WO2013183844A1 - White light-emitting diode - Google Patents

Abstract

The present invention relates to a white light-emitting diode. The white light-emitting diode includes a light-emitting device and a light-emitting unit containing a phosphor. The light-emitting unit includes a glass layer and a phosphor layer, which includes a phosphor and a binder.

Description

White light emitting diode

The present invention relates to a white light emitting diode.

White light emitting diodes (LEDs), which are developed as lighting devices, are implemented using a combination of three primary colors of light, and a method using a combination of a blue LED and a yellow phosphor is most common. As a yellow phosphor, YAG (Yttrium Aluminum Garnet) -based phosphors containing Ce are representative, and various phosphors such as TAG (Terbium Aluminum Garnet), silicate, and nitride are developed and used. In addition, the development of a method using a combination of red and green phosphor to improve color reproducibility is in progress. However, YAG series phosphors, which have been used since the earliest of phosphor materials for white LEDs, have various advantages such as material stability and high light conversion efficiency, so most of the currently available white LED products use YAG series phosphors. Such a phosphor is mixed with an epoxy or silicon binder in a powder form and coated on the blue LED to form a phosphor layer.

White LED is used for LCD rear light source, auxiliary lighting and various indicators, and white LED for main lighting is also developed and sold.

High brightness and high power are required for the white LED for lighting, and the amount of current applied to the gallium nitride-based blue LED used as a light source of the high output white LED increases. As a result, when the ambient temperature of the blue LED rises above 200 ° C., the epoxy and silicon binders used as the carriers of the phosphor powder are modified to cause yellowing, browning, and deformation. Since the modification temperature of the organic carrier is lower than the modification temperature of the blue LED, the decrease in light output due to the modification of the organic carrier becomes a factor that determines the lifetime of the entire white LED element.

In addition, when the epoxy binder is exposed to ultraviolet rays, yellowing occurs similarly, and thus has a short lifespan and is not suitable for outdoor lighting device applications.

Thus, research on the use of a glass material as a phosphor binder has recently been conducted, and when the glass material is used as a phosphor binder, it exhibits excellent mechanical strength and chemical stability in a high temperature and ultraviolet exposure environment and has an advantage of easy large area.

However, when using a glass material as a binder, there is a problem in that the phosphor layer is formed of a thin film in order to realize appropriate optical properties, and therefore vulnerable to external impact.

One embodiment of the present invention is to provide a white light emitting diode exhibiting improved mechanical stability and excellent light extraction efficiency.

An embodiment of the present invention includes a light emitting device and a phosphor-containing light emitting unit, and the light emitting unit provides a white light emitting diode including a glass layer and a phosphor layer including a phosphor and a binder.

In one embodiment of the present invention, the glass layer may be located above and / or below the phosphor layer. When the glass layer is an upper glass layer positioned on the phosphor layer, the upper glass layer may have a refractive index greater than the refractive index of the atmosphere (n = 1) and smaller than the refractive index of the phosphor layer. In addition, the glass layer is a lower glass layer positioned below the phosphor layer, and the lower glass layer has a refractive index greater than the refractive index of the atmosphere (n = 1) and smaller than the refractive index of the light emitting device (n = 2.5). Can be.

The glass layer may be positioned to be in contact with the light emitting device, and the surface of the glass layer which is in contact with the light emitting device may be subjected to light extraction activation processing.

When the glass layer is an upper glass layer positioned on the phosphor layer, a texture pattern may be formed on the surface of the glass layer not in contact with the phosphor layer or on one surface of the glass layer in contact with the phosphor layer. In addition, when the glass layer is a lower glass layer positioned below the phosphor layer, a texture pattern may be formed on the surface of the glass layer not in contact with the phosphor layer.

The texture pattern may be hemispherical, inverse hemispherical, pyramidal, inverted pyramidal, conical or a combination thereof, and the texture pattern has a width in the range of 10 μm to 100 μm and a height in the range of 10 μm to 50 μm. Can be.

In addition, in one embodiment of the present invention, when the glass layer is an upper glass layer positioned above the phosphor layer, a convex bent center may be formed on the surface of the glass layer not in contact with the phosphor layer. . When the glass layer is a lower glass layer positioned below the phosphor layer, a concave bent center may be formed on a surface of the glass layer not in contact with the phosphor layer.

The height of the bend may be 0.5mm to 2mm.

In one embodiment of the present invention, the light emitting portion may exist in a hemispherical shape to surround the light emitting device.

Other specific details of embodiments of the present invention are included in the following detailed description.

The white light emitting diode according to the embodiment of the present invention exhibits improved mechanical stability and is excellent in light extraction efficiency. In addition, since the manufacturing process is simple, economical and high production yield can be expected. In addition, since the fine refractive index and the shape can be controlled as compared to the case of including only the phosphor layer, the light extraction efficiency can be improved to reduce power consumption of the light emitting diode white light source and to improve output and lifespan.

1 is a light emitting unit according to an embodiment of the present invention, a view showing a structure in which a glass layer is bonded to the upper and lower portions of the phosphor layer.

2 is a view schematically showing a structure of a light emitting diode in which a light emitting unit is separated from a light emitting device according to an embodiment of the present invention.

3 is a view schematically illustrating a structure of a light emitting diode in which a light emitting unit is bonded to a light emitting device according to an embodiment of the present invention.

Figure 4 is a schematic view showing a structure in which a hemispherical pattern is formed on the upper glass support surface according to an embodiment of the present invention.

5 is a view schematically showing a structure in which a bend is formed on a surface of an upper glass support according to an embodiment of the present invention.

FIG. 6 is a view schematically showing a structure in which a light emitting part shows a hemispherical shape according to one sphere of the present invention and surrounds the light emitting device. FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

An embodiment of the present invention includes a light emitting device and a phosphor-containing light emitting unit, and the light emitting unit provides a white light emitting diode including a glass layer and a phosphor layer including a phosphor and a binder.

The binder of the phosphor layer may be a glassy binder. It is preferable to use a glassy binder because it can secure mechanical, thermal, and photochemical stability as compared with the case of using an epoxy and a silicone binder.

It is preferable that the refractive index of the glassy binder is similar to the phosphor used, and specifically, the condition of 0 <refractive index of the phosphor-binder <0.2 is satisfied.

When the refractive index of the glassy binder and the phosphor satisfies the above conditions, the decrease in light extraction efficiency due to the difference in refractive index between the binder and the phosphor can be suppressed, and the problem of total reflection in the binder can be suppressed, thereby reducing the light loss. have.

Light extraction efficiency is an important characteristic in lighting devices using LEDs. The internal quantum efficiency, which is an inherent characteristic of the light source, refers to the amount of light generated inside the phosphor by the injected energy, and the external quantum efficiency, which is an intrinsic characteristic of the device, refers to the amount of light emitted to the outside of the device relative to the injected energy. The light extraction efficiency is a measure of how much light generated inside the phosphor can be emitted to the outside of the device, and the external quantum efficiency can be estimated by combining the internal quantum efficiency and the light extraction efficiency.

The glassy binder is an oxide of a glass forming element selected from the group consisting of oxides of metals selected from the group consisting of Pb, Bi, Ti, Ga or combinations thereof, P, Si, Ge or combinations thereof, and Na, K , Ca or an oxide of an alkali metal or an alkaline earth metal selected from the group consisting of a combination thereof. Specific examples of such glassy binders include PbO-SiO ₂ -B ₂ O ₃ based glass used as a PDP encapsulant, lithium borosilicate glass used in LTCC (low temperature co-fired ceramic), and the like. Can be mentioned.

The glassy binder exhibits a glass transition point of 300 ° C. to 800 ° C., and is an organic material capable of sintering at a temperature of 200 ° C. to 600 ° C., that is, a sintering temperature of 200 ° C. to 600 ° C.

When an organic material having a sintering temperature in the above range is used as the glassy binder, sintering is possible at a temperature lower than the strain point of the glass layer, so that deformation in the process is less likely to occur. In the case where an organic material having a low sintering temperature of 200 ° C to 250 ° C is used as the organic binder, after the glass layer is placed on the light emitting element, the phosphor layer can be directly formed on the glass layer. For example, when a blue LED is used as a light emitting device, a blue LED generally has a problem of deterioration when fired at a temperature of 250 ° C. or higher, and when a glassy binder having a sintering temperature of 250 ° C. or higher is used, a phosphor layer is separately provided. The white light emitting diode can be manufactured by a simpler process as compared with the step of forming and bonding the phosphor layer to a blue LED.

The phosphor contained in the phosphor layer may include a phosphor selected from the group consisting of the following Chemical Formulas 1 to 3.

[Formula 1]

(YA) ₃ (AlX) ₅ O ₁₂ : (RE) ³⁺

[Formula 2]

D ₂ SiO ₄ : (RE) ²⁺

[Formula 3]

D ₃ SiO ₅ : (RE) ³⁺

(In Chemical Formulas 1 to 3,

A consists of a lanthanide element, Tb, Sr, Ca, Ba, Mg, Zn, and combinations thereof,

X is composed of Si, B, P, Ga and combinations thereof,

D is composed of Mg, Ca, Sr, Ba, or a combination thereof,

RE is a lanthanide rare earth metal element).

As the light emitting device, a blue LED emitting blue light may be used, and a UV LED emitting light emitting ultraviolet (UV) light may be used.

In the case of using a blue LED as a light emitting device, a white light can be realized through a combination of blue light and yellow light using a phosphor that converts emitted blue light into yellow light, and when using a UV LED as a light emitting device, By using a phosphor that converts UV light into visible light of red, blue, and green in combination, white light may be realized by combining red, blue, and green light expressed from the phosphor.

The phosphor content in the phosphor layer is 5 wt% to 30 wt% with respect to the total weight of the phosphor layer, and the content of the binder is 70 wt% to 95 wt% with respect to the total weight of the phosphor layer. When the content of the phosphor and the binder is within the above range, when the light generated from the light emitting device and the light transmitted through the sample and the light absorbed and converted into the sample are mixed, a mixing ratio suitable for realizing white light may be obtained.

In one embodiment of the present invention, the glass layer may be located above and / or below the phosphor layer. That is, the glass layer may be located above or below the phosphor layer, and may be located both above and below the phosphor layer. In FIG. 1, a schematic structure of the light emitting part 1 in which the glass layer is positioned on both the upper portion 14 and the lower portion 16 of the phosphor layer 12 is illustrated in FIG. 1.

As such, as the glass layer is positioned above and / or below the phosphor layer, mechanical strength of the phosphor layer using the glassy binder may be improved. In other words, when a glassy binder is used to form a phosphor layer, mechanical, thermal, and photochemical stability can be secured compared to an epoxy or silica binder, but it must be manufactured to have a thin thickness in order to realize proper optical characteristics, and therefore, is vulnerable to external impact. The problem can be solved in one embodiment of the present invention by improving the mechanical strength as the glass layer is formed on and / or under the phosphor layer.

The light emitting part according to the embodiment of the present invention is coated with a phosphor-forming composition mixed with a phosphor and a binder on a glass plate, and then compressed, or sandwiched between two glass plates to perform a sintering process or to melt the phosphor-forming composition It can be prepared by putting between two glass plates and compressing the two glass plates. The sintering process may be carried out at the sintering temperature of the binder, the melting process may be carried out at a temperature higher than the melting temperature of the binder, lower than the temperature causing the phosphor to denature. At this time, it may be bonded by the interface wet phenomenon of the binder and the glass layer.

In one embodiment of the present invention, the glass layer is made of a material that transmits visible light and / or near ultraviolet light (for example, near ultraviolet light) and is free from deformation and modification at the sintering temperature or melting temperature of the glassy binder. proper. It is also suitable to be made of a material that exhibits a transmittance of at least 80% for visible, near-ultraviolet, or both. As a material constituting the glass layer, various materials such as general soda lime glass of SiO ₂ -Na ₂ O-CaO composition and tempered gorilla glass of SiO ₂ -Na ₂ O-Al ₂ O ₃ composition can be used in the visible light region. Glass may be used, and when used in an ultraviolet region, for example, near ultraviolet rays, CaO-P ₂ O ₅ composition-based glass may be used to secure ultraviolet transmittance.

When the glass layer is an upper glass layer positioned above the phosphor layer, the upper glass layer is larger than the refractive index of the atmosphere (n = 1) and is about the refractive index of the phosphor layer (for example, the phosphor of Formula 1). 1.8, and the refractive index of the glassy binder may have a refractive index smaller than that of the phosphor layer, using a value similar to that of the phosphor. In this case, the refractive index of the upper glass layer may be 1.4 to 1.7.

When the upper refractive index is greater than 1.8, the difference in the interfacial refractive index between the phosphor layer and the glass layer is alleviated, so that the total reflection is less likely to occur, thus increasing the efficiency in which light generated in the phosphor is extracted to the outside, but due to the total reflection The proportion of light extracted from the layer into the atmosphere is rather reduced and not appropriate.

Thus, when the upper glass layer has a refractive index between the refractive index of the atmosphere and the refractive index of the phosphor layer, especially in the case of 1.4 to 1.7, the ratio of light transmitted at each interface may be increased to improve light extraction efficiency of the entire phosphor part. have.

The upper glass layer serves to improve light extraction efficiency from the phosphor layer. When the refractive index of the upper glass layer is within the above range regardless of whether the upper glass layer is in contact with the light emitting device, the difference in the refractive index between the phosphor layer and the atmosphere is alleviated. The light extraction efficiency can be improved.

In addition, when the glass layer is a lower glass layer positioned below the phosphor layer, the lower glass layer has a refractive index greater than the refractive index of the atmosphere (n = 1) and less than the refractive index of the light emitting device (n = about 2.5). Can have In this case, the refractive index of the lower glass layer may be determined according to the type and position of the light emitting device. When using a blue LED as a light emitting element and making the lower glass layer contact with a blue LED, it is appropriate to have a refractive index of the range which is smaller than 2.5 which is the refractive index of a blue LED, and larger than 1.8 which is the refractive index of a phosphor layer. In addition, when the UV LED is used as the light emitting element and the lower glass layer is brought into contact with the UV LED, it is more appropriate to have a refractive index between the refractive index of the UV LED and the refractive index of the phosphor layer.

On the other hand, when the LED is used as the light emitting device, and the lower glass layer is not in contact with the LED, it is appropriate to have a refractive index of 1.4 to 1.7 like the upper glass layer. As described above, when the refractive index of the lower glass layer is in the above range, the difference in refractive index between the light emitting element and the atmosphere can be alleviated, and the light extraction efficiency can be improved.

In one embodiment of the present invention, when used in contact with a light emitting device such as a blue LED, the refractive indices a, b and c of the lower glass layer, the phosphor layer and the upper glass layer gradually decrease (a> b> c), As the refractive index gradually decreases as described above, the amount of light emitted to the outside can be increased, which is appropriate. In addition, when not in contact with the light emitting device, the refractive index of the phosphor layer is adjusted to the highest value (b> a = c), and when configured in this way, the amount of light transmitted from the light emitting device to the phosphor layer and emitted from the phosphor layer to the outside It is appropriate because it can increase.

When the glass layer is a lower glass layer existing below the phosphor layer, the lower glass layer may be positioned to contact the light emitting device, or may not be in contact with the light emitting device. If the lower glass layer is not in contact with the light emitting device, there may be an air or encapsulation material between the light emitting device and the phosphor layer. At this time, the sealing material may be a low-temperature sealing glass frit, such as epoxy resin, silicone resin, or lead silicate glass used as the sealing material in the conventional LED structure.

2, a light emitting diode package in which the light emitting part 20 includes all of the phosphor layer 22, the upper part 24, and the lower glass layer 26, and the lower glass layer 26 does not contact the light emitting element 28. (2) The structure is shown schematically. In FIG. 2, reference numeral 29 denotes a package substrate, and an arrow denotes light. The structure shown in Fig. 2 is referred to as a light emitting diode structure of a separation type. In addition, an atmosphere or encapsulation material may be present between the lower glass layer 26 and the package substrate 29.

In the structure shown in FIG. 2, the light emitted from the light emitting element 28 in the upward direction is transmitted through the lower glass layer 26 to the phosphor layer 22 and the phosphor layer 22. The transmitted light is partially passed through to the upper glass layer 24, and some of the light causes wavelength conversion, and the transmitted light and the converted light are mixed to realize white light throughout the entire visible spectrum. do. In this case, a material such as a metal film, a silicone resin, or polyphthalamide (PPA) may be coated on the substrate 29 of the LED package to efficiently reflect the light emitted from the LED. At this time, a metal film containing Ag, Al or SUS of a high reflectance type may be used as the metal film. In addition, in the manufacture of a light emitting diode package, a package substrate in which a light emitting unit and a light emitting element are positioned may be generally bonded using an organic resin, bonded by local heating, or bonded by ceramic cement. Since the bonding of the light emitting part and the package substrate is well known in the art, detailed description thereof will be omitted.

In FIG. 3, the light emitting unit 30 includes all of the phosphor layer 32, the upper portion 34, and the lower glass layer 36, while the lower glass layer 36 contacts the light emitting element 38. The structure is shown schematically. In FIG. 3, reference numeral 38 denotes a light emitting element, and an arrow denotes light. The structure shown in FIG. 3 is called the light emitting diode structure of the junction system. Such a structure can be used by bonding a plurality of light emitting elements to a large light emitting portion. In the manufacture of the LED package, the bonding of the light emitting unit and the light emitting device may be performed by a conventional method such as a bonding method through local heating.

The glass layer may be positioned to be in contact with the light emitting device, and the surface of the glass layer that is in contact with the light emitting device may be subjected to light extraction activation processing.

When the glass layer is an upper glass layer positioned on the phosphor layer, a texture pattern may be formed on the surface of the glass layer not in contact with the phosphor layer or on one surface of the glass layer in contact with the phosphor layer. In addition, when the glass layer is a lower glass layer positioned below the phosphor layer, a texture pattern may be formed on the surface of the glass layer not in contact with the phosphor layer. If the texture pattern is not formed, a problem arises in that the light is totally reflected back from the interface.However, when the texture pattern is formed, the light reflection randomly changes due to the diffuse reflection or forms an incident angle smaller than the critical angle. The mechanism allows the interface to pass through the interface without total reflection, thereby reducing the percentage of light lost and increasing light extraction efficiency.

The texture pattern may be a hemispherical, inverse hemispherical, pyramid, inverted pyramidal, or conical pattern. In this case, the width of the texture pattern may range from 10 to 100 μm, and the height of the texture pattern may range from 10 to 50 μm. When the size of the texture pattern is within the above range, several phosphor particles may exist under one texture pattern unit, so that light emitted uniformly in all directions from the phosphor particles may be more efficiently scattered and extracted to the upper part of the device. have.

A light emitting diode having a light emitting part 40 having a hemispherical texture pattern formed on one surface of the upper glass layer 44, that is, the surface of the glass layer not contacting the phosphor layer, without forming a texture pattern on the lower glass layer 46. Structure 4 is schematically shown in FIG. 4. In FIG. 4, reference numeral 48 denotes a light emitting element, 49 denotes a package substrate, and an arrow denotes light.

In one embodiment of the present invention, when the glass layer is an upper glass layer positioned on the phosphor layer, a convex bent center may be formed on the surface of the glass layer not in contact with the phosphor layer. When the glass layer is a lower glass layer positioned below the phosphor layer, a concave bent center may be formed on a surface of the glass layer not in contact with the phosphor layer. That is, when the glass layer is the upper glass layer, the convex lens-shaped curvature is formed, and when the glass layer is the lower glass layer, it is appropriate that the concave lens-shaped curvature is formed. As such, when the bend is formed, the ratio of the light emitted radially around the point light source may be totally reflected inside, and the light extraction efficiency may be increased.

The height of the bend may be 0.5 to 2mm. When the height of the bend is included in the above range, it is possible to minimize the difference in light transmittance at the center and the periphery of the device due to the bend and at the same time obtain the total reflection mitigation effect through the surface spheronization. If the height of the bend is too high, the thickness of the center is thicker than the periphery, so there is a risk of weakening the light intensity from the center.

The light emitting part 50 in which the curved portion of the convex lens is formed on one surface of the upper glass layer 54, that is, the surface of the glass layer that is not in contact with the phosphor layer 52, is not formed in the lower glass layer 56. The light emitting diode structure 5 having is schematically shown in FIG. In FIG. 5, reference numeral 58 denotes a light emitting element, and an arrow denotes light. Although Fig. 5 shows a junction type light emitting diode structure, the bending formation need not be limited to this structure, and it can be applied to the separation type light emitting diode structure. In addition, when using a plurality of point light source can be formed to be repeated in a lattice method.

In one embodiment of the present invention, the light emitting portion may exist in a hemispherical shape to surround the light emitting device. The light emitted radially from the light emitting element is incident on the hemispherical phosphor layer, and the light incident on the hemispherical phosphor layer is lower than the light incident on the flat phosphor layer, and thus has a low total reflection ratio. In FIG. 6, the light emitting part 60 is present in a hemispherical shape, and the structure of the light emitting diode 6 surrounding the light emitting element 66 is schematically illustrated. In FIG. 6, reference numeral 58 denotes a light emitting element, 59 denotes a package substrate, and an arrow denotes light.

Hereinafter, specific embodiments of the present invention are presented. However, the embodiments described below are merely for illustrating or explaining the present invention in detail, and thus the present invention is not limited thereto.

(Example 1)

YAG: Ce ³⁺ phosphor powder and PbO-SiO ₂ -B ₂ O ₃ glass frit powder were mixed in a 1: 9 weight ratio. The mixture was placed between the upper glass plate and the lower glass plate, and sintered at 600 ° C. to produce a light emitting part having a phosphor layer located between the upper glass layer and the lower glass layer.

The light emitting diode having the structure shown in FIG. 2 was manufactured using the manufactured light emitting portion and the light emitting element. As a result of measuring the external quantum efficiency of this light emitting diode, excellent results were obtained.

The present invention is not limited to the above embodiments, but may be manufactured in various forms, and a person skilled in the art to which the present invention pertains has another specific form without changing the technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (19)

Light emitting element; And A phosphor-containing light emitting part, The light emitting unit includes a glass layer and a phosphor layer including a phosphor and a binder. White light emitting diode. The method of claim 1, Wherein the glass layer is positioned above and / or below the phosphor layer. The method of claim 1, Wherein said glass layer is an upper glass layer positioned on top of said phosphor layer, said upper glass layer having a refractive index greater than the refractive index of the atmosphere (n = 1) and less than the refractive index of said phosphor layer. The method of claim 2, The refractive index of the upper glass layer is a white light emitting diode of 1.4 to 1.7. The method of claim 1, The glass layer is a lower glass layer positioned below the phosphor layer, and the lower glass layer has a refractive index larger than the refractive index of the atmosphere (n = 1) and smaller than the refractive index of the light emitting device (n = 2.5). White light emitting diode. The method of claim 1, The glass layer is positioned in contact with the light emitting element, the surface of the glass layer in contact with the light emitting element is a white light emitting diode is subjected to light extraction activation processing. The method of claim 1, The glass layer is located on top of the phosphor layer, the white light emitting diode to form a texture pattern on the surface of the glass layer does not contact with the phosphor layer. The method of claim 1, The glass layer is located on top of the phosphor layer, the white light emitting diode to form a texture pattern on one surface of the glass layer in contact with the phosphor layer. The method of claim 1, Wherein the glass layer is located under the phosphor layer, the white light emitting diode to form a texture pattern on the surface of the glass layer not in contact with the phosphor layer. The method according to any one of claims 7 to 9, The texture pattern is hemispherical, inverted hemispherical, pyramidal, inverted pyramidal, conical or a combination thereof. The method according to any one of claims 7 to 9, Wherein said texture pattern has a width in the range of 10 to 100 μm and a height in the range of 10 to 50 μm. The method of claim 1, Wherein the glass layer is located on top of the phosphor layer, the white light emitting diode is formed in the convex bent in the center on the surface of the glass layer not in contact with the phosphor layer. The method of claim 1, Wherein the glass layer is located under the phosphor layer, the white light emitting diode is formed in the concave bent in the center of the surface of the glass layer not in contact with the phosphor layer. The method according to claim 12 or 13, The height of the bend is a white light emitting diode of 0.5 to 2mm. The method of claim 1, The white light emitting diode is present in a hemispherical shape so as to surround the light emitting element. The method of claim 1, The phosphor layer is a white light emitting diode comprising a phosphor selected from the group consisting of the following formula 1 to 3 [Formula 1] (YA) ₃ (AlB) ₅ O ₁₂ : (RE) ³⁺ [Formula 2] C ₂ SiO ₄ : (RE) ²⁺ [Formula 3] C ₃ SiO ₅ : (RE) ³⁺ (In the above Chemical Formulas 1 to 3, A consists of a lanthanide element, Tb, Sr, Ca, Ba, Mg, Zn and combinations thereof, B is made of Si, B, P, Ga and combinations thereof, C is composed of Mg, Ca, Sr, Ba, or a combination thereof, RE is a lanthanide rare earth metal element), The method of claim 1, The binder is an oxide of a glass forming element selected from the group consisting of oxides of metals selected from the group consisting of Pb, Bi, Ti, Ga or combinations thereof, P, Si, Ge or combinations thereof, and Na, K, A white light emitting diode which is a glassy binder comprising an oxide of an alkali metal or an alkaline earth metal selected from the group consisting of Ca or a combination thereof. The method of claim 1, The phosphor content of the phosphor layer is 5% to 30% by weight based on the total weight of the phosphor layer, the content of the binder is 70% to 95% by weight relative to the total weight of the phosphor layer. The method of claim 1, Wherein said binder exhibits a glass transition point of 300 ° C. to 800 ° C. and is a sinterable organic material at a temperature of 200 ° C. to 600 ° C. 2.

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