-counterfeiting and white LED lighting fields.

Claims

1. A high heat-resistant red luminescent material, characterized in that: Its general chemical formula is CaLaTiTaO7: x Eu 3+ , and 0 <x≤0.8。 2. The high heat-resistant red luminescent material according to claim 1, characterized in that: Its general chemical formula is CaLaTiTaO7: x Eu 3+ , where x = 0.1, 0.2, 0.4, 0.6 or 0.

8.

3. The high heat-resistant red luminescent material according to claim 2, characterized in that: Its general chemical formula is CaLaTiTaO7: x Eu 3+ , where x = 0.

6.

4. The method for preparing the high heat-resistant red luminescent material according to any one of claims 1-3, characterized in that: It includes the following steps: According to the stoichiometric ratio, CaCO3, La2O3, TiO2, Ta2O5, and Eu2O3 were weighed and placed in an agate mortar and ground thoroughly for 20 min. Then, the thoroughly ground sample was placed in a crucible and calcined twice. The first calcination was carried out in a muffle furnace at 850℃ for 8 h. After a second grinding, the sample was calcined again at 1200℃ in air for 8 h. Finally, the sintered product was cooled and ground again to obtain the target sample, which is the high heat-resistant red luminescent material with the chemical formula CaLaTiTaO7. x Eu 3+ , of which 0 <x≤0.8; The relevant reaction formulas are as follows: 。 5. The application of the high heat-resistant red luminescent material as described in any one of claims 1-3 in the preparation of composite films.

6. A composite thin film, characterized in that: It is made using the high heat-resistant red luminescent material as described in any one of claims 1-3.

7. The method for preparing the composite thin film as described in claim 6, characterized in that: It includes the following steps: First, polydimethylsiloxane prepolymer and curing agent are uniformly mixed to obtain PDMS; then, high heat-resistant red luminescent material is weighed and added to PDMS, and magnetically stirred at 500 r / min for 2 h to obtain emulsion; the mixed emulsion is poured into a petri dish, placed in a vacuum drying oven, and heated and cured at 150℃ for 15 min; after the sample cools to room temperature, it is demolded to obtain a flexible composite film.

8. The application of the high heat resistance red luminescent material as described in claim 1 in the preparation of white LED devices.

9. A white LED device, characterized in that: It is made using the high heat-resistant red luminescent material described in any one of claims 1-3.

10. The white LED device as described in claim 9, characterized in that: It is composed of the aforementioned high heat-resistant red luminescent material and blue powder (BAM: Eu). 2+ ), Green Powder (BSS: Eu) 2+ The high-heat-resistant red luminescent material was obtained by encapsulating it on a 395 nm chip at a mass ratio of 1:0.5:6; the chemical formula of the material is CaLaTiTaO7. x Eu 3+ And x = 0.6.

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