JP2006206892A - Fluorescent substance, method for producing the same and lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent substance using excitation light expanded from an ultraviolet region to a visual light region to enable an easily available LED to be used as an excitation light source, and emitting a wide range light of from yellow to red. <P>SOLUTION: The fluorescent substance contains gallium oxide as a parent component and europium as an activator, and further contains one or more kinds of oxides and oxysulfides of rare earth elements, one or more kinds of oxides and sulfides of alkaline earth metals, and one or more kinds of sulfur and sulfur compounds. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a phosphor that can be excited by visible light, and more particularly to a phosphor that can increase the brightness of a white LED.

  In recent years, illumination with high brightness and long life using light emitting diodes has been proposed. In addition, the great advantage of using a light emitting diode includes the possibility of energy saving. As a white light emitting diode, one is a combination of a light emitting diode chip having a peak in the blue region and a phosphor having an absorption band in that region and a light emitting peak in the yellow region. There is known a structure in which a yellow color is mixed to make a white color (for example, see Patent Document 1).

As conventional phosphors, red is Y ₂ O ₃ : Eu, Y ₂ O ₂ S: Eu, green is LaPO ₄ : Tb: Ce, ZnS: Cu, Al, and blue is BAM, that is, barium, magnesium, and aluminate. Salt, ZnS: Ag, and the like (see, for example, Patent Document 2). However, most of them emit light with high energy ultraviolet rays or electron beam excitation, and very few emit light with low energy visible light.
Among these, a material obtained by activating a sulfide of the alkaline earth elements gallium, aluminum, and indium with europium (Eu) has been proposed (see, for example, Patent Document 3 and Patent Document 4).
However, if the entire base is made of sulfide, the body color of the base may become strong, and energy that is not used for light emission may be absorbed.
Among them, YAG: Ce is used for white LEDs because it emits yellow light by blue LED excitation, but the excitation wavelength is limited to the blue region near 460 nm.
JP-A-11-31845 JP-A-8-085787 JP-T-2004-505167 JP-T-2004-505172

Conventionally, there are many phosphors that emit blue, green, yellow, orange, and red when excited by ultraviolet rays. However, those that emit light when excited with visible light are limited. Among them, the above-mentioned YAG: Ce is a phosphor capable of emitting yellow light by white light excitation and whitening. However, the excitation wavelength of YAG: Ce is limited to around 460 nm and does not have a wide excitation range, and the red component also emits little light.
An object of the present invention is to expand the excitation region from ultraviolet to near ultraviolet, and further to the vicinity of the visible light region from 400 nm to 600 nm, and to obtain red light emission of about 630 nm.
The present invention extends the excitation light range from the ultraviolet range to the visible light range of 400 to 600 nm, so that a wide range of excitation light sources can be selected and used, and the emission color is limited to the yellow range around 550 nm. However, it is an object to improve color rendering properties by changing the color to yellow, orange with red, or red near 630 nm.
That is, an object of the present invention is to provide a phosphor that emits yellow, orange, and red light when excited by visible light.
According to the present invention, for example, blue LEDs and other LEDs emitting various wavelengths can be used as the excitation light source, and warm-colored white light to which red light emission or redness is added is obtained using an easily available LED as an excitation light source. Will be able to.

The present invention has been made to solve the above problems, and includes the following inventions. That is,
(1) A phosphor containing gallium oxide as a base component and europium as an activator, comprising at least one kind of rare earth element oxide or oxysulfide, alkaline earth metal oxide or sulfide Phosphors containing one or more of them, one or more of sulfur or sulfur compounds,
(2) The phosphor according to (1), wherein the rare earth element is one or more of lanthanum, gadolinium, ytterbium, and yttrium.
(3) The phosphor according to (1) or (2), wherein a part of Ga of the gallium oxide is substituted with at least one of Al, In, Ge, and Si.
(4) The phosphor according to any one of (1) to (3), wherein the content of europium is 0.5 to 10 atoms with respect to a total of 100 atoms of gallium and rare earth elements,
(5) The phosphor according to any one of (1) to (4), wherein the content of sulfur (S) is 3 to 20% by mass,
(6) In X-ray diffraction, any one of (1) to (5) having a complex oxide peak having a d value of 2.74Å, 2.51Å, 1.64Å, and 3.07Å as a main diffraction peak The phosphor according to claim 1,
(7) The phosphor according to any one of (1) to (6), wherein an emission spectrum having a peak from a wavelength of 530 nm to a wavelength of 560 nm is obtained by excitation light having a wavelength of 300 nm to 500 nm.
(8) The phosphor according to any one of (1) to (6), wherein an emission spectrum having a peak from a wavelength of 630 nm to a wavelength of 640 nm is obtained by excitation light having a wavelength of 440 nm to 600 nm.
(9) Gallium oxide, rare earth element oxide, europium oxide, alkaline earth metal compound in molar ratio (2-4) :( 1-3) :( 0.025-0.5) :( 1 To 12), followed by heat treatment after mixing so that
(10) The method for producing a phosphor according to (9), wherein the alkali metal compound is further added at a molar ratio of 0 to 2 mol (not including 0) in the molar ratio.
(11) The method for producing a phosphor according to (9) or (10), wherein the heat treatment is performed in a reducing atmosphere,
(12) The method for producing a phosphor according to (9) or (10), wherein the heat treatment is a heat treatment in a reducing atmosphere and then a heat treatment in an inert gas atmosphere.
(13) After the heat treatment is performed in a reducing atmosphere, heat treatment is performed in an atmosphere in which hydrogen sulfide is 0 to 1 vol%, hydrogen is 0 to 2 vol%, and the balance is an inert gas (9) or (10) A method for producing the phosphor according to claim 1,
(14) The method for producing a phosphor according to any one of (11) to (13), wherein the reducing atmosphere contains hydrogen sulfide and hydrogen, and the balance is made of an inert gas.
(15) The method for producing a phosphor according to any one of (9) to (14), wherein the alkaline earth metal compound is at least one of MgO, CaO, SrO, and BaO.
(16) A phosphor manufactured by the method for manufacturing a phosphor according to any one of (9) to (15),
(17) A lamp comprising the phosphor according to (16) and a light emitting diode that emits ultraviolet to green light as a light source for exciting the phosphor,
(18) The lamp according to (17), wherein an emission wavelength of a light source for exciting the phosphor is 300 nm to 600 nm,
(19) Each of the inventions of the lamp according to (17) or (18), wherein the light emitting diode which is a light source for exciting the phosphor is made of a gallium nitride compound semiconductor.

The phosphor in a preferred embodiment of the present invention can use a wide wavelength range from 300 nm ultraviolet to 400 to 600 nm as an excitation wavelength, and can change the emission wavelength from yellow to red. And it can be used for preparation of white LED excellent in color rendering.
Thus, since it is rich in diversity, it can be used for a display, a liquid crystal backlight, a white LED, and an illumination LED.

The phosphor in a preferred embodiment of the present invention is a phosphor containing gallium oxide as a matrix component and europium as an activator, and one or more of rare earth oxides or oxysulfides, alkaline earths The phosphor contains one or more of metal oxides or sulfides and one or more of sulfur or sulfur compounds.
In a preferred embodiment of the present invention, the phosphor comprises a rare earth element oxide (R ₂ O ₃ : R is a rare earth element) and a gallium oxide (Ga ₂ O ₃ ) composite oxide, other oxides, and oxysulfides. It is a phosphor comprising, activated with divalent europium ions (Eu ⁺² ) as a luminescent agent, and extended in excitation wavelength with sulfur ions (S ⁻² ).
The phosphor in a preferred embodiment of the present invention is represented by bB.cGa ₂ O ₃ .dR ₂ O ₃ : Eu: S. Here, B is an alkaline earth metal oxide, R is a rare earth element excluding Eu, Eu is europium, S is sulfur, and the value of b: c: d is a molar ratio of (1-12) :( 2 ~ 4): (1-3).
In the phosphor according to a preferred embodiment of the present invention, a phosphor in which Ga part of Ga ₂ O ₃ which is the main matrix is replaced with an oxide of at least one of Al, In, Ge and Si can be used. . By using such an oxide, the light emission characteristics are improved. Further, it may be difficult to sinter by heat treatment at the time of manufacturing the phosphor, and it may be easy to handle the powder when the subsequent phosphor is powder processed.
As rare earth element oxides, oxides of La, Gd, Yb, and Y can be used among rare earth elements excluding Eu as a luminescent agent. In order to add red or emit red light, oxides of Y and Gd are more preferable.

As the alkaline earth metal compound, any of oxides or carbonates of Mg, Ca, Sr, and Ba can be used. Alkaline earth metal oxide B is preferably used to change the color tone of light emission. For example, CaO is most preferable for obtaining yellow light, BaO is used for obtaining yellowish light with a bluish green color, and MgO can be used for obtaining yellowish light with a greenish color.
Depending on the type and ratio of the oxide used as the base material, the wavelength of light emission can be widely changed.
Rare earth element oxysulfides, alkaline earth metal sulfides, and other sulfides formed in the phosphor manufacturing process are also used as a base material. Here, the rare earth element oxysulfide is in the form of R ₂ O ₂ S, and is an oxide of the rare earth element partially sulfided in the raw material sulfidation process.

In the phosphor of the present invention, an alkali metal compound can be added, and for example, an oxide or carbonate of Li, Na, K can be used. For example, Li ₂ O is effective in improving the green light-emitting property, but it is not necessarily an essential component and may be added according to the color development wavelength.

Europium (Eu) acts as a luminescent agent. In the phosphor according to a preferred embodiment of the present invention, a part of Eu may be substituted with one or more of Sm, Tm, Yb, and Ce rare earth elements. In the conventional oxide-based phosphor, the anion is oxygen and does not have an energy absorption band in the visible light region even when excited by ultraviolet rays. In a preferred embodiment of the present invention, in order to extend this excitation region to the visible region, europium ions or the vicinity of the ions are partially sulfided while reducing the base oxide to almost no sulfidation while reducing europium bivalently.
It is preferable that part or all of Eu, which is a luminescent agent contained in the phosphor, be divalent ions, and that it be reduced to a divalent ion by a considerable ratio to obtain a desired emission wavelength. More preferred for obtaining. By using divalent europium as the luminescent agent, it is possible to obtain light emission with broad and good color rendering as compared with the case where trivalent europium is used as the luminescent agent. By using Eu as a luminescent agent and partially sulfiding the europium ion or the vicinity of the ion, the excitation wavelength range can be expanded from the ultraviolet range to the near ultraviolet, and further to the blue portion of the visible range. It is preferable because a visible light excitation light source can be used and light emission of various colors can be obtained.
The content of Eu exhibiting such effects is preferably 0.5 to 10 atoms, more preferably 1 to 4 atoms, based on a total of 100 atoms of gallium and rare earth elements.

As described above, sulfur (S) is effective for extending the excitation range to the visible light region.
When a gas containing S in the presence of an alkaline earth oxide, rare earth oxide, or gallium oxide is flowed, alkaline earth metal having a high affinity for S and Eu in a divalent state react preferentially. In addition, it is considered that a part of the rare earth element oxide becomes an oxysulfide. Thus, by partially replacing oxygen and sulfur in the oxide around Eu, which is a luminescent agent, and partially sulfiding the light emitting part, the absorption wavelength for exciting the phosphor is lengthened to the visible region, The emission color can be changed from yellow to red.
It is confirmed by X-ray diffraction that the reaction product by this partial sulfidation treatment is a peak of a complex oxide of rare earth elements and gallium, such as d values of 2.74, 2.51, 1.64, and 3.07. Has been. However, the crystalline peak of gallium sulfide Ga ₂ S ₃ such as d value of 3.20Å, 3.00Å, 1.85Å, 2.82Å is not recognized. The content of S that brings about such a state is preferably 3 to 20 wt%, more preferably about 5 to 15 wt%. This analysis of sulfur can be measured by, for example, a carbon / sulfur analyzer (manufactured by LECO).

Thus, a composite oxide of Ga ₂ O ₃ and R ₂ O ₃ , oxides of other rare earth elements, oxysulfides, etc. are phosphors constituting the matrix, and activated with divalent europium ions, By partially sulfiding the vicinity of the europium ion with sulfur ions, the excitation wavelength range is expanded from the 300 nm ultraviolet range to the visible light range 600 nm, and light emission with a wavelength of 530 nm to 640 nm using a visible light excitation light source such as a blue LED is used. Until now.

Next, a method for producing a yellow phosphor according to a preferred embodiment of the present invention will be described.
In a preferred embodiment of the present invention, the phosphor production method comprises gallium oxide, rare earth element oxide, europium oxide, and alkaline earth metal oxide or carbonate in a molar ratio of (2-4) :( 1 3): (0.025 to 0.5): After mixing to be (1 to 12), heat treatment is performed at 800 ° C. or higher in a reducing atmosphere containing sulfur. Instead of gallium oxide, any one or more of Al ₂ O ₃ , In ₂ O ₃ , GeO ₂ , and SiO ₂ can be added.
As the alkaline earth metal oxide, any one or more of MgO, CaO, SrO, BaO or alkaline earth metal carbonates (MgCO ₃ , CaCO ₃ , SrCO ₃ , BaCO _3, etc.) 1 or more types can be used. In order to obtain white light by emitting yellow light with blue LED excitation, it is most preferable to use CaO. BaO or MgO becomes a bluish white. The preferable amount of CaO for obtaining yellow light emission is 2-4 mol in the said molar ratio.
If necessary, an alkali metal oxide such as lithium oxide (Li ₂ O) can be added in a range of 2 mol or less as a raw material.

The constituents of this phosphor are mainly composed of a composite oxide of 3R ₂ O ₃ · 5Ga ₂ O ₃ by X-ray diffraction, and other peaks such as R ₂ O ₂ S, R ₂ O ₃ , and CaGa ₂ S ₄ appear. . It should be noted that d values (3.20, 3.00, 1.85) of gallium sulfide, for example, Ga ₂ S ₃ are not recognized.
In the phosphor thus obtained, an emission spectrum having a peak wavelength from 530 nm to 560 nm can be obtained by excitation light having a wavelength from 300 nm to 500 nm.

As the sulfur source for the sulfiding treatment, any of powdered sulfur, carbon disulfide and sodium sulfide can be used, but preferably hydrogen sulfide is used. At this time, it is not necessary to make the whole base sulfide or oxysulfide, and it is preferable to perform partial sulfidation to such an extent that the crystal phase of the composite oxide of rare earth oxide and gallium oxide as the main base is not changed, For example, it is more preferable that a part of oxygen atoms existing in the vicinity of europium is replaced with sulfur atoms.
This sulfidation treatment uses a reducing gas in which hydrogen sulfide and hydrogen gas are mixed with an inert gas such as argon gas or nitrogen gas, and simultaneously performs sulfidation treatment to reduce Eu to divalent ions. Preferably it is done.
The concentration of hydrogen sulfide gas in the reduction / sulfurization treatment is 2 to 20 Vol%, preferably 5 to 10 Vol%. It is more preferable to add 0.5 to 10% by volume of hydrogen gas to the mixed gas.
In this case, the heat treatment time is 800 to 1200 ° C, preferably 900 to 1100 ° C.
The heat treatment time is preferably about 1 to 10 hours, more preferably about 1 to 5 hours.

Next, a method for producing a red phosphor according to a preferred embodiment of the present invention will be described.
In the method for producing a phosphor in a preferred embodiment of the present invention, the molar ratio of gallium oxide, rare earth oxide, europium oxide and calcium oxide is (2-4) :( 1-3) :( 0.025-0. 5): After mixing to be (2-12), heat treatment is performed at 900 ° C. or higher in a reducing atmosphere containing sulfur or a sulfur compound. In order to obtain a red-emitting phosphor, calcium oxide or calcium carbonate is preferably used as the alkaline earth metal. The amount of calcium oxide is particularly preferably 4 to 10 mol in the above molar ratio.
Next, the phosphor obtained by the above method is heat-treated in an inert gas atmosphere at a temperature of 800 to 1200 ° C., more preferably 900 to 1100 ° C. for 3 to 10 hours. Hydrogen gas may be added to the inert gas at 2 vol% or less, and hydrogen sulfide gas may be added at 1 vol% or less, or 0 to 5 vol% air may be added. If the amount of air is too large, the divalent Eu ions of the luminescent agent are oxidized to trivalent Eu ions, and the light-emitting portion that is further partially sulfided also changes to an oxide state, so that red light emission tends to be deactivated.
This heat treatment reduces the sulfur content in the phosphor, and the yellow light emission disappears. Instead, the red emission intensity at a wavelength of about 630 nm increases. The excitation wavelength of this red phosphor is 440 to 600 nm.

Constituent components of the obtained red phosphor are mainly composed of 3R ₂ O ₃ · 5Ga ₂ O ₃ complex oxide and other peaks such as R ₂ O ₂ S, R ₂ O ₃ , and CaS are revealed by X-ray diffraction. . Note sulfide gallium, for example, d values of _{Ga 2 S 3 (3.20Å, 3.00Å} , 1.85Å, 2.82Å) is not observed. From this, it is considered that the crystalline Ga ₂ S ₃ is not contained or is contained in a trace amount even if it is contained.
The phosphor thus obtained has an emission spectrum having a peak wavelength from 630 nm to 640 nm by excitation light having a wavelength from 440 nm to 600 nm.

This phosphor has the same constituent components, and the emission color can be changed from yellow, reddish yellow, and further red by adjusting the amount of calcium oxide and the gas concentration and temperature during heat treatment. Therefore, the target emission color can be obtained if the sulfurization reaction is terminated at any time in the processing conditions and processing steps suitable for the desired color tone phosphor.
Further, since the constituent components of the phosphor are the same, the color tone can be adjusted by mixing the yellow phosphor or the red phosphor at an arbitrary ratio. For example, if 5 to 20 wt% of a red phosphor is mixed with a yellow phosphor, white light with red added can be obtained. Furthermore, in order to obtain warm white light close to the white point, a mixing ratio of about 10 wt% is more preferable. In addition, since the matrix constituent components are the same, even if they are mixed, a phenomenon in which the light emission is inhibited and the light emission intensity is greatly reduced is not recognized.

Next, a light emitting device such as a lamp will be described.
In the case of forming a light-emitting device such as a lamp using the phosphor according to a preferred embodiment of the present invention, a light-emitting device can be configured by combining semiconductor light-emitting elements that emit light in a wavelength region of 300 to 600 nm. . The semiconductor light emitting device can be used without limitation as long as the emission spectrum can emit light from 250 nm to 600 nm, and for example, ZnSe or a group III nitride semiconductor can be used. Group III nitride _{semiconductor, In α Al β Ga 1-} α _{over beta} N (where, 0 ≦ α, 0 ≦ β , α + β ≦ 1) is represented by. Of these, gallium nitride compound semiconductors are preferably used from the viewpoint of efficiency. These are formed on the substrate as light emitting elements by MOCVD, HVPE, or the like. Examples of the semiconductor structure include a homostructure, a heterostructure, or a double heterostructure having a MIS junction, a PIN junction, a pn junction, or the like. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. In addition, a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed in a thin film in which a quantum effect is generated can be used.

The phosphor layer provided on the semiconductor light emitting device may be arranged in a layered manner in which at least one kind of phosphors is a single layer or a plurality of layers, or a plurality of phosphors are mixed and arranged in a single layer. You may do it. As a form of providing the phosphor layer on the light emitting element, a form in which the phosphor is mixed with a coating member that covers the surface of the light emitting element, a form in which the phosphor is mixed with the mold member, or a fluorescent substance is applied to the covering on the mold member. The form which mixes a body, Furthermore, the form which arrange | positions the translucent plate which mixed the fluorescent substance in the light emission side front of an LED lamp etc. are mentioned.
Moreover, you may add at least 1 sort (s) or more of fluorescent substance to the mold member on a light emitting element. Furthermore, you may provide the 1 or more types of fluorescent substance layer of the said fluorescent substance on the outer side of a light emitting element.
As a form provided on the outside of the light emitting element, a form in which the phosphor is applied in a layered manner on the outer surface of the mold member of the light emitting element, or a molded body in which the phosphor is dispersed in rubber, resin, elastomer, low melting point glass, etc. And a form in which the light-emitting element is coated with the light-emitting element, or a form in which the molded body is processed into a flat plate shape and disposed in front of the light-emitting element.
When the phosphor is mixed with the resin, the charging ratio of the phosphor to the resin can be, for example, in the range of 0.001% by mass to 50% by mass, but is not necessarily limited thereto. The optimum charging ratio varies depending on the efficiency of the phosphor, the particle diameter, the specific gravity, the viscosity of the resin, and the charging ratio is generally determined according to these.

Example 1
8.0 g of calcium carbonate, 22.5 g of gallium oxide, 18.0 gr of yttrium oxide, and 1.41 g of europium oxide were weighed and mixed well. This was put in an alumina crucible and subjected to sulfiding treatment at 925 ° C. for 3 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. The sulfur content in the obtained phosphor was 12 wt%. As a result of X-ray diffraction measurement, the main component coincided with d values of 3Y ₂ O ₃ · 5Ga ₂ O ₃ composite oxide: 2.74２, 3.07Å, and 2.51Å. The constituents of this phosphor are 3Y ₂ O ₃ .5Ga ₂ O ₃ , Y ₂ O ₂ S, Y ₂ O ₃ , CaGa ₂ S ₄ : Eu: S, and have a peak wavelength of about 553 nm. It was a body. This phosphor emitted yellow light by black light, near-ultraviolet LED, and blue LED excitation. The excitation-emission spectrum of this phosphor is shown in FIG. The emission spectrum of FIG. 1 shows the case where the excitation wavelength is 460 nm.

(Example 2)
8.0 g of calcium carbonate, 22.5 g of gallium oxide, 29.0 gr of gadolinium oxide, and 1.41 g of europium oxide were weighed and mixed well. This was put in an alumina crucible and subjected to sulfiding treatment at 925 ° C. for 3 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. When the obtained phosphor was confirmed by X-ray diffraction measurement, the main component coincided with the d values of the 3Gd ₂ O ₃ · 5Ga ₂ O ₃ composite oxide: 2.77Å, 3.09Å, and 2.53Å.
The constituents of this phosphor were 3Gd ₂ O ₃ .5Ga ₂ O ₃ , Gd ₂ O ₂ S, CaGa ₂ S ₄ : Eu: S, and were yellow phosphors having a peak wavelength of about 553 nm. . This phosphor emitted yellow light by black light, near-ultraviolet LED, and blue LED excitation.
Subsequently, the yellow phosphor was gently reddished. That is, the addition of hydrogen sulfide gas and hydrogen gas was stopped, and heat treatment was performed in an argon gas atmosphere at a temperature of 925 ° C. for 1 hour. By this treatment, a yellow phosphor with a main peak wavelength of 553 nm and a sub-peak wavelength of 630 nm added with redness was obtained. The excitation-emission spectrum of this phosphor is shown in FIG. The emission spectrum of FIG. 2 shows the case where the excitation wavelength is 460 nm.

(Example 3)
8.0 g of calcium carbonate, 22.5 g of gallium oxide, 29.0 gr of gadolinium oxide, and 1.41 g of europium oxide were weighed and mixed well. This was put in an alumina crucible and subjected to sulfiding treatment at 925 ° C. for 3 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. This yellow phosphor was subsequently heat treated at 950 ° C. for 3 hours in an argon gas atmosphere to obtain a red phosphor. The obtained phosphor had a sulfur content of about 5 wt%. The constituents of this phosphor were 3Gd ₂ O ₃ .5Ga ₂ O ₃ , Gd ₂ O ₂ S, and CaS: Eu: S, and were red phosphors having a peak wavelength of about 635 nm. This phosphor emitted red light when excited by a blue LED.

Example 4
24.0 g of calcium carbonate, 22.5 g of gallium oxide, 18.0 gr of yttrium oxide, and 2.82 g of europium oxide were weighed and mixed well. It was placed in an alumina crucible and subjected to sulfiding treatment at 950 ° C. for 4 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. Subsequently, heat treatment was performed at 950 ° C. for 4 hours in an argon gas atmosphere. The sulfur content in the obtained phosphor was 12 wt%. As a result of X-ray diffraction measurement, the main component coincided with d values of 3Y ₂ O ₃ · 5Ga ₂ O ₃ composite oxide: 2.74２, 3.07Å, and 2.51Å.
The constituents of this phosphor were 3Y ₂ O ₃ .5Ga ₂ O ₃ , Y ₂ O ₂ S, and CaS: Eu: S, and were red phosphors having a peak wavelength of about 630 nm. This phosphor emitted red light when excited by a blue LED.
The excitation-emission spectrum of this phosphor is shown in FIG. The emission spectrum of FIG. 3 shows the case where the excitation wavelength is 460 nm.

(Example 5)
23.6 g of strontium carbonate, 22.5 g of gallium oxide, 18.0 gr of yttrium oxide, and 1.41 g of europium oxide were weighed and mixed well. This was put in an alumina crucible and subjected to sulfiding treatment at 950 ° C. for 3 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. The obtained phosphor had an orange body color, and as a result of confirmation by X-ray diffraction measurement, the main component was d value of 3Y ₂ O ₃ · 5Ga ₂ O ₃ composite oxide: 2.74Å, 3.07Å, 2 Matched 51 Å.
This phosphor emitted yellowish yellow light when excited by near-ultraviolet LED and blue LED.
This phosphor was subsequently heat-treated at 1000 ° C. for 3 hours in an argon gas atmosphere, but the emission color did not change and no red emission was obtained. The constituents of this phosphor are represented by 3Y ₂ O ₃ .5Ga ₂ O ₃ , Y ₂ O ₂ S, SrS: Eu: S.

(Example 6)
20.2 g of magnesium carbonate, 22.5 g of gallium oxide, 18.0 gr of yttrium oxide, and 2.82 g of europium oxide were weighed and mixed well. This was put in an alumina crucible, and sulfidation treatment was performed at 925 ° C. for 3 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. The obtained phosphor showed a yellowish green color. This phosphor was subsequently heat-treated at 1000 ° C. for 3 hours in an argon gas atmosphere, but the emission color did not change and no red emission was obtained.

(Example 7)
23.7 g of barium carbonate, 11.2 g of gallium oxide, 9.0 gr of yttrium oxide, and 1.41 g of europium oxide were weighed and mixed well. This was put in an alumina crucible and subjected to sulfiding treatment at 950 ° C. for 3 hours while flowing a reducing reaction gas adjusted by adding 7 vol% of hydrogen sulfide and 5 vol% of hydrogen gas in argon gas. The obtained phosphor showed a blue-green body color. This phosphor was subsequently heat-treated at 1000 ° C. for 3 hours in an argon gas atmosphere, but the emission color did not change and no red emission was obtained.

(Example 8)
To 10.0 gr of the yellow phosphor of Example 1, 1.0 gr of the red phosphor of Example 4 was added and mixed well. When the obtained mixed phosphor was excited by a blue LED emitting 460 nm, it emitted reddish warm white light. Since the yellow and red light emitters used have almost the same constituent components, the light emission of each other is not hindered, and it has been confirmed that warm-colored white synthesized light having good color rendering properties is emitted.

  If the phosphor of the present invention is used, the industrial utility value is very large as a phosphor for white LED or illumination LED.

FIG. 3 is an excitation-emission spectrum diagram of a yellow phosphor. FIG. 3 is an excitation-emission spectrum diagram of a red addition yellow phosphor. FIG. 3 is an excitation-emission spectrum diagram of a red phosphor.

Claims (19)

  A phosphor containing gallium oxide as a base component and europium as an activator, and one or more of oxides or oxysulfides of rare earth elements, oxides or sulfides of alkaline earth metals A phosphor comprising at least one species and at least one of sulfur or a sulfur compound.   The phosphor according to claim 1, wherein the rare earth element is at least one of lanthanum, gadolinium, ytterbium, and yttrium.   3. The phosphor according to claim 1, wherein a part of Ga of the gallium oxide is substituted with at least one of Al, In, Ge, and Si.   The phosphor according to any one of claims 1 to 3, wherein a content of europium is 0.5 to 10 atoms with respect to a total of 100 atoms of gallium and rare earth elements.   The phosphor according to any one of claims 1 to 4, wherein the content of sulfur (S) is 3 to 20% by mass.   6. The X-ray diffraction has a complex oxide peak having d values of 2.74, 2.51, 1.64, and 3.07 as main diffraction peaks. The phosphor according to item 1.   The phosphor according to any one of claims 1 to 6, wherein an emission spectrum having a peak from a wavelength of 530 nm to a wavelength of 560 nm is obtained by excitation light having a wavelength of 300 nm to 500 nm.   The phosphor according to any one of claims 1 to 6, wherein an emission spectrum having a peak from a wavelength of 630 nm to a wavelength of 640 nm is obtained by excitation light having a wavelength of 440 nm to 600 nm.   Molar ratios of gallium oxide, rare earth oxide, europium oxide, and alkaline earth metal compound are (2-4) :( 1-3) :( 0.025-0.5) :( 1-12), respectively. And then heat-treating the mixture so as to obtain a phosphor.   Furthermore, the manufacturing method of the fluorescent substance of Claim 9 characterized by adding an alkali metal compound in the molar ratio of 0-2 mol (it does not contain 0) in the said molar ratio.   The method for producing a phosphor according to claim 9 or 10, wherein the heat treatment is performed in a reducing atmosphere.   The method for manufacturing a phosphor according to claim 9 or 10, wherein the heat treatment is performed in a reducing atmosphere and then in an inert gas atmosphere.   The heat treatment is performed in a reducing atmosphere, followed by heat treatment in an atmosphere containing 0 to 1 vol% hydrogen sulfide, 0 to 2 vol% hydrogen, and the balance being an inert gas. Item 11. A method for producing a phosphor according to Item 10.   The method for producing a phosphor according to any one of claims 11 to 13, wherein the reducing atmosphere contains hydrogen sulfide and hydrogen, and the balance is made of an inert gas.   The method for producing a phosphor according to any one of claims 9 to 14, wherein the alkaline earth metal compound is at least one of MgO, CaO, SrO, and BaO.   A phosphor manufactured by the phosphor manufacturing method according to any one of claims 9 to 15.   A lamp comprising: the phosphor according to claim 16; and a light emitting diode that emits ultraviolet to green light as a light source for exciting the phosphor.   The lamp according to claim 17, wherein an emission wavelength of a light source for exciting the phosphor is 300 nm to 600 nm. The lamp according to claim 17 or 18, wherein the light emitting diode as a light source for exciting the phosphor is made of a gallium nitride compound semiconductor.

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