JP2001123165A - Phosphor for vacuum ultraviolet-excitable luminous element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a green light emitting phosphor for a vacuum ultraviolet- excitable element such as a plasma display panel(PDP) good in luminous sufficiency and a vacuum, ultraviolet-excitable element sing the phosphor. SOLUTION: (1) This phosphor for a vacuum ultraviolet-excitable luminous element is characterized by being represented by the general formula Gd1-aTbaAlO3 (0.003<=a<=0.5) (2) The vacuum ultraviolet-excitable luminous element is characterized as comprising the phosphor described in the above (1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor suitable for a vacuum ultraviolet ray excited light emitting device such as a plasma display panel (hereinafter referred to as "PDP") and a rare gas lamp, and a vacuum ultraviolet device using the phosphor. It is.

[0002]

2. Description of the Related Art In recent years, a vacuum ultraviolet ray excited light emitting device having a structure in which a phosphor is excited by vacuum ultraviolet light radiated by rare gas discharge has been actively developed. A typical example is the development of PDPs. Since a PDP can have a large and thin screen, a cathode ray tube (CR)
Attention has been paid to flat panel displays that can replace T). A PDP is a display element in which a large number of minute discharge spaces (hereinafter, may be abbreviated as “display cells”) are arranged in a matrix, and a discharge electrode is provided in each display cell, and an inner wall of each display cell is provided. Is coated with a phosphor. He-Xe, Ne-X
A rare gas such as e or Ar is sealed, and when a voltage is applied to the discharge electrode, discharge of the rare gas occurs in the display cell, and vacuum ultraviolet rays are emitted. The phosphor is excited by the vacuum ultraviolet rays, and emits visible light. An image is displayed by light emission of the phosphor of the display cell at a predetermined position of the display element. As the phosphor used for each display cell,
A full-color display can be performed by using phosphors that emit blue, green, and red, and applying these in a matrix.

Recently, there has been a tendency to reduce harmful mercury due to environmental problems, and a rare gas lamp that emits vacuum ultraviolet rays by discharging only a rare gas without using mercury and excites a phosphor to emit light has attracted attention. ing.

In recent years, phosphors that emit light by being excited by vacuum ultraviolet rays or the like radiated by rare gas discharge have been actively developed. For example, for PDPs, BaMgAl ₁₀ O ₁₇ : Eu is used as a blue light emitting phosphor, Zn ₂ SiO ₄ : Mn is used as a green light emitting phosphor, and (Y, Gd) BO ₃ : Eu is used as a red light emitting phosphor. I have. However, in order to improve the characteristics of a full-color PDP,
Improvements in the luminance, color purity, and life of the phosphor have been desired.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a green light emitting phosphor for a vacuum ultraviolet excitation element such as a PDP, which has good luminous efficiency, and a vacuum ultraviolet excitation element using the same.

[0006]

Under such circumstances, the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result,
The present inventors have found that a phosphor in which a Tb ³⁺ ion is activated in a host crystal system of a d-Al-O component system or a Gd-Y-Al-O component system is useful, and have completed the present invention.

That is, the present invention provides the following (1) to (4)
It is about. (1) A phosphor for a VUV-excited light emitting device, wherein Tb is added to a compound substrate made of Gd, Al, and O. (2) In formula _{Gd 1 - a Tb a AlO 3} ( provided that 0.003
.Ltoreq.a.ltoreq.0.5).
The phosphor for a vacuum ultraviolet ray excited light emitting device according to the above. (3) The phosphor for a vacuum ultraviolet ray excited light emitting device according to the above (1) or (2), wherein 0.5 to 95 mol% of Gd is substituted by Y. (4) A VUV-excited light-emitting device comprising the phosphor according to any one of (1) to (3).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The phosphor for a VUV-excited light emitting device of the present invention is G
A green light-emitting phosphor in which Tb is added as an activator to a compound base composed of d, Al, and O. In a Gd—Al—O component-based host crystal system, Tb (Tb ³⁺
If the addition of ions), General Gd ₁ - _a Tb _a AlO
₃ (however, 0.003 ≦ a ≦ 0.5) is preferably a phosphor for a vacuum ultraviolet ray excited light emitting element.

Further, the present invention relates to a case where Tb (Tb ³⁺ ion) is activated as an activator in a host crystal system of a Gd—Y—Al—O component system in which a part of Gd is substituted by yttrium (Y). And a phosphor in which 0.5 to 95 mol% of Gd is substituted by Y.

[0010] The general formula Gd ₁ - _a Tb _a in AlO ₃ Gd
In a phosphor in which a part of is replaced with Y, the composition ratio a of Tb, which is particularly effective as an activator for the phosphor, is 0.1 in terms of emission intensity.
It is preferably from 003 to 0.5.

Further, the present invention is also applicable to a phosphor for vacuum ultraviolet excitation elements which is excited by ultraviolet rays, X-rays and electron beams other than the vacuum ultraviolet region, and to an element using the same.

The method for producing (synthesizing) the phosphor according to the present invention is not particularly limited. For example, it is produced by blending the respective phosphor raw materials so as to have a predetermined component composition as described below. You. Examples of the aluminum material include high-purity (99.9% or more) α-alumina and γ-alumina, and similarly high-purity (99% or more) aluminum hydroxide, nitrate, and halide. Oxides of high purity (99% or more) or hydroxides of high purity (99% or more),
Carbonates, nitrates, halides, oxalates and the like that can be decomposed at high temperatures to form oxides can be used.

As a raw material of terbium as an activator for causing the phosphor to emit light, a high-purity (99% or more) oxide, a high-purity (99% or more) hydroxide, carbonate Salts, nitrates, halides, oxalates, and the like that can be decomposed at high temperatures to become oxides can be used.

These materials are mixed using a ball mill, a V-type mixer, or a stirrer, and then mixed at 900 ° C. to 11 ° C.
Firing at a temperature of 00 ° C. for several hours to obtain a phosphor. In the case where materials such as hydroxides, carbonates, nitrates, halides, and oxalates which can be decomposed at high temperatures and become oxides are used as raw materials, calcinate at 600 to 800 ° C. before main firing. It is also possible. The firing atmosphere at this time is not particularly limited, but is preferably an oxygen atmosphere, an air atmosphere, or the like. Also, an appropriate amount of flux may be added to promote the firing reaction.

Further, the product obtained by the above method is pulverized by using a ball mill, a jet mill or the like, and then washed, but classified if necessary. Further, in order to further enhance the crystallinity of the obtained phosphor, re-firing is performed as necessary.

According to the invention described above, when used in a vacuum ultraviolet ray excited light emitting device such as a PDP and a rare gas lamp, a suitable phosphor can be obtained with high luminous intensity.

[0017]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0018] Example 1 gadolinium oxide (Gd ₂ O ₃₎ 3.64g, aluminum nitrate nonahydrate _{[Al (NO 3) 3 ·} 9H 2 O] 7.92
g, terbium oxide (Tb ₂ O ₃ ) 0.19 g of each phosphor material was mixed, and nitric acid was added and dissolved by stirring to obtain a nitric acid aqueous solution of the phosphor material. The obtained aqueous nitric acid solution was heated and evaporated to dryness to obtain a mixed nitrate of Gd, Tb and Al.
The obtained mixed nitrate was filled in an alumina boat and calcined in air at a temperature of 1000 ° C. for 24 hours. Thus, a green light-emitting phosphor represented by a composition formula of Gd _0.95 Tb _0.05 AlO ₃ was obtained. When this phosphor was excited by, for example, a 147 nm emission line emitted by discharge in a He-Xe mixed gas, it emitted green light with high luminance.

[0019]

According to the present invention, when used in a vacuum ultraviolet ray excited light emitting device such as a PDP and a rare gas lamp, a high emission intensity, a suitable phosphor can be obtained, and a high brightness vacuum ultraviolet excited light emitting device can be realized. It is extremely useful industrially.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Susumu Miyazaki 6 Kitahara, Tsukuba-shi, Ibaraki Sumitomo Chemical Co., Ltd. F-term (reference) 4H001 CA07 XA08 XA13 XA39 XA64 XA65 YA65

Claims (4)

[Claims] 1. A compound substrate comprising Gd, Al, O
A phosphor for a VUV-excited light-emitting device, characterized by being added with: 2. A general formula _{Gd 1 - a Tb a AlO 3} ( where, 0.
3. The phosphor for a VUV-excited light-emitting device according to claim 1, wherein: 3. The phosphor for a vacuum ultraviolet ray excited light emitting device according to claim 1, wherein 0.5 to 95 mol% of Gd is substituted by Y. 4. A VUV-excited light emitting device comprising the phosphor according to claim 1.