Spectrally tunable fluorescent glass thin film and preparation method and application thereof

Abstract

The application discloses a kind of spectrum adjustable fluorescent glass film and preparation method and application thereof, belong to luminescent glass technical field.The raw material of the spectrum adjustable fluorescent glass film includes glass powder and red fluorescent powder CASN3:Eu with mass ratio of 1~16:1 2+ ;Wherein, the material of glass powder is CdS quantum dot silicate glass.The application uses CdS QDs as yellow light emitting center, through compounding with CASN:Eu 2+ Red fluorescent powder, the proportion of both is accurately controlled to realize the compensation of red light component in spectrum, so that the spectrum continuously adjustable fluorescent glass film is obtained.The fluorescent glass film material prepared by the application is safe and environmentally friendly, and has uniform light emission, easy processing, high luminous efficiency, good thermal conductivity and good laser irradiation resistance.Under blue light excitation, the emission spectrum can be adjusted by changing the content of red fluorescent powder, and it is suitable for laser display field.

Description

Technical Field

[0001] This invention belongs to the field of luminescent glass technology, specifically relating to a spectrally tunable fluorescent glass film, its preparation method, and its application. Background Technology

[0002] Laser display technology is considered the next-generation display technology after LCD and OLED displays, boasting significant advantages such as high brightness, wide color gamut, long lifespan, and low power consumption. In this technology, phosphor conversion materials are the core components for achieving white light output, and their performance directly determines key parameters such as the luminous efficiency, color rendering index, color gamut coverage, and operational stability of the laser display light source. Currently, mainstream laser display phosphor converters use blue laser diodes to excite yellow phosphor materials, forming white light through the mixing of yellow light with the remaining blue light. However, the most widely used YAG:Ce... 3+ Yellow phosphors, lacking red light components in their spectrum, have a narrow white light color gamut and a low color rendering index, making it difficult to meet the stringent color saturation requirements of high-end displays. To expand the color gamut, researchers have attempted to introduce KSF:Mn... 4+ CaAlSiN3:Eu 2+ Spectral compensation is performed using red phosphors, and organic resins or silicone are used as encapsulation substrates. However, under long-term irradiation by high-power-density lasers, organic materials have poor thermal conductivity and are prone to yellowing, carbonization, or even ablation, leading to a sharp drop in the luminous efficiency of the phosphor material and even device failure, which seriously restricts the practical application of laser display technology.

[0003] To address this issue, researchers have developed all-inorganic encapsulation solutions such as fluorescent glass, fluorescent ceramics, and fluorescent glass thin films. Among these, fluorescent glass thin films have become a research hotspot in recent years due to their simple fabrication process and ability to be combined with high thermal conductivity substrates. However, existing fluorescent glass thin film technologies still suffer from limitations such as limited spectral modulation methods and the difficulty in simultaneously achieving high red light emission efficiency and stability.

[0004] Therefore, developing a novel fluorescent glass film with good thermal stability, red light emission, and tunable spectrum is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the above problems, this invention provides a spectrally tunable fluorescent glass thin film, its preparation method, and its applications.

[0006] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of this invention is to provide a spectrally tunable fluorescent glass film, the raw materials of which include glass powder and red phosphor CASN3:Eu in a mass ratio of 1~16:1. 2+ The glass powder is made of CdS quantum dot (QDs) silicate glass.

[0007] This invention uses CdS QDs as the yellow light emission center, and through interaction with CASN3:Eu 2+ By combining red phosphors and precisely controlling their ratio to compensate for the red light component in the spectrum, a fluorescent glass film with continuously tunable spectrum can be obtained.

[0008] Preferably, the preparation steps of the glass powder include: mixing and grinding the raw materials of silicate matrix glass and CdS raw materials, melting them to obtain glass liquid, annealing the glass liquid after pouring, and then heat treating it to obtain CdS quantum dot glass, and then grinding it through a 200-mesh sieve to obtain the glass powder.

[0009] More preferably, the raw materials of the glass powder, by molar percentage, are SiO2: 50%, ZnO: 10%, BaO: 10%, Na2O: 10%, K2CO3: 10%, B2O3: 6%, and CdS: 4%.

[0010] In this molar ratio of glass powder, SiO2 and B2O3 form a glass network framework, ensuring the thermal stability and mechanical properties of the glass; ZnO, BaO, Na2O, and K2CO3 act as network modifiers, regulating the melting temperature and crystallization behavior, promoting the in-situ precipitation and uniform distribution of CdS quantum dots; CdS, as a luminescent dopant, forms quantum dots through heat treatment, providing stable yellow light emission.

[0011] The design of this component also takes into account the bonding strength with the sapphire substrate and the controllable growth environment of the quantum dots.

[0012] More preferably, the annealing temperature is 450°C and the time is 6 hours.

[0013] More preferably, the heat treatment temperature is 500°C and the time is 12 hours.

[0014] The second technical solution of the present invention provides a method for preparing the above-mentioned spectrally tunable fluorescent glass thin film, comprising the following steps: Glass powder, red phosphor CASN3:Eu 2+ The mixture is mixed with a curing adhesive and ground, then coated onto a substrate, dried, and annealed to obtain the spectrally tunable fluorescent glass film.

[0015] Optionally, the curing adhesive is a terpineol-ethyl cellulose organic adhesive; the mass ratio of terpineol to ethyl cellulose in the terpineol-ethyl cellulose organic adhesive is 20:1; the curing adhesive and the glass powder and red phosphor CASN3:Eu 2+ The mass ratio of the total mass is 3:5.

[0016] Optionally, the substrate is made of sapphire.

[0017] Optionally, the drying temperature is 100°C and the time is 12 hours.

[0018] Optionally, the annealing temperature is 500°C and the time is 6 hours.

[0019] The third technical solution of the present invention provides an application of the above-mentioned spectrally tunable fluorescent glass film in the field of laser display.

[0020] The beneficial technical effects of the present invention are as follows: This invention uses CdS QDs as the yellow light emission center, and through CASN:Eu 2+ By combining red phosphors and precisely controlling their ratio to compensate for the red light component in the spectrum, a fluorescent glass film with continuously tunable spectrum can be obtained.

[0021] The fluorescent glass thin film material prepared by this invention is safe and environmentally friendly, emits light uniformly, is easy to process, has high luminous efficiency, good thermal conductivity, and good resistance to laser irradiation. Under blue light excitation, its emission spectrum can be controlled by changing the content of red phosphor, making it suitable for the field of laser display. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 Comparison of the XRD pattern of the glass powder prepared for Case 1 with the CdS crystal phase standard card.

[0024] Figure 2 The fluorescence spectra of the fluorescent glass films prepared for Examples 2-6 in the 380-850 nm wavelength range after being excited by a 396 nm laser are shown.

[0025] Figure 3 The white light color coordinates of the fluorescent glass thin films prepared for implementation of Cases 2-6 under 396 nm laser excitation. Detailed Implementation

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0027] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0028] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0030] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0031] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0032] All raw materials used in the embodiments of this invention are commercially available.

[0033] Implementation Case 1 Preparation of glass powder: Weigh out the raw materials according to the following molar percentages: 50% SiO2, 10% ZnO, 10% BaO, 10% Na2O, 10% K2CO3, 6% B2O3, and 4% CdS. Grind each raw material separately for 30 minutes and then mix them evenly to obtain a mixture. Place the mixture in an alumina crucible and then transfer it to a carbon rod electric furnace at 1200℃ for melting for 30 minutes. After homogenization and clarification, a uniform, bubble-free glass melt is obtained. Then, quickly pour the mixture into a brass mold preheated to 450℃ to form the glass. Finally, place the poured glass into a muffle furnace preheated to 450℃ and hold it for 6 hours. After the muffle furnace is turned off and the temperature is lowered to room temperature, the glass is transferred to an annealing furnace at 500℃ for heat treatment and crystallization for 12 hours. Finally, crush the glass block and grind it in an agate mortar through a 200-mesh sieve to obtain glass powder.

[0034] Implementation Case 2 Preparation of fluorescent glass thin films: Weigh the glass powder and red phosphor CASN3:Eu prepared in Example 1 at a mass ratio of 1:1. 2+As a mixed powder, terpineol-ethyl cellulose organic glue (the mass ratio of terpineol to ethyl cellulose is 20:1) is added, and the mass ratio of the mixed powder to the organic glue is 5:3. After mixing, the mixture is ground for 20 min, and then coated onto sapphire. The sapphire is then transferred to a dryer at 100 ℃ and dried for 12 h. After cooling to room temperature, it is finally transferred to an annealing furnace at 500 ℃ and held for 6 h to obtain a fluorescent glass film with a thickness of 110 μm.

[0035] Implementation Case 3 Preparation of fluorescent glass thin films: The only difference from Implementation Case 2 is the glass powder and the red phosphor CASN3:Eu 2+ The mass ratio is 4:1, and the remaining steps are the same as in Implementation Case 2.

[0036] Implementation Case 4 Preparation of fluorescent glass thin films: The only difference from Implementation Case 2 is the glass powder and the red phosphor CASN3:Eu 2+ The mass ratio is 8:1, and the remaining steps are the same as in Implementation Case 2.

[0037] Implementation Case 5 Preparation of fluorescent glass thin films: The only difference from Implementation Case 2 is the glass powder and the red phosphor CASN3:Eu 2+ The mass ratio is 12:1, and the remaining steps are the same as in Implementation Case 2.

[0038] Implementation Case 6 Preparation of fluorescent glass thin films: The only difference from Implementation Case 2 is the glass powder and the red phosphor CASN3:Eu 2+ The mass ratio is 16:1, and the remaining steps are the same as in Implementation Case 2.

[0039] The glass powder prepared in Example 1 was subjected to XRD testing. The comparison between its XRD pattern and the CdS crystal phase standard card is shown in the figure below. Figure 1 As shown, the test results indicate that the XRD pattern of the fluorescent glass material prepared in Example 1 has a large and broad main peak, which is consistent with the characteristics of XRD pattern of glass material. At the same time, the crystal characteristic peaks that appear are consistent with the CdS standard card, and no impurities are generated, indicating that CdS has been successfully crystallized in the glass matrix.

[0040] The photoluminescence properties of the fluorescent glass films prepared in Examples 2-6 were tested. The photoluminescence spectra in the 380-850 nm wavelength range under excitation by a 396 nm laser pump source are shown below. Figure 2 .like Figure 2As shown, the broad emission peak centered at 500 nm in the 450–580 nm range is the characteristic emission peak of CdS QDs, while the emission peak centered at 660 nm is that of the red phosphor CASN3:Eu. 2+ The characteristic emission peaks are clearly visible. It can be clearly seen that with the increase of glass powder, the intensity of yellow light first increases and then decreases, while the intensity of red light shows roughly the opposite trend. This indicates that the spectral shape of the glass film is effectively adjusted, and at the same time, it shows that the red light band of the fluorescent glass material is effectively supplemented, which is beneficial to the adjustment and broadening of the spectral range.

[0041] The white light color coordinate diagram under 396 nm excitation is shown below. Figure 3 The color coordinates are shown in Table 1.

[0042] Table 1 Table 1 and Figure 3 The results showed that as the proportion of quantum dots increased, the color coordinates shifted from the lower right to the upper left. Analysis revealed that by adjusting the ratio of CdS quantum dots to red phosphor, the emitted color could be continuously controlled from deep red-violet to blue-violet, verifying the feasibility of spectral modulation of fluorescent glass films. The color coordinates near 12:1 were closest to the white light region, with a color rendering index of approximately 79, making it suitable for lighting or display backlighting.

[0043] In summary, the fluorescent glass thin film material prepared by this invention is safe and environmentally friendly, emits light uniformly, is easy to process, has high luminous efficiency, good thermal conductivity, and good resistance to laser irradiation. Under blue light excitation, its emission spectrum can be controlled by changing the phosphor content, making it suitable for the field of laser display.

[0044] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A spectrally tunable fluorescent glass thin film, characterized in that, The raw materials include glass powder in a mass ratio of 1 to 16:1 and red phosphor CASN3:Eu. 2+ The glass powder is made of CdS quantum dot silicate glass.

2. The spectrally tunable fluorescent glass thin film according to claim 1, characterized in that, The preparation steps of the glass powder include: mixing and grinding the raw materials of silicate matrix glass and CdS raw materials, melting them to obtain glass liquid, annealing the glass liquid after pouring, and then heat treating it to obtain CdS quantum dot glass, and then grinding it through a 200-mesh sieve to obtain the glass powder.

3. The spectrally tunable fluorescent glass thin film according to claim 2, characterized in that, The raw materials of the glass powder, by molar percentage, are SiO2: 50%, ZnO: 10%, BaO: 10%, Na2O: 10%, K2CO3: 10%, B2O3: 6%, and CdS: 4%.

4. The spectrally tunable fluorescent glass thin film according to claim 3, characterized in that, The annealing temperature was 450°C and the time was 6 hours.

5. The spectrally tunable fluorescent glass thin film according to claim 3, characterized in that, The heat treatment was performed at a temperature of 500°C for 12 hours.

6. A method for preparing a spectrally tunable fluorescent glass thin film according to any one of claims 1 to 5, characterized in that, Includes the following steps: Glass powder, red phosphor CASN3:Eu 2+ The mixture is mixed with the curing adhesive and ground for 20 minutes, then coated onto the substrate, dried and annealed to obtain the spectrally tunable fluorescent glass film.

7. The method for preparing a spectrally tunable fluorescent glass thin film according to claim 6, characterized in that, The curing adhesive is a terpineol-ethyl cellulose organic adhesive; the mass ratio of terpineol to ethyl cellulose in the terpineol-ethyl cellulose organic adhesive is 20:1; the curing adhesive, glass powder, and red phosphor CASN3:Eu 2+ The mass ratio of the total mass is 3:

5.

8. The method for preparing a spectrally tunable fluorescent glass thin film according to claim 6, characterized in that, The substrate is made of sapphire.

9. The method for preparing a spectrally tunable fluorescent glass thin film according to claim 6, characterized in that, The drying temperature is 100℃ and the time is 12h; the annealing temperature is 500℃ and the time is 6h.

10. The application of the spectrally tunable fluorescent glass film according to any one of claims 1 to 5 in the field of laser display.

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