JP2006104445A - Fluorescent substance for vacuum ultraviolet-excited light-emitting diode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent substance for vacuum ultraviolet-excited light-emitting diodes having high emission brightness. <P>SOLUTION: This fluorescent substance for vacuum ultraviolet-excited light-emitting diodes comprises a compound expressed by the formula Ca<SB>a</SB>Sr<SB>b</SB>Eu<SB>1-a-b</SB>MgSi<SB>2</SB>O<SB>6</SB>(wherein a is ≥0.4 and ≤0.7 and b is ≥0.4 and ≤0.7 and a+b is ≤0.990). In the formula, a is preferably ≥0.46 and ≤0.52 and b is preferably ≥0.46 and ≤0.52. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a phosphor. In detail, it is related with the fluorescent substance suitable for a vacuum ultraviolet ray excitation light emitting element.

Phosphors are used in vacuum ultraviolet-excited light emitting elements such as plasma display panels (hereinafter referred to as “PDP”) and rare gas lamps. For example, phosphors represented by the formula BaMgAl ₁₀ O ₁₇ : Eu and the formula CaMgSi ₂ O ₆ : Eu have been put to practical use as blue phosphors for PDP. Or it has been proposed (for example, see Non-Patent Document 1), but the luminance was not sufficient.

Therefore, the present inventors have already proposed a phosphor made of a compound represented by the formula Ca _0.9215 Sr _0.0485 Eu _0.03 MgSi ₂ O ₆ as a phosphor suitable for a vacuum ultraviolet light-excited light emitting device (see Patent Document 1). However, there has been a demand for a phosphor exhibiting higher luminance.

"IEICE Transaction on Electronics Specials on Electronic Displays", (Japan), The Institute Of Electronics, Information and Communication Engineers (E-85-C, November 2002, p. 15), The Institute of Electronics, Information and Communication Engineers. 1888-1894 JP 2002-332481 A

  The objective of this invention is providing the fluorescent substance for vacuum ultraviolet ray excitation light emitting elements which shows high brightness | luminance.

  As a result of intensive studies on the composition of the silicate phosphor to solve the above-mentioned problems, the present inventors have used a specific silicate containing a specific amount of Ca, Sr and Mg as an activator. It has been found that a phosphor containing a specific amount of Eu exhibits high luminance when used for a vacuum ultraviolet ray-excited light emitting device, and the present invention has been completed.

That is, the present invention has the formula _{Ca a Sr b Eu 1-ab} MgSi 2 O 6 ( provided that 0.7 the following range in a 0.4 or formula, b is in the range of 0.4 to 0.7 A + b ≦ 0.990)). A phosphor for a vacuum ultraviolet ray-excited light emitting device, characterized by comprising the compound represented by:

  The phosphor for a vacuum ultraviolet ray excited light emitting device of the present invention exhibits high luminance by vacuum ultraviolet ray excitation, and is therefore suitable for a vacuum ultraviolet ray excited light emitting device such as a PDP and a rare gas lamp. Is extremely useful industrially.

The phosphor of the present invention has the formula (1)
Formula _{Ca a Sr b Eu 1-ab} MgSi 2 O 6 (1)
It consists of the compound shown by these. Here, a is in the range of 0.4 to 0.7, b is in the range of 0.4 to 0.7, and a + b ≦ 0.990. When a and b are values within this range, the phosphor made of the compound represented by the formula (1) exhibits high luminance by vacuum ultraviolet excitation.

  In the formula (1), both a and b are preferably in the range of 0.46 or more and 0.52 or less, more preferably in the range of greater than 0.47 and 0.52 or less, and even more preferably a = b. On the other hand, when 0.9 <a + b ≦ 0.990, that is, when 1-ab indicating the amount of Eu as an activator is 0.010 or more and less than 0.1, the phosphor is high. It is preferable because it shows luminance. Further, when 0.98 ≦ a + b ≦ 0.990, that is, when 1-ab indicating the amount of Eu as an activator is 0.010 or more and 0.02 or less, The phosphor is more preferable because it exhibits high luminance even at a high temperature of about 100 ° C.

Next, a method for manufacturing the phosphor of the present invention will be described.
The phosphor of the present invention can be manufactured, for example, as follows. The phosphor of the present invention can be produced by firing a metal compound mixture that becomes a phosphor composed of the compound represented by the formula (1) by firing. That is, it can be manufactured by weighing the metal compound so as to have a predetermined composition, mixing, and firing. Specifically, Ca, Sr, Eu, Mg, and Si have a molar ratio of Ca: Sr: Eu: Mg: Si of a: b: (1-ab): 1: 2 (where a is 0). By firing the metal compound mixture contained so as to satisfy the following condition: b is in the range of 0.4 to 0.7, b is in the range of 0.4 to 0.7, and a + b ≦ 0.990. Can be manufactured. For example, a phosphor composed of a compound represented by the composition formula Ca _0.47 Sr _0.47 Eu _0.06 MgSi ₂ O ₆ , which is one of the preferred compositions, includes CaCO ₃ , SrCO ₃ , Eu ₂ O ₃ , MgO, and SiO ₂ as Ca: Sr. : Eu: Mg: Si can be manufactured by weighing the mixture so that the molar ratio is 0.47: 0.47: 0.06: 1: 2, mixing and firing.

  Examples of metal compounds for producing the phosphor of the present invention, that is, calcium compounds, strontium compounds, europium compounds, magnesium compounds, and silicon compounds, include, for example, high-purity (99% or more) hydroxides, carbonates, nitrates, halogens. An oxide having a high purity (purity of 99% by weight or more) that can be decomposed at a high temperature such as a chemical compound or oxalate can be used.

  Moreover, you may use the composite salt containing 2 or more types chosen from the said calcium compound, a strontium compound, a europium compound, a magnesium compound, and a silicon compound as a metal compound for manufacturing the fluorescent substance of this invention.

  For mixing these raw materials, for example, a generally industrially used apparatus such as a ball mill, a V-type mixer or a stirrer can be used.

  The metal compound mixture obtained by mixing is, for example, in the temperature range of 900 to 1500 ° C., preferably in the temperature range of 1000 ° C. to 1200 ° C., more preferably in the temperature range of 1100 ° C. to 1160 ° C. The phosphor of the present invention can be obtained by firing for a period of time, more preferably 1 to 10 hours. When starting materials such as hydroxides, carbonates, nitrates, halides, oxalates and the like that can be decomposed into oxides at high temperatures are used, the metal compound mixture is, for example, 400 ° C. or higher before firing. By holding and calcining in a temperature range lower than the firing temperature, it is possible to form an oxide or remove crystal water.

The atmosphere during firing is preferably a reducing atmosphere such as nitrogen containing 0.1 to 10% by volume of hydrogen and argon containing 0.1 to 10% by volume of hydrogen. Further, in order to fire in a stronger reducing atmosphere, an appropriate amount of carbon may be added and fired. The calcination atmosphere may be an oxidizing atmosphere such as an air atmosphere or a reducing atmosphere. Further, in order to enhance the crystallinity of the obtained phosphor, an appropriate amount of flux such as NH ₄ Cl may be contained in the metal compound mixture and fired.

  Furthermore, the phosphor obtained by the above method can be pulverized using, for example, a ball mill, a jet mill or the like. It can also be washed and classified. Moreover, in order to further improve the brightness | luminance of the fluorescent substance obtained, baking can also be performed twice or more.

  The phosphor of the present invention thus obtained is excited by vacuum ultraviolet rays having a wavelength of 200 nm or less such as 146 nm and 172 nm generated by plasma discharge such as Xe, and emits intense blue light, and is about 100 ° C. Since the phosphor of the present invention emits light with high brightness even when the temperature rises due to the operation of the vacuum ultraviolet light-emitting light emitting element, it is used for vacuum ultraviolet light excited light emitting elements such as PDPs and rare gas lamps. Is preferred.

  Here, PDP is mentioned as an example of the vacuum ultraviolet ray excitation light emitting display element using the fluorescent substance of this invention, and the manufacturing method is demonstrated. As a method for producing the PDP, for example, a known method as disclosed in JP-A-10-195428 can be used. That is, phosphors for vacuum ultraviolet light-excited light emitting elements for emitting blue, green, and red light are mixed with a binder made of a polymer compound such as a cellulose compound and polyvinyl alcohol and an organic solvent to obtain a phosphor paste. Prepare. A phosphor paste is applied to the stripe-shaped substrate surface and the partition wall surface, which are partitioned by the partition walls and provided with the address electrodes, on the inner surface of the rear substrate by a method such as screen printing, and baked in a temperature range of 300 to 600 ° C. The phosphor layer is formed. A surface glass substrate provided with a transparent electrode and a bus electrode in a direction orthogonal to the phosphor layer and provided with a dielectric layer and a protective layer on the inner surface is laminated and bonded thereto. A PDP can be manufactured by exhausting the inside and enclosing a rare gas such as low-pressure Xe or Ne to form a discharge space.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

Comparative Example 1
Calcium carbonate (manufactured by Ube Materials Co., Ltd., CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide SiO ₂ (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ) Each raw material has a molar ratio of CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ is 0 892: 0.1: 0.004: 1: 2 Weighed and mixed, and then calcined by holding at 1180 ° C. for 2 hours in N ₂ atmosphere containing ₂ % by volume of H ₂ . Firing was performed twice. Thus, the phosphor (1) comprising the compound having the composition formula Ca _0.892 Sr _0.1 Eu _0.008 MgSi ₂ O ₆ (in the formula (1), a = 0.892 and b = 0.1). Got.

This phosphor (1) was subjected to vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, model H0012) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted blue light, and the resulting luminance was set to 100. It is shown in Table 1.

This phosphor (1) was subjected to vacuum ultraviolet rays using an excimer 172 nm lamp (USHIO, H0016 type) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted blue light, and the resulting luminance was set to 100. It is shown in Table 2.

This phosphor (1) is heated to 100 ° C. in a vacuum tank of 6.7 Pa (5 × 10 ⁻² Torr) or less and irradiated with vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, model H0012). As a result, blue light was emitted, and the obtained luminance was set to 100. It is shown in Table 3.

Example 1
Calcium carbonate (manufactured by Ube Materials Co., Ltd., CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ), each raw material has a CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ molar ratio of 0.48. : 0.5: 0.01: 1: 2 Weighed and mixed, and then calcined by holding at 1100 ° C. for 2 hours in N ₂ atmosphere containing ₂ % by volume H ₂ . Firing was performed twice. Thus, the phosphor (2) comprising the compound whose composition formula is represented by Ca _0.48 Sr _0.5 Eu _0.02 MgSi ₂ O ₆ (in the formula (1), a = 0.48, b = 0.5). Got.

The phosphor (2) was subjected to vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, model H0012) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted, blue light was emitted and the relative luminance was 106, which was higher than that of Comparative Example 1. The obtained results are shown in Table 1.

This phosphor (2) was subjected to vacuum ultraviolet rays using an excimer 172 nm lamp (USHIO, H0016 type) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light, a relative luminance of 163, which was higher than that of Comparative Example 1. The obtained results are shown in Table 2.

This phosphor (2) is heated to 100 ° C. in a vacuum tank of 6.7 Pa (5 × 10 ⁻² Torr) or less and irradiated with vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corp., H0012 type). As a result, blue light was emitted and the relative luminance was 114, which was higher than that of Comparative Example 1. The obtained results are shown in Table 3.

Example 2
Calcium carbonate (manufactured by Ube Materials Co., Ltd., CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ) each raw material has a molar ratio of CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ of 0.49. : 0.49: 0.01: 1: 2 Weighed and mixed, and then calcined by holding at a temperature of 1160 ° C. for 2 hours in an N ₂ atmosphere containing ₂ % by volume of H ₂ . Firing was performed twice. Thus, the phosphor (3) comprising the compound having the composition formula Ca _0.49 Sr _0.49 Eu _0.02 MgSi ₂ O ₆ (in the formula (1), a = 0.49, b = 0.49). Got.

This phosphor (3) was subjected to vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, model H0012) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light and a relative luminance of 111, which was higher than that of Comparative Example 1. The obtained results are shown in Table 1.

This phosphor (3) was subjected to vacuum ultraviolet rays using an excimer 172 nm lamp (USHIO, H0016 type) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light, a relative luminance of 214, which was higher than that of Comparative Example 1. The obtained results are shown in Table 2.

This phosphor (3) is heated to 100 ° C. in a vacuum tank of 6.7 Pa (5 × 10 ⁻² Torr) or less, and irradiated with vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, H0012 type). As a result, blue light was emitted and the relative luminance was 129, which was higher than that of Comparative Example 1. The obtained results are shown in Table 3.

Example 3
Calcium carbonate (manufactured by Ube Materials Co., Ltd., CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ), each raw material has a CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ molar ratio of 0.48. : 0.48: 0.02: 1: 2 Weighed and mixed, and then calcined by holding at 1150 ° C. for 2 hours in N ₂ atmosphere containing ₂ % by volume H ₂ . Firing was performed twice. Thus, the phosphor (4) comprising the compound whose composition formula is represented by Ca _0.48 Sr _0.48 Eu _0.04 MgSi ₂ O ₆ (in the formula (1), a = 0.48, b = 0.48). Got.

This phosphor (4) was subjected to vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, model H0012) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light, a relative luminance of 109, which was higher than that of Comparative Example 1. The obtained results are shown in Table 1.

This phosphor (4) was subjected to vacuum ultraviolet rays using an excimer 172 nm lamp (USHIO Inc., H0016 type) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted, blue light was emitted, and the relative luminance was 199, which was higher than that of Comparative Example 1. The obtained results are shown in Table 2.

This phosphor (4) is heated to 100 ° C. in a vacuum chamber of 6.7 Pa (5 × 10 ⁻² Torr) or less and irradiated with vacuum ultraviolet rays using an excimer 146 nm lamp (Hushi type, manufactured by USHIO INC.). As a result, blue light was emitted and the relative luminance was 146, which was higher than that of Comparative Example 1. The obtained results are shown in Table 3.

Comparative Example 2
Calcium carbonate (manufactured by Ube Materials Co., Ltd., CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ) each raw material has a molar ratio of CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ of 0.592. : 0.4: 0.004: 1: 2 Weighed and mixed, and then calcined by holding at 1180 ° C. for 2 hours in N ₂ atmosphere containing ₂ % by volume H ₂ . Firing was performed twice. Thus, the phosphor (5) comprising the compound represented by the composition formula Ca _0.592 Sr _0.4 Eu _0.008 MgSi ₂ O ₆ (in the formula (1), a = 0.492 and b = 0.4). Got.

This phosphor (5) was subjected to vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, model H0012) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light, the relative luminance was 73, and the luminance was lower than that of Comparative Example 1. The obtained results are shown in Table 1.

Example 4
Calcium carbonate (manufactured by Ube Materials Co., Ltd., CaCO ₃ ), strontium carbonate (manufactured by Wako Pure Chemical Industries, Ltd., SrCO ₃ ), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., Eu ₂ O ₃ ), magnesium carbonate ( Kyowa Chemical Co., Ltd., MgCO ₃ ), silicon oxide (manufactured by Nippon Aerosil Co., Ltd., SiO ₂ ) each raw material has a molar ratio of CaCO ₃ : SrCO ₃ : Eu ₂ O ₃ : MgCO ₃ : SiO ₂ of 0.494. : 0.494: 0.006: 1: 2 Weighed and mixed, and then calcined by holding at 1150 ° C. for 2 hours in N ₂ atmosphere containing ₂ % by volume H ₂ . Firing was performed three times. Thus, the phosphor (6) comprising the compound whose composition formula is represented by Ca _0.494 Sr _0.494 Eu _0.012 MgSi ₂ O ₆ (in the formula (1), a = 0.494, b = 0.494). Got.

This phosphor (6) was subjected to vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corp., H0012 type) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light, a relative luminance of 116, which was higher than that of Comparative Example 1. The obtained results are shown in Table 1.

This phosphor (6) was subjected to vacuum ultraviolet rays using an excimer 172 nm lamp (USHIO, H0016 type) in a vacuum chamber at room temperature (about 25 ° C.) of 6.7 Pa (5 × 10 ⁻² Torr) or less. Was emitted with blue light, and the relative luminance was 193, which was higher than that of Comparative Example 1. The obtained results are shown in Table 2.

This phosphor (6) is heated to 100 ° C. in a vacuum tank of 6.7 Pa (5 × 10 ⁻² Torr) or less and irradiated with vacuum ultraviolet rays using an excimer 146 nm lamp (Hushio Corporation, H0012 type). As a result, blue light was emitted and the relative luminance was 160, which was higher than that of Comparative Example 1. The obtained results are shown in Table 3.

Claims (5)

Formula _{Ca a Sr b Eu 1-ab} MgSi 2 O 6 ( where, a formula is in the range of 0.4 to 0.7, b is in the range of 0.4 to 0.7, a + b ≦ 0.990.) A phosphor for a vacuum ultraviolet ray-excited light emitting device, characterized by comprising the compound represented by   2. The phosphor according to claim 1, wherein a is in the range of 0.46 to 0.52, and b is in the range of 0.46 to 0.52.   The phosphor according to claim 1, wherein a = b in the above formula.   A vacuum ultraviolet ray-excited light emitting device comprising the phosphor according to claim 1. Formula _{Ca a Sr b Eu 1-ab} MgSi 2 O 6 ( where, a formula is in the range of 0.4 to 0.7, b is in the range of 0.4 to 0.7, a + b ≦ 0.990)), wherein Ca, Sr, Eu, Mg and Si are mixed at a molar ratio of Ca: Sr: Eu: Mg: Si of a: b: (1-ab): 1: 2 (where a is in the range of 0.4 to 0.7, b is in the range of 0.4 to 0.7, and a + b ≦ 0.990. The method for producing a phosphor is characterized in that the metal compound mixture contained so as to satisfy the following conditions is held and fired in a reducing atmosphere in a temperature range of 1100 ° C. to 1160 ° C. for 0.3 to 100 hours: .