JP2005064189A - Light emitting device, lighting device and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device having a high emission intensity by combination of an exciting source for generating a light of 350 to 480 nm and a phosphor. <P>SOLUTION: In the device obtained by combination of the exciting source for generating a light of 350 to 480 nm and the phosphor, the phosphor containing a crystal phase having the chemical composition of a general formula [1] is employed. In the general formula [1], M<SP>1</SP>represents a metal element of a positive ionic valence containing Sr, Ba and Mg of 80 mol% or more in total excluding Eu, Ga, Al, In and B; M<SP>2</SP>represents at least one type of element selected from a group of Ga, Al, In and B, and Ga is 80 mol% or more; and M<SP>3</SP>represents at least one type of element selected from a group of S, Se, Te and O, and S is 80 mol% or more. The reference symbol b is a number satisfying 0.08<b<1, the symbols a and b are numbers satisfying 0.9≤(a+b)≤1.1, and the symbol c is a number satisfying 3.6≤c≤4.4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light-emitting device, and more specifically, a first light emitter that emits light from ultraviolet light to visible light region by a power source, and absorbs light in the visible light region from the ultraviolet light to generate long-wavelength visible light. The present invention relates to a light-emitting device capable of generating high-intensity light emission regardless of the use environment by combining with a second light-emitting material as a wavelength conversion material having a phosphor containing a phosphor containing a luminescent center ion.

  Combining phosphors as wavelength conversion materials with light sources such as gallium nitride (GaN) light-emitting diodes (LEDs) and laser diodes (LDs), which are semiconductor light-emitting devices with low voltage and high emission intensity developed in recent years A white light emitting device has been proposed as a light emitting source of an image display device or a lighting device taking advantage of the feature of low power consumption and long life. For example, Japanese Patent Application Laid-Open No. 10-242513 discloses a light emitting device using the nitride semiconductor LED or LD chip and using yttrium, aluminum, and garnet as the phosphor. This is a combination of the blue light source of semiconductor and the yellow light emission of the phosphor to emit white light, but the white light emission method using this [blue + yellow] color mixture never gives a high color rendering property. Have some disadvantages.

Therefore, in recent years, phosphors that receive near-ultraviolet light from LEDs and LDs and emit blue, red, and green light respectively, or phosphors that receive blue light from blue LEDs and emit light in green and red, respectively. For example, phosphors have been proposed to emit white light having high color rendering properties in combination. For example, in WO00 / 33389, phosphors (Sr, Ca, Ba) (Al, Ga) ₂ S ₄ that receive blue light from a blue LED and emit green light for the purpose of white or green illumination: Eu ^{2+ and the} like are shown. However, a specific composition range is not described in this publication, and further, activated by 1 to 5 mol% Eu which has been considered good as a conventional 254 nm excitation phosphor (Sr, Ca, Ba). ) In a light emitting device in which (Al, Ga) ₂ S ₄ is a phosphor used for the second light emitter and combined with the blue LED which is the first light emitter, the intensity of the green light emission is low, so white light However, it is not satisfactory as green light, and further improvement is demanded as a light source such as a display, a backlight light source, and a traffic light. JP-A-2002-60747 proposes phosphor rare earth-activated sulfide that receives blue light from a blue LED and emits green or red light for the purpose of white or green illumination. In Journal of the Electrochemical Society, 150 , H57-H60 (2003), an experimental example in which a blue LED and SrGa ₂ S ₄ activated by 5 mol% Eu are combined for the purpose of white illumination is shown. However, they still cannot be said to have sufficient light emission intensity, and it is required to further improve the intensity of green light emission.
Japanese Patent Laid-Open No. 10-242513 WO00 / 33389 JP 2002-60747 A Journal of the Electrochemical Society, 150, H57-H60 (2003)

  The present invention has been made in view of the above-described prior art, and has been made to develop a light-emitting device having a high light emission intensity. Therefore, the present invention is a double light-emitting light-emitting device that is easy to manufacture and has a high light emission intensity. The purpose is to provide that.

  As a result of intensive studies to solve the above problems, the inventor of the present invention has a first light emitter that generates light of 350 to 480 nm and a second light that generates visible light by irradiation of light from the first light emitter. When using a phosphor containing a crystal phase having the following specific chemical composition as the second phosphor, the phosphor is irradiated with light in the vicinity of 350-480 nm, As a result of causing visible light emission at a high intensity, the inventors have found that the object can be achieved, and have reached the present invention.

  That is, the present invention relates to a light emitting device having a first light emitter that generates light of 350 to 480 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter. The gist of the light-emitting device is that the second light-emitting body contains a phosphor having a crystal phase having a chemical composition represented by the general formula [1].

(However, M ¹ represents a positive valence metal element including Sr, Ba, and Mg in total of 80 mol% or more except Eu, Ga, Al, In, and B, and M ² represents Ga, Al, Represents at least one element selected from the group consisting of In, B, Ga is 80 mol% or more, M ³ represents at least one element selected from the group consisting of S, Se, Te, O; And S is 80 mol% or more, b is a number that satisfies 0.08 <b <1, and a and b are numbers that satisfy 0.9 ≦ (a + b) ≦ 1.1, c is a number satisfying 3.6 ≦ c ≦ 4.4.)

  According to the present invention, a light emitting device having high emission intensity can be provided.

  The present invention is a light-emitting device in which a first light-emitting body that generates light of 350 to 480 nm and a second light-emitting body that is a phosphor are combined, and the second light-emitting body is represented by the following general formula [1]. It contains a phosphor having a crystal phase having a chemical composition.

The element M ¹ in the formula [1] is a positive valence metal element containing 80 mol% or more of Sr, Ba, and Mg in total except for Eu, Ga, Al, In, and B. In view of the above, the total of Sr and Mg or the total of Ba and Mg preferably occupies 80 mol% or more, and more preferably, M ¹ represents at least one selected from Sr, Ba, and Mg. Further, the ratio of the molar ratio of Mg to the total molar ratio of the elements constituting M ¹ is preferably 0.8 or less. Furthermore, when the total of Sr and Mg is 80 mol% or more, the ratio of the molar ratio of Mg to the total molar ratio of the elements constituting M ¹ is more preferably 0.7 or less. In the case where Mg is contained as a metal element in M ^{1 and} the light from the first light emitter has a short wavelength, particularly 350 to 415 nm, Ba has an absorption band in a shorter wavelength region than Sr. because there is, as the remaining metal elements M ^1, it is preferable to use a large amount of Ba than Sr, among others to the total molar ratio of elements constituting the M ^1, a molar ratio of Ba is 0.2 or more, The molar ratio of Mg is preferably 0.2 or more, and the total molar ratio of Ba and Mg is preferably 0.8 or more.

When a metal element having a positive valence other than Sr, Ba, Mg is included in the crystal as the metal element in M ¹ , the metal element is not particularly limited, but the same valence as Sr, Ba, Mg, that is, 2 It is preferable to include a valent metal element such as Mn, Ca, Zn, or Sn because the crystal structure is easily retained. The monovalent, tetravalent, pentavalent, or hexavalent metal elements in M ¹ are meant to assist crystallization of thiogallate by diffusion in the solid during firing of these divalent metal elements and the emission center Eu ^2+. A small amount of a metal element such as may be introduced. In order to adjust the emission wavelength and emission intensity, a small amount of a metal element such as Mn which can be a sensitizer may be substituted.

Elements ^{M 2} in the formula [1], Ga, represents Al, In, and at least one element selected from the group consisting of B, and is Ga or more 80 mol%. M ² is preferably at least one element selected from the group consisting of Ga and Al, and more preferably M ² is Ga.

The element M ³ in the formula [1] represents at least one element selected from the group consisting of S, Se, Te, and O, and S is 80 mol% or more. M ³ is preferably at least one element selected from the group consisting of S and Se, and M ³ is more preferably S.

The molar ratio b of Eu in the formula [1] is a number satisfying 0.08 <b <1. If the content of Eu ²⁺ , which is the luminescent center ion, is too small, the luminescence intensity tends to decrease. On the other hand, if too much, the luminescence intensity tends to decrease due to a phenomenon called concentration quenching. The lower limit is preferably 0.1 <b, and the upper limit is preferably b ≦ 0.25.

In the crystal phase M ¹ _a Eu _b M ² ₂ M ³ _c represented by the general formula [1], a cation site (M ¹ and Eu) where Eu ²⁺ is substituted, a cation site mainly occupied by Ga ( M ² ) and the basic total molar ratio of anion sites (M ³ ) mainly occupied by S are 1, 2, and 4, respectively. However, even if some cation deficiency or anion deficiency occurs, the fluorescence performance for this purpose is improved. Since there is no significant influence, when the total molar ratio of cation sites mainly occupied by Ga is fixed to 2 in the chemical formula, the total molar ratio (a + b) of the sites where Eu ²⁺ is substituted is 0.9 ≦ ( a + b) ≦ 1.1, among which a + b = 1 is preferable. Further, the total molar ratio c of anion sites mainly occupied by S is in the range of 3.6 ≦ c ≦ 4.4, and it is preferable that c = 4 among them. Furthermore, it is preferable that a + b = 1 and c = 4.

The phosphor used in the present invention includes compounds of M ¹ source, M ² source, M ³ source and element source compound of luminescent center ion (Eu) as shown in the general formula [1] (A The mixture prepared by the mixing method) can be produced by heat treatment and baking.
(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., pulverization using mortar and pestle, etc., mixer such as ribbon blender, V-type blender and Henschel mixer, or mortar and pestle Dry mixing method combined with mixing.
In addition, when the said element source compound is not a sulfide, the wet-mixing method of the following (B) is also preferable.
(B) Using a pulverizer or a mortar and pestle, etc., add water etc. and mix in a slurry or solution state with a pulverizer, mortar and pestle, or evaporating dish and stirrer, spray drying, heating Wet mixing method that is dried by drying or natural drying.

  As a heat treatment method of the mixture obtained by these mixing methods, in a heat-resistant container such as a crucible or tray made of alumina or quartz, usually at a temperature of 600 to 1400 ° C., preferably 700 to 1300 ° C., hydrogen sulfide, air , Oxygen, carbon monoxide, carbon dioxide, nitrogen, hydrogen, argon and the like alone or in a mixed atmosphere for 10 minutes to 24 hours for heating. In addition, after heat processing, washing | cleaning, drying, a classification process, etc. are made | formed as needed.

  As the heating atmosphere, an atmosphere necessary for obtaining an ion state (valence) in which the element of the emission center ion contributes to light emission is selected. In the case of divalent Eu or the like in the present invention, a neutral or reducing atmosphere such as hydrogen sulfide, carbon monoxide, nitrogen, hydrogen, and argon is preferable. However, as long as the conditions are also selected under an oxidizing atmosphere such as air and oxygen. Is possible.

M ¹ source, M ² source, and Eu source compounds include sulfides, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates of M ¹ , M ² , and Eu. , halide and the like, as the compound of ^{M 3} source, to S of of ^{M 3,} the element ^{M 1} source, ^{M 2} source, sulfides such as NH _4, oxysulfide, hydrogen sulfide, NH ₄ SH, CS ₂ , S, (CH ₃ ) ₂ NCS ₂ Na and the like, and Se in M ³ is selenide such as element M ¹ source, M ² source, NH ₄ , hydrogen selenide, selenium. Acid, ammonium selenate, selenium, or Te of M ³ , element M ¹ source, M ² source, telluride such as NH ₄ , hydrogen telluride, telluric acid, ammonium tellurate, tellurium, to oxygen of M ^3, the element ^{M 1} source, ^{M 2} source, oxides such as NH _4, hydroxide , Carbonates, nitrates, and the like, among these, chemical composition, reactivity, and, NO _x during the firing, is selected in view of the non-occurrence of such as SO _x.

The Sr to preferred for metal element group ^{M 1,} Ba, and the Mg, if specific examples thereof ^{M 1} source compound, the Sr source compound, SrS, SrSe, SrTe, SrO , Sr ( OH) ₂ · 8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (OCO) ₂ · H ₂ O, Sr (OCOCH ₃ ) ₂ · 0.5H ₂ O, SrCl _2, etc. Ba source compounds include BaS, BaSe, BaTe, BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (OCO) ₂ .2H ₂ O, Ba ( OCOCH ₃
) _2, BaCl ₂ or the like, also as the Mg source _{compound, MgO, Mg (OH) 2} , MgCO 3, Mg (OH) 2 · 3MgCO 3 · 3H 2 O, Mg (NO 3) 2 · 6H 2 O , MgSO ₄ , Mg (
OCO) ₂ · 2H ₂ O, Mg (OCOCH ₃ ) ₂ · 4H ₂ O, MgCl _{2 and the} like. In addition to the above, examples of the metal element that can be M ¹ include Mn as described above.
As the Mn source compound, MnS, MnSe, MnTe, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , MnO, Mn (OH) ₂ , MnCO ₃ , Mn (NO ₃ ) ₂ , Mn (OCOCH ₃ ) _{2 · 2H 2 O, Mn (OCOCH} 3) 3 · nH 2 O, MnCl 2 · 4H 2 O , and the like.

Further, with respect to Eu, which is preferable as the element of the luminescent center ion, specific examples of the element source compound include EuS, EuSe, EuTe, Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ ,
Examples include Eu ₂ (OCO) ₆ , EuCl ₂ , EuCl ₃ , EuF ₃ , Eu (NO ₃ ) ₃ .6H ₂ O, and the like.

In the present invention, the first light emitter that irradiates the phosphor with light generates light having a wavelength of 350 to 480 nm. Preferably, a light emitter that generates light having a peak wavelength in a wavelength range of 350 to 480 nm is used. In terms of facilitating color adjustment in the case of a light emitting device, it is preferable to use a light emitter that generates light having a wavelength of 350 nm to 415 nm, and generates light having a peak wavelength in the range of 350 nm to 415 nm. More preferably, a light emitter is used. Specific examples of the first light emitter that generates light having a wavelength of 350 to 480 nm include a light emitting diode (LED) and a laser diode (LD). Laser diodes are preferred because they consume less power. Of these, GaN LEDs and LDs using GaN compound semiconductors are preferred. Because GaN LED and LD
This is because the light emission output and the external quantum efficiency are remarkably large as compared with SiC-based LEDs that emit light in this region, and when combined with the phosphor, very bright light emission can be obtained with very low power. . For example, for a current load of 20 mA, the GaN system usually has a light emission intensity 100 times or more that of the SiC system. When a GaN-based compound semiconductor is used, a near-ultraviolet light source of 350 nm or more and 415 nm or less emits light more strongly than a blue light source of more than 415 nm and 480 nm or less, which is particularly preferable. GaN-based LEDs and LDs preferably have an Al x GaYN light emitting layer, a GaN light emitting layer, or an In x GaYN light emitting layer. Among GaN-based LEDs, those having an InXGaYN light-emitting layer are particularly preferable because the light emission intensity is very strong, and in GaN-based LDs, those having a multiple quantum well structure of an InXGaYN layer and a GaN layer have a light emission intensity. It is particularly preferred because it is very strong. In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics. A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is sandwiched between n-type and p-type AlxGaYN layers, GaN layers, or InxGaYN layers. Those having a heterostructure are preferably high in luminous efficiency, and those having a heterostructure in a quantum well structure are further preferable because of higher luminous efficiency.

  In the present invention, it is particularly preferable to use a surface-emitting type illuminant, particularly a surface-emitting GaN-based laser diode, as the first illuminant because the luminous efficiency of the entire light-emitting device is increased. A surface-emitting type illuminant is an illuminant that emits strong light in the surface direction of a film. In a surface-emitting GaN-based laser diode, the crystal growth of a light-emitting layer or the like is controlled, and a reflective layer or the like is successfully performed. By devising, the light emission in the surface direction can be made stronger than the edge direction of the light emitting layer. When the surface emitting type is used, the light emission cross-sectional area per unit light emission amount can be increased compared to the type that emits light from the edge of the light emitting layer. As a result, the phosphor of the second light emitter is irradiated with the light. Since the irradiation area can be made very large with the same amount of light and the irradiation efficiency can be improved, stronger light emission can be obtained from the phosphor that is the second light emitter.

  When a surface-emitting type is used as the first light emitter, the second light emitter is preferably a film. As a result, the cross-sectional area of the light from the surface-emitting type light emitter is sufficiently large. Therefore, when the second light emitter is formed into a film in the direction of the cross section, the irradiation cross-section area of the phosphor from the first light emitter is irradiated. Becomes larger per unit amount of phosphor, so that the intensity of light emitted from the phosphor can be further increased.

  Further, when a surface-emitting type is used as the first light emitter and a film-like one is used as the second light emitter, the second light emitter directly in the form of a film on the light-emitting surface of the first light emitter. It is preferable to have a shape in which is contacted. Contact here refers to creating a state in which the first light emitter and the second light emitter are in perfect contact with each other without air or gas. As a result, it is possible to avoid a light amount loss in which light from the first light emitter is reflected by the film surface of the second light emitter and oozes out, so that the light emission efficiency of the entire apparatus can be improved.

  FIG. 1 is a schematic perspective view showing the positional relationship between the first light emitter and the second light emitter in an example of the light emitting device of the present invention. In FIG. 1, 1 is a film-like second light emitter having the phosphor, 2 is a surface-emitting GaN-based LD as the first light emitter, and 3 is a substrate. In order to create a state in which they are in contact with each other, the LD 2 and the second light emitter 1 may be formed separately and the surfaces may be brought into contact with each other by an adhesive or other means, or the light emitting surface of the LD 2 A second light-emitting body may be formed (molded) on the top. As a result, the LD 2 and the second light emitter 1 can be brought into contact with each other.

The light from the first illuminant and the light from the second illuminant are usually directed in all directions. However, when the phosphor powder of the second illuminant is dispersed in the resin, the light is out of the resin. A part of the light is reflected when exiting, so the direction of the light can be adjusted to some extent. Accordingly, since light can be guided to a certain degree in an efficient direction, it is preferable to use a phosphor in which the phosphor powder is dispersed in a resin as the second luminous body. Further, when the phosphor is dispersed in the resin, the total irradiation area of the light from the first light emitter to the second light emitter is increased, so that the light emission intensity from the second light emitter can be increased. It also has the advantage of being able to. Examples of the resin that can be used in this case include various resins such as silicon resin, epoxy resin, polyvinyl resin, polyethylene resin, polypropylene resin, and polyester resin, which are preferable in terms of good dispersibility of the phosphor powder. Is silicon resin or epoxy resin. When the powder of the second luminous body is dispersed in the resin, the weight ratio of the powder of the second luminous body to the whole of the resin is usually 10 to 95%, preferably 20 to 90%, more preferably. Is 30-80%. If the phosphor is too much, the luminous efficiency may be reduced due to aggregation of the powder, and if it is too little, the luminous efficiency may be lowered due to light absorption or scattering by the resin.

  The light-emitting device of the present invention includes the phosphor as a wavelength conversion material and a light-emitting element that emits light of 350 to 480 nm, and the phosphor absorbs light of 350 to 480 nm emitted from the light-emitting element. In addition, it is a light emitting device that has good color rendering properties and can generate high-intensity visible light regardless of the use environment, and a light source such as a backlight light source and a traffic light, and an image display device such as a color liquid crystal display. And suitable for light sources such as lighting devices such as surface emitting.

  The light emitting device of the present invention will be described with reference to the drawings. FIG. 2 is a schematic cross-sectional view showing one embodiment of a light emitting device having a first light emitter (350-480 nm light emitter) and a second light emitter. 4 is a light emitting device, 5 is a mount lead, 6 is an inner lead, 7 is a first light emitter (350-480 nm light emitter), 8 is a phosphor-containing resin portion as a second light emitter, 9 Is a conductive wire, and 10 is a mold member.

  As shown in FIG. 2, the light emitting device as an example of the present invention has a general bullet shape, and a first light emitter made of a GaN-based light emitting diode or the like is disposed in the upper cup of the mount lead 5. (350 to 480 nm illuminant) 7 is a phosphor formed as a second illuminant by mixing and dispersing the phosphor in a binder such as silicon resin, epoxy resin or acrylic resin and pouring it into the cup. It is fixed by being covered with the body-containing resin portion 8. On the other hand, the first light emitter 7 and the mount lead 5, and the first light emitter 7 and the inner lead 6 are each electrically connected by a conductive wire 9, and these are entirely covered with a mold member 10 made of epoxy resin or the like, Protected.

  Further, as shown in FIG. 3, the surface emitting illumination device 11 incorporating the light emitting element 1 has a large number of light emission on the bottom surface of a rectangular holding case 12 whose inner surface is light-opaque such as a white smooth surface. The device 13 is arranged with a power supply and a circuit (not shown) for driving the light emitting device 13 provided outside thereof, and a milky white acrylic plate or the like is provided at a position corresponding to the lid portion of the holding case 12. The diffusion plate 14 is fixed for uniform light emission.

  Then, the surface emitting illumination device 11 is driven to apply light to the first light emitter of the light emitting element 13 to emit light of 350 to 480 nm, and a part of the light emission is used as the second light emitter. The phosphor in the phosphor-containing resin part absorbs and emits visible light, while light emission with high color rendering properties is obtained by mixing with blue light or the like that is not absorbed by the phosphor. 14, is emitted upward in the drawing, and illumination light with uniform brightness is obtained within the surface of the diffusion plate 14 of the holding case 12.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

Ga ₂ S ₃ ; 6.391 g, SrS; 2.759 g, and EuF ₃ ; 0.850 g were pulverized and mixed in an agate mortar, and the mixture obtained in an alumina crucible at 1000 ° C. under argon gas flow for 8 hours. The phosphor Sr _0.85 Eu _0.15 Ga ₂ S ₄ that emits blue light was manufactured by firing and then controlling the particle size by pulverization. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the emission intensity at the emission peak wavelength when the emission peak wavelength and the emission intensity when the phosphor obtained in Comparative Example 1 was excited at 465 nm and 400 nm were set to 100 (hereinafter referred to as “emission intensity”). Relative light emission intensity).

Phosphor Sr _0.6375 Mg in the same manner as in Example 1 except that the charged raw materials were changed to Ga ₂ S ₃ ; 6.704 g, SrS; 2.171 g, MgS; 0.341 g, and EuF ₃ ; 0.893 _{g. 0.2125} Eu _0.15 Ga ₂ S ₄ was produced. GaN-based blue light-emitting diode and GaN
The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the near-ultraviolet light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

The charged materials are Ga ₂ S ₃ ; 6.314 g, SrS; 2.566 g, and EuF ₃ ; 1
. A phosphor Sr _0.8 Eu _0.2 Ga ₂ S ₄ was produced in the same manner as in Example 1 except that the amount was changed to 12 g. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

The charging materials were Ga ₂ S ₃ ; 6.469 g, SrS; 2.957 g, and EuF ₃ ; 0
. A phosphor Sr _0.9 Eu _0.1 Ga ₂ S ₄ was produced in the same manner as in Example 1 except that 574 g was used. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

The raw materials were Ga ₂ S ₃ ; 6.24 g, SrS; 2.377 g, and EuF ₃ ;
A phosphor Sr _0.75 Eu _0.25 Ga ₂ S ₄ was produced in the same manner as in Example 1 except that 383 g was used. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Phosphor Ba _0.425 Mg in the same manner as in Example 1 except that the charged raw materials were changed to Ga ₂ S ₃ ; 6.561 g, BaS; 2.006 g, MgS; 0.668 g, and EuF ₃ ; 0.874 g. _0.425 Eu _0.15 Ga ₂ S ₄ was produced. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Phosphor Sr _0.4 in the same manner as in Example 1 except that the charged raw materials were changed to Ga ₂ S ₃ ; 6.971 g, SrS; 1.505 g, MgS; 0.709 g, and EuF ₃ ; 0.928 g.
₂₅ Mg _0.425 Eu _0.15 Ga ₂ S ₄ was produced. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Phosphor Sr _0.2125 Mg in the same manner as in Example 1 except that the charged materials were changed to Ga ₂ S ₃ ; 7.26 g, SrS; 0.784 g, MgS; 1.108 g, and EuF ₃ ; 0.967 _{g. 0.6375} Eu _0.15 Ga ₂ S ₄ was produced. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity.
(Comparative Example 1)
The charged materials were Ga ₂ S ₃ ; 6.582 g, SrS; 3.176 g, and EuF ₃ ; 0
. Sr _0.95 Eu _0.05 Ga ₂ S ₄ was obtained in the same manner as in Example 1 except that the amount was changed to 292 g. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the light emission peak and the light emission intensity (each of which is 100, based on these). It can be seen that the emission intensity of the phosphor of Example 1 excited by excitation at 465 nm and 400 nm is 1.4 times and 1.3 times that of the phosphor of Comparative Example 1, respectively.
(Comparative Example 2)
The charged raw materials were Ga ₂ S ₃ ; 6.582 g, BaS; 4.685 g, and EuF ₃ ; 0
. A phosphor Ba _0.99 Eu _0.01 Ga ₂ S ₄ was produced in the same manner as in Example 1 except that the amount was changed to 058 g. The phosphor was excited at 465 nm and 400 nm, which are the main wavelengths of the GaN-based blue light-emitting diode and GaN-based near-ultraviolet light-emitting diode, and emission spectra were measured respectively. Table 1 shows the wavelength of the emission peak and the relative emission intensity. It can be seen that the emission intensity of the phosphor of Example 1 excited by 400 nm is 2.3 times that of the phosphor of Comparative Example 2.

The figure which shows an example of the light-emitting device which made the film-like fluorescent substance contact or shape | mold to the surface emitting type GaN-type diode. It is typical sectional drawing which shows one Example of the light-emitting device comprised from the fluorescent substance in this invention, and a 1st light-emitting body (350-480 nm light-emitting body). The typical sectional view showing an example of the surface emitting illumination device of the present invention.

Explanation of symbols

1; second light emitter 2; surface-emitting GaN-based LD
3; Substrate 4; Light emitting device 5; Mount lead 6; Inner lead 7; First light emitter (light emitter of 350 to 480 nm)
8; Resin part containing phosphor in the present invention 9; Conductive wire 10; Mold member 11; Surface-emitting illumination device 12 incorporating a light-emitting element; Holding case 13; Light-emitting device 14;

Claims (18)

In a light-emitting device including a first light-emitting body that generates light of 350 to 480 nm and a second light-emitting body that generates visible light when irradiated with light from the first light-emitting body, the second light-emitting body includes: A light-emitting device comprising a phosphor having a crystal phase having a chemical composition represented by the general formula [1].

(However, M ¹ represents a positive valence metal element including Sr, Ba, and Mg in total of 80 mol% or more except Eu, Ga, Al, In, and B, and M ² represents Ga, Al, Represents at least one element selected from the group consisting of In, B, Ga is 80 mol% or more, M ³ represents at least one element selected from the group consisting of S, Se, Te, O; And S is 80 mol% or more, b is a number that satisfies 0.08 <b <1, and a and b are numbers that satisfy 0.9 ≦ (a + b) ≦ 1.1, c is a number satisfying 3.6 ≦ c ≦ 4.4.) 2. The light emitting device according to claim ^1, wherein in M ¹ , the sum of Sr and Mg or the sum of Ba and Mg is 80 mol% or more. The light emitting device according to claim 1, wherein 0.1 <b ≦ 0.25 is satisfied. 4. The light emitting device according to claim 1, wherein a ratio of a molar ratio of Mg to a total molar ratio of elements constituting M ¹ is 0.8 or less. The light-emitting device according to claim 1, wherein M ² is made of Ga. The light emitting device according to claim 1, wherein M ³ is made of S. The light emitting device according to any one of claims 1 to 6, wherein M ¹ represents at least one selected from Sr, Ba, and Mg. The light-emitting device according to claim 1, wherein a and b satisfy a + b = 1, and c satisfies c = 4. The light-emitting device according to claim 1, wherein a first light-emitting body that generates light of 350 to 415 nm is used. The light emitting device according to claim 1, wherein the first light emitter is a laser diode or a light emitting diode. The light emitting device according to claim 10, wherein the first light emitter is a laser diode. The light emitting device according to any one of claims 1 to 11, wherein the first light emitter uses a GaN-based compound semiconductor. The light-emitting device according to claim 1, wherein the first light emitter is a surface-emitting GaN-based laser diode. 14. The material group including the second light emitter is in the form of a film, and the light from the surface light emitting GaN-based diode is irradiated onto the film of the second light emitter. The light emitting device according to any one of the above. The visible light is directly generated in a form in which a film containing the second light emitter is brought into contact with or directly on the light emitting surface of the first light emitter which is a surface-emitting GaN-based diode. The light emitting device according to any one of 1 to 14. 16. The light emitted from the first light emitter is irradiated onto a powder obtained by dispersing the second light emitter in a silicon resin and / or an epoxy resin. Light emitting device. An image display device comprising the light emitting device according to claim 1. An illumination device comprising the light emitting device according to claim 1.

Images