JP5326986B2 - Phosphor used in light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device which combines a first luminescent material (excitation source) and a second luminescent material (phosphor), each emitting light 350-415 nm, and has high emission intensity. <P>SOLUTION: In a device which combines the first luminescent material (excitation source) and the second luminescent material (phosphor) for each emitting light 350-415 nm, the light emitting device satisfies the following conditions, (A) and/or (B):(A) quantum absorption efficiency &alpha;<SB>q</SB>of the phosphor is not less than 0.8; and (B) the product of the quantum absorption efficiency &alpha;<SB>q</SB>of the phosphor and internal quantum efficiency &eta;<SB>i</SB>, &alpha;<SB>q</SB>&times;&eta;<SB>i</SB>, is not less than 0.55. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

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. by matrix compound emitted by the combination of the second light emitter and the wavelength converting material having a phosphor containing an emission center ion, good color rendering properties regardless of the use environment, and generating a light emission with high intensity The present invention relates to a light emitting device that can be made to operate.

In order to generate white and other various colors uniformly and with good color rendering by mixing blue, red, and green, a light emitting device in which the light emission color of an LED or LD is converted with a phosphor has been proposed. For example, in JP-B-49-1221, phosphor a beam of laser emitting a radiation beam having a wavelength of _{300-530nm (Y 3-xy Ce x} Gd y M 5-z Ga z O 12 (Y is Y, Lu , Or La,
M represents Al, Al—In, or Al—Sc. )), And a method for forming a display by emitting light is shown. Further, in recent years, a white light emitting device configured by combining a gallium nitride (GaN) LED or LD with high luminous efficiency, which has been attracting attention as a blue light emitting semiconductor light emitting element, and a phosphor as a wavelength conversion material. However, it has been proposed as a light-emitting source for an image display device and a lighting device, taking advantage of the feature of low power consumption and long life. Actually, Japanese Patent Application Laid-Open No. 10-242513 discloses a light emitting device using this nitride semiconductor LED or LD chip and using yttrium, aluminum, garnet as a phosphor. . In U.S. Pat. No. 6,294,800, Ca ₈ Mg (SiO ₄ ) ₄ Cl _{2 is a} substance capable of generating white light emission upon irradiation with light in the 330 to 420 nm region typified by light from an LED. : A substance comprising a combination of a green phosphor containing Eu ²⁺ and Mn ²⁺ , a red phosphor and a blue phosphor is disclosed, and (Sr, Ba, Ca) ₅ (PO ₄ ) ₃ Cl is used as the blue phosphor. : Eu ²⁺ is listed.

However, so far, the first illuminant such as an LED or the like emits light such as a combination of an yttrium / aluminum / garnet phosphor as disclosed in JP-A-10-242513 as the second illuminant. The apparatus cannot be said to have sufficient light emission intensity, and further improvements are required as light sources such as displays, backlight sources, and traffic lights. Further, it is described as a material for converting LED light into blue visible light as shown in US Pat. No. 6,294,800 (Sr, Ba, Ca) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ The same is true for, and higher emission intensity is required.

Japanese Patent Publication No.49-1221 Japanese Patent Laid-Open No. 10-242513 US Pat. No. 6,294,800

  The present invention has been made in view of the above-described prior art to develop a light emitting device with extremely high light emission intensity. Accordingly, the present invention is a double light emitter type that is easy to manufacture and has extremely high light emission intensity. An object is to provide a light emitting device.

As a result of intensive studies to solve the above problems, the inventor of the present invention has a first light emitter that emits light of 350 to 415 nm and a second light that generates visible light by irradiation of light from the first light emitter. (A) quantum absorption efficiency α _q as the second light emitter.
And / or (B) a phosphor satisfying the condition that α _q · η _{i, which} is a product of quantum absorption efficiency and internal quantum efficiency, is 0.55 or more, the phosphor is 350 As a result of being irradiated with light at around −415 nm and emitting visible light at a high intensity, the inventors have found that the object can be achieved, and reached the present invention. In addition, by using a phosphor containing a crystal phase having a chemical composition represented by the general formula [1] as the second luminous body, the above object can be achieved, and preferable specific examples include (Sr, Among the crystal phases having a basic composition of Ba, Ca) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , a composition having a higher ratio of Sr is used and / or a composition having a higher ratio of Eu is used. As a result, the inventors have found that the object can be achieved, and have reached the present invention.

_{Eu a Sr b M 5-ab} (PO 4) c X d ······ [1]
(In the above general formula [1], M represents a metal element other than Eu and Sr, and X represents PO _4.
Represents a monovalent anionic group other than c and d are 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1
It is a number that satisfies a is a number such that a> 0, b is b ≧ 0, and a + b ≦ 5, and satisfies the condition of a ≧ 0.1 or b ≧ 3. )
Here, 5-a-b, d, c, a, and b are respectively the molar ratio of the element corresponding to the element M, the molar ratio of the anionic group X, the molar ratio of the PO ₄ group, and the molar ratio of the Eu atom. , And the molar ratio of Sr atoms. For example, in the case of a composition of Eu _0.5 Sr _3.5 Ba _0.8 Mn _0.195 Sm _0.005 (PO ₄ ) ₃ Cl _0.95 F _0.05 , M represents Ba, Mn, and Sm, and X represents Cl and F. Therefore, Eu _0.5 Sr Since it can be expressed as _3.5 M _1.0 (PO ₄ ) ₃ X _1.0 , it falls within the category of the formula [1].

In general, other divalent metal elements such as Eu ²⁺ may be substituted at the A site in the crystal of A ₅ (PO ₄ ) ₃ Cl (A is an alkaline earth metal), and the substituted substance has an Hg resonance line of 254 nm. It is known that it can be used as a phosphor for a lamp by utilizing the fact that it emits light by being excited by short ultraviolet rays. In the present invention, the emission intensity of excitation light near 400 nm having a wavelength different from the above differs greatly depending on the type of alkaline earth metal A of A ₅ (PO ₄ ) ₃ Cl, and the amount of Sr as alkaline earth metal A is large. When the contained substance is used, a large emission intensity can be obtained by excitation of light around 400 nm specifically, and the emission intensity with respect to the same excitation light is specific when the content ratio of Eu as an activator is high. It is based on knowing that it will grow.

Accordingly, the gist of the present invention is the following (1) to (21).
(1) In the light emitting device including the first light emitter that generates light of 350 to 415 nm and the second light emitter that generates visible light when irradiated with light from the first light emitter, The luminous body of the following (A) and / or (B)
(A) Quantum absorption efficiency α _q is 0.8 or more,
(B) light-emitting device product α _q · η _i of a quantum absorption efficiency alpha _q and internal quantum efficiency eta _i is characterized by containing 0.55 or more satisfying phosphor.
(2) The phosphor is represented by the following general formula [1]
_{Eu a Sr b M 5-ab} (PO 4) c X d ······ [1]
(In the above general formula [1], M represents a metal element other than Eu and Sr. X represents a monovalent anionic group other than PO _4. C and d are 2.7 ≦ c ≦ 3. 3, 0.9 ≦ d ≦ 1.
It is a number that satisfies 1. a is a number such that a> 0, b is b ≧ 0, and a + b ≦ 5, and satisfies the condition of a ≧ 0.1 or b ≧ 3. )
The light emitting device according to claim 1, comprising a crystal phase having a chemical composition of: (3) In the light emitting device including the first light emitter that generates light of 350 to 415 nm and the second light emitter that generates visible light when irradiated with light from the first light emitter, The phosphor of the following general formula [1]
_{Eu a Sr b M 5-ab} (PO 4) c X d ······ [1]
(In the general formula [1], M represents a metal element other than Eu and Sr. X represents PO.
Represents a monovalent anionic group other than ₄ . c and d are 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.
It is a number that satisfies 1. a is a number such that a> 0, b is b ≧ 0, and a + b ≦ 5, and satisfies the condition of a ≧ 0.1 or b ≧ 3. )
A light-emitting device comprising a phosphor having a crystal phase having a chemical composition of:
(4) The light-emitting device according to (3), wherein b is b> 0.
(5) The light emitting device according to any one of (1) to (4), wherein the first light emitter is a laser diode or a light emitting diode.
(6) The light emitting device according to (5), wherein the first light emitter is a laser diode.
(7) a and b satisfy 0.1 ≦ a <5 and 0.01 ≦ b <5, or satisfy 0.0001 ≦ a <5 and 3 ≦ b <5 (2) The light-emitting device as described in any one of (6).
(8) Any one of (2) to (7), wherein 70 mol% or more of the element M is at least one element selected from the group consisting of Ba, Mg, Ca, Zn, and Mn. The light emitting device according to 1.
(9) The light emitting device according to any one of (2) to (8), wherein 50 mol% or more of X is Cl.
(10) The light emitting device according to any one of (2) to (9), wherein a and b satisfy a ≧ 0.1 and b ≧ 3.
(11) The light emitting device according to any one of (2) to (10), wherein a satisfies a> 0.2.
(12) The light-emitting device according to (11), wherein a satisfies 0.2 <a ≦ 3.
(13) The light emission according to any one of (2) to (12), wherein the element M is at least one selected from the group consisting of Ba, Mg, Ca, Zn, and Mn, and X is Cl. apparatus.
(14) The light emitting device according to any one of (2) to (13), wherein the element M is at least one selected from the group consisting of Ba, Mg, and Ca, and X is Cl.
(15) The light-emitting device according to any one of (1) to (14), wherein the first light-emitting body uses a GaN-based compound semiconductor.
(16) The light emitting device according to any one of (1) to (15), wherein the first light emitter is a surface-emitting GaN-based laser diode.
(17) The light emitting device according to any one of (1) to (16), wherein the second light emitter is in the form of a film.
(18) The light emitting device according to (17), wherein the film surface of the second light emitter is brought into direct contact with the light emitting surface of the first light emitter.
(19) The light emitting device according to any one of (1) to (18), wherein the second light emitter is obtained by dispersing phosphor powder in a resin.
(20) The extracted light from the light emitting device is light obtained by mixing the light from the first light emitter and the light from the second light emitter, and the extracted light is white (1) ) To (19).
(21) A lighting device having the light-emitting device according to any one of (1) to (20).

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

X-ray diffraction pattern of Sr ₅ (PO ₄ ) ₈ Cl (converted to X-ray source Cu Kα) FIG. 2 is a schematic perspective view showing an example of a light emitting device in which a film-like phosphor is brought into contact with a surface emitting GaN-based diode. It is typical sectional drawing which shows one Example of the light-emitting device of this invention. X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 1 of the present invention A spectrum obtained by superimposing the emission spectra of the phosphors of Example 1, Comparative Example 1, and Comparative Example 2 of the present invention irradiated with a GaN-based light emitting diode having an emission wavelength of 400 nm. X-ray diffraction pattern of the phosphor of Example 2 of the present invention (X-ray source: Cu Kα) X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 3 of the present invention X-ray diffraction pattern of the phosphor of Example 4 of the present invention (X-ray source: Cu Kα) The typical sectional view showing an example of the surface emitting illumination device of the present invention. X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 5 of the present invention X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 6 of the present invention X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 7 of the present invention X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 8 of the present invention X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 9 of the present invention X-ray diffraction pattern (X-ray source: Cu Kα) of the phosphor of Example 10 of the present invention Spectrum I _ref (λ) when measured with a reflector attached to the spectrophotometer Spectrum I (λ) measured with a spectrophotometer attached with a sample to measure quantum absorption efficiency α _q and internal quantum efficiency η _i

The present invention is a light-emitting device in which a first light-emitting body that generates light of 350 to 415 nm and a second light-emitting body including a phosphor are combined, and the phosphor included in the second light-emitting body is (A ) Quantum absorption efficiency α _q is 0.8 or more, more preferably 0.9 or more, more preferably 0.95 or more, and / or (B) α _{q which is} the product of quantum absorption efficiency and internal quantum efficiency Η _i is 0.55 or more, preferably 0.6 or more, more preferably 0.65 or more. In practice, the upper limit of the value that α _q can take is 1, and the upper limit of the value that η _i can take is 0.99. When the phosphor satisfies the condition (A), the number of photons emitted from the first light emitter that can cause elementary excitation in the phosphor increases, resulting in a unit time from the phosphor. The number of photons emitted per hit can be increased, that is, a light emitting device having high emission intensity can be obtained. Here, elementary excitation refers to energy excitation (generally referred to as emission center excitation) due to a change in the spin state of Eu, and energy excitation due to a change in the average number of electrons having an existence probability in the vicinity of each ion. (Generally referred to as CT excitation), energy excitation due to interband transition of electrons (generally referred to as band excitation), and the like. In addition, when the phosphor satisfies the condition (B), the proportion of the elementary excitations caused by the photons emitted from the first light emitters that follow the process of causing the formation of photons further increases. As a result, the number of photons emitted from the phosphor per unit time can be increased, that is, a light emitting device having a high emission intensity can be obtained. In addition, when the phosphor satisfies the condition (B), the ranges of values that α _q and η _i can normally take are 0.55 ≦ α _q ≦ 1, 0.55 ≦ η _i ≦ 0, respectively. .99.

A method for obtaining the quantum absorption efficiency α _q and the internal quantum efficiency η _i will be described below. First, a powder sample or the like to be measured is packed in a cell with a sufficiently smooth surface so that measurement accuracy is maintained, and is attached to a spectrophotometer equipped with an integrating sphere. An example of this spectrophotometer is MCPD2000 manufactured by Otsuka Electronics Co., Ltd. An integrating sphere or the like is used so that all the photons reflected by the sample and the photons emitted from the sample by photoluminescence can be counted, that is, photons that are not counted and fly out of the measurement system are eliminated. A light source for exciting the phosphor is attached to the spectrophotometer. This light emission source is, for example, an Xe lamp or the like, and is adjusted using a filter or the like so that the emission peak wavelength is 400 nm. A sample to be measured is irradiated with light from a light source adjusted to have a wavelength peak of 400 nm, and the emission spectrum is measured. This measurement spectrum actually includes the amount of excitation light reflected by the sample in addition to the photons emitted from the sample by photoluminescence with light from the excitation light source (hereinafter simply referred to as excitation light). Photon contributions overlap. The absorption efficiency α _q is a value obtained by dividing the number of photons _Nabs of the excitation light absorbed by the sample by the total number of photons N of the excitation light.
First, the total number of photons N of the latter excitation light is obtained as follows. That is, a substance having a reflectance R of approximately 100% with respect to excitation light, for example, a reflector such as Spectralon manufactured by Labsphere (having a reflectance of 98% with respect to excitation light of 400 nm) is used as the measurement target. Mount on a photometer and measure the reflection spectrum I _ref (λ). Here, the numerical value obtained from (Equation 1) from the reflection spectrum I _ref (λ) is proportional to N.

Here, the integration interval may be substantially only the interval in which I _ref (λ) has a significant value. FIG. 16 shows an example of I _ref (λ). In this case, it is sufficient to take a range from 380 nm to 420 nm. The former _Nabs is proportional to the amount obtained by (Equation 2).

Here, I (λ) is a reflection spectrum when a target sample for which α _q is to be obtained is attached. The integration range of (Expression 2) is the same as the integration range defined in (Expression 1). By limiting the integration range in this way, the second term of (Equation 2) corresponds to the number of photons generated by the target sample reflecting the excitation light, that is, out of all photons generated from the target sample. This corresponds to the one excluding the photons generated by the photoluminescence by the excitation light. Since an actual spectrum measurement value is generally obtained as digital data divided by a certain finite bandwidth with respect to λ, the integrals of (Equation 1) and (Equation 2) are obtained by the sum based on the bandwidth. From the above, α _q = N _abs / N = (Expression 2) / (Expression 1).

Next, a method for obtaining the internal quantum efficiency η _i will be described. η _i is a value obtained by dividing the number N _PL of photons generated by photoluminescence by the number _Nabs of photons absorbed by the sample.
Here, N _PL is proportional to the amount obtained by (Equation 3).

∫λ ・ I (λ) dλ ――― (Formula 3)
At this time, the integration interval is limited to the wavelength range of photons generated from the sample by photoluminescence. This is because the contribution of photons reflected from the sample is removed from I (λ). Specifically, the lower limit of the integration of (Expression 3) is the upper end of the integration of (Expression 1), and the upper limit is a range suitable for including a photoluminescence-derived spectrum. FIG. 17 shows an example of I (λ). In this case, 420 nm to 520 nm may be taken as the integration range in (Expression 3). Thus, η _i = (Expression 3) / (Expression 2) is obtained. It should be noted that the integration from the spectrum that has become digital data is the same as the case where α _q is obtained.

In general, increasing the quantum absorption efficiency α _q itself leads to an increase in the number of photons of the excitation light source incorporated into the sample, so that there is an expectation that the emission luminance will increase. However, in practice, if the increase of α _q is attempted, for example, by increasing the concentration of Eu or the like, which is the emission center, the energy is transferred to the sample crystal before the photon reaches the final photoluminescence process. The probability of switching to phonon excitation increased, and sufficient light emission intensity could not be obtained. However, when the wavelength of the excitation light source is particularly selected from 350 to 415 nm and a phosphor having a high quantum absorption efficiency α _q is used as the second light emitter of the light emitting device, the non-photoluminescence process is suppressed, and a high emission intensity is obtained. It has been found that a light emitting device is realized. Also here, in addition to alpha _q is high, by combining a second light emitter which the value of α _q · η _i is used a high phosphor, the first light emitter having a wavelength of 350-415Nm, It has also been found that a light emitting device having more favorable characteristics can be obtained.

  As long as the above conditions (A) and / or (B) are satisfied, the material constituting the phosphor is not particularly limited, but preferably has a crystal phase and has a chemical composition represented by the following general formula [1]. It is more preferable to select from those having a phase (hereinafter sometimes abbreviated as a crystal phase of the general formula [1]). Note that the phosphor may contain other components, for example, a light scattering material, in a range that does not impair the performance. Therefore, the ratio of the crystalline phase contained in the phosphor is preferably 10 wt% or more, preferably Is 50 wt% or more, more preferably 80 wt% or more.

_{Eu a Sr b M 5-ab} (PO 4) c X d ······ [1]
However, M represents metal elements other than Eu and Sr. X represents a monovalent anionic group other than PO ₄ . c and d are numbers satisfying 2.7 ≦ c ≦ 3.3 and 0.9 ≦ d ≦ 1.1. a is a number such that a> 0, b is b ≧ 0, and a + b ≦ 5, and satisfies the condition of a ≧ 0.1 or b ≧ 3.

  The second light emitter is a novel light emitting device of the present invention containing the phosphor of the general formula [1], and has a light emission intensity superior to that of the conventional light emitting device. However, the second luminous body containing the phosphor satisfying the condition (A) and / or (B) is preferable among the phosphors of the general formula [1] as the phosphor contained therein. It tends to be obtained by selecting. Hereinafter, the phosphor of the general formula [1] will be described. The element M in the formula [1] represents a metal element other than Eu and Sr. Regarding the element M, it is preferable that the ratio of the total of Ba, Mg, Ca, Zn, and Mn to the element M is 70 mol% or more from the viewpoint of light emission intensity and the like, and among these, the total of Ba, Mg, and Ca The proportion of element M is preferably 70 mol% or more, more preferably 90 mol% or more of the total of elements M of Ba, Mg, and Ca, and all of element M is Ba, Mg, Ca. It is more preferable to use at least one element selected from the group consisting of Zn, Zn, and Mn, and it is most preferable that all of the elements M be at least one element selected from the group consisting of Ba, Mg, and Ca.

When a metal element other than the above is included in the crystal as a metal element in element M, the metal element is not particularly limited, but contains the same valence as Sr or these five metal elements, that is, a divalent metal element. In this case, the crystal structure is easily retained, which is desirable. A monovalent, trivalent, tetravalent, pentavalent, or hexavalent metal element is used to help crystallization of the composite oxide by diffusion in the solid during the firing of the divalent metal element and the luminescent center Eu ^2+. A small amount may be introduced. And one _{example, Sr 5 (PO 4) 3} Cl: part of Sr ²⁺ of Eu phosphor equimolar Li ⁺ and Ga ³⁺ can be substituted while retaining the charge compensation effect . A small amount of a metal element that can be a sensitizer may be substituted.

The metal element M is not contained, that is, the value of a + b can be set to 5.
X in the general formula [1] is a monovalent group other than PO ₄ . With respect to X, from the viewpoint of light emission intensity and the like, 50 mol% or more of X is preferably a halogen atom, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. Examples of the halogen atom include Cl, F, Br and the like, and Cl is preferred. When 50 mol% or more of X is a halogen atom, X may contain a hydroxyl group or the like as the remaining anionic group. In the most preferred embodiment, 50 mol% or more, particularly 70 mol% or more, more preferably 90 mol% or more of the anionic group X is Cl. In this case, examples of the remaining group include other halogen atoms and OH groups.

The molar ratio b of Sr in the general formula [1] is b ≧ 0, preferably b> 0, specifically 0 ≦ b <5, preferably 0 <b <5, and usually 0. 0.01 or more, preferably 0.1 or more, more preferably 0.2 or more, but most preferably 3 or more, particularly 4 or more from the viewpoint of light emission intensity. In general, a crystal phase having a basic composition of (Sr, Ba, Ca) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ can take a wide range of molar ratios of Sr. By adopting a relatively large numerical value with b <5 as the upper limit, a remarkably high light emission intensity can be obtained. On the other hand, when the molar ratio of Sr is small, that is, by making the value of b a small value, particularly 0, it is preferable because the raw material cost can be reduced, and in particular, Ca is preferably 50 mol% or more. Even in this case, a relatively high emission intensity can be obtained.

The Eu molar ratio a in the general formula [1] is 0 <a <5, usually 0.0001 or more, preferably 0.001 or more, more preferably 0.005 or more. In general, a ≧ 0.1, preferably a ≧ 0.2, more preferably a> 0.2, still more preferably a ≧ 0.3, and in particular, a ≧ 0.4, and even a Most preferably, ≧ 0.45. If the molar ratio a of the luminescent center ion Eu ²⁺ is too small, the luminescence intensity tends to decrease, but if the value of a is too large, the luminescence intensity tends to decrease due to a phenomenon called concentration quenching. Usually, a ≦ 4.8, preferably a ≦ 3, more preferably a ≦ 2.5, particularly preferably a ≦ 2, and most preferably a ≦ 1.5. In the general formula [1], when a> 0.2 and further a ≧ 0.3 are used, the second light emitter having a phosphor satisfying the conditions (A) and / or (B) is formed. It is particularly preferable for obtaining a light emitting device.

  In the present invention, if either a ≧ 0.1 or b ≧ 3 is satisfied, sufficient emission intensity can be obtained. Therefore, if one of a and b satisfies the above equation, the other does not necessarily satisfy the above equation. Therefore, if a preferable combination of the values of a and b is enumerated in this respect, (1) a ≧ 0.1 and b ≧ 0.01, (2) a ≧ 0.1 and b ≧ 0.1, (3) a ≧ 0.1 and b ≧ 0.2, (4) a ≧ 0.2 and b ≧ 0.01, (5) a ≧ 0.2 and b ≧ 0.1, (6) 0.0001 ≦ a, and b ≧ 3, (7) 0.001 ≦ a, and b ≧ 3, ( 8) 0.005 ≦ a and b ≧ 3, (9) 0.0001 ≦ a and b ≧ 4, (10) 0.001 ≦ a and b ≧ 4, (11) 0.005 ≦ a, And b> = 4 etc. can be mentioned. However, in the present invention, it is particularly preferable that both a ≧ 0.1 and b ≧ 3 are satisfied in that the emission intensity can be further increased. With regard to this point, preferable combinations of values a and b are listed. (1) a ≧ 0.1 and b ≧ 3, (2) a ≧ 0.1 and b ≧ 4, (3) a ≧ 0.2 and b ≧ 3, (4) a ≧ 0.2 and b ≧ 4 etc. can be mentioned. In particular, by satisfying both of a> 0.2 and b ≧ 3, the emission intensity can be further increased. In this regard, if more preferable combinations of the values of a and b are listed, (1) a > 0.2 and b ≧ 3, (2) a> 0.2 and b ≧ 4, (3) a ≧ 0.3 and b ≧ 3, (4) a ≧ 0.3 and b ≧ 4, (5 ) A ≧ 0.4 and b ≧ 3, (6) a ≧ 0.4 and b ≧ 4, (7) a ≧ 0.45 and b ≧ 3, (8) a ≧ 0.45 and b ≧ 4, etc. Can be mentioned.

In the general formula [1], c and d are 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1.
However, c is preferably 2.8 ≦ c ≦ 3.2, and more preferably 2.9.
≦ c ≦ 3.1, and d is preferably 0.93d ≦ 1.07, more preferably 0.95 ≦ d ≦ 1.05.
In the basic crystal Eu _a Sr _b M _5-ab (PO ₄ ) _c X _d of the general formula [1], even if some lattice defects occur, the fluorescence performance for this purpose is not greatly affected. Can be used in the range of b, c, d inequality.

In general, a crystal of A ₅ (PO ₄ ) ₃ Cl (A is an alkaline earth metal) has a hexagonal structure, and its space group is P6 ₃ / m.
The crystal structure in the present invention is usually the A ₅ (PO ₄ ) ₃ Cl structure shown above. FIG. 1 shows an X-ray diffraction pattern of a typical Sr ₅ (PO ₄ ) ₃ Cl (from a powder X-ray diffraction database). The Sr site of Sr ₅ (PO ₄ ) ₃ Cl can be substituted with a divalent metal such as Ba, Mg, Ca, Zn and Mn in a wide composition range. Further, if the amount is small, metals having different valences such as Na and La can be substituted. The Cl site can be substituted with anionic species such as F, Br, and OH, and the structure is maintained. In the present invention, among these substitution products, a substitution product using Sr as a normal cation species is used as a base material, and further, it corresponds to a crystal phase in which Eu ²⁺ is substituted at the cation site as an activator.

The phosphor used in the present invention is excited by light of 350 to 415 nm from the first light emitter, and generates visible light. The phosphor generates visible light having a very strong emission intensity by excitation of light of 350 to 415 nm.
The phosphor used in the present invention includes an M source, an X source, a PO ₄ source compound, a Sr source compound, and a luminescent center ion (Eu) element source compound as shown in the general formula [1]. , After pulverizing using a dry pulverizer such as a hammer mill, roll mill, ball mill, jet mill, etc., and then mixing with a blender such as a ribbon blender, V-type blender, Henschel mixer, etc. Use dry method to pulverize, or add these compounds in a medium such as water and pulverize and mix them using a wet pulverizer such as a medium agitating pulverizer, or use a dry pulverizer to remove these compounds. After the pulverization, the prepared pulverized mixture is heated and fired by a wet method in which a slurry prepared by adding and mixing in a medium such as water is spray-dried or the like. Ri can be produced.

  Among these pulverization and mixing methods, in particular, in the element source compound of the luminescent center ion, it is preferable to use a liquid medium because it is necessary to uniformly mix and disperse a small amount of the compound over the whole. The latter wet method is preferable from the viewpoint of obtaining uniform mixing in the element source compound as a whole, and the heat treatment method is usually 700 to 1500 ° C. in a heat-resistant container such as alumina or quartz crucible or tray. The heating is preferably performed at a temperature of 900 to 1300 ° C. for 10 minutes to 24 hours in a single or mixed atmosphere of a gas such as air, oxygen, carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon. 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 carbon monoxide, nitrogen, hydrogen, and argon is preferable, but it can be selected even under an oxidizing atmosphere such as air and oxygen. .
Here, as the compounds of M source, X source, Sr source, and Eu source, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates of M, X, Sr, and Eu, Examples of the PO ₄ source compound include hydrogen phosphates such as element M and NH ₄ , phosphates, metaphosphates, pyrophosphates, P ₂ O ₅ , and PX _3. , PX ₅ , M ₂ PO ₄ X, phosphoric acid, metaphosphoric acid, pyrophosphoric acid, etc., and examples of the X source compound include MX, NH ₄ X, HX, M ₂ PO ₄ X, etc. Among them, the chemical composition, reactivity, and non-generation of NO _x , SO _x, etc. during firing are selected.

SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , Sr (OCO) ₂ .H ₂ O, SrO, Sr (OH) ₂ .8H ₂ O, Sr (OCO) ₂ .H ₂ O, Sr (OCOC
H ₃ ) ₂ · 0.5H ₂ O, SrCl _{2 and the} like.
Specific examples of compounds for synthesis raw materials of Ba, Mg, Ca, Zn, or Mn in the metal element group M include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , B
a (NO ₃ ) ₂ , BaSO ₄ , Ba (OCO) ₂ .2H ₂ O, Ba (OCOCH ₃ ) ₂ , BaC
l ₂ etc., and Mg source compounds include MgO, Mg (OH) ₂ , MgCO ₃ , Mg (OH
₂ ) 3MgCO ₃ .3H ₂ O, Mg (NO ₃ ) ₂ .6H ₂ O, Mg (OCO) ₂ .2H ₂ O, Mg (OCOCH ₃ ) ₂ .4H ₂ O, MgCl _2, etc. Source compounds include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, Ca (OCO) ₂ .H ₂ O, Ca (
OCOCH ₃ ) ₂ .H ₂ O, CaCl _2, etc., and Zn source compounds include ZnO, Zn (OH) ₂ , ZnCO ₃ , Zn (NO ₃ ) ₂ .6H ₂ O, Zn (OCO) ₂ , Zn (OCOCH ₃ ) ₂ , ZnCl _{2 and the} like, and as the Mn source compound, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , MnOOH, 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 Eu ₂ O ₃ , Eu (OCOCH ₃ ) ₃ .4H ₂ O, EuCl ₃ .6H ₂ O, Eu ₂ (OCO) 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 415 nm. Preferably, a light emitter that generates light having a peak wavelength in the wavelength range of 350 to 415 nm is used. Specific examples of the first light emitter include a light emitting diode (LED) or a laser diode (LD). A laser diode is more preferable because it consumes less power. Of these, GaN LEDs and LDs using GaN compound semiconductors are preferred. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. 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. GaN-based LEDs and LDs preferably have an Al _x Ga _y N light emitting layer, a GaN light emitting layer, or an In _x Ga _y N light emitting layer. Among GaN-based LEDs, those having an In _X Ga _Y N light-emitting layer are particularly preferred because the emission intensity is very strong, and in GaN-based LDs, the multiple quantum of the In _X Ga _Y N layer and the GaN layer is preferred. A well structure is particularly preferable because the emission intensity is very strong. In the above, the value of X + Y is usually 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 made of n-type and p-type Al _X Ga _Y N layers, GaN layers, or In _X. Those having a heterostructure sandwiched between Ga _Y N layers and the like have high luminous efficiency, and those having a heterostructure having a quantum well structure have higher luminous efficiency and are more preferable.

  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 well By devising, the light emission in the surface direction can be made stronger than the edge direction of the light emitting layer. Compared with the type that emits light from the edge of the light emitting layer by using a surface emitting type, the light emission cross-sectional area per unit light emission amount can be increased. As a result, the phosphor constituting the second light emitting body is irradiated with the light. In this case, the irradiation area can be greatly increased with the same amount of light, and the irradiation efficiency can be improved, so that more intense light emission can be obtained from the phosphor.

  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. 2 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. 2, 1 denotes a film-like second light emitter having the phosphor, 2 denotes a surface-emitting GaN-based LD as the first light emitter, and 3 denotes 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 The second light emitter may be formed (molded) on 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 light emitter and the light from the second light emitter are usually directed in all directions, but when the phosphor powder used as the second light emitter is dispersed in the resin, the light is resin A part of the light is reflected when going out of the room, so that the direction of 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. As the phosphor powder, those having an average particle diameter of about 0.5 to 15 μm are usually used. Since the light of the first illuminant can be used effectively, the average particle size is preferably 0.8 to 5 μm, more preferably 0.8 to 2 μm. 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 resins that can be used in this case include epoxy resins, polyvinyl resins, polyethylene resins, polypropylene resins, polyester resins, and the like. From the viewpoint of good dispersibility of the phosphor powder, epoxy resins are preferable. It is. When the phosphor powder is dispersed in the resin, the weight ratio of the phosphor powder to the entire resin is usually 10 to 95%, preferably 20 to 90%, more preferably 30 to 80%. . If there are too many phosphors, luminous efficiency may decrease due to powder aggregation,
If the amount is too small, the luminous efficiency may be lowered due to light absorption or scattering by the resin.

  In the light-emitting device of the present invention, light extracted from the light-emitting device can be made white by mixing light from the first light-emitting body and light from the second light-emitting body. At this time, in addition to the phosphor of the present invention as the second light emitter, other phosphors, for example, blue, green, and red phosphors can be combined to make white as necessary. Moreover, you may use a color filter etc. as needed. By making the extracted light white light, the color rendering property of the object irradiated by the light emitting device is enhanced. This is particularly important when the light emitting device is applied to lighting applications.

  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 415 nm, and the phosphor absorbs light of 350 to 415 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. 3 shows a first light emitter (350-41).
FIG. 5 is a schematic cross-sectional view showing an embodiment of a light emitting device having a 5 nm light emitter and a second light emitter; 4 is a light emitting device, 5 is a mount lead, 6 is an inner lead, and 7 is a first light emitter. (350-415 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. 3, 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. (350-415 nm phosphor) 7 is a phosphor-containing resin formed as a second phosphor by mixing and dispersing a phosphor in a binder such as an epoxy resin or an acrylic resin and pouring the mixture into a cup. It is fixed by being covered with the part 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.

  In addition, as shown in FIG. 9, the surface emitting illumination device 98 incorporating the light emitting element 1 has a large number of light emission on the bottom surface of a rectangular holding case 910 whose inner surface is light-opaque such as a white smooth surface. The device 91 is arranged with a power supply and a circuit (not shown) for driving the light emitting element 91 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 910. The diffusion plate 99 is fixed for uniform light emission.

  Then, the surface emitting illumination device 98 is driven to apply light to the first light emitter of the light emitting element 91 to emit light of 350 to 415 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. 99 is emitted upward in the drawing, and illumination light with uniform brightness is obtained within the surface of the diffusion plate 99 of the holding case 910.

  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. In addition, the relative luminescence intensity in the following Examples and Comparative Examples was expressed as a relative value with the luminescence intensity in Comparative Example 1 being 100.

Example 1
SrHPO ₄ ; 0.1055 mol, SrCO ₃ ; 0.0352 mol, SrCl ₂ ; 0.0
176 mol and Eu ₂ O ₃ ; 0.00088 mol together with pure water were pulverized and mixed in a wet ball mill of an alumina container and beads, dried, passed through a nylon mesh, and the obtained pulverized mixture was In an alumina crucible, it is fired by heating at 1200 ° C. for 2 hours under a flow of nitrogen gas containing 4% hydrogen, followed by washing with water, drying, and classification to obtain phosphor Sr _4.5 Eu _0.5 (PO ₄ ) ₃ Cl was produced. FIG. 4 shows an X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 4 is coincident in crystal structure with that of Sr ₅ (PO ₄ ) ₃ Cl in FIG. FIG. 5 shows an emission spectrum when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode. Table 1 shows the wavelength of the emission peak, the relative emission intensity, the quantum absorption efficiency α _{q of} the phosphor, and the quantum of the phosphor when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode. showed the product α _q · η _i of absorption efficiency alpha _q and internal quantum efficiency eta _i.

Example 2
Example 1 was repeated except that the raw materials were changed to SrHPO ₄ ; 0.1055 mol, SrCO ₃ ; 0.0176 mol, SrCl ₂ ; 0.0176 mol, and Eu ₂ O ₃ ; 0.0176 mol. Thus, the phosphor Sr ₄ Eu ₁ (PO ₄ ) ₃ Cl was manufactured. FIG. 6 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 6 matches the crystal structure of that of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Wavelength of the emission peak in Table 1, the relative emission intensity showed quantum absorption efficiency alpha _q of the phosphor, the product α _q · η _i of a quantum absorption efficiency alpha _q and internal quantum efficiency eta _i of the phosphor.

Example 3
Phosphor Sr _3.5 Eu _1.5 (similar to Example 1 except that the charged materials were changed to SrHPO ₄ ; 0.1055 mol, SrCl ₂ ; 0.0176 mol, and Eu ₂ O ₃ ; 0.0264 mol. PO ₄ ) ₃ Cl was produced. FIG. 7 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 7 is identical in crystal structure to that of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Wavelength of the emission peak in Table 1, the relative emission intensity showed quantum absorption efficiency alpha _q of the phosphor, the product α _q · η _i of a quantum absorption efficiency alpha _q and internal quantum efficiency eta _i of the phosphor.

Example 4
Examples were changed except that the raw materials were changed to SrHPO ₄ ; 0.0879 mol, SrCl ₂ ; 0.0176 mol, Eu ₂ O ₃ ; 0.0352, and (NH ₄ ) ₂ HPO ₄ ; 0.0176 mol. The phosphor Sr ₃ Eu ₂ (PO ₄ ) ₃ Cl was produced in the same manner as in Example 1. FIG. 8 shows an X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 8 matches the crystal structure of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Example 5
SrHPO ₄ ; 0.1055 mol, SrCO ₃ ; 0.0484 mol, SrCl ₂ ; 0.0176 mol, CaCO ₃ ; 0.00176 mol, basic magnesium carbonate (Mg mole number 0.00088 mol) , And Eu ₂ O ₃ ; phosphor Sr _4.875 Ca _0.05 Mg _0.025 Eu _0.05 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 1 except that the amount was changed to 0.0008 mol. FIG. 10 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 10 is identical in crystal structure to that of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Wavelength and relative emission intensity of the emission peak in Table 1, showing the quantum absorption efficiency alpha _q of the phosphor, the product α _q · η _i of a quantum absorption efficiency alpha _q and internal quantum efficiency eta _i of the phosphor.

Example 6
SrHPO ₄ ; 0.1055 mol, SrCO ₃ ; 0.0396 mol, BaCO ₃ ; 0.00879 mol, basic magnesium carbonate (Mg mole number 0.00264 mol), BaCl ₂ ; 0.0176 mol , And Eu ₂ O ₃ ; phosphor Sr _4.125 Ba _0.75 Mg _0.075 Eu _0.05 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 1 except that the amount was changed to 0.00088 mol. FIG. 11 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 11 is identical in crystal structure with that of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Example 7
Except that the raw materials were changed to SrHPO ₄ ; 0.0527 mol, SrCl ₂ ; 0.0176 mol, Eu ₂ O ₃ ; 0.0527, and (NH ₄ ) ₂ HPO ₄ ; 0.0527 mol. In the same manner as in Example 1, a phosphor Sr ₂ Eu ₃ (PO ₄ ) ₃ Cl was produced. FIG. 12 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 12 is identical in crystal structure to that of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Wavelength of the emission peak in Table 1, the relative emission intensity, quantum absorption efficiency alpha _q of the phosphor, the quantum absorption efficiency of the phosphor alpha _q and internal quantum efficiency eta _i
The product α _q · η _i is shown.

Example 8
The raw materials are SrCl ₂ ; 0.0176 mol, Eu ₂ O ₃ ; 0.0791, and (N
A phosphor Sr _0.5 Eu _4.5 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 1 except that H ₄ ) ₂ HPO ₄ ; FIG. 13 shows an X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 13 matches the crystal structure of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Example 9
SrHPO ₄ ; 0.1055 mol, SrCO ₃ ; 0.0302 mol, CaCO ₃ ; 0.0199 mol, basic magnesium carbonate (Mg mole number 0.00088 mol), BaCl ₂ ; 0.0176 mol , And Eu ₂ O ₃ ; phosphor Sr _3.86 Ba _0.5 Ca _0.565 Mg _0.025 Eu _0.05 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 1 except that the amount was changed to 0.00088 mol. FIG. 14 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 14 matches the crystal structure of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Example 10
SrHPO ₄ ; 0.1055 mol, SrCO ₃ ; 0.0121 mol, BaCO ₃ ; 0.0204 mol, CaCO ₃ ; 0.0176 mol, basic magnesium carbonate (Mg mole number 0.00088 mol) , BaCl ₂ ; 0.0176 mol, and Eu ₂ O ₃ ; 0.00088 mol, and the phosphor Sr _3.345 Ba _1.08 Ca _0.5 Mg _0.025 Eu _0.05 (PO ₄ ) ₃ Cl in the same manner as in Example 1. Manufactured. FIG. 15 shows the X-ray diffraction pattern of this phosphor. It can be seen that the peak pattern in FIG. 15 matches the crystal structure of Sr ₅ (PO ₄ ) ₃ Cl in FIG. The phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the emission spectrum was measured. Table 1 shows the wavelength of the emission peak and the relative emission intensity.

Example 11
Calcium chloride dihydrate; 0.01382 mol, europium chloride hexahydrate; 0.00028 mol were weighed and dissolved in 20 ml of water. To this aqueous solution, 0.00846 mol of 85% phosphoric acid as phosphoric acid was added, and the mixed solution was transferred to a magnetic dish to make the total solution amount to 30 to 40 ml. This solution was heated and dried with stirring. The dried solid was collected and pulverized in an agate mortar. A part of the pulverized product was transferred to an alumina crucible and fired at 1000 ° C. for 2 hours under a nitrogen gas flow containing 4% hydrogen to produce phosphor Ca _4.9 Eu _0.1 (PO ₄ ) ₃ Cl.

Table 1 shows the wavelength of the emission peak and the relative emission intensity when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode.
Example 12
Calcium chloride dihydrate; 0.01325 mol, europium chloride hexahydrate; 0.00055 mol were weighed and dissolved in 20 ml of water. To this aqueous solution, 0.00828 mol of 85% phosphoric acid as phosphoric acid was added, and the mixed solution was transferred to a magnetic dish to make the total solution amount to 30 to 40 ml. This solution was heated and dried with stirring. Thereafter, the phosphor Ca _4.8 Eu _0.2 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 11.

Table 1 shows the wavelength of the emission peak and the relative emission intensity when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode.
Example 13
Calcium chloride dihydrate; 0.0122 mol, europium chloride hexahydrate; 0.00106 mol were weighed and dissolved in 20 ml of water. To this aqueous solution, 0.00796 mol of 85% phosphoric acid as phosphoric acid was added, and the mixed solution was transferred to a magnetic dish to make the total solution amount to 30 to 40 ml. Further, 50 microliters of 35% hydrochloric acid aqueous solution was dropped, and the mixture was heated and dried with stirring. Thereafter, a phosphor Ca _4.6 Eu _0.4 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 11.

Table 1 shows the wavelength of the emission peak and the relative emission intensity when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode.
Example 14
Calcium chloride dihydrate; 0.0117 mol, europium chloride hexahydrate; 0.0013 mol were weighed and dissolved in 20 ml of water. To this aqueous solution, 0.0078 mol of 85% phosphoric acid as phosphoric acid was added, and the mixed solution was transferred to a magnetic dish to make the total solution volume 30-30 ml. Further, 50 microliters of 35% hydrochloric acid aqueous solution was dropped, and the mixture was heated and dried with stirring. Thereafter, the phosphor Ca _4.5 Eu _0.5 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 11.

Table 1 shows the wavelength of the emission peak and the relative emission intensity when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode.
Example 15
Calcium chloride dihydrate; 0.01054 mol, europium nitrate hexahydrate; 0.00186 mol were weighed and dissolved in 20 ml of water. To this aqueous solution, 0.00744 mol of 85% phosphoric acid as phosphoric acid was added, and the mixed solution was transferred to a magnetic dish to make the total solution amount to 30 to 40 ml. Furthermore, 100 microliters of 35% hydrochloric acid aqueous solution was dropped, and the mixture was heated and dried with stirring. Thereafter, the phosphor Ca _4.25 Eu _0.75 (PO ₄ ) ₃ Cl was produced in the same manner as in Example 11. It was found that the X-ray diffraction pattern of this phosphor coincided with the crystal structure of Ca ₅ (PO ₄ ) ₃ Cl.

Table 1 shows the wavelength of the emission peak and the relative emission intensity when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode.
Example 16
Calcium chloride dihydrate; 0.00948 mol, europium nitrate hexahydrate; 0.00237 mol were weighed and dissolved in 20 ml of water. To this aqueous solution, 0.00711 mol of 85% phosphoric acid was added as phosphoric acid, and the mixed solution was transferred to a magnetic dish to make the total solution volume 30-30 ml. Further, 150 microliters of 35% hydrochloric acid aqueous solution was dropped, and the mixture was heated and dried with stirring. Thereafter, the phosphor Ca ₄ Eu ₁ (PO ₄ ) ₃ Cl was produced in the same manner as in Example 11.

Table 1 shows the wavelength of the emission peak and the relative emission intensity when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode.
Comparative Example 1
BaCO ₃ ; 0.0103 mol, basic magnesium carbonate (0.0103 mol of Mg), and γ-Al ₂ O ₃ ; 0.0570 mol, and Eu ₂ O ₃ as the element source compound of the luminescent center ion; 0.00057 mol together with pure water was pulverized and mixed in an alumina container and a bead wet ball mill, dried, passed through a nylon mesh, and the resulting pulverized mixture was added to 4% in an alumina crucible. Baking by heating at 1500 ° C. for 2 hours under a nitrogen gas flow containing hydrogen, followed by washing with water, drying, and classification to produce a phosphor emitting blue light Ba _0.9 Eu _0.1 MgAl ₁₀ O ₁₇ did. FIG. 5 shows an emission spectrum when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode, and the performances of the blue light emitting phosphors of Example 1 and Comparative Example 1 are compared. 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 by excitation at 400 nm is 5.1 times that of the phosphor of Comparative Example 1.

Comparative Example 2
The raw materials used were SrHPO ₄ ; 0.0897 mol, BaCO ₃ ; 0.0325 mol, CaCO ₃ ; 0.0176 mol, basic magnesium carbonate (Mg mole number 0.00088 mol), BaCl ₂ ; 0.0176 mol , BaHPO ₄ ; 0.0158 mol, and Eu ₂ O ₃ ; 0.00088 mol, except that the phosphors Sr _2.55 Ba _1.875 Ca _0.5 Mg _0.025 Eu _0.05 (PO ₄ ) ₃ Cl Manufactured. Table 1 shows the wavelength and relative intensity of the emission peak when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of the GaN-based light emitting diode. FIG. 5 shows an emission spectrum when the phosphor is excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode, and the performances of the blue-emitting phosphors of Example 1 and Comparative Example 2 are compared. 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 5.1 times that of the phosphor of Comparative Example 2.

DESCRIPTION OF SYMBOLS 1; 2nd light-emitting body 2; Surface emitting GaN-type LED
3; Substrate 4; Light emitting device 5; Mount lead 6; Inner lead 7; First light emitter (light emitter of 350 to 415 nm)
8; Resin part containing phosphor in the present invention 9; Conductive wire 10; Mold member

Claims (8)

In a light emitting device having a first light emitter that generates light of 350 to 415 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter.
Said second luminous body, has a crystal phase having a chemical composition of the general formula [1], the relative emission intensity of the emission peak when excited with _{400nm, Ba 0.9 Eu 0.1 MgAl 10} O 17 A light emitting device comprising a blue light emitting phosphor of 419 or more, with 100 being 100.
_{Eu a Sr b M 5-ab} (PO 4) c X d ······ [1]
(In the above general formula [1], M represents at least one element selected from the group consisting of Ba, Mg and Ca. X is a monovalent anionic group other than PO ₄ , and 70 mol% or more thereof. C and d are numbers satisfying 2.7 ≦ c ≦ 3.3 and 0.9 ≦ d ≦ 1.1, and a and b are 0.5 ≦ a ≦. 1.5, b ≧ 3, and a + b ≦ 5.) 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 1, wherein X is Cl. First light emitter, formed by a GaN-based compound semiconductor light emitting device according to any one of claims 1 to 3. The light-emitting device according to claim 1, wherein the first light emitter is a surface-emitting GaN-based laser diode. The light emitting device according to any one of claims 1 to 5, wherein the second light emitter has a film shape. The light-emitting device according to claim 6, wherein the light- emitting surface of the first light-emitting body is in direct contact with the film surface of the second light-emitting body. The light emitting device according to any one of claims 1 to 7, wherein the second light emitter is obtained by dispersing phosphor powder in a resin.

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