KR102471078B1 - Glass composite comprising light emitting nanoparticle and LED device comprinsing the same - Google Patents

Abstract

The present invention relates to a glass composite comprising glass containing nanoparticles having light-emitting properties and glass having a different softening point, and wherein the glass containing nanoparticles is supported in the form of powder or particles on another glass. It is possible to provide a technology capable of overcoming the limitations of various characteristics of the organic/inorganic color conversion materials used.

Description

Glass composite comprising light emitting nanoparticle and LED device comprinsing the same}

The present invention relates to a glass composite comprising two or more different types of glass and at least one glass containing luminescent nanoparticles, and an LED device and display using the same.

The traditional white LED used in various lighting devices and LCD backlights is coated on the blue LED by mixing a silicone or epoxy-based organic binder and phosphor. manufacture The more popular silicone resin has low thermal and chemical stability, so there is a problem of reduced efficiency and shortened lifespan during long-term operation. In addition, durability against high heat and moisture is not good compared to inorganic color converters including glass or ceramics. In particular, inorganic color converters may be more suitable for high-power LEDs.

Representative inorganic color conversion materials used in LED manufacturing include PC (Phosphor Ceramic), PGC (Phosphor Glass Ceramic), PiG (Phosphor in Glass), and BGP (Bulk Glass Phosphor), and Korean Patent Publication No. 10-2019-0043346 and A related invention is disclosed in No. 10-2020-0018839 and the like.

However, inorganic color conversion materials also have technical limitations that need to be addressed. PC has high light conversion, but the usable phosphor is limited and requires an advanced sintering process, and PGC does not require a separate phosphor, but has a problem of low efficiency because it is difficult to control the amount and degree of crystallized phosphor. In addition, PiG can easily adjust the chromaticity of light with a simple manufacturing process and can easily apply high-efficiency phosphors, but requires a frit material that does not react with phosphors while being fired at a low temperature that does not damage the phosphors. , BGP uses active ions or quantum dots in a light-emitting glass material as a light emitting body, and can be molded freely with a simple process, but commercialization is difficult due to low efficiency.

Korean Patent Publication No. 10-2019-0043346 Korean Patent Publication No. 10-2020-0018839

The present invention is a glass composite that can minimize the disadvantages while having the advantages of various inorganic color conversion materials such as color conversion in a wide range, high efficiency light conversion, long-lasting light emission, improvement in luminous flux reduction, and easy manufacturing process. And to provide a manufacturing method thereof.

The glass composite according to the present invention includes first-class glass including nanoparticles having light-emitting properties after heat treatment;

Including a second type glass having a lower softening point than the first type glass,

The first type glass is characterized in that it is dispersed in the form of particles in the second type glass.

In the glass composite according to an embodiment of the present invention, the nanoparticles may be quantum dots or nanocrystals.

In the glass composite according to an embodiment of the present invention, the first type glass may be dispersed in the second type glass in the form of particles.

In the glass composite according to an embodiment of the present invention, the nanoparticles may be 10 nm or less.

In the glass composite according to an embodiment of the present invention, the nanoparticles are selected from the group consisting of CdS, CdSe, CdSSe, CdTe, PbS, PbSe, PbSSe, InP, InGaP and CsPbX ₃ (X = Cl, Br or I) It may be one or more.

In the glass composite according to an embodiment of the present invention, the first type of glass is germanate, boro-germanate, silicate, boro-silicate, and aluminosilicate. -silicate), borate, phosphate, tellurite, oxyfluoride, and oxynitride.

In the glass composite according to an embodiment of the present invention, the second type of glass is silicate, boro-silicate, alumino-silicate, borate, phosphate, and tellurium. It may be at least one selected from the group consisting of tellurite, oxyfluoride, and oxynitride.

In the glass composite according to an embodiment of the present invention, the weight ratio of the first type glass to the second type glass may be 1:9 to 5:5.

In the glass composite according to an embodiment of the present invention, the first type glass and the second type glass frit may be heat treated and fired at 600° C. or less.

The glass composite according to an embodiment of the present invention may further include a phosphor.

In the glass composite according to an embodiment of the present invention, the phosphor is a YAG-based phosphor, a silicate-based phosphor, a nitride-based phosphor, a fluoride-based phosphor, a sulfide-based phosphor, and an oxysulfide phosphor. It may include at least one selected from an oxysulfide-based phosphor, an oxynitride-based phosphor, and an oxyfluoride-based phosphor.

In the glass composite according to an embodiment of the present invention, the phosphor may be coated on one surface of the glass composite.

The present invention also provides a color conversion material comprising the glass composite according to an embodiment of the present invention.

The present invention also provides an LED device including the color conversion material and a display including the LED device.

The glass composite of the present invention can emit light of various colors and at the same time realize a wide range of color gamut. In addition, the glass composite of the present invention can maintain a constant light intensity (Light Intensity, Luminous Intensity) even when used for a long time, and can be used for manufacturing LEDs with significantly improved luminous flux loss characteristics. In addition, it can be manufactured through a relatively simple manufacturing process without being limited to phosphors, and furthermore, it is possible to provide a glass composite having uniform and high-efficiency light conversion characteristics.

1 shows an LED device using a glass composite including a first type glass (Glass-1) and a second type glass (Glass-2) of the present invention as a color conversion material.
Figure 2 shows a sequence from manufacturing the glass composite of the present invention to measuring properties according to an embodiment.
Figure 3 schematically shows the manufacturing sequence of Preparation Example 1 and Preparation Example 2.
4 is a view showing the observation of the glass composite of Preparation Example 1 with FE-SEM and EDS.
FIG. 5 shows whether blue light is transmitted through each of the QiG-type and QDEG-type LED elements, and the intensity of green light (EL: Electro Luminescence, PL: photo luminescence).
6 shows the luminous intensity level (A) and the luminous flux reduction change (B) of each of the QiG type and QDEG type LED elements over time.
7 shows transmission intensity and color conversion characteristics according to the mixing ratio of the first type glass and the second type glass.
8 shows color conversion characteristics in a QiG type LED device including a red phosphor therein.
9 schematically illustrates the structure of an LED device including a red phosphor layer.
10 shows an emission spectrum of an LED device including a red phosphor layer.
11 illustrates a color reproduction range of an LED device including a red phosphor layer.

Advantages and characteristics of the embodiments of the present invention, and methods for achieving them will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the embodiment of the present invention, which may vary according to the intention or custom of a user or operator. Therefore, the definition should be made based on the contents throughout this specification.

The glass composite according to the present invention includes first-class glass including nanoparticles having light-emitting properties after heat treatment;

Including a second type glass having a lower softening point than the first type glass,

The first type glass is characterized in that it is dispersed in the form of particles in the second type glass.

The present invention relates to a glass composite containing nanoparticles having light-emitting properties and a method for manufacturing the glass composite. Can be used as a minor.

The glass composite of the present invention is a glass composite including two or more types of glass, and characteristics may vary depending on the composition of each glass constituting the glass composite and the particles or crystals included in the glass. In addition, the glass composite can exhibit superior properties compared to conventional inorganic color conversion materials due to the morphological characteristics formed by different types of glasses.

The glass composite of the present invention may include two different types of glass. At this time, the two different types of glass are classified as first type glass and second type glass.

Type 1 glass and Type 2 glass have different softening points, and the softening point of Type 1 glass is lower than that of Type 2 glass. In a glass composite due to different softening points, the first type glass can be supported on the second type glass. Specifically, it is as follows.

In the process of manufacturing the glass composite of the present invention, a mixture of first-class glass frit and second-class glass frit prepared through pulverizing after melting-quenching is pressed and heat treated going through the process Since Type 1 glass and Type 2 glass have different softening points, Type 2 glass with a relatively low softening point forms a matrix form while softening during the heat treatment process, and Type 1 glass with a relatively high softening point is in the form of powder or particles. As a result, the second-class glass is evenly distributed in the formed matrix.

In the glass composite including the first type glass and the second type glass of the present invention, the first type glass includes nanoparticles having light emitting characteristics after heat treatment. The nanoparticles included in the first type glass are preferably quantum dots or nanocrystals, and may include light emitting particles formed during the heat treatment of the first type glass. And, in the present invention, the first type glass including the light-emitting particles may be dispersed in the form of particles in the second type glass. In this regard, a more detailed explanation through an embodiment of the present invention is as follows.

According to an embodiment of the present invention, the first type glass of the glass composite in which the nanoparticles included in the first type glass are quantum dots is glass containing quantum dots (Quantum Dots Embedded Glasses, hereinafter referred to as 'QDEG'), and the second type glass The type glass can be said to be a form encapsulating QDEG, which is a type 1 glass. In other words, the particulate QDEG is softened to become a glass composite dispersed in the second type glass forming the matrix.

This glass composite structure according to an embodiment of the present invention is similar to PiG (Phosphor in Glass), and in the manufacture of PiG, phosphor powder and glass powder are mixed and mixed, and QDEG is mixed with glass powder and fired after uniaxial pressing. By mixing, a process similar to that of PiG manufacturing can be followed. This concept of the present invention is expressed as QiG (Quantum dot in-glass) (FIG. 1).

Unlike QDEG, QiG can transmit blue light, and when phosphors of different colors are added, it can easily emit light in various colors and can easily control the color. In addition, as a completely inorganic color conversion material, stability against heat generated from blue LED chips can be further improved, and a wide color reproduction range can be implemented in high definition. For example, the glass composite of the present invention produces one kind of quantum dots in the glass, which is a disadvantage of glass (QDEG) containing CsPbX ₃ (X=Cl, Br, I) quantum dots of a perovskite structure It is possible to solve the problem of single color light emission (green light emission by generating single quantum dots of CsPbX ₃ (X=Cl, Br, I)) and inability to transmit blue light due to very high efficiency.

In the glass composite of the present invention, the size of the nanoparticles included in the first type glass is 25 nm or less, 20 nm or less, 15 nm or less, preferably 10 nm or less. When the size of nanoparticles is 25 nm or more, it is difficult to expect light emission characteristics due to the quantum confinement effect, and there is an advantage of having excellent visible light emission characteristics at 10 nm or less.

In the glass composite of the present invention, the first type glass and the second type glass may be appropriately selected in consideration of desired characteristics and design of the glass composite and morphological characteristics.

In the glass composite of the present invention, the first type of glass is germanate, boro-germanate, silicate, boro-silicate, alumino-silicate, and borate. (borate), phosphate (phosphate), tellurite (tellurite), oxyfluoride (oxyfluoride) and oxynitride (oxynitride) may include one or more types of glass selected from the group consisting of.

In the glass composite of the present invention, the second type of glass is silicate, boro-silicate, alumino-silicate, borate, phosphate, tellurite, oxy It may include at least one selected from the group consisting of oxyfluoride and oxynitride.

Preferably, in the glass composite according to an embodiment of the present invention, the first type glass may be germanate or boro-germanate glass, and the second type glass may be silicate, It may include one or more types of glass selected from boro-silicate and alumino-silicate. In the case of using the combination of the first type glass and the second type glass, the second type glass, which has relatively excellent stability against heat and chemicals, protects the first type glass to secure excellent durability, and a high unit price product It has the advantage of showing excellent optical properties even though the amount of first-class glass used is low.

In the glass composite of the present invention, the nanoparticles of the first type of glass are CdS, CdSe, CdSSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, PbS, PbSe, PbSSe, InP, InGaP and CsPbX ₃ (X=Cl, Br or I ) may include one or more selected from the group consisting of. Among them, when the perovskite structured CsPbX ₃ (X = Cl, Br or I) quantum dots are included, the single-color emission problem and blue light transmission of the QDEG including the previously known CsPbX ₃ (X = Cl, Br or I) It can solve the problem that does not work.

In the glass composite including the first type glass and the second type glass according to the present invention, the weight of the second type glass included in the glass composite is preferably greater than or equal to the weight of the first type glass. In the process of uniaxially pressing and heat-treating the mixture of the first-class glass frit and the second-class glass frit, the second-class glass, which has a lower softening point than the first-class glass, forms a matrix, and the first-class glass forms a second-class glass. Since the glass is distributed in the form of powder or particles in the formed matrix, it may be difficult to realize the desired shape of the glass composite in the present invention when the weight of the first type glass exceeds the second type glass. More specifically, the weight ratio of the first type glass to the second type glass may be 1:9 to 5:5, preferably 1:9 to 3:7.

The first type glass and the second type glass frit of the glass composite of the present invention are heat-treated and fired at 900°C or less, 800°C or less, 700°C or less, preferably 600°C or less. Heat treatment and firing of the first type glass and the second type glass may be performed after uniaxially pressing. If the heat treatment and sintering temperature is higher than 900 ℃, the quantum dots deteriorate and the luminous efficiency rapidly decreases, or the secondary crystal phase may precipitate. There is a problem in that it is difficult to implement a glass composite due to insufficient fluidity.

The glass composite according to an embodiment of the present invention may further include a phosphor. Specifically, the glass composite may further include a phosphor therein, or may include a phosphor coating layer on one or both surfaces of the glass composite, but the present invention is not limited thereto.

The phosphor can be used without limitation if it is a phosphor applicable to an LED device, and the present invention is not limited thereto. As a specific and non-limiting example, the phosphor is a YAG-based phosphor, a silicate-based phosphor, a nitride-based phosphor, a fluoride-based phosphor, a sulfide-based phosphor, and an oxysulfide-based phosphor. It may include one or two or more selected from phosphors, oxynitride-based phosphors, and oxyfluoride-based phosphors.

Furthermore, when the phosphor layer is prepared by coating the phosphor, it is obvious that it can be applied by mixing with silicon, etc., and the phosphor layer may have a thickness of 60 to 100 μm from the viewpoint of preventing a decrease in light transmittance, but the present invention This is not limited to this.

The glass composite of the present invention can be used as a color conversion material for various color conversion materials.

The color conversion material comprising the glass composite of the present invention is suitable for an LED device, but is not limited thereto. When the color conversion material including the glass composite of the present invention is applied to an LED device, it is particularly useful for manufacturing high-output white LEDs because it can overcome the inherent limitations of LEDs using organic binders or LEDs using inorganic color conversion materials. can do.

An LED device including a color conversion material using the glass composite of the present invention may be particularly optimized for an LCD display, but is not limited thereto.

The manufacturing method of the glass composite of the present invention is as follows, and will be described based on the glass composite including the first type glass and the second type glass.

preparing a first-type glass and a second-type glass composition, melting and then quenching to prepare a first-type glass and a second-type glass having a desired composition; pulverizing the first type glass and the second type glass to prepare and mix a first type glass frit and a second type glass frit; uniaxially pressing the mixture of the first type glass frit and the second type glass frit; heat-treating and firing a mixture of a first-class glass frit and a second-class glass frit that are uniaxially pressed; and optically polishing (Figs. 2 and 3).

Melting in the glass composite manufacturing method of the present invention may be different depending on the glass composition to be manufactured. According to an embodiment of the present invention, the melting temperature of the first type glass including nanoparticles having light emitting characteristics after heat treatment is 1000 ° C to 1400 ° C, 1050 ° C to 1350 ° C, 1100 ° C to 1300 ° C, preferably 1150 ° C to 1250 °C. If the melting temperature is too high, there is a problem in that highly reactive substances such as halides (Br, I) vaporize quickly, and if the melting temperature is too low, a problem in which the melting is not performed smoothly may occur. The melting time may be preferably 15 minutes to 55 minutes, 20 minutes to 50 minutes, 20 minutes to 45 minutes, 20 minutes to 40 minutes, preferably 25 minutes to 35 minutes. If the melting time is too long, there is a problem in that highly reactive substances such as halides (Br, I) vaporize quickly, and if it is too short, a problem occurs in the homogeneity of the produced glass, making it difficult to obtain a reproducible material.

The particle size of the glass frit produced in the grinding step of the glass composite manufacturing method of the present invention may be 150 μm or less, 140 μm or less, 130 μm or less, 120 μm or less, 110 μm or less, preferably 100 μm or less. If the size of the first type glass frit particle exceeds 150 μm, many pores or voids may be generated after firing, which may cause scattering and result in a decrease in efficiency.

In the pressing step of the glass composite manufacturing method of the present invention, the pressing is performed in a uniaxial direction, and the pressure may be appropriately adjusted according to the amount of the mixture or the mixed glass frit. Applying the pressure at a level of 3 to 4 MPa is advantageous for maintaining the sample in the subsequent firing process.

In the heat treatment and firing steps of the glass composite manufacturing method of the present invention, the pressurized first-class glass and second-class glass frit mixture is heat-treated and fired at 900°C or less, 800°C or less, 700°C or less, preferably 600°C or less. . If the heat treatment and sintering temperature is too high, such as 900 ° C. or higher, the quantum dots may deteriorate and crystallize the second type glass, and if it is too low, the flowability of the second type glass is low, making it difficult to provide sufficient matrix and voids affecting efficiency ( void) may occur. The heat treatment and firing times may be preferably 500 to 700 minutes, 500 to 650 minutes, 550 to 700 minutes, and preferably 550 to 650 minutes. If the heat treatment and firing are too long, the quantum dots may deteriorate and crystallize the second type glass, and if the second type glass has low fluidity, it is difficult to provide a sufficient matrix and voids may occur that affect the efficiency. .

In the optical polishing step of the glass composite manufacturing method of the present invention, the thickness of the glass composite is preferably 200 μm to 280 μm, 210 μm to 270 μm, 220 μm to 270 μm, 230 μm to 270 μm, 235 μm to 265 μm, Preferably, it can be polished to 240 μm to 260 μm . If the glass composite is too thick, more than 500 μm, it is difficult to transmit blue light and the light efficiency decreases. The thickness of the glass composite can be adjusted in proportion to the content of the first type glass contained in the glass, and is preferably adjusted to a thickness below which blue light can be transmitted.

Hereinafter, the present invention will be specifically described by Examples and Comparative Examples. The following examples are only for helping understanding of the present invention, and the scope of the present invention is not limited by the following examples.

[Manufacture Example 1] Manufacturing of a glass composite (Quantum dots in Glass, QiG) in which type 1 glass particles including QDEG (Quantum Dots Embedded Glasses) are included in a type 2 glass matrix

51GeO ₂ -21B ₂ O ₃ -5ZnO-3CaO-3PbO-5Cs ₂ O-12NaBr mol% composition (glass transition temperature (T _g ): 460 ℃, softening point (T _ds ): 560 ℃) having a first class glass and A second type glass having a composition of 65SiO ₂ -15Na ₂ O-5BaO-5ZnO-10Li ₂ O (glass transition temperature (T _g ): 430 °C, softening point (T _ds ): 500 °C) was prepared according to the following method.

After weighing and mixing the raw materials of the first type glass and the second type glass according to the glass composition, they are uniformly mixed through a ball milling process, and then the blended materials are charged into an alumina crucible. They were melted at 1200 °C and 1400 °C for 30 minutes in a melting furnace, respectively, and the melt was poured into a brass mold and rapidly cooled, and then glass was manufactured.

A glass frit was prepared by pulverizing Type 1 glass and Type 2 glass to a particle diameter of about 100 μm. The glass frit was mixed so that the weight ratio of Type 2 glass to the first glass was 9:1, and was pressed uniaxially to form a certain shape. It was molded so that it could be maintained. Thereafter, the uniaxially pressed mixture was heat treated at 480° C. for 10 hours. Referring to FIG. 4 , during the heat treatment process, the second type glass included in the mixture was softened to form a matrix, and the first type glass was uniformly distributed in the second type glass matrix in a particle (powder) state. .

[Production Example 2] Manufacturing of QDEG (Quantum Dots Embedded Glasses)

Glass raw materials were blended and mixed in the same composition as the first type glass of Preparation Example 1, and then glass was manufactured by a general melting-quenching method. The prepared glass was heat-treated at 480° C. for 10 hours and then polished to a thickness of 250 μm.

[Example 1] Confirmation of optical properties according to the type of glass composite

The blue LED chip installed in the integrating sphere, the glass composite of Preparation Example 1 and the QDEG of Preparation Example 2, respectively, were fabricated with color conversion materials to manufacture LED devices, and the characteristics of each LED device were measured.

Unlike the LED device including the QDEG of Preparation Example 2 (hereinafter referred to as 'QDEG type'), the LED device including the glass composite of Preparation Example 1 (hereinafter referred to as 'QiG type') can transmit blue light, and the intensity of green light ( intensity) was also confirmed to increase (FIG. 5).

In addition, it was confirmed that the QiG type maintained a high emission intensity over time compared to the QDEG type, and the luminous flux reduction characteristic was also greatly improved (FIG. 6).

In addition, transmittance intensity and color conversion characteristics according to the mixing ratio of the first type glass (G1) and the second type glass (G2) were observed. Class 2 glass: The intensity is the highest when the mixing ratio of Class 1 glass is 9:1, and it is easy to control the luminous intensity of blue light and green light according to the mixing ratio of Class 1 glass and Class 2 glass. There is an advantage in that color coordinates can be easily adjusted (FIG. 7).

[Example 2] Confirmation of optical properties according to addition of red phosphor

It was prepared in the same manner as in Preparation Example 1, but the red phosphor, CASN: Eu ²⁺ was not included, and 1% by weight, 2% by weight and 3% by weight were mixed, and then the color coordinates were measured, and the results are shown in FIG. 8 . Referring to FIG. 8 , it can be confirmed that color coordinates can be controlled by adding a phosphor.

[Example 3] Confirmation of optical characteristics according to formation of red phosphor coating layer

On one side of the glass composite prepared in Preparation Example 1, silicone resin and KSF:Mn ⁴⁺ red phosphor were mixed at a ratio of 1:2 by weight , coated to a thickness of 80 μm, and optical properties were confirmed. 9 shows the structure of an LED device including a glass composite including a red phosphor coating layer, FIG. 10 shows an emission spectrum of this LED device, and FIG. 11 shows a color reproduction range of this LED device. Referring to FIGS. 10 and 11 , it can be confirmed that a wide color reproduction range is possible with a blue, green, and red spectrum having a narrow emission line width even in a process of coating one surface with a phosphor.

Claims (14)

First-class glass containing nanoparticles having light-emitting properties after heat treatment;
Including a second type glass having a lower softening point than the first type glass,
The first type glass is a color conversion glass composite dispersed in the form of particles in the second type glass. According to claim 1,
The glass composite wherein the nanoparticles are quantum dots or nanocrystals. According to claim 1,
The nanoparticles are glass composites of 10 nm or less. According to claim 1,
The nanoparticle is one or more selected from the group consisting of CdS, CdSe, CdSSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, PbS, PbSe, PbSSe, InP, InGaP and CsPbX ₃ (X = Cl, Br or I) glass composite. According to claim 1,
The first type glass is germanate, boro-germanate, silicate, boro-silicate, alumino-silicate, borate, phosphate A glass composite comprising at least one member selected from the group consisting of phosphate, tellurite, oxyfluoride and oxynitride. According to claim 1,
The second type glass is silicate, boro-silicate, alumino-silicate, borate, phosphate, tellurite, oxyfluoride and at least one glass composite selected from the group consisting of oxynitride. According to claim 1,
The glass composite wherein the weight ratio of the first type glass to the second type glass is 1:9 to 5:5. According to claim 1,
The glass composite wherein the first type glass and the second type glass frit are heat-treated and fired at 600° C. or less. According to claim 1,
The glass composite according to claim 1 , wherein the glass composite further comprises a phosphor. According to claim 9,
The phosphor is a YAG-based phosphor, a silicate-based phosphor, a nitride-based phosphor, a fluoride-based phosphor, a sulfide-based phosphor, an oxysulfide-based phosphor, and an oxynitride. A glass composite comprising at least one selected from a )-based phosphor and an oxyfluoride-based phosphor. According to claim 9,
The glass composite according to claim 1 , wherein the phosphor is coated on one surface of the glass composite. A color conversion material comprising the glass composite of any one of claims 1 to 11. An LED device comprising the color conversion material of claim 12. An LCD display comprising the LED element of claim 13.

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