JP2001181625A - Fluorescent material for light-emitting element excitable by vacuum ultraviolet ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluorescent material for light-emitting element excitable by vacuum ultraviolet rays such as plasma display panel having high light- emission efficiency and provide a light-emitting element excitable by vacuum ultraviolet rays and produced by using the fluorescent material. SOLUTION: The present invention relates to (1) a fluorescent material for light-emitting element excitable by vacuum ultraviolet rays and produced by adding Tb as a dopant to a compound substrate expressed by the general formula M2O2CN2 (M is one or more elements selected from La, Y and Gd), (2) a fluorescent material for light-emitting element excitable by vacuum ultraviolet rays, described in the term (1) and expressed by the general formula La2-aTbaO2 CN2 (0.003<=a<=1), (3) a fluorescent material for a light-emitting element excitable by vacuum ultraviolet rays and described in the term (1) or (2) wherein 0.5-100 mol% of La is substituted with Y, (4) a fluorescent material for a light- emitting element excitable by vacuum ultraviolet rays and described in the term (2) or (3) wherein 0.5-100 mol% of La is substituted with Gd and (5) a light-emitting element excitable by vacuum ultraviolet rays and containing the fluorescent material described in either one of the above terms (1) to (4).

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 An object of the present invention is to provide a 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]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that the general formula M ₂ O ₂ C
It has been found that a phosphor in which Tb is activated in a host crystal system of N ₂ (where M is one or more elements selected from La, Y and Gd in the composition formula) is useful. Reached.

That is, the present invention provides the following (1) to (5)
It is about. (1) General formula M ₂ O ₂ CN ₂ (where M is L
A phosphor for a vacuum ultraviolet ray excited light emitting device, characterized in that Tb is added as an activator to a compound substrate represented by one or more elements selected from a, Y and Gd). (2) In formula _{La 2-a Tb a O 2} CN 2 ( where, 0.003
.Ltoreq.a.ltoreq.1). The phosphor for a vacuum ultraviolet ray excited light emitting element as described in (1) above, wherein (3) The phosphor for a vacuum ultraviolet ray excited light emitting device according to the above (2), wherein 0.5 to 100 mol% of La is substituted with Y. (4) The phosphor for a VUV-excited light emitting device according to the above (2) or (3), wherein 0.5 to 100 mol% of La is substituted with Gd. (5) A VUV-excited light-emitting device comprising the phosphor according to any one of (1) to (4).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The phosphor for a vacuum ultraviolet ray excited light emitting device of the present invention has a general formula M ₂ O ₂ CN ₂ (where M is La, Y and G in the composition formula).
Tb is added as an activator to a compound substrate represented by one or more elements selected from d).

M ₂ O ₂ CN ₂ has a layered structure in which M ₂ O ₂ ^2- layers and CN ₂ ^2- layers are alternately stacked. When Tb is added as an activator to the compound substrate represented by M ₂ O ₂ CN ₂ to form a phosphor, quenching due to energy transfer between activators can be suppressed. It became possible to activate the concentration, and it became possible to produce a phosphor with high brightness by vacuum ultraviolet excitation.

In the case of the phosphor for a vacuum ultraviolet ray excited light emitting device of the present invention, for example, a phosphor in which Tb (Tb ³⁺ ion) is added as an activator to a compound substrate represented by La ₂ O ₂ CN ₂ , formula _{La 2-a Tb a O 2} CN 2 ( where, 0.003 ≦
A phosphor for a vacuum ultraviolet ray excited light emitting device represented by a ≦ 1) is preferable.

Further, the phosphor for a vacuum ultraviolet excitation device of the present invention can be applied to a phosphor excited by ultraviolet rays, X-rays and electron beams other than the vacuum ultraviolet region, and 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. As a raw material of lanthanum, gadolinium, and yttrium, those that can be decomposed at high temperature to become oxides, such as high-purity (99% or more) oxides, carbonates, hydroxides, halides, and nitrates 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 raw materials are mixed using a mortar, a ball mill, a V-type mixer, a stirrer, or the like, and then fired at 900 ° C. to 1100 ° C. for several hours to several tens hours to obtain a phosphor. In the case where materials such as hydroxides, carbonates, nitrates, halides, and oxalates that can be decomposed at high temperatures to become oxides are used as raw materials, the temperature must be reduced from 600 ° C. to 80 ° C. before the main firing.
It is also possible to calcine in the range of 0 ° C.

Preferably, a carbon source such as graphite is simultaneously charged during firing, and a gas having a nitrogen source such as ammonia gas is used as the firing atmosphere. Also, an appropriate amount of flux may be added to promote the firing reaction.

Further, the product obtained by the above method is pulverized 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 or a rare gas lamp, a suitable phosphor can be obtained with high light emission intensity.

[0018]

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

Example 1 In producing La _1.7 Tb _0.3 O ₂ CN ₂ , lanthanum oxide La ₂ O ₃ and terbium oxide Tb _{2 were used} as starting materials.
O ₃ was used. These raw materials were blended so that the molar ratio of La ₂ O ₃ : Tb ₂ O ₃ was 1.7: 0.3,
The mixture was thoroughly wet-mixed in a mortar and dried. The obtained mixed raw material and graphite were charged in a tubular furnace, and calcined at 970 ° C. for 30 hours in an ammonia stream (50 ml / min). Using a powder X-ray diffractometer [Rigaku Electric Co., Ltd., Geigerflex, SG-7 type], La _1.7 Tb _0.3 O ₂ CN ₂
It was confirmed that a single phase was formed. 5 × 10 ^-2 T
Excimer 1 was added to the obtained phosphor in a vacuum layer of orr or less.
Irradiation with ultraviolet rays using a 46 nm lamp (manufactured by Ushio Inc.) showed strong green light emission.

[0020]

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.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H001 CA04 CA07 XA06 XA07 XA08 XA39 XA57 XA64 YA65 5C040 GG08 MA02 MA03

Claims (5)

[Claims] 1. A compound represented by the general formula: M ₂ O ₂ CN ₂ (wherein M in the composition formula)
Is one or more elements selected from La, Y and Gd)
A phosphor for a vacuum ultraviolet ray excited light emitting device, wherein Tb is added as an activator to the compound substrate represented by the formula: 2. A general formula _{La 2-a Tb a CN 2} ( however, 0.0
3. The phosphor for a VUV-excited light emitting device according to claim 1, wherein the phosphor is represented by the following formula: 03 ≦ a ≦ 1). 3. The phosphor for a vacuum ultraviolet ray excited light emitting device according to claim 2, wherein 0.5 to 100 mol% of La is substituted with Y. 4. The phosphor for a vacuum ultraviolet ray excited light emitting device according to claim 2, wherein 0.5 to 100 mol% of La is substituted with Gd. 5. A VUV-excited light-emitting device comprising the phosphor according to claim 1.