JP4614083B2 - Indium and / or gallium-containing oxides - Google Patents

Description

  The present invention relates to an oxide containing In and / or Ga having characteristic fluorescence characteristics.

Indium or gallium is used in a red light emitting phosphor having a composition of (Ga, In, Y) ₂ O ₃ : Eu (Patent Document 1: Japanese Patent Publication No. 61-44117), La ₂ O ₂ S: Eu, A Tb-activated rare earth metaborate phosphor having an effect of improving temperature characteristics by adding 1000 ppm or less as In ₂ O ₃ to the phosphor represented by Sm (Patent Document 2: Japanese Patent Laid-Open No. 2003-160785). By replacing up to about 30 atomic% of the rare earth element, the luminance of light emission by vacuum ultraviolet excitation is improved (Patent Document 3: Japanese Patent Laid-Open No. 2003-201475) or blue activated by divalent Eu. Addition of a trace amount to the luminescent aluminate and silicate phosphors has the effect of suppressing deterioration (Patent Document 4: JP 2003-342564 A, Patent Document 5: JP 2005). JP), etc. 8764, it has been used in the phosphor. However, most of the examples of the response to photoexcitation, especially the fluorescence characteristics, of systems in which only indium or gallium is added without lanthanoid elements such as europium, terbium and cerium, and luminescent elements such as manganese are added. Absent.

Japanese Examined Patent Publication No. 61-44117 JP 2003-160785 A JP 2003-201475 A JP 2003-342564 A Japanese Patent Laid-Open No. 2005-8764

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an indium and / or gallium-containing oxide that emits fluorescence in the near ultraviolet to blue wavelength region when excited by light in the vacuum ultraviolet region. .

  As a result of intensive studies to achieve the above object, the present inventor is an oxide containing Al, Si, P or B, and further containing In and / or Ga having a wavelength of 200 nm or less. When excited with vacuum ultraviolet light, it emits light in the near ultraviolet to blue wavelength region of 280 to 450 nm, and is found to be useful as a phosphor used in ultraviolet light-emitting devices such as black light, and has led to the present invention. .

That is, the present invention is an oxide containing Y and P, B or Al, or Mg and Al or Si as main elements, further containing In, and constituting elements excluding oxygen in the oxide Among them, In is 0.05 atomic% or more and 10 atomic% or less, 89 atomic% or more is composed of the main element, and when excited by vacuum ultraviolet light having a wavelength of 200 nm or less, near ultraviolet to blue of 280 to 450 nm. together emits light in a wavelength region, the peak wavelength of the emission energy is provided an oxide, wherein the near-ultraviolet region near Rukoto of 300-380 nm.

  The oxide of the present invention efficiently exhibits fluorescence in the near ultraviolet to blue region having a wavelength of 280 to 450 nm when excited with light in the vacuum ultraviolet region such as 147 nm of resonance line emission of xenon atom, and is free of mercury such as black light. In combination with phosphors that emit visible light when excited by near-ultraviolet light, they can be used in a wide range of applications such as illumination, display, and monitoring of vacuum ultraviolet light.

  The oxide according to the present invention emits light in the near ultraviolet to blue region having a wavelength of 280 to 450 nm, particularly in the near ultraviolet region where the peak wavelength of the emission energy is 300 to 380 nm when excited by vacuum ultraviolet light having a wavelength of 200 nm or less. Oxide containing one or more elements selected from Al, Si, P, and B, and further containing In and / or Ga (oxyacid salt) Or composite oxide).

In the indium and / or gallium-containing oxide of the present invention, the crystal phase identified by X-ray diffraction is YPO ₄ (mineral name xenotime), YBO ₃ , Y ₃ Al ₅ O ₁₂ (common name YAG), MgAl ₂ O _4. It is preferably an oxide obtained by adding and activating indium and / or gallium to a mother crystal such as (mineral name spinel) or Mg ₂ SiO ₄ (mineral name forsterite). In this case, it is considered that indium and / or gallium can be dissolved in the mother crystal to a considerable amount.

  In the present invention, as an element added to the mother crystal, among indium and gallium, indium is more preferable because it has better fluorescence emission efficiency.

  In the oxide of the present invention, in addition to O, Al, Si, P, B, Y, Lu, Gd, Mg, and In, Ga, alkali metals, alkaline earth metals, Ge, F, Cl, S, and the like are included. Although it can be contained, if the amount increases, there is a possibility that the phase that is different from the phase that contributes to fluorescence by dissolving In or Ga increases, or the transparency to ultraviolet light is impaired and the fluorescence emission efficiency may be lowered. Because there is, it is not preferable. Therefore, among the constituent elements excluding O, 89 atomic% or more is composed of one or more elements selected from Al, Si, P, B, Y, Lu, Gd, and Mg (provided that at least one element is selected) Is preferably Al, Si, P or B), more preferably 93 atomic% or more. The upper limit of this ratio is not particularly limited, and all except for indium and / or gallium may be composed of the above element group.

  The activation amount of indium and / or gallium, particularly indium, is preferably 0.05 atomic% or more, more preferably 0.1 atomic% or more, and more preferably 10 atomic% among all the constituent elements excluding O. The following is preferable, and more preferably 7 atomic% or less. If the content of indium and / or gallium is too small, fluorescence may be weakened, and if it is too much, there is no advantage, and another phase that does not emit solid light and does not emit light may be formed. Considering a certain thing, it is not preferable.

  In this case, the oxygen content can usually be a content corresponding to the valence of the metal.

Next, a method for producing the oxide (oxyacid salt or composite oxide) of the present invention will be described.
The production method of the present invention is not particularly limited, but as a raw material, each element constituting the oxide of the present invention, that is, an oxide or hydroxide containing each element such as Al, Si, Y, Mg, In, and Ga Further, ammonium phosphate, boric acid, ammonium borate, phosphoric acid powder or liquid is mixed, and the mixture is preferably 900 ° C. or higher and 1800 ° C. or lower, more preferably 1000 ° C. or higher and 1500 ° C. In the following, the method of heating and reacting preferably under the conditions of 30 minutes or more and 24 hours or less, more preferably 1 hour or more and 8 hours or less, is the most general, has a wide range of applications, and can be suitably employed. If the reaction temperature and time are below the above range, the reaction may not occur sufficiently, and if it exceeds the above range, not only is it uneconomical, but the whole reaction product is sintered and a powder sample is obtained. May require a large amount of energy.

  As an example, it may be effective without problems to use a material obtained by reacting some of the elements constituting the present invention in advance, such as using yttrium phosphate.

  Each raw material is preferably weighed and mixed according to the target composition. However, the P and B raw materials may be weighed and mixed slightly more than the target composition in some cases. In this case, a range up to 1.5 times the target composition is appropriate.

  The method for mixing the powders is not particularly limited, and can be performed using a mortar, a fluid mixer, an inclined rotary mixer, or the like.

  The above reaction can be carried out in an inert gas atmosphere such as nitrogen or argon, or any atmosphere in the air, but the air is preferable in terms of simplicity.

  After performing the above reaction, the reaction product is recovered, and if necessary, pulverized and mixed to obtain the target composite oxide.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following example.

[Example 1]
65.3 g of industrial 75% phosphoric acid (containing 0.5 mol of H ₃ PO ₄ ) and 4650 cm ^{3 of} pure water were placed in a 5 liter beaker and stirred while heating to 70-80 ° C. in a water bath. To this, an aqueous solution of YCl ₃ (Y concentration 0.833 mol / dm ³ , volume 300 cm ³ ) was poured while stirring. After further stirring for 10 minutes, the precipitate was filtered off with a Buchner funnel, then washed with water, recovered, and calcined at 900 ° C. in the atmosphere. As a result, YPO ₄ was obtained.
8.91 g of YPO ₄ , 0.208 g of indium oxide (In ₂ O ₃ ) (rare metallic 4N product), and diammonium hydrogen phosphate (reagent special grade (NH ₄ ) ₂ HPO ₄ , Wako Pure Chemical Industries, Ltd.) (Product made) 0.198 g was mixed in an automatic mortar, placed in an alumina crucible, heated to 1200 ° C. in an electric furnace in an air atmosphere, kept for 3 hours, and then cooled. The obtained sample was pulverized with a mortar to form powder. The composition obtained from the result of taking a part of this sample and performing ICP emission spectroscopic analysis by decomposing it with an acid is Y 47.5 atomic%, In 1.5 atomic, assuming that all elements other than oxygen are 100%. %, P 51.0 atomic%.

[Example 2]
Magnesium oxide (MgO) (500A, manufactured by Ube Materials Co., Ltd.) 2.02g, aluminum oxide (Daiming Chemical's Tymicron TM-DA) 5.00g, and indium oxide 0.278g were mixed in an automatic mortar, and alumina It was put in a crucible, heated to 1250 ° C. in an electric furnace in an atmospheric atmosphere, kept for 3 hours, and then cooled. The obtained sample was pulverized with a mortar to form powder. The compositions determined in the same manner as in Example 1 were Mg 33.3 atomic%, Al 65.4 atomic%, and In 1.3 atomic%.

[Example 3]
Yttrium oxide (Y ₂ O ₃ , 4N-UU product manufactured by Shin-Etsu Chemical Co., Ltd.) 6.44 g, aluminum oxide 5.10 g, indium oxide 0.416 g, and barium fluoride (reagent special grade BaF ₂ , Wako Pure Chemical Industries, Ltd.) 0.701 g (manufactured by Co., Ltd.) was mixed in an automatic mortar, placed in an alumina crucible, heated to 1500 ° C. in an electric furnace in an air atmosphere, cooled for 3 hours and then cooled. The obtained sample was pulverized with a mortar to form powder. The composition obtained in the same manner as in Example 1 was Y 34.8 atomic%, Al 61.0 atomic%, In 1.8 atomic%, Ba 2.2 atomic%, and F 0.2 atomic%.

[Example 4]
3.79 g of magnesium oxide, 0.416 g of indium oxide, lithium fluoride (reagent special grade LiF, manufactured by Wako Pure Chemical Industries, Ltd.) 0.117 g, and silicon oxide (SiO ₂ ) (1-FX, manufactured by Tatsumori) 3.01 g was mixed in an automatic mortar, placed in an alumina crucible, heated to 1200 ° C. in an electric furnace in an air atmosphere, kept for 4 hours, and then cooled. The obtained sample was pulverized with a mortar to form powder. The composition obtained in the same manner as in Example 1 was Mg 62.7 atomic%, Si 33.3 atomic%, In 2.0 atomic%, Li 1.8 atomic%, and F 0.2 atomic%.

[Example 5]
10.84 g of yttrium oxide, 0.555 g of indium oxide, and 6.80 g of boric acid (special grade H ₃ BO ₃ , manufactured by Wako Pure Chemical Industries, Ltd.) are mixed in an automatic mortar, placed in an alumina crucible, and air atmosphere It was heated to 1120 ° C. in a furnace, kept for 3 hours and then cooled. The obtained sample was pulverized with a mortar to form powder. The composition determined in the same manner as in Example 1 was Y 47.3 atomic%, In 2.0 atomic%, and B 50.7 atomic%.

[Comparative Example 1]
9.19 g of YPO ₄ obtained in the intermediate stage of Example 1 was put in an alumina crucible, heated to 1200 ° C. in an electric furnace in an air atmosphere, kept for 3 hours, and then cooled. The obtained sample was pulverized with a mortar to form powder. The compositions determined in the same manner as in Example 1 were Y 49.0 atomic% and P 51.0 atomic%.

[Comparative Example 2]
A powder sample was obtained in the same manner as in Example 2 except that indium oxide was not used and the amount of aluminum oxide used was 5.10 g. The compositions determined in the same manner as in Example 1 were Mg 33.3 atomic% and Al 66.7 atomic%.

[Measurement of fluorescence characteristics]
About each sample of Examples 1-5 and Comparative Examples 1 and 2, the fluorescence spectrum when excited by light of 147 nm was measured using a vacuum ultraviolet absorption / fluorescence measuring device manufactured by Spectrometer Co., Ltd. The samples of Comparative Examples 1 and 2 that did not contain indium did not show the level of fluorescence required for observation. For Examples 1 to 5, the fluorescence excitation spectrum at the fluorescence peak at 147 nm excitation was also measured. The results are shown in Table 1.
Furthermore, as an example of the spectrum, the excitation spectrum at the sample emission peak of Example 1 and the emission spectrum when excited at the peak of the excitation spectrum are shown in FIG. Here, the excitation spectrum is for emission of 339.8 nm, and the emission spectrum is when excited by light of 161.8 nm. In addition, the level | step difference seen in the place of 390 nm in FIG. 1 appears inevitably for switching of a spectroscopy system, and is considered not to be an actual light emission peak.

注：１）実施例１を１００として規格化。
２）発光強度がピークの半分になるピーク両側の波長の差。
３）励起ピークで励起時の発光強度／１４７ｎｍで励起時の発光強度

Note: 1) Normalized with Example 1 as 100.
2) The difference in wavelength on both sides of the peak where the emission intensity is half the peak.
3) Emission intensity at excitation at the excitation peak / Emission intensity at excitation at 147 nm

2 is a fluorescence spectrum of the sample of Example 1. FIG.

Claims (1)

The main element is an oxide containing Y and P, B or Al, or Mg and Al or Si, and further contains In. Among the constituent elements excluding oxygen in the oxide, In is 0. .05 atomic% or more and 10 atomic% or less, and 89 atomic% or more is composed of the main element and emits light in the near ultraviolet to blue wavelength region of 280 to 450 nm when excited by vacuum ultraviolet light having a wavelength of 200 nm or less. with exhibits, oxides peak wavelength of the emission energy is characterized near ultraviolet region near Rukoto of 300-380 nm.

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