Red fluorescent glass: materials, methods, and applications

Abstract

The present invention discloses a red fluorescent glass material, a method and uses thereof. The red fluorescent glass material has a chemical composition as shown in formula (1): aMO·bY2O3·cSiO2·dRO2·xEu2O3 (1), wherein M is selected from one or more of Ca, Sr and Ba, and R is selected from one or more of Zr, Ti and Ge; a represents the molar coefficient of MO, 0 < a < 1; b represents the molar coefficient of Y2O3, 0 < b < 1; c represents the molar coefficient of SiO2, 0 < c < 1; d represents the molar coefficient of RO2, 0 < d < 1; x represents the molar coefficient of Eu2O3, 0 < x < 0.1. The red fluorescent glass material of the present invention can emit red fluorescence under the excitation of blue light.

Description

Technical Field

[0001] This invention relates to a red fluorescent glass material, method, and application. Background Technology

[0002] Fluorescent glass is a luminescent material prepared by doping phosphor into a glass matrix. It combines the optical properties of phosphor with the heat resistance and transparency of glass, and can avoid the aging and efficiency reduction problems caused by silicone encapsulation in LED applications.

[0003] Red fluorescent glass can be used in the white LED industry to supplement the red light component of lamps packaged with blue LEDs and YAG:Ce, solving the problem of missing red light and improving the color rendering index of white LEDs. White LEDs generally refer to LEDs that use blue LED chips to excite YAG phosphors to emit yellow light, which mixes with the remaining blue light to form white light. YAG phosphor is short for yttrium aluminum garnet phosphor.

[0004] CN109628092A discloses a europium ion-doped red phosphor for white LEDs, whose general chemical formula is: CaY 2-x-y Ln y Ge 4-z M z O 12 :xEu 3+ Ln is one or more of Sc, Gd, and La, and M is one of Si and Ti. This phosphor emits red fluorescence covering the 550–700 nm range with a main emission peak at 612 nm when excited by near-ultraviolet light.

[0005] CN107827354A discloses a red fluorescent glass made of the following effective materials: a matrix glass component raw material with a mass fraction of 1:0.002 to 0.01 and CaSrAlSiN3:Eu 2+ The phosphor comprises a matrix glass consisting of 10–50 mol% Bi₂O₃, 30–80 mol% B₂O₃, 5–10 mol% ZnO, and 5–10 mol% Al₂O₃, with a total molar fraction of 100%. This red fluorescent glass has an excitation wavelength of 470 nm and poor light transmittance.

[0006] CN113387568A discloses a red fluorescent glass with the following composition: aCaO:bY2O3:cT2O:dSiO2:eZO2:nPr6O 11: xEr2O3, where T is selected from one or more of Li, Na, and K; Z is selected from one or more of Zr, Ti, and Ge; a, b, c, d, e, n, and x represent the molar fractions of each component; 0 < a < 1, 0 < b < 1, 0 < c < 1, 0 < d < 1, and 2a + b + c = 4(d + e); n = (0.0001 - 0.1) / 6; x = (0.0001 - 0.1) / 2. There are relatively more components in this red fluorescent glass, and moreover, the heavy rare earth element erbium is used.

[0007] CN113387562A discloses a rare earth - doped red fluorescent glass and its preparation process. The rare earth - doped red fluorescent glass has a chemical composition represented by (MO)x(Y2O3)y(T2O)z(SiO2)a(EO2)b(Pr6O 11 )c(Eu2O3)d; where M is selected from at least one of Mg or Ba; T is selected from at least one of Li, Na, and K; E is selected from at least one of Zr, Ti, and Ge; x, y, z, a, b, c, and d respectively represent the molar fractions of MO, Y2O3, T2O, SiO2, EO2, Pr6O 11 and Eu2O3; x is 0.0001 - 0.5, y is 0.5 - 0.99, z is 0.001 - 0.3, a is 从0.01到0.6, b is 0.0001 - 0.2, c is 0.00001 - 0.001, d is 0.00001 - 0.001. There are still relatively more components in this red fluorescent glass. SUMMARY OF THE INVENTION

[0008] In view of this, an object of the present invention is to provide a red fluorescent glass material that can emit red fluorescence under the excitation of blue light, which has a higher visible light transmittance and luminous intensity while using fewer components.

[0009] Another object of the present invention is to provide a method for preparing the above - mentioned red fluorescent glass material.

[0010] Another object of the present invention is to provide the use of the above - mentioned red fluorescent glass material.

[0011] The present invention adopts the following technical solutions to achieve the above objects.

[0012] On the one hand, the present invention provides a red fluorescent glass material having a chemical composition as shown in formula (1):

[0013] aMO·bY2O3·cSiO2·dRO2·xEu2O3(1),

[0014] where,

[0015] Note: In the translation of the molar fraction range of "a" in , the original text "a为0.01~0.6" is translated as "a is from 0.01 to 0.6" to be more in line with English expression habits. If you have specific requirements for this part, please let me know and I will adjust it accordingly.M is selected from one or more of Ca, Sr, and Ba, and R is selected from one or more of Zr, Ti, and Ge;

[0016] a represents the molar coefficient of MO, where 0 < a < 1; b represents the molar coefficient of Y2O3, where 0 < b < 1; c represents the molar coefficient of SiO2, where 0 < c < 1; d represents the molar coefficient of RO2, where 0 < d < 1; x represents the molar coefficient of Eu2O3, where 0 < x < 0.1.

[0017] For the red fluorescent glass material according to the present invention, preferably, M is selected from one of Ca, Sr, and Ba.

[0018] For the red fluorescent glass material according to the present invention, preferably, R is selected from one of Zr, Ti, and Ge.

[0019] For the red fluorescent glass material according to the present invention, preferably, 0.1 < a < 0.9 and 0.05 < b < 0.5. [[ID=]14]

[0020] For the red fluorescent glass material according to the present invention, preferably, 0.05 < c < 1 and 0.01 < d < 0.9.

[0021] For the red fluorescent glass material according to the present invention, preferably, 0.005 < x < 0.1.

[0022] For the red fluorescent glass material according to the present invention, preferably, it has any of the following chemical compositions:

[0023] 0.7CaO·0.15Y2O3·0.8SiO2·0.2GeO2·0.035Eu2O3;

[0024] 0.7CaO·0.15Y2O3·0.9SiO2·0.1GeO2·0.035Eu2O3;

[0025] 0.7CaO·0.15Y2O3·0.7SiO2·0.3GeO2·0.035Eu2O3;

[0026] 0.7CaO·0.15Y2O3·0.6SiO2·0.4GeO2·0.035Eu2O3;

[0027] 0.7CaO·0.15Y2O3·0.5SiO2·0.5GeO2·0.035Eu2O3.

[0028] On the other hand, the present invention also provides a method for preparing the red fluorescent glass material as described above, comprising the following steps:

[0029] 1) According to the chemical composition, the raw materials are mixed to obtain a mixture; the mixture is calcined at 1200-1800℃ for 1-10 hours to obtain the calcined product;

[0030] 2) The calcined product is poured to obtain a glass product;

[0031] 3) The glass product is further heat-treated at 300-800℃ to obtain red fluorescent glass material.

[0032] According to the method of the present invention, preferably, the calcination temperature is 1300-1700°C and the calcination time is 1-8 hours.

[0033] In another aspect, the present invention also provides the use of the red fluorescent glass material as described above in the packaging of light-emitting diodes.

[0034] The red fluorescent glass material of this invention can emit red fluorescence under blue light excitation, and uses fewer components while having high visible light transmittance. The emission spectrum ranges from 570 to 630 nm, with the emission peak wavelength at 613 nm. Attached Figure Description

[0035] Figure 1 This is a photograph of the red fluorescent glass material obtained in Example 1.

[0036] Figure 2 The emission spectrum of the red fluorescent glass material obtained in Example 1 is shown.

[0037] Figure 3 The image shows the excitation spectrum of the red fluorescent glass material obtained in Example 1.

[0038] Figure 4 The visible light transmittance test curve of the red fluorescent glass material obtained in Example 1 is shown. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0040] The red fluorescent glass material of the present invention can emit red fluorescence when excited by blue light, and uses fewer components while having high visible light transmittance and luminous intensity.

[0041] <Red Fluorescent Glass Material>

[0042] The present invention provides a red fluorescent glass material having the chemical composition shown in formula (1):

[0043] aMO·bY2O3·cSiO2·dRO2·xEu2O3(1),

[0044] Among them, M is selected from one or more of Ca, Sr, and Ba, and R is selected from one or more of Zr, Ti, and Ge; a represents the molar coefficient of MO, 0 < a < 1; b represents the molar coefficient of Y2O3, 0 < b < 1; c represents the molar coefficient of SiO2, 0 < c < 1; d represents the molar coefficient of RO2, 0 < d < 1; x represents the molar coefficient of Eu2O3, 0 < x < 0.1. Such a red fluorescent glass material can emit red fluorescence under the excitation of blue light, and has a high visible light transmittance, luminous intensity, and high transparency.

[0045] The red fluorescent glass material of the present invention consists only of the above components and inevitable impurities, and does not contain Pr6O 11 , Li2O, Na2O, and K2O. Compared with the prior art CN113387562A, the present invention omits praseodymium oxide and alkali metal oxides, emits red fluorescence under the excitation of blue light, and the visible light transmittance is also improved, which does not belong to a conventional selection.

[0046] The red fluorescent glass of the present invention can be excited by blue light with a wavelength of 465 nm. The emission spectrum ranges from 570 to 630 nm.

[0047] According to a specific embodiment of the present invention, under the excitation of blue light with a wavelength of 465 nm, the emission peak wavelength of the emission spectrum is at 613 nm.

[0048] In the present invention, M can be selected from one or more of Ca, Sr, and Ba, preferably selected from one of Ca, Sr, and Ba. Ca is calcium element, Sr is strontium element, and Ba is barium element. a represents the molar coefficient of MO, 0 < a < 1, preferably, 0.1 < a < 0.9, more preferably, 0.3 < a < 0.9, still more preferably, 0.5 < a < 0.9. For example, a can be 0.5, 0.6, 0.7, 0.8. Such a range is more conducive to making the obtained red fluorescent glass material emit red fluorescence under the excitation of blue light and have a higher luminous intensity.

[0049] In the present invention, Y2O3 is yttrium oxide. b represents the molar coefficient of Y2O3, 0 < b < 1, preferably, 0.05 < b < 0.5, more preferably, 0.08 < b < 0.4, still more preferably, 0.09 < b < 0.3. For example, b can be 0.1, 0.15, 0.2.

[0050] In the present invention, SiO2 is silicon dioxide. c represents the molar coefficient of SiO2, 0 < c < 1, preferably, 0.05 < c < 1, more preferably, 0.1 < c < 1, still more preferably, 0.2 < c < 1. For example, c can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9.

[0051] In the present invention, R is selected from one or more of Zr, Ti, and Ge, preferably selected from one of Zr, Ti, and Ge, and more preferably Ge. Zr is the zirconium element. Ti is the titanium element. Ge is the germanium element.

[0052] In the present invention, d represents the molar coefficient of RO2, where 0 < d < 1. Preferably, 0.01 < d < 0.9, more preferably, 0.05 < d < 0.9, and still more preferably, 0.07 < d < 0.8. For example, d can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7. These elements can adjust and affect the crystal field environment around the activator ions, thereby enhancing the fluorescence emission efficiency.

[0053] In the present invention, Eu2O3 is europium trioxide. x represents the molar coefficient of Eu2O3, where 0 < x < 0.1. Preferably, 0.005 < x < 0.1, more preferably, 0.008 < x < 0.09, and still more preferably, 0.01 < x < 0.08. For example, x is 0.035. This is beneficial for obtaining better fluorescence emission intensity of the resulting red fluorescent glass material under the excitation of blue light.

[0054] According to a preferred embodiment of the present invention, the red fluorescent glass material has a chemical composition as shown in formula (1):

[0055] aMO·bY2O3·cSiO2·dRO2·xEu2O3(1),

[0056] where M is selected from one or more of Ca, Sr, and Ba, and R is selected from one or more of Zr, Ti, and Ge; a represents the molar coefficient of MO, 0.5 < a < 1; b represents the molar coefficient of Y2O3, 0.05 < b < 0.5; c represents the molar coefficient of SiO2, 0.1 < c < 1; d represents the molar coefficient of RO2, 0.05 < d < 0.9; and x represents the molar coefficient of Eu2O3, 0.005 < x < 0.1.

[0057] According to a specific embodiment of the present invention, the red fluorescent glass material has the following chemical composition: 0.7CaO·0.15Y2O3·0.8SiO2·0.2GeO2·0.035Eu2O3. [[ID=二十一]]

[0058] [[ID=二十二]]According to another specific embodiment of the present invention, the red fluorescent glass material has the following chemical composition: 0.7CaO·0.15Y2O3·0.9SiO2·0.1GeO2·0.035Eu2O3.

[0059] According to another specific embodiment of the present invention, the red fluorescent glass material has the following chemical composition: 0.7CaO·0.15Y2O3·0.7SiO2·0.3GeO2·0.035Eu2O3.

[0060] According to another specific embodiment of the present invention, the red fluorescent glass material has the following chemical composition: 0.7CaO·0.15Y2O3·0.6SiO2·0.4GeO2·0.035Eu2O3.

[0061] According to another specific embodiment of the present invention, the red fluorescent glass material has the following chemical composition: 0.7CaO·0.15Y2O3·0.5SiO2·0.5GeO2·0.035Eu2O3.

[0062] <Preparation Method>

[0063] This invention also provides a method for preparing the red fluorescent glass material as described above, comprising the following steps: 1) a mixing and calcination step; 2) a casting and molding step; and 3) a heat treatment step. These are described in detail below.

[0064] Mixing and calcination steps

[0065] According to the chemical composition shown in formula (1), the raw materials are mixed to obtain a mixture; the mixture is calcined at 1200-1800℃ for 1-10 hours to obtain the calcined product.

[0066] The raw material source of MO in formula (1) can be an oxide, carbonate, sulfate, nitrate or hydroxide of M, preferably an oxide of M.

[0067] The raw material source of Y2O3 in formula (1) can be yttrium trioxide or yttrium carbonate.

[0068] The raw material source of SiO2 in formula (1) can be silicon dioxide or silicate.

[0069] The raw material source of GeO2 in formula (1) can be germanium dioxide or germanium salts. Germanium salts can be germanium carbonate, germanium sulfate, germanium nitrate, etc. The source of Eu2O3 in formula (1) can be europium trioxide or europium salts. Europium salts can be europium carbonate, europium nitrate, europium sulfate, etc.

[0070] According to a specific embodiment of the present invention, calcium oxide (CaO), yttrium oxide (Y2O3), silicon dioxide (SiO2), germanium dioxide (GeO2), and europium oxide (Eu2O3) are mixed in appropriate molar proportions.

[0071] In this invention, the calcination temperature can be 1200–1800°C, preferably 1300–1700°C, and more preferably 1400–1600°C. The calcination time can be 1–10 h, preferably 1–8 h, and more preferably 1–5 h.

[0072] Casting process

[0073] The calcined product is poured into a mold to obtain a glass product. According to a specific embodiment of the present invention, the calcined product is poured into a mold to form a glass product.

[0074] Heat treatment steps

[0075] Further heat treatment of the glass product yields a red fluorescent glass material. This method is beneficial for obtaining a red fluorescent glass material with stable performance.

[0076] In this invention, the temperature for further heat treatment can be 300–800°C, preferably 400–700°C, and more preferably 500–600°C. The heat treatment time can be 1–20 hours, preferably 2–18 hours, and more preferably 5–8 hours. This helps to eliminate internal stress and obtain a red fluorescent glass material with stable performance.

[0077] <Applications>

[0078] This invention also provides a use for a red fluorescent glass material, specifically its use in light-emitting diode (LED) packaging. After the obtained red fluorescent glass is cut and polished, it is encapsulated within a YAG+ blue LED chip using a cover-up encapsulation method, thus supplementing the red light emission.

[0079] Test method:

[0080] Relative luminescence intensity: Using a fluorescence spectrometer, the red fluorescent glass material is excited by 465nm blue light. The relative luminescence intensity of the fluorescent glass is characterized by integrating the emission spectrum or selecting the intensity value at a specific wavelength and comparing it with a standard sample.

[0081] Visible light transmittance: The visible light transmittance of the fluorescent glass is obtained by measuring the ratio of the intensity of the light transmitted through the fluorescent glass to the intensity of the reference light using a spectrophotometer to generate continuous wavelengths of visible light.

[0082] Example 1

[0083] In this embodiment, the chemical composition of the red fluorescent glass material is 0.7CaO·0.15Y2O3·0.8SiO2·0.2GeO2·0.035Eu2O3.

[0084] The preparation steps are as follows: Weigh the corresponding weights of CaO (analytical grade), Y2O3 (analytical grade), SiO2 (analytical grade), GeO2 (purity 99.99%), and Eu2O3 (purity 99.99%) according to the molar ratio in the above chemical composition. Put the weighed raw materials into an agate mortar and mix them evenly to obtain a mixture.

[0085] The mixture was placed in a crucible and heated to 1550°C in a resistance furnace. It was then calcined at 1550°C for 1 hour to obtain the calcined product. The calcined product was poured into a preheated mold to obtain the formed red fluorescent glass material.

[0086] The formed red fluorescent glass material was heat-treated at 500℃ for 5 hours to eliminate the internal stress of the red fluorescent glass material, thus obtaining the red fluorescent glass material.

[0087] The prepared red fluorescent glass material, such as Figure 1 As shown (actual product image). From Figure 1 It can be seen that the red fluorescent glass material obtained in this embodiment has good visible light transmittance and high transparency.

[0088] Example 2

[0089] In this embodiment, the chemical composition of the red fluorescent glass material is 0.7CaO·0.15Y₂O₃·0.9SiO₂·0.1GeO₂·0.035Eu₂O₃. The corresponding raw materials are weighed according to this chemical composition. The remaining operating steps and process parameters are the same as in Example 1.

[0090] Example 3

[0091] In this embodiment, the chemical composition of the red fluorescent glass material is 0.7CaO·0.15Y₂O₃·0.7SiO₂·0.3GeO₂·0.035Eu₂O₃. The corresponding raw materials are weighed according to this chemical composition. The remaining operating steps and process parameters are the same as in Example 1.

[0092] Example 4

[0093] In this embodiment, the chemical composition of the red fluorescent glass material is 0.7CaO·0.15Y₂O₃·0.6SiO₂·0.4GeO₂·0.035Eu₂O₃. The corresponding raw materials are weighed according to this chemical composition. The remaining operating steps and process parameters are the same as in Example 1.

[0094] Example 5

[0095] In this embodiment, the chemical composition of the red fluorescent glass material is 0.7CaO·0.15Y₂O₃·0.5SiO₂·0.5GeO₂·0.035Eu₂O₃. The corresponding raw materials are weighed according to this chemical composition. The remaining operating steps and process parameters are the same as in Example 1.

[0096] Comparative Example 1

[0097] In this embodiment, the chemical composition of the fluorescent glass material is 0.7CaO·0.15Y₂O₃·SiO₂·0.035Eu₂O₃. The corresponding raw materials are weighed according to this chemical composition. The remaining operating steps and process parameters are the same as in Example 1.

[0098] Performance testing

[0099] Fluorescence spectroscopy was used to test the fluorescent glasses prepared in Examples 1, 2, 3, 4, 5, and Comparative Example 1. The performance test results are shown in Table 2. The emission spectrum of Example 1 is shown below. Figure 2 Excitation spectrum see Figure 3 When excited by blue light at a wavelength of 465 nm, it exhibits fluorescence emission in the range of 570 nm to 710 nm, with an emission peak at 613 nm.

[0100] Visible light transmittance was measured using a spectrophotometer, and the results are shown in Table 2. The visible light transmittance test curve for Example 1 is shown below. Figure 4 .

[0101] Table 1

[0102] Example 1 <![CDATA[0.7CaO·0.15Y2O3·0.8SiO2·0.2GeO2·0.035Eu2O3]]> Example 2 <![CDATA[0.7CaO·0.15Y2O3·0.9SiO2·0.1GeO2·0.035Eu2O3]]> Example 3 <![CDATA[0.7CaO·0.15Y2O3·0.7SiO2·0.3GeO2·0.035Eu2O3]]> Example 4 <![CDATA[0.7CaO·0.15Y2O3·0.6SiO2·0.4GeO2·0.035Eu2O3]]> Example 5 <![CDATA[0.7CaO·0.15Y2O3·0.5SiO2·0.5GeO2·0.035Eu2O3]]> Comparative Example 1 <![CDATA[0.7CaO·0.15Y2O3·SiO2·0.035Eu2O3]]>

[0103] Table 2

[0104]

[0105] Note: In Table 2, the relative luminous intensity is based on the luminous intensity of Example 1 and is set to 100%. The luminous intensity of other examples and comparative examples is compared with that of Example 1.

[0106] This invention is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this invention fall within the scope of this invention.

Claims

1. A red fluorescent glass material, characterized in that, It has a chemical composition as shown in formula (1): 0.7CaO•0.15Y2O3•cSiO2•dGeO2•0.035Eu2O3 (1), where c represents the molar coefficient of SiO2, 0.7 < c < 0.9; d represents the molar coefficient of GeO2, 0.1 < d < 0.3; the red fluorescent glass material emits red fluorescence under blue light excitation, the emission spectrum ranges from 570 to 630 nm, and the emission peak wavelength is at 613 nm.

2. The red fluorescent glass material according to claim 1, characterized in that, It has the following chemical composition:

3. A method for preparing the red fluorescent glass material as described in any one of claims 1 to 2, characterized in that, 0.7CaO•0.15Y2O3•0.8SiO2•0.2GeO2•0.035Eu2O3. It includes the following steps: 1) According to the chemical composition, mix each raw material to obtain a mixture; calcine the mixture at 1200 - 1800 °C for 1 - 10 h to obtain a calcined product; 2) Pour the calcined product to obtain a glass product; 4. The method according to claim 3, characterized in that, 3) Further heat-treat the glass product at 300 - 800 °C to obtain the red fluorescent glass material. The calcination temperature is 1300 - 1700 °C, and the calcination time is 1 - 8 h.

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