Phosphor, method for producing the same and light emission device using the same

The present invention relates to a fluorescent substance that is efficiently excited and emits light by ultraviolet rays or visible light, and a light emitting device using the fluorescent substance. This phosphor is particularly suitable for red emission.

A light emitting element such as a nitride compound semiconductor capable of efficiently emitting ultraviolet rays or visible light and a phosphor that is efficiently excited by ultraviolet rays or visible light to emit light are combined to emit light emitting diodes having various emission wavelengths (hereinafter referred to as light emitting diodes). Also called LED) is being developed. Currently, as a phosphor whose application to such applications is being considered, the emission color is blue (Sr, Ca, Ba).₁₀(PO₄)₆Cl₂: Eu, green 3 (Ba, Mg, Mn) O 8Al₂O₃: Eu, red Y₂O₂S: Eu is disclosed (see Patent Document 1). Many emission colors can be produced by mixing these three color phosphors in an arbitrary ratio, but in the case of a white system, the red component Y₂O₂Since the luminous efficiency of the S: Eu phosphor is considerably lower than that of other phosphors, there is a problem that the mixing ratio becomes large. Furthermore, in the white system, white can be obtained by the emission balance of red, green, and blue, but since the emission efficiency of the red component is poor, the amount of emission of the green and blue phosphors must be suppressed to a low level, resulting in high brightness. White color was not obtained.

Further, a phosphor that is excited by long-wavelength ultraviolet rays or near-ultraviolet rays in a wavelength range of 300 to 410 nm and emits light is expected to be mixed with a light emitting screen, for example, concrete or glass, and used for a decorative plate or an indirect lighting fixture. However, in order to fully exert the effect, a phosphor having a higher emission brightness is required.

<patcit num="1"><text>JP-A-2002-203991</text></patcit>

<p> An object of the present invention is to solve the above-mentioned problems, and to provide a phosphor that is efficiently excited by ultraviolet rays or visible light and suitable for emitting red light, and a light emitting device using the same.</p>

<p> As a result of diligent studies to achieve the above object, the present inventor has a general formula of Eu._2-xLn_xM₃O₁₂Fluorescent material represented by (where 0 x &lt;2, Ln in the composition is at least one selected from Y, La and Gd, and M is at least one selected from W and Mo. ) However, it has been newly found that the red emission intensity by ultraviolet rays or visible light excitation in the wavelength range of 220 to 550 nm is high, and a light emitting device such as a light emitting diode using this red light emitting phosphor has excellent light emitting characteristics. It came to be completed.</p><p> That is, the phosphor of the present invention comprises the inventions of the following items.</p><p>(1) The general formula is Eu_2-xLn_xM₃O₁₂A phosphor characterized by being represented by. However, 0 x &lt;2, Ln in the composition is at least one selected from Y, La and Gd, and M is at least one selected from W and Mo. (2) The phosphor according to (1) above, wherein 0 x 1.8. (3) The phosphor according to (1) or (2) above, wherein M is W. (4) The phosphor according to any one of (1) to (3) above, wherein the average particle size is 50 μm or less. (5) The phosphor according to any one of (1) to (4) above, which is characterized by emitting red light. (6) A light emitting device in which the phosphor and a light emitting element according to any one of (1) to (5) above are combined. (7) The light emitting device according to (6) above, wherein the light emitting element is a nitride semiconductor light emitting device, and the light emitting wavelength of the light emitting element is in the range of 220 nm to 550 nm. (8) A light emitting screen using the phosphor according to any one of (1) to (5) above. (9) Europium oxide or a compound that becomes europium oxide by heating, at least one of ittium oxide, lanthanum oxide, gadolinium oxide or a compound that becomes these oxides by heating, and tungsten oxide and molybdenum oxide. Alternatively, the preparation of the phosphor according to any one of (1) to (5) above, wherein a mixture with at least one of these oxide compounds is fired at 800 to 1300 ° C. Method.</p>

<p> Since the phosphor of the present invention is efficiently excited and emits light by ultraviolet rays or visible light in the wavelength range of 220 to 550 nm, it can be effectively used in a light emitting device such as a light emitting screen, a light emitting diode, or a fluorescent lamp. Furthermore, by using the phosphor of the present invention or a plurality of types of phosphors containing the phosphor of the present invention, LEDs having various emission colors can be produced, and in the case of a white LED, the color rendering property and brightness are improved. be able to.</p>

General formula Eu of the present invention_2-xLn_xM₃O₁₂(However, 0 x &lt;2, Ln in the composition is at least one selected from Y, La and Gd, and M is at least one selected from W and Mo). , Very high emission intensity can be obtained in a wide composition range.

In the phosphor of the present invention, since europium ions are luminescent ions, the emission intensity generally depends on the europium concentration, and when the europium concentration is maximum, the emission intensity is also maximum.

On the other hand, when the luminescent ion concentration is high, (i) cross-relaxation occurs between the luminescent ions due to resonance transfer, and a part of the excitation energy is lost. (ii) Excitation migration occurs due to resonance transfer between luminescent ions, which promotes the transfer and extinction of excitation to the crystal surface and non-emission center. (iii) It is known that concentration quenching occurs due to reasons such as agglomeration of luminescent ions or formation of an ion pair, which changes to a non-luminescent center or a killer (fluorescence inhibitor).

For this reason, in the phosphor of the present invention, high emission intensity can be obtained in a wide composition range of 0 x &lt;2. The emission intensity becomes even higher in the range of 0 x 1.8. In particular, a very high emission intensity can be obtained in the range of 0 x 1.5.

FIG. 1 shows the excitation spectrum for the emission of the phosphor of Example 1. From the figure, it can be seen that the excitation spectrum of this phosphor exists in the wavelength region of 220 nm to 550 nm, and the phosphor of the present invention is efficiently excited by ultraviolet rays or visible light in this wavelength region and emits red light. In addition, since it is efficiently excited even with 254 nm ultraviolet rays, it can be effectively used for ordinary fluorescent lamps.

Further, since the phosphor of the present invention is excited by long-wavelength ultraviolet rays to near-ultraviolet rays (wavelength range 300 to 410 nm) and emits light, it can be mixed with a light emitting screen, for example, concrete or glass, and used for a decorative plate or an indirect lighting fixture. This decorative plate exerts a decorative effect and an indirect lighting effect by the display effect under sunlight or a normal fluorescent lamp and the display effect under long wavelength to near ultraviolet irradiation emitted by a UV lamp.

The optimum concentration when the phosphor is dispersed in a resin or the like is affected by the type of matrix of the resin or the like used, the temperature and viscosity of the forming process, the particle shape of the phosphor, the particle size, the particle size distribution, and the like. Therefore, various distribution concentrations of the phosphor can be selected depending on the usage conditions and the like. For the purpose of controlling such distribution with good dispersibility, the average particle size of the phosphor is preferably 50 μm or less, more preferably 0.1 to 10 μm.

The phosphor of the present invention is obtained as follows. As the raw material compound, for example, when a europium compound, an yttrium compound, or a tungsten compound that forms an oxide by heating is used as the phosphor raw material, the ratio of the general formula Eu2-xYxW3O12 (however, 0 x &lt;2) is used for each compound. The compounds are weighed and mixed, or if necessary, flux is added to these phosphor raw materials and mixed to obtain a raw material mixture. This raw material mixture is filled in an alumina crucible or the like and fired in the air at 800 to 1300 ° C. for several hours. After cooling, it is dispersed and pulverized with a ball mill or the like, washed with water if necessary, and after solid-liquid separation, it is dried, crushed and classified to obtain the phosphor of the present invention.

As the phosphor raw material, the following oxides or compounds that form oxides by heating are preferably used. For example, europium compounds include europium carbonate, europium oxide, europium hydroxide and the like, yttrium compounds include yttrium carbonate, yttrium oxide and yttrium hydroxide, and lantern compounds include lanthanum carbonate, lanthanum oxide and lanthanum hydroxide as gadolinium compounds. Is preferably a compound such as gadolinium carbonate, gadrinium oxide, gadolinium hydroxide or the like, a tungsten compound such as tungsten oxide or tungsten acid, and a molybdenum compound such as molybdenum oxide or molybdic acid, or a compound thereof. In addition to the above, the phosphor and raw material of the present invention may be prepared by heating, or by a vapor phase method or a liquid phase method, using an organic metal compound containing europium, yttrium, lanthanum, gadolinium, tungsten and molybdenum. A mixture can be obtained. The flux is preferably a halide of an alkali metal, a halide of an alkaline earth metal, ammonium fluoride or the like, and is added in the range of 0.01 to 1.0 parts by weight with respect to 100 parts by weight of the phosphor raw material, for example.

Since the phosphor of the present invention is efficiently excited by ultraviolet rays or visible light of 220 nm to 550 nm, it is not only effective for fluorescent lamps, but also the phosphor and light emission spectrum of the present invention are in the wavelength range of 220 nm to 550 nm. By combining with a light emitting diode, it can be applied to LEDs of various emission colors. For example, when the phosphor of the present invention is combined with a light emitting diode that emits ultraviolet rays or near ultraviolet rays having an emission spectrum within 220 to 410 nm, an LED having a red emission color can be obtained.

Further, when the phosphor of the present invention is combined with a light emitting diode that emits visible light having an emission spectrum within 400 to 550 nm, the light emitted by the red light emitting phosphor excited by the visible light and the visible light of the light emitting diode are mixed. LEDs of various emission colors are obtained. Furthermore, LEDs of various emission colors can be produced by combining the above-mentioned light emitting diode with a plurality of types of phosphors including the phosphor of the present invention. In particular, in a white LED, the color rendering property and the brightness can be improved by using the phosphor of the present invention.

The light emitting device of the present invention is a light emitting device such as an LED or a fluorescent lamp, but here, an LED light emitting device will be described. This light emitting device is a light emitting device formed by combining the phosphor of the present invention and a semiconductor light emitting device that emits light in the wavelength range of 220 nm to 550 nm, and examples of the semiconductor light emitting device include various semiconductors such as ZnSe and GaN. The light emitting device used in the present invention has a light emitting spectrum capable of emitting light from 220 nm to 550 nm, and a gallium nitride based compound semiconductor capable of efficiently exciting the phosphor is preferably used. The light emitting device is obtained by forming a nitride compound semiconductor on a substrate by a MOCVD method, an HVPE method, or the like, and is preferably In._αAl_βGa_1-α-βN (however, 0 α, 0 β, α + β 1) is formed as a light emitting layer. Examples of the semiconductor structure include a homostructure having a MIS junction, a PIN junction, a pn junction, a heterostructure, and a double heterostructure. Various emission wavelengths can be selected depending on the material of the semiconductor layer and its mixed crystalliteness. Further, a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed on a thin film in which a quantum effect is generated can be used.

The phosphor layer provided on the light emitting element may be formed by stacking at least one or more kinds of phosphors as a single layer or a plurality of layers in a layered manner, or a plurality of phosphors may be mixed and arranged in a single layer. You may. Examples of the form in which the phosphor layer is provided on the light emitting element include a form in which a phosphor is mixed with a coating member covering the surface of the light emitting element, a form in which a phosphor is mixed with a mold member, or a form in which a coating material covering the mold member is fluorescent. Examples thereof include a form in which the body is mixed, and a form in which a translucent plate mixed with a phosphor is arranged in front of the light emitting side of the LED lamp.

Further, as for the above-mentioned phosphor, at least one or more kinds of phosphors may be added to the mold member on the light emitting element. Further, one or more phosphor layers of the above phosphor may be provided outside the light emitting diode. Examples of the form provided on the outside of the light emitting diode include a form in which the phosphor is coated in a layer on the outer surface of the mold member of the light emitting diode, or a molded body in which the phosphor is dispersed in rubber, resin, elastomer, low melting point glass or the like (for example). A form in which a cap shape is produced and the LED is covered with the cap shape, or a form in which the molded body is processed into a flat plate shape and the molded body is arranged in front of the LED can be mentioned.

2 and 3 are schematic views showing an embodiment of the light emitting device of the present invention in which a phosphor and a light emitting element are combined, FIG. 4 is a schematic view showing a white LED, and FIG. 5 is a schematic view of a light emitting screen using a phosphor. Is shown.

In the light emitting device of FIG. 2, 1 is a stem, 2 is a lead wire, 3 is a semiconductor light emitting device chip (LED), 4 is a gold wire, 5 is a coated lid made of transparent resin or low melting point glass, and 6 is a phosphor layer. is there. The semiconductor light emitting device chip (LED) 3 mounted on the stem 1 is housed in a covering lid 5 of a transparent resin or a low melting point glass, and the phosphor layer 6 is a covering lid 5 of the transparent resin or the low melting point glass. It is formed as an inner layer. The light emitted from the semiconductor light emitting device chip (LED) 3 is converted into red light by the phosphor of the present invention in the phosphor layer 6, and if necessary, mixed with light of another color to obtain light of a desired color. To.

In the light emitting device of FIG. 3, 11 is a header, 12 is a lead wire, 13 is a semiconductor light emitting device chip (LED), 14 is a gold wire, 15 is a transparent resin or low melting point glass lens, and 16 is a phosphor layer. In this light emitting device, the phosphor layer 16 directly covers the semiconductor light emitting device chip (LED) 13.

In the white LED shown in FIG. 4, 21 is a phosphor layer, 22 is a sapphire substrate, 23 is a group III nitride semiconductor layer, 24 and 25 are electrodes, 26 is a mount lead, 27 is an inner lead, and 28 is a resin mold. In this LED, the group III nitride semiconductor layer 23 is a blue or purple semiconductor LED formed on the sapphire substrate 22, and the emitted light is converted into white by the phosphor layer 21.

FIG. 5 shows a light emitting screen made of a wall 31 in which a phosphor is mixed with cement, glass, or the like, and the phosphor in the wall 31 is excited by illumination light or natural light 32 to emit light of a predetermined color.

Hereinafter, examples of the present invention will be described, but it goes without saying that the present invention is not limited to specific examples. In the following examples, the emission spectrum was measured using FP-6500 manufactured by JASCO Corporation.

[Example 1] WO as a constituent raw material for a phosphor₃68.89g of powder and Eu₂O₃24.40g of powder and Y₂O₃6.71 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 4.5 μm_1.4Y_0.6W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum (relative intensity, the same applies hereinafter) was set to 100. The excitation spectrum of this phosphor is shown in FIG.

[Example 2] WO as a constituent raw material for a phosphor₃66.40g of powder and Eu₂O₃33.60 g of the powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.8 μm₂W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 71.

[Example 3] WO as a constituent raw material for a phosphor₃67.21g of powder and Eu₂O₃30.61g of powder and Y₂O₃2.18 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 4.7 μm_1.8Y_0.2W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 91.

[Example 4] WO as a constituent raw material for a phosphor₃70.66g of powder and Eu₂O₃17.87g of powder and Y₂O₃11.47 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and EuYW with an average particle size of 5.1 μm₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 96.

[Example 5] WO as a constituent raw material for a phosphor₃72.51g of powder and Eu₂O₃11.01g of powder and Y₂O₃16.48 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu has an average particle size of 5.3 μm._0.6Y_1.4W₃O₁₂A phosphor was obtained. When the phosphor was made to emit light under excitation at 395 nm, red emission was observed, and the intensity of the emission spectrum was 83.

[Example 6] WO as a constituent raw material for a phosphor₃74.47g of powder and Eu₂O₃3.77g of powder and Y₂O₃21.76 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.8 μm_0.2Y_1.8W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 48.

[Example 7] WO as a constituent raw material for a phosphor₃66.34g of powder and Eu₂O₃30.21g of powder and Gd₂O₃3.46 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.1 μm_1.8Gd_0.2W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 89.

[Example 8] WO as a constituent raw material for a phosphor₃66.20g of powder and Eu₂O₃23.45g of powder and Gd₂O₃10.35 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.8 μm_1.4Gd_0.6W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 99.

[Example 9] WO as a constituent raw material for a phosphor₃66.07g of powder and Eu₂O₃16.71g of powder and Gd₂O₃17.21 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and EuGdW with an average particle size of 5.5 μm.₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 96.

[Example 10] WO as a constituent raw material for a phosphor₃65.94g of powder and Eu₂O₃10.01g of powder and Gd₂O₃24.06 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu has an average particle size of 5.5 μm._0.6Gd_1.4W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 83.

[Example 11] WO as a constituent raw material for a phosphor₃65.80g of powder and Eu₂O₃3.33g of powder and Gd₂O₃30.87 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.8 μm_0.2Gd_1.8W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 53.

[Example 12] WO as a constituent raw material for a phosphor₃67.58g of powder and Eu₂O₃10.26g of powder and La₂O₃22.16 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.8 μm_0.6La_1.4W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 79.

[Example 13] MoO as a constituent raw material for a phosphor₃57.89g of powder and Eu₂O₃33.03g of powder and Y₂O₃9.08 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 4.7 μm_1.4Y_0.6Mo₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 88.4.

[Example 14] WO as a constituent raw material for a phosphor₃68.89g of powder and Eu₂O₃24.40g of powder and Y₂O₃6.71 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 2.4 μm_1.4Y_0.6W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 97.

[Example 15] WO as a constituent raw material for a phosphor₃68.89g of powder and Eu₂O₃24.40g of powder and Y₂O₃6.71 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 27.8 μm._1.4Y_0.6W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 91.

[Example 16] WO as a constituent raw material for a phosphor₃68.89g of powder and Eu₂O₃24.40g of powder and Y₂O₃6.71 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 41.4 μm_1.4Y_0.6W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 87.

[Example 17] WO as a constituent raw material for a phosphor₃66.57g of powder and Eu₂O₃30.31g of powder and La₂O₃3.12 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.6 μm_1.8La_0.2W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 73.

[Example 18] WO as a constituent raw material for a phosphor₃66.90g of powder and Eu₂O₃23.70g of powder and La₂O₃9.40 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu has an average particle size of 5.5 μm._1.4La_0.6W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 81.

[Example 19] WO as a constituent raw material for a phosphor₃67.24g of powder and Eu₂O₃17.01g of powder and La₂O₃15.75 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and EuLaW with an average particle size of 5.9 μm₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 87.

[Example 20] WO as a constituent raw material for a phosphor₃67.93g of powder and Eu₂O₃3.44g of powder and La₂O₃28.64 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Eu with an average particle size of 5.8 μm_0.2La_1.8W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, red light emission was observed, and the intensity of the emission spectrum was 45.

[Example 21] When the phosphor obtained in Example 1 was made to emit light under 465 nm excitation, red light emission was observed, and the intensity of the emission spectrum was 86.1.

[Example 22] When the phosphor obtained in Example 1 was made to emit light under 256 nm excitation, red light emission was observed, and the intensity of the emission spectrum was 98.

[Comparative Example 1] WO as a constituent raw material for a phosphor₃75.49g of powder and Y₂O₃24.51 g of powder was accurately weighed and mixed uniformly using a ball mill to obtain a raw material mixture. Next, the obtained raw material mixture was placed in an alumina crucible and calcined in the air at a temperature of 1000 ° C. for 6 hours. The obtained fired product is finely crushed and classified by a ball mill, and Y has an average particle size of 6.2 μm.₂W₃O₁₂Fluorescent material was obtained. When the phosphor was made to emit light under excitation at 395 nm, the intensity of the emission spectrum was 0.

[Comparison example 2] Existing Y₂O₂When the S: Eu phosphor was emitted under 395 nm excitation, red emission was observed, and the intensity of the emission spectrum was 18.2.

[Example 23] The phosphor obtained in Example 1 was mixed with silicone rubber in an amount of 20% by mass, and this was molded into a cap shape using a heating press. When this was coated on the outside of a near-ultraviolet LED having an emission wavelength of 395 nm and emitted, red emission was observed. In addition, no change due to the phosphor was observed even after lighting for 500 hours at a temperature of 60 ° C and 90% RH.

[Example 24] The phosphor obtained in Example 1 and Sr as a blue emitting phosphor₅(PO₄)₃Cl: Eu and BaMg as a green luminescent phosphor₂Al₁₆O₂₇When: Eu and Mn were mixed with silicone rubber in the above order by 22.7% by mass, 3.8% by mass and 3.4% by mass and mounted on a 395 nm near-ultraviolet light emitting element to prepare a white LED, the average color rendering of the obtained white light was obtained. The number of evaluations was 89.

[Example 25] The phosphor obtained in Example 1 and Y as a yellow luminescent phosphor.₃Al₅O₁₂When: Ce was mixed with epoxy resin in the above order by 8.8% by mass and 17.6% by mass and mounted on a 465 nm blue light emitting device to prepare a white LED, the average color rendering index of the obtained white light was 81.

[Example 26] The phosphor obtained in Example 1 and Sr as a blue emitting phosphor₅(PO₄)₃Cl: Eu and BaMg as a green luminescent phosphor₂Al₁₆O₂₇: Eu, Mn are mixed with silicone rubber in the above order by 22.7% by mass, 3.8% by mass, and 3.4% by mass, and mounted on a 395nm near-ultraviolet light emitting device to produce a white LED and Y as a red light emitting phosphor.₂O₂S: Eu, Sr as a blue luminescent phosphor₅(PO₄)₃Cl: Eu and BaMg as a green luminescent phosphor₂Al₁₆O₂₇: Eu, Mn were mixed with silicone rubber in the above order by 45.8% by mass, 3.8% by mass, and 3.4% by mass, and compared with a white LED manufactured by mounting on a 395 nm near-ultraviolet light emitting device, as a red light emitting phosphor. Y₂O₂White light with 2.7 times the brightness was obtained as compared with the case of using S: Eu.

The phosphor of the present invention can be mixed with a light emitting screen, for example, concrete or glass, and can be used for a decorative plate, an indirect lighting fixture, or the like. Further, it can be effectively used for a light emitting device such as a light emitting diode or a fluorescent lamp.

<figref num="1">It is an excitation spectrum diagram of the phosphor of Example 1.</figref><figref num="2">It is a schematic cross-sectional view which shows one Example of the light emitting device of this invention.</figref><figref num="3">It is a schematic cross-sectional view which shows the Example of another type of the light emitting device of this invention.</figref><figref num="4">It is a schematic diagram which shows the cross-sectional structure of a white LED.</figref><figref num="5">It is a schematic diagram which shows the light emitting screen.</figref>