JP5646567B2 - Method for manufacturing phosphor - Google Patents

Description

  The present invention relates to a method for producing a phosphor.

  LED lamps using light emitting diodes are used in various display devices such as portable devices, PC peripheral devices, OA devices, various switches, backlight light sources, and display boards. These LED lamps are strongly desired to be highly efficient. In addition, there is a demand for high color rendering for general lighting applications and wide color gamut for backlight applications. In order to meet these demands, it is necessary to improve the phosphor corresponding to the light emitting portion of the light emitting diode. For example, to increase the efficiency of the lamp, it is necessary to increase the efficiency of the phosphor used in the LED. In addition, in order to increase the color rendering or color gamut of the lamp, it is desired to improve the chromaticity of light emitted from the phosphor.

  Moreover, it is common that high load LED generate | occur | produces heat | fever by driving and the temperature of fluorescent substance rises to about 100-200 degreeC. When such a temperature rise occurs, the emission intensity of the phosphor generally decreases. For this reason, the phosphor is desired to have a small decrease in emission intensity (temperature quenching) even when the temperature rises.

As such a phosphor with improved temperature quenching, a sialon red phosphor based on silicon and aluminum has been reported (Patent Document 1). This phosphor is, for example, those represented by the general formula _{(Sr 1-x Eu x)} a Si b Al c O d N e, Sr 2 Si 5 N 8 was known until then: Eu and CaS: Eu Temperature quenching is improved compared to the above.

International Publication No. 2007/105631 Pamphlet

  However, according to the study by the present inventors, for the purpose of improving the chromaticity, the sialon red phosphor has a reduced luminous efficiency, temperature characteristics, and emission wavelength when the activation concentration of Eu is increased. It has been found that the visibility tends to deteriorate as the wavelength increases. For this reason, there has been a demand for a red light emitting phosphor that simultaneously satisfies the luminous efficiency and the color purity while maintaining good temperature characteristics.

A method according to an embodiment of the present invention comprises:
A compound containing a metal element M ¹ selected from the group consisting of tetravalent metal elements;
A compound containing a metal element M ² selected from the group consisting of trivalent metal elements excluding In (III) and Ga (III);
A compound containing a metal element M selected from the group consisting of metal elements different from M ¹ , M ² , In (III) and Ga (III);
A compound containing an emission center element EC different from any of the above metal elements;
Performing a step of firing a mixture with a compound containing a metal element L selected from the group consisting of In (III) and Ga (III) at a temperature of 1500 to 2500 ° C. under a pressure of atmospheric pressure or higher. This is a method for producing a phosphor exhibiting light emission having a peak between wavelengths 570 to 650 nm when excited with light having a wavelength of 250 to 500 nm.

According to the phosphor according to an embodiment of the present invention, a red phosphor having good chromaticity can be obtained even when the concentration of the luminescent center element such as Eu ²⁺ is low. In addition, a red phosphor having a luminous efficiency equal to or higher than that without lowering the lumen equivalent and having good chromaticity can be obtained. In addition, when the red phosphor of the present invention is used, a light emitting device for a display having a higher luminous efficiency and color reproduction range, and an illumination excellent in luminous efficiency and color rendering than the red phosphor containing conventional Sr. A light-emitting device or a light-emitting device module obtained by modularizing them can be manufactured.

  Furthermore, in the phosphor according to one embodiment of the present invention, compared to the conventional red phosphor containing Sr, the generation of a different phase emitting blue to green light is less, and the half-value width of the emission spectrum is narrower. . As a result, the phosphor according to the present invention has improved chromaticity as compared with the conventional red phosphor containing Sr. Moreover, in the phosphor of the present invention, the size of the primary particles of the phosphor is larger and the luminous efficiency is improved as compared with the red phosphor containing Sr in the conventional example.

  Since the phosphor according to the present invention exhibits the same temperature characteristics as the red phosphor containing Sr of the conventional example with good temperature characteristics, it is suitable for white LED module applications where good temperature characteristics of the phosphor are required. Yes.

XRD profile of _{Sr 2 Al 3 Si 7 ON 13} . 1 is a schematic cross-sectional view showing a configuration of a light emitting device using a phosphor according to an embodiment. The schematic sectional drawing showing the structure of another light-emitting device using the fluorescent substance concerning one Embodiment. The emission spectrum in 458 nm excitation of the red fluorescent substance of Example 1,2. The emission spectrum in 458 nm excitation of the red fluorescent substance of Example 3, 4. The emission spectrum in 458 nm excitation of the red fluorescent substance of Example 5 and Comparative Example 7. The emission spectrum in 365 nm excitation of the red fluorescent substance of Example 1, 2 and the comparative example 1. FIG. The emission spectrum in 365 nm excitation of the red fluorescent substance of Example 3, 4 and the comparative example 1. FIG. The emission spectrum in 365 nm excitation of the red fluorescent substance of Example 5 and the comparative example 1. FIG. The chromaticity points of the red phosphors of Examples 1 and 2 and Comparative Example 1. The chromaticity points of the red phosphors of Examples 3 and 4 and Comparative Example 1. The chromaticity point of the red phosphor of Example 5 and Comparative Example 1. 6 is a graph showing the temperature characteristics of the red phosphor of Example 3. The transmittance | permeability spectrum of the color filter used for the light-emitting device of the application examples 101-105 and the application comparative examples 102-106. The emission spectrum of the light-emitting device of the application examples 101-105. Schematic of the light-emitting device module of application Examples 151-155 and application comparative examples 152-156. The graph which shows the relationship between the luminous efficiency of the light-emitting device module of application Examples 151-155 and application comparative examples 152-156, and NTSC ratio. The emission spectrum of the light-emitting device of the application examples 201-205. Schematic of the light emitting device module of application examples 251 to 255 and application comparative examples 252 to 254 and 256. FIG. The graph which shows the relationship between the luminous efficiency and NTSC ratio of the light emitting device module of the application examples 251 to 255, the application comparative examples 252 to 254, and 256.

  Hereinafter, the red phosphor according to the present invention and a light emitting device using the red phosphor will be described.

Method for Producing Red Light-Emitting Phosphor One feature of the method for producing a red phosphor that is one embodiment of the present invention is that a compound containing In (III) or Ga (III) is used as a raw material. The oxynitride phosphor according to the present invention is based on so-called sialon phosphor, silicon or a tetravalent metal substituted for it, aluminum or a trivalent metal substituted for it, oxygen and nitrogen. Such an oxynitride phosphor is manufactured by mixing and firing the compound containing the above element. In the present invention, the compound containing In (III) or Ga (III) is included in the raw material mixture. Are mixed.

The raw materials used in the method for producing the oxynitride phosphor according to the present invention are the following (1) to (5).
(1) a tetravalent compound containing a metal element ^{M 1} selected from the group consisting of metal elements (2) an In (III) and Ga (III) metal element selected from the group consisting of trivalent metal element excluding Compound (3) containing M ² Compound (4) containing metal element M selected from the group consisting of metal elements different from M ¹ , M ² , In (III) and Ga (III) Any one of the above metal elements (5) A compound containing a metal element L selected from the group consisting of In (III) and Ga (III)

The metal element M ¹ contained in the raw material (1) is silicon constituting the sialon-based phosphor targeted by the present invention or an alternative element, and is selected from a tetravalent metal element group. The tetravalent metal element is preferably selected from the group IVA and group IVB, specifically, Si, Ge, Sn, Ti, Zr, Hf and the like can be mentioned, and Si is most preferable. Elements M ¹ may be a single element or two or more elements may be combined. The compound of the element M ^1, nitrides, oxides, or carbide is preferably used.

Metal elements M ² contained in the raw material (2), the present invention is aluminum or elements to replace it constitutes the sialon-based phosphor of interest is selected from trivalent metal element group. The trivalent element M ² is preferably selected from Group IIIA and Group IIIB, and specifically includes Al, B, Sc, Y, La, Gd, and Lu, and Al is most preferable. Incidentally, In (III) and Ga (III) is not included in the element ^{M 2.} Elements M ^2, even a single element or two or more elements may be combined. In addition, as the element M ² compound, nitride, oxide, or carbide is preferably used.

The metal element M contained in the raw material (3) is selected from elements different from the aforementioned M ¹ , M ² , In (III) and Ga (III). Specifically, the metal element M is a group IA (alkali metal) element such as Li, Na, and K, a group IIA (alkaline earth metal) element such as Mg, Ca, Sr, and Ba, and a group IIIA such as B. Those selected from Group III elements, Group IIIB elements such as Y and Sc, rare earth elements such as Gd, La and Lu, and Group IVA elements such as Ge are preferred. Of these, the metal element M is most preferably Sr. The metal element M may be a single element or a combination of two or more elements. In addition, as the compound containing the element M, nitrides or other carbides such as cyanamide are preferably used.

The metal element M exemplified here and the element M ¹ or M ² include the same element. However, in the phosphor according to the present invention, M includes M ¹ and M ² . Different elements are selected.

The metal element EC contained in the raw material (4) functions as the emission center of the phosphor.
That is, the phosphor in the present invention has a crystal structure based on the above-described elements M, M ¹ , M ² and O, and / or N, but a part of M is substituted with the luminescent center element EC. Is.

Examples of the luminescent central element EC include Eu, Ce, Mn, Tb, Yb, Dy, Sm, Tm, Pr, Nd, Pm, Ho, Er, Cr, Sn, Cu, Zn, As, Ag, Cd, and Sb. , Au, Hg, Tl, Pb, Bi, and Fe. Of these, it is preferable to use at least one of Eu and Mn in consideration of the variability of the emission wavelength.
As the compound containing the metal element EC, an oxide, nitride, or carbonate is preferably used.

The raw material (5) is a compound containing In (III) or Ga (III). Examples of such compounds include oxides and nitrides such as In ₂ O ₃ , Ga ₂ O ₃ and GaN.

The mixing ratio of these raw materials is appropriately adjusted according to the composition of the target oxynitride phosphor.
That is, the oxynitride phosphor targeted by the production method according to the present invention exhibits light emission having a peak between wavelengths 570 and 650 nm when excited with light having a wavelength of 250 to 500 nm. The phosphor exhibiting such light emission characteristics typically has a crystal structure of M ₂ M ¹ ₇ M ² ₃ ON ₁₃ . A part of M is replaced by EC. Therefore, it is general that the molar ratio of the sum of M and EC, M ¹ , and M ² is approximately 2: 7: 3. However, since this ratio can be adjusted for the peak wavelength of light emission and the like, it is not necessary to strictly be this ratio.

  Further, it is desirable that the luminescent center element EC replaces at least 0.1 mol% of the element M. When the substitution amount is less than 0.1 mol%, it is difficult to obtain a sufficient light emitting effect. The luminescence center element R may replace the entire amount of the element M, but when the substitution amount is less than 50 mol%, a decrease in the light emission probability (concentration quenching) can be suppressed as much as possible. The red phosphor (R) according to the present invention exhibits light emission in a region ranging from yellow to red when excited with light having a wavelength of 250 to 500 nm, that is, light having a peak between wavelengths of 570 to 650 nm.

In addition, the method for producing a phosphor according to the present invention is characterized by using the raw material (5) (compound containing the metal element L). Here, in the method of the present invention, it is essential that the raw material (5) coexists, but this does not necessarily mean that the metal element L is incorporated in the crystal structure of the oxynitride phosphor. . For example, when a relatively large amount of raw material (5) is used, the presence of element L may be confirmed by analyzing the obtained oxynitride phosphor. Therefore, there is a possibility that the element L in phosphor is replaced by a metal M ^1. However, on the other hand, when a relatively small amount of the raw material (5) is used, the analysis result of the oxynitride phosphor clearly confirms the effect of the present invention even though the element L is below the measurement limit. There was a case. Therefore, it is considered that the raw material (5) may be incorporated into the crystal itself and may have an action of controlling crystal growth. For example, it is considered that the raw material (5) added at the time of firing generates a liquid phase or a gas phase at the time of firing the phosphor, and this gas phase or liquid phase affects the crystal growth and brings about the effect of the present invention. It is done.

  In addition, such an effect is recognized only to the compound containing In (III) or Ga (III), and the effect of the present invention is not exhibited even when other metals such as Sc (III) are used similarly. .

In the phosphor manufactured by the manufacturing method of the present invention, the emission characteristics are changed as compared with the red phosphor containing Sr of the conventional example. For example, by using an In compound as a raw material, the generation of a heterogeneous phase emitting blue to green light is suppressed, and the half width of the emission spectrum is narrowed.
As a result, the phosphor manufactured by the manufacturing method of the present invention has improved chromaticity as compared with the red phosphor containing Sr of the conventional example. Moreover, in the phosphor formed by the manufacturing method of the present invention, the luminous efficiency is improved because the particle size is larger and the absorption efficiency is better than the red phosphor containing Sr of the conventional example. It is considered a thing. Such a feature of the phosphor produced by the method of the present invention is presumed to be due to the contribution of the raw material (5) during crystal growth as described above.

As has been described, the metal element L contained in the material (5) is not necessarily to replace the trivalent metal M ² contained in the crystal structure of the phosphor. Accordingly, the compounding ratio of the raw material (5) may not always be appropriate, for determining, based on the M ^2. However, here as the reference metal elements ^{M 2} contained in conveniently material (3), when displaying the ratio of L contained in the raw material (5), L against ^{M 2} is 0.1 mol% to 50 It is preferable that it is mol%, and it is more preferable that it is 0.1 mol%-20 mol%. When the ratio of the metal element L is increased, the amount of heterogeneous phase tends to increase during the production of the phosphor, and the yield of the phosphor may be lowered.

The method for producing a red light-emitting phosphor according to the present invention includes mixing the above-described raw materials at a desired ratio, generally pulverizing and mixing them with a mortar or the like, and firing. More specifically, contains Sr as the element M, Eu as an emission center element EC, Si as the element ^{M 1,} Al as the element ^{M 2,} if you select the In as the element L _is, Sr ₃ N 2, AlN Si ₃ N ₄ , Al ₂ O ₃ , In ₂ O ₃ and EuN can be used as starting materials. Instead of Sr ₃ N ₂ , Ca ₃ N ₂ , Ba ₃ N ₂ , Sr ₂ N, SrN, or the like, or a mixture thereof may be used. Other In compounds may be used instead of In ₂ O ₃ . These are weighed and mixed so as to have a desired composition, and the obtained mixed powder is fired to obtain the target phosphor. In mixing, for example, a technique of mixing a mortar in a glove box can be mentioned. The material of the crucible may be boron nitride, silicon nitride, silicon carbide, carbon, aluminum nitride, sialon, aluminum oxide, molybdenum, tungsten, or the like.

The method for producing an oxynitride phosphor according to the present invention includes firing a mixture of these starting materials for a predetermined time. The firing is desirably performed at a pressure of atmospheric pressure or higher. In particular, in order to suppress decomposition of the raw material (2) such as silicon nitride at a high temperature, 5 atmospheres or more is more preferable. The firing temperature is preferably in the range of 1500 to 2000 ° C, more preferably 1800 to 2000 ° C. If the firing temperature is less than 1500 ° C., it may be difficult to form the target phosphor. On the other hand, if it exceeds 2000 ° C., there is a risk of sublimation of the material or product. In addition, since the raw material AlN is easily oxidized, it is desired to fire in an N ₂ atmosphere, but a mixed atmosphere of nitrogen and hydrogen may be used.

  The phosphor according to the embodiment can be obtained by subjecting the fired powder to post-treatment such as washing as necessary. When washing is performed, for example, pure water washing or acid washing can be performed.

Red light emitting phosphor The first red light emitting phosphor according to the present invention is a phosphor manufactured by the method described above.
That is, it has a peak between wavelengths 570 to 650 nm when excited by light having a wavelength of 250 to 500 nm, which is obtained by firing the aforementioned raw materials (1) to (4) in the presence of the raw material (5). It is an oxynitride phosphor that emits light.

The crystal structure of the phosphor can be identified by X-ray diffraction or neutron diffraction. That is, for the crystal structure of the red light emitting phosphor according to the present invention, a substance showing the same profile as the XRD profile of the basic Sr ₂ Al ₃ Si ₇ ON ₁₃ is desirable, and the constituent elements are replaced with other elements. It is also desirable for the lattice constant to vary within a certain range. FIG. 1 shows a basic XRD profile of Sr ₂ Al ₃ Si ₇ ON ₁₃ . Here, the constituent element is replaced with another element means that Sr in the Sr ₂ Al ₃ Si ₇ ON ₁₃ crystal is the element M and / or the luminescent center element EC, and the position of the element Si is a tetravalent element. Group, for example, a group consisting of one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf, wherein the position of Al is a trivalent element, such as B, Sc, Y, La, Gd A crystal in which one or more elements selected from the group consisting of Lu and substituted at the position of O or N with one or more elements selected from the group consisting of O, N and C It is. Moreover, at the same time that Al is replaced with Si, O and N are replaced, for example, Sr ₂ Al ₂ Si ₈ N ₁₄ , Sr ₂ Al ₄ Si ₆ O ₂ N ₁₂ , Sr ₂ A ₁₅ Si ₅ O ₃ N ₁₁ , Sr ₂ Al ₆ Si ₄ O ₄ N _{10 and the} like also have a crystal structure based on Sr ₂ Al ₃ Si ₇ ON ₁₃ .

Furthermore, when the amount of solid solution is small, there is the following method as a simple determination method of the crystal structure based on Sr ₂ Al ₃ Si ₇ ON ₁₃ . When the diffraction peak position of the XRD profile measured for a new substance coincides with the main peak, the crystal structure can be identified as the same. As the main peak, it is good to judge with ten lines having strong diffraction intensity.

In addition, among the oxynitride phosphors obtained by the above-described method, a part of the oxynitride phosphors can be expressed by a composition formula. That is, what is represented by the following general formula (I) is the second red-emitting phosphor according to the present invention.
(M _1-x EC _x ) _a M ¹ _b M ² L _c O _d N _e (I)
(Where
M ¹ is a metal element selected from the group consisting of tetravalent metal elements,
M ² is a metal element selected from the group consisting of trivalent metal elements excluding In (III) and Ga (III);
L is a metal element selected from the group consisting of In (III) and Ga (III),
M is a metal element selected from the group consisting of metal elements different from M ¹ , M ² , In (III) and Ga (III);
EC is an emission center element different from any of the above metal elements,
0 <x <0.4, preferably 0.02 ≦ x ≦ 0.2,
0.65 <a <0.80, preferably 0.66 ≦ a ≦ 0.73,
2 <b <3, preferably 2.2 ≦ b ≦ 2.7,
0 <c <0.1, preferably 0 <c ≦ 0.05,
0.3 <d <0.6, preferably 0.35 ≦ d ≦ 0.49,
4 <e <5, preferably 4.2 ≦ e ≦ 4.7)

  Here, the composition ratio of the metal element L exceeds 0, but this does not mean that it is below the measurement limit of the analyzer. That is, even when L is not detected when a certain phosphor is analyzed with the analyzer having the highest detection accuracy at that time, the detection accuracy is improved by the advancement of the technology, and L is detected. If present, the phosphor is a second phosphor according to the present invention. Moreover, even if L is below the detection limit, if the raw material (5) is used at the time of manufacturing the phosphor, the phosphor is the first red phosphor according to the present invention. it is obvious.

The composition of the oxynitride phosphor can be measured by any conventionally known method. For example, the following method can be used.
M, M ¹ , M ² , and EC can be measured, for example, by inductively coupled plasma emission spectroscopy (sometimes referred to as ICP emission spectroscopy). Specifically, a sample of the oxynitride phosphor is weighed into a platinum crucible, decomposed by alkali melting, an internal standard element Y is added to prepare a measurement solution, and measurement is performed by ICP emission spectroscopic analysis. As the measuring device, for example, an SPS-4000 type ICP emission spectroscopic analyzer (manufactured by SII Nanotechnology Inc.) can be used.

O and N can be measured, for example, by an inert gas melting method. Specifically, a sample of an oxynitride phosphor is heated and melted in a graphite crucible, O contained in the sample is converted to CO by an inert gas transfer method, and further oxidized to CO ₂ , and then an infrared absorption method is used. The oxygen content is measured, and after removing CO ₂ , the N content is measured by a heat conduction method. As the measuring apparatus, for example, a TC-600 type oxygen / nitrogen / hydrogen analyzer (manufactured by LECO Corporation (USA)) can be used.

  In can be measured by ICP emission spectroscopic analysis. Specifically, a sample of the oxynitride phosphor is weighed in a pressure decomposition vessel, subjected to pressure acid decomposition to prepare a measurement solution, and measured by ICP emission spectroscopic analysis. As the measuring device, for example, an SPQ-9000 type ICP emission spectroscopic analyzer (manufactured by SII Nanotechnology Inc.) can be used.

  Ga can also be measured by ICP emission spectroscopic analysis. In this case, a measurement solution can be prepared in the same manner as M and measured using, for example, an SPS-1500V type ICP emission spectroscopic analyzer (manufactured by SII Nanotechnology Co., Ltd.).

Light-emitting device and light-emitting device module A light-emitting device according to the present invention comprises the above-described red light-emitting phosphor and a light-emitting element that can excite it.

  One embodiment of the light-emitting device according to the present invention includes a light-emitting element such as an LED that is an excitation source, and the red phosphor (R) and the green phosphor that are excited by light emitted from the light-emitting element and emit fluorescence. A combination with (G). At this time, the light emitting device emits light in which light emitted from the light emitting element, light emitted from the red phosphor, and light emitted from the green phosphor are combined.

In another embodiment of the light emitting device according to the present invention, a light emitting element that is an excitation source, the red phosphor (R) that emits fluorescence when excited by light emitted from the light emitting element, and the green A combination of the phosphor (G) and the blue phosphor (B) is provided.
In any of these embodiments, either the first phosphor or the second phosphor according to the present invention can be used.

  As the light emitting element used in the light emitting device, an appropriate one is selected depending on the phosphor to be used. That is, it is necessary that the light emitted from the light emitting element is capable of exciting the phosphor used. Furthermore, when the light emitting device preferably emits white light, a light emitting element that emits light having a wavelength that supplements the light emitted from the phosphor is preferable.

  From such a viewpoint, in the fluorescent device using the red fluorescent substance and the green fluorescent substance as the fluorescent substance, the light emitting element (S1) is generally selected to emit light having a wavelength of 250 to 500 nm. In the fluorescent device using the red phosphor, the green phosphor, and the blue phosphor, the light emitting element (S2) that generally emits light having a wavelength of 250 to 430 nm is selected.

  The light emitting device according to the present invention can be in the form of any conventionally known light emitting device. FIG. 2 shows a cross section of a package cup type light emitting device according to an embodiment of the present invention.

  In the light-emitting device shown in FIG. 2, a resin system 200 as a substrate has a lead 201 and a lead 202 formed by molding a lead frame, and a resin portion 203 formed integrally therewith. The resin portion 203 has a concave portion 205 whose upper opening is wider than the bottom portion, and a reflective surface 204 is provided on the side surface of the concave portion.

  A light emitting element 206 is mounted with Ag paste or the like at the center of the substantially circular bottom surface of the recess 205. As the light emitting element 206, for example, a light emitting diode, a laser diode, or the like can be used. Furthermore, what performs ultraviolet light emission can be used, and it is not specifically limited. In addition to ultraviolet light, light emitting elements capable of emitting wavelengths such as blue, blue-violet, and near ultraviolet light can also be used. For example, a GaN-based semiconductor light emitting element or the like can be used. The electrodes (not shown) of the light emitting element 206 are connected to the leads 201 and 202 by bonding wires 207 and 208 made of Au or the like, respectively. The arrangement of the leads 201 and 202 can be changed as appropriate.

  The fluorescent layer 209 is formed by dispersing or precipitating the phosphor mixture 210 according to the embodiment of the present invention at a rate of 5 wt% to 50 wt% in the transparent resin layer 211 made of, for example, a silicone resin. Can do. In the phosphor according to the embodiment, oxynitride having high covalent bond is used as a base material. For this reason, the phosphor according to the present invention is generally hydrophobic and has very good compatibility with the resin. Therefore, scattering at the interface between the resin and the phosphor is remarkably suppressed, and the light extraction efficiency is improved.

  As the light emitting element 206, a flip chip type having an n-type electrode and a p-type electrode on the same plane can be used. In this case, problems caused by the wire such as wire breakage and peeling and light absorption by the wire are solved, and a highly reliable and high-luminance semiconductor light-emitting device can be obtained. Further, an n-type substrate may be used for the light emitting element 206 to have the following configuration. Specifically, an n-type electrode is formed on the back surface of the n-type substrate, a p-type electrode is formed on the upper surface of the semiconductor layer on the substrate, and the n-type electrode or the p-type electrode is mounted on a lead. The p-type electrode or the n-type electrode can be connected to the other lead by a wire. The size of the light emitting element 206 and the size and shape of the recess 205 can be changed as appropriate.

FIG. 3 shows a cross section of a bullet-type light emitting device according to another embodiment of the present invention.
In the light-emitting device shown in FIG. 3A, for example, a light-emitting diode 301 having an emission peak wavelength of 445 nm is bonded onto a substrate 302 which is a package made of AlN or the like using solder, and the conductive wire 303 is interposed. Connected to the electrode. A transparent resin layer 304 such as a silicone resin is applied on the light emitting diode 301 in a dome shape, and a transparent resin layer 305 including a red light emitting phosphor, a transparent resin layer 306, and a transparent resin including a green light emitting phosphor are formed thereon. Layers 307 are sequentially stacked. The light-emitting device illustrated in FIG. 3 includes a light-emitting element and a red light-emitting phosphor and a green light-emitting phosphor that emit light by excitation light emitted from the light-emitting element. Can also be laminated. A cross section of such a light emitting device is as shown in FIG. In this device, a transparent resin layer 308 and a layer 309 containing a blue light-emitting phosphor are stacked on a layer 307 containing a green phosphor, compared to the device shown in FIG. As for the light emitting diode used for the apparatus of FIG. 3 (B), it is common that the light radiated | emitted than the apparatus shown to FIG. 3 (A) does not contain blue light. A light emitting device that emits a desired color, for example, white light, is obtained by the excitation light and the light emission from each phosphor.

The light emitting device according to the embodiment of the present invention is not limited to the package cup type light emitting device as shown in FIG. 2 and the bullet type light emitting device as shown in FIG. 3, and can be changed as appropriate.
Specifically, the surface-mounted light-emitting device can obtain the same effect by applying the phosphor of the embodiment.

Furthermore, the light-emitting device module according to the present invention is obtained by arranging a plurality of the above-described light-emitting devices on a substrate. The light emitting device used in such a light emitting device module can be arbitrarily selected from those using the phosphor according to the present invention as described above. For example, the above-described bullet-type light emitting device is one preferred light emitting device. That is, in such a light emitting device module, a plurality of any of the following light emitting devices are arranged.
(1) The phosphor dispersed on a transparent resin on which a hemispherical dome is formed of a transparent resin on a light emitting element (S1) that emits light having a wavelength of 250 nm to 500 nm provided on a substrate. A light emitting device having a laminated structure in which (R) is applied and a green light emitting phosphor (G) dispersed in a transparent resin is applied thereon (2) Emits light with a wavelength of 250 nm to 430 nm provided on the substrate A green luminescent phosphor dispersed in a transparent resin is formed by forming a hemispherical dome with a transparent resin on the light emitting element (S2) to be coated, applying the phosphor (R) dispersed in the transparent resin on the dome. A light emitting device having a laminated structure in which (G) is applied and a blue light emitting phosphor (B) dispersed in a transparent resin is applied thereon

The material of the substrate is not particularly limited, and can be selected from any conventionally known materials according to the purpose. Specifically, glass, silicon, semiconductor, resin, or the like is used.
Various processings can be performed on the substrate surface as necessary. For example, a wiring or an isolation structure for forming a light emitting device can be formed, or a heat dissipation layer for improving heat dissipation can be formed. Further, the substrate itself can be a heat radiating substrate having excellent thermal conductivity.

  Here, the green light-emitting phosphor exhibits light emission having a peak between wavelengths of 490 to 580 nm when excited by irradiation light from the light-emitting element (S1) or (S2). , Which emits light having a peak between wavelengths of 400 to 490 nm when excited by irradiation light from the light emitting element (S1) or (S2).

  Such light emitting devices are regularly or irregularly arranged on the substrate to form a light emitting device module. Here, since the phosphor according to the present invention is excellent in temperature characteristics, it is not easily affected by heat generated by driving. For this reason, the arrangement density of the light emitting devices using the phosphor can be increased, that is, the distance between the light emitting devices can be shortened. For example, a bullet-type light emitting device as described above is generally a circle or an ellipse when viewed from above, but when the major axis is a and the shortest distance between the light emitting devices is d, 1 ≦ The light emitting device can be arranged so that (d / a) ≦ 5. Here, the long diameter means the longest diameter of the horizontal sectional shape of the light emitting device. That is, it is equal to the diameter when the horizontal cross-sectional shape of the light emitting device is circular, and equal to the major axis when it is elliptical. Since the light emitting device can take any shape as necessary, for example, square, polygon, linear, etc., the interval when arranging them cannot be specified uniformly, but the phosphor according to the present invention has a temperature characteristic. Excellent, since the influence of heat by driving adjacent light emitting devices is small, the interval between the light emitting devices arranged in the light emitting device module can be narrowed, thereby increasing the brightness of the entire light emitting device module it can.

  Here, the light emitting device or the light emitting device module according to the present invention must use the red light emitting phosphor according to the present invention, but the green light emitting phosphor (G) and the blue light emitting phosphor (B) are not particularly limited. Any one can be used. However, the red light-emitting phosphor (R) according to the present invention has the characteristics that it has excellent temperature characteristics and is not easily affected by temperature changes. The body (G) and the blue light emitting phosphor (B) are also preferably excellent in temperature characteristics. With such a configuration, when the temperature changes, the change in the emission intensity of the red light emitting phosphor is small, and the change in the emission intensity of each color phosphor is also small, so that a light emitting device combining these, The color change of the light emitting module using it becomes small.

  These light-emitting devices or light-emitting modules are particularly suitable for use in a high-temperature environment because the red light-emitting device used has excellent temperature characteristics and the light emission hardly changes due to temperature changes.

  One of the green light-emitting phosphors (G) preferred for the light-emitting device or light-emitting device module of the present invention is a sialon-based oxynitride phosphor similar to the red phosphor described above, although the basic crystal structure is different.

This green-emitting phosphor (G) is based on Sr ₃ Si ₁₃ Al ₃ O ₂ N ₂₁ . The Sr ₃ Si ₁₃ Al ₃ O ₂ N ₂₁ crystal is orthorhombic. As in the above-described red phosphor, a part of the constituent elements is replaced with a light emitting element. Although the crystal structure may be slightly changed by the element replacement or the like, the effects of the present invention can be achieved as long as the basic crystal structure does not change. Such a range in which the basic crystal structure does not change is the same as the above-described red fluorescence.

Such a green light emitting phosphor can be identified by X-ray diffraction or neutron diffraction. That is, in addition to the substance showing the same profile as the XRD profile of Sr ₃ Si ₁₃ Al ₃ O ₂ N ₂₁ shown here, there are also those whose lattice constants are changed in a certain range by replacing the constituent elements with other elements The green light emitting phosphor is included.

Specific examples of blue phosphors excellent in temperature characteristics that are preferable for the light emitting device or light emitting device module of the present invention include (Ba, Eu) MgAl ₁₀ O ₁₇ , (Sr, Ca, Ba, Eu) ₁₀ (PO ₄ ) ₅ Cl ₂ , (Sr, Eu) Si ₉ Al ₁₉ ON _{31 and the} like.

  Hereinafter, the present invention will be described in more detail with reference to various examples, but the present invention is not limited to only these examples.

Example 1
Sr ₃ N ₂ , EuN, Si ₃ N ₄ , Al ₂ O ₃ , AlN and Ga ₂ O ₃ were prepared as starting materials. Each of these 2.308 g, 0.697 g, 4.583 g, 0.454 g, 1.339 g, 0.039 g was weighed in a vacuum glove box and then dry mixed in an agate mortar, and filled in a BN crucible, The phosphor was synthesized by firing at 1850 ° C. for 4 hours in a 7.5 atmosphere N ₂ atmosphere.

Example 2
A phosphor was synthesized in the same manner as in Example 1 except that the amounts of Al ₂ O ₃ and Ga ₂ O ₃ were changed to 0.262 g and 0.394 g, respectively.

Example 3
Sr ₃ N ₂ , EuN, Si ₃ N ₄ , Al ₂ O ₃ , AlN and GaN were prepared as starting materials. Each of these 2.308 g, 0.697 g, 4.583 g, 0.476 g, 1.322 g, 0.035 g was weighed in a vacuum glove box and then dry mixed in an agate mortar, and filled into a BN crucible, The phosphor was synthesized by firing at 1850 ° C. for 4 hours in a 7.5 atmosphere N ₂ atmosphere.

Example 4
A phosphor was synthesized in the same manner as in Example 3 except that the amounts of AlN and GaN were changed to 1.167 g and 0.352 g, respectively.

Comparative Example 1
Examples were used except that 2.308 g, 0.697 g, 4.583 g, 0.476 g, and 1.339 g of Sr ₃ N ₂ , EuN, Si ₃ N ₄ , Al ₂ O _3, and AlN were used as starting materials, respectively. In the same manner as in _Example 1, a phosphor having a design composition of (Sr _0.85 Eu _0.15 ) ₂ Al ₃ Si ₇ ON ₁₃ was synthesized.

Comparative Example 2
The phosphor of this comparative example was synthesized under the same conditions as in comparative example 1 except that the masses of Sr ₃ N ₂ and EuN were changed to 2.443 g and 0.465 g. A phosphor having a designed composition of (Sr _0.9 Eu _0.1 ) ₂ Al ₃ Si ₇ ON ₁₃ was synthesized.

Comparative Example 3
The phosphor of this comparative example was synthesized under the same conditions as in comparative example 1 except that the masses of Sr ₃ N ₂ and EuN were changed to 2.172 g and 0.929 g. A phosphor having a designed composition of (Sr _0.8 Eu _0.2 ) ₂ Al ₃ Si ₇ ON ₁₃ was synthesized.

Comparative Example 4
The phosphor of this comparative example was synthesized under the same conditions as in comparative example 1 except that the masses of Sr ₃ N ₂ and EuN were changed to 1.629 g and 1.859 g. A phosphor having a designed composition of (Sr _0.6 Eu _0.4 ) ₂ Al ₃ Si ₇ ON ₁₃ was synthesized.

Comparative Example 5
The phosphor of this comparative example was synthesized under the same conditions as in comparative example 1 except that the masses of Sr ₃ N ₂ and EuN were changed to 1.357 g and 2.324 g. A phosphor having a designed composition of (Sr _0.5 Eu _0.5 ) ₂ Al ₃ Si ₇ ON ₁₃ was synthesized.

Comparative Example 6
The phosphor of this comparative example was synthesized under the same conditions as in comparative example 1 except that the masses of Sr ₃ N ₂ and EuN were changed to 0.543 g and 3.718 g. A phosphor having a designed composition of (Sr _0.2 Eu _0.8 ) ₂ Al ₃ Si ₇ ON ₁₃ was synthesized.

Example 5
Sr ₃ N ₂ , EuN, Si ₃ N ₄ , Al ₂ O ₃ , AlN and In ₂ O ₃ were prepared as starting materials. Each of these 2.308 g, 0.697 g, 4.583 g, 0.262 g, 1.339 g, 0.583 g was weighed in a vacuum glove box and then dry mixed in an agate mortar, and filled into a BN crucible, The phosphor was synthesized by baking at 1850 ° C. for 4 hours in a 7.5 atmosphere N ₂ atmosphere.

Comparative Example 7
A phosphor was synthesized in the same manner as in Example 5 except that 0.290 g of Sc ₂ O ₃ was used instead of 0.583 g of In ₂ O ₃ .

  When the composition analysis was performed about the fluorescent substance of Examples 1-5, it turned out that it is a composition as Table 1 shows. The composition ratios are all normalized with Al as 1. In Examples 1 and 3, the molar ratio of Al and Ga contained in the raw material is 99: 1. In Examples 2 and 4, the molar ratio of Al and Ga contained in the raw material is 90:10. In Example 5, charging is performed so that the molar ratio of Al to In contained in the raw material is 90:10. However, none of the phosphors contained In or Ga at the added ratio, and it was found that In and Ga were contained in the phosphor obtained by synthesis in a smaller amount than the added ratio.

  The red powders of Examples 1 to 5 and Comparative Example 7 were excited using a light emitting diode having a peak wavelength of 458 nm as a light source after crushing. The obtained emission spectra were as shown in FIGS. 4 to 6, the band having a peak at 458 nm is due to reflection of excitation light. From each of the red powders of Examples 1 to 5, single band emission having a peak wavelength at 615 to 620 nm was obtained. Further, from the red powder of Comparative Example 7, single band emission having a peak wavelength at 610 to 615 nm was obtained.

  The red powder of Comparative Example 7 emits light and emits significantly less light than the red powder of Example 5, and is inferior as a phosphor compared to the red powder of Example 5. That is, when a compound containing Ga or In is used as a raw material at the time of producing the phosphor, the effect of the present invention can be obtained. I can't get it.

  The red powders of Examples 1 to 5 and Comparative Example 1 were excited using a light source having a peak wavelength of 365 nm after crushing. The obtained emission spectra were as shown in FIGS. Moreover, the chromaticity points calculated based on this spectrum were as shown in FIGS.

  The red phosphors of Examples 1 to 5 were found to have less light emitting components from 400 nm to 580 nm than the red phosphor of Comparative Example 1.

The chromaticity coordinates (values in chromaticity coordinates (x, y) in the CIE1931 chromaticity diagram) of the red phosphors of Examples 1 to 5 and Comparative Example 1 are as shown in Table 2.

  Next, the red powders of Example 3 and Comparative Example 1 were excited while increasing the sample temperature with a heater from room temperature to 200 ° C., and the change in emission spectrum was measured. For excitation, a light emitting diode having a peak wavelength of 458 nm was used. The temperature dependence of the peak intensity of the emission spectrum at each temperature is as shown in FIG. The y-axis in FIG. 13 is a value normalized with the emission intensity at room temperature of each phosphor as 1.

  From FIG. 13, it was found that the red phosphor of Example 3 had the same temperature characteristics as the phosphor of Comparative Example 1 having good temperature characteristics.

Application Examples 101 to 105 and Application Comparative Examples 102 to 106
Using the phosphor of Example 1, a light emitting device of Application Example 101 was manufactured. This light emitting device was manufactured according to FIG. Specifically, a light emitting diode 301 having an emission peak wavelength of 440 nm was bonded onto an AlN package substrate 302 having an 8 mm square shape using solder and connected to an electrode via a gold wire 303. A transparent resin 304 is coated on the light emitting diode in a dome shape, and a transparent resin 305 mixed with the red light emitting phosphor of Example 1 is coated on the light emitting diode, and a transparent resin layer 306, a peak wavelength is coated thereon. A transparent resin 307 mixed with a 520 nm green phosphor was sequentially laminated and applied to manufacture a light emitting device.

  Further, light emitting devices of Application Examples 102 to 105 and Application Comparative Examples 102 to 106 were manufactured in the same manner as Application Example 101 except that the phosphors of Examples 2 to 5 and Comparative Examples 2 to 6 were used.

  FIG. 15 shows emission spectra measured for the light emitting devices of Application Examples 101 to 105. In the figure, the relative intensity of the spectrum is normalized so that the area surrounded by the spectrum curve and the horizontal axis is constant.

Application Examples 151-155 and Application Comparative Examples 152-156
Using the phosphor of Example 1, a light-emitting device module of Application Example 151 was manufactured. FIG. 16 is a conceptual diagram of a light emitting device module according to an application example 151. In this light emitting device module, a plurality of bullet-type light emitting devices 1600 are arranged on the surface of the heat dissipation substrate 1601. This bullet-type light emitting device has the structure shown in FIG. Specifically, this light emitting device module was manufactured as follows. First, 16 light emitting diodes 301 having an emission peak wavelength of 440 nm were prepared. They were placed on the heat dissipation substrate 1601 so that the center portions of the respective light emitting diodes were spaced at 6 mm, joined using solder, and further connected to the electrodes via the gold wires 303. A transparent resin layer 304 is formed on the light-emitting diode in a dome shape, and a transparent resin layer 305 mixed with the red light-emitting phosphor of Example 1 is formed on the light-emitting diode, and the transparent resin layer 306 is further formed thereon. A transparent resin layer 307 mixed with a green phosphor having a peak wavelength of 520 nm was sequentially laminated and applied to manufacture a light emitting device module. Here, the shape seen from the upper surface of each light emitting device was circular, and its diameter was 2.8 mm.

  Further, the light emitting devices (modules) of the application examples 152 to 155 and the application comparison examples 152 to 156 are the same as the application example 151 except that the phosphors of the examples 2 to 5 and the comparison examples 2 to 6 are used. Manufactured.

  Measured for the light emitting devices of Application Examples 151 to 155 and Application Comparative Examples 152 to 156, the luminous efficiency, and the NTSC ratio when transmitted through the diffusion plate / color filter (chromaticity coordinate system u on the CIE 1976 chromaticity diagram u The value of “v” was as shown in Table 3 and FIG.

  From this result, it can be seen that it is difficult to achieve both the high luminous efficiency and the NTSC ratio in the light emitting device modules of the comparative examples 152 to 156 using conventional phosphors. However, it can be seen that the application examples 151 to 155 according to the present invention achieve both high efficiency and a high NTSC ratio as compared with the application comparative examples.

Application Examples 201-205 and Application Comparative Examples 202-204 and 206
Using the phosphor of Example 1, a light emitting device of Application Example 201 was manufactured. This light emitting device was manufactured according to FIG. Specifically, a light emitting diode 301 having an emission peak wavelength of 390 nm was bonded onto an AlN package substrate 302 having an 8 mm square shape using solder and connected to an electrode via a gold wire 303. A transparent resin 304 is applied on the light emitting diode in a dome shape, and a transparent resin 305 mixed with the red light emitting phosphor of Example 1 is applied on the light emitting diode, and a transparent resin 306 having a peak wavelength of 520 nm is applied thereon. A transparent resin 307 mixed with a green phosphor and a transparent resin 308 were sequentially applied in layers, and a transparent resin 309 mixed with a blue phosphor having a peak wavelength of 452 nm was further coated thereon to manufacture a light emitting device. .

  The light emitting devices of Application Examples 202 to 205 and Application Comparison Examples 202 to 204 and 206 are the same as Application Example 101 except that the phosphors of Examples 2 to 5 and Comparative Examples 2 to 4 and 6 are used. Manufactured.

  FIG. 18 shows emission spectra measured for the light emitting devices of the application examples 201 to 205. In the figure, the relative intensity of the spectrum is normalized so that the area surrounded by the spectrum curve and the horizontal axis is constant.

Application Examples 251 to 255 and Application Comparative Examples 252 to 254 and 256
Using the phosphor of Example 1, a light emitting device module of Application Example 251 was manufactured. FIG. 19 is a schematic diagram of a light emitting device module according to an application example 251. In this light emitting device module, a plurality of bullet-type light emitting devices 1900 are arranged on the surface of a heat dissipation board 1901. This bullet-type light emitting device has the structure shown in FIG. Specifically, this light emitting device module was manufactured as follows. First, 16 light emitting diodes 301 having an emission peak wavelength of 390 nm were prepared. They were placed on the heat dissipation substrate 1901 so that the central portion of each light emitting diode was 6 mm apart, joined using solder, and further connected to the electrode via the gold wire 303. A transparent resin layer 304 is formed on the light-emitting diode in a dome shape, and a transparent resin layer 305 mixed with the red light-emitting phosphor of Example 1 is formed on the light-emitting diode, and the transparent resin layer 306 is further formed thereon. Then, a transparent resin layer 307 mixed with a green phosphor having a peak wavelength of 520 nm, a transparent resin layer 308, and a transparent resin layer 309 mixed with a blue phosphor having a peak wavelength of 452 nm were sequentially stacked and applied to manufacture a light emitting device module. . Here, the shape seen from the upper surface of each light emitting device was circular, and its diameter was 3.0 mm.

  The light emitting devices of Application Examples 252 to 255 and Application Comparative Examples 252 to 254 and 256 are the same as Application Example 251, except that the phosphors of Examples 2 to 5 and Comparative Examples 2 to 4 and 6 are used. A module was manufactured.

Application Examples 251 to 255, Comparative Examples 252 to 254 and 256 Light-Emitting Devices Measured Luminous Efficiency and NTSC Ratio when Transmitting through Diffuser / Color Filter (Chromaticity Coordinate System u on CIE1976 Chromaticity Diagram u The value of “v” was as shown in Table 4 and FIG.

  From this result, it can be seen that in the light emitting device of the comparative application example using the conventional phosphor, it is difficult to achieve both the high luminous efficiency and the NTSC ratio. However, it can be seen that the application examples 251 to 255 according to the present invention achieve both high efficiency and a high NTSC ratio as compared with the application comparison examples.

200 Substrate 201, 202 Lead 203 Resin portion 204 Reflection surface 205 Recess 206 Light emitting chip 207, 208 Bonding wire 209 Fluorescent layer 210 Phosphor 211 Resin layer 301 Light emitting diode 302 Substrate 303 Conductive wire 304, 306, 308 Transparent resin layer 305 Red Transparent resin layer 307 containing light emitting phosphor Transparent resin layer 309 containing green light emitting phosphor Transparent resin layer 1600, 1900 light emitting device 1601, 1901 containing blue light emitting phosphor

Claims (5)

The following general formula (I):
(M _1-x EC _x ) _a M ¹ _b M ² L _c O _d N _e (I)
(Where
M ¹ is Si;
M ² is Al,
L is a metal element selected from the group consisting of In (III) and Ga (III),
M is a group IIA element selected from the group consisting of Sr, Mg, Ca, and Ba,
EC is Eu, Ce, Mn, Tb, Yb, Dy, Sm, Tm, Pr, Nd, Pm, Ho, Er, Cr, Sn, Cu, Zn, As, Ag, Cd, Sb, Au, Hg, Tl, An emission center element selected from the group consisting of Pb, Bi, and Fe;
0 <x <0.4,
0.65 <a <0.80,
2 <b <3,
0 <c <0.00150,
0.3 <d <0.6,
4 <e <5)
A phosphor having a composition represented by formula (1) and exhibiting light emission having a peak between wavelengths 570 and 650 nm when excited with light having a wavelength of 250 to 500 nm,
A compound comprising M ¹ ;
A compound comprising M ² ;
A compound comprising M ;
A compound comprising E C;
Under pressure a mixture of more than atmospheric pressure with a compound containing L, and the you and performing firing at a temperature of 1500 to 2000 ° C., the manufacturing method of the fluorescent bodies. The method for producing an oxynitride phosphor according to claim 1 , wherein the compound containing L is an oxide or a nitride. The method for producing an oxynitride phosphor according to claim 1 or 2 , wherein firing is performed under a pressure of 5 atm or more. The method for producing an oxynitride phosphor according to any one of claims 1 to 3 , wherein firing is performed in a nitrogen atmosphere or a mixed atmosphere of nitrogen and hydrogen. The method for producing an oxynitride phosphor according to any one of claims 1 to 4 , wherein a washing treatment is further performed after firing.

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