KR20060087301A - Low temperature synthesis method of phosphor - Google Patents

Abstract

The present invention is a phosphor containing aluminum (Al) among the elements constituting various compounds, more specifically strontium aluminate (SrAl ₂ O ₄ ) series phosphor, YAG (Yttrium Aluminum Garnet) phosphor and TAG A method of reducing the synthesis temperature of a multi-component metal oxide phosphor in which aluminum (Al) is a component of a metal oxide, such as a (Terbium Aluminum Garnet) -based phosphor, is used. By selecting preferably, the synthesis temperature of the phosphors of the phosphors can be lowered.

Therefore, the present invention preferably selects only the type of the aluminum-containing compound without affecting the various properties of the existing phosphors containing aluminum (Al), in particular the light emission characteristics, so that aluminum (Al) is a metal oxide It relates to a manufacturing method that can reduce the manufacturing cost and investment cost of the phosphor by lowering the synthesis temperature of the phosphor of some constituents.

Phosphor, aluminum-containing oxide, multicomponent metal oxide, strontium aluminate (SrAl2O4) series, YAG (Yttrium Aluminum Garnet) series, Terbium Aluminum Garnet (TAG) series, aluminum oxide (Al2O3), aluminum hydroxide (Al (OH) 3), synthesis temperature

Description

Low Temperature Synthesis of Phosphors

FIG. 1A illustrates a strontium (Sr) compound, an aluminum (Al) -containing compound, and an europium (Eu) -containing compound as an activator in order to synthesize SrAl ₂ O ₄ : Eu ^{+ 2-} based phosphors according to the present invention. After preparing a mixed powder of the present invention, a diagram showing the weight change rate (TG) according to the temperature change of the mixed powder in a reducing atmosphere containing hydrogen (H ₂ ) gas, wherein the aluminum (Al) -containing compound is amorphous- It was an aluminum oxide (amorphous-Al ₂ O ₃ ) powder.

1B is a strontium (Sr) compound, an aluminum (Al) -containing compound, and an europium (Eu) -containing compound as an activator in order to synthesize SrAl ₂ O ₄ : Eu ^{+ 2-} based phosphors according to the present invention. After preparing a mixed powder of the present invention, a diagram showing the weight change rate (TG) according to the temperature change of the mixed powder in a reducing atmosphere containing hydrogen (H ₂ ) gas, wherein the aluminum (Al) -containing compound is alpha- It was an aluminum oxide (α-Al ₂ O ₃ ) powder.

Figure 2a shows three kinds of aluminum oxide (alpha-aluminum oxide [α-Al ₂ O ₃ ], gamma-aluminum oxide [γ-Al ₂ O ₃ ], amorphous-aluminum oxide [amorphous-Al ₂ O _{3] in the present invention} ]) SrAl prepared by solid phase reaction of mixed powder of aluminum hydroxide [Al (OH) ₃ ] powder with a certain composition ratio, respectively at 800 ℃ for 3 hours in a reducing atmosphere containing hydrogen (H ₂ ) gas. ₂ O _4: Eu ⁺² is an XRD analysis result of the base phosphor.

2b shows three types of aluminum oxide (alpha-aluminum oxide [α-Al ₂ O ₃ ], gamma-aluminum oxide [γ-Al ₂ O ₃ ], amorphous-aluminum oxide [amorphous-Al ₂ O _{3] in the present invention.} ]) SrAl prepared by solid phase reaction of mixed powder of powder and aluminum hydroxide [Al (OH) ₃ ] powder at 1300 ℃ for 3 hours in a reducing atmosphere containing hydrogen (H ₂ ) gas. ₂ O _4: Eu ⁺² is an XRD analysis result of the base phosphor.

FIG. 3 shows representative excitation and emission spectra of SrAl ₂ O ₄ : Eu ⁺² -based phosphors synthesized using amorphous-Al ₂ O ₃ according to the present invention.

Figure 4 shows three kinds of aluminum oxide (alpha-aluminum oxide [α-Al ₂ O ₃ ], gamma-aluminum oxide [γ-Al ₂ O ₃ ], amorphous-aluminum oxide [amorphous-Al ₂ O _{3] in the present invention} ]) The result of measuring the afterglow intensity change according to the time variation of the phosphor prepared by solid-phase reaction of powder and aluminum hydroxide [Al (OH) ₃ ] powder with a constant composition ratio, respectively, at 1300 ° C. for 3 hours. to be.

The present invention is a phosphor containing aluminum (Al) among the elements constituting various compounds, more specifically strontium aluminate (SrAl ₂ O ₄ ) series phosphor, YAG (Yttrium Aluminum Garnet) phosphor and TAG (Terbium Aluminum Garnet) is a method of reducing the synthesis temperature of a multi-component metal oxide phosphor, such as aluminum (Al) as part of the metal oxide, such as phosphors, and more specifically, the aluminum (Al) is In the production method that can reduce the synthesis temperature of the phosphors in a range that does not affect the various properties of the phosphors, in particular the light emission characteristics by selecting only the kind of the aluminum-containing compound in the synthesis of the phosphors contained therein It is about.

Sulfide-based phosphors, which are used as phosphors for displays, lamps and phosphorescent phosphors to date, are materials doped with an activator to a host such as CaS, ZnS, CdS, ZnCdS, and the like. However, these sulfide-based phosphors are known to be difficult to further increase efficiency due to chemically unstable mother crystals. Furthermore, since the recent trend of display devices requires high quality and light weight and thinness, the conventional cathode ray is used. Sulfide-based phosphors used in CRT displays have many problems in terms of practicality, which can lead to a decrease in vacuum and performance as sulfides are decomposed in high vacuum flat panel displays and field emission displays (FEDs). However, since oxide-based phosphors are very stable in the emission energy source of ultraviolet rays or electron beams, they are used not only for conventional cathode ray tube (CRT) displays or fluorescent lamps, but also for high vacuum flat panel displays and field emission displays (FEDs). It is an excellent material that can be used as a photoluminescent material that emits bright and prolonged light in the dark for safety measures and safety when light is blocked.

In particular, the study of green long afterglow phosphors of the strontium aluminate (SrAl ₂ O ₄ ) family, which uses Europium (Eu) as an activator, was conducted by FC Palilla, AK Levine and MR Tomkus (Journal of Electrochemical Society). J. Electrochem. Soc . : SOLID STATE SCIENCE, vol. 115, p642 [1968]) and also disclosed in US Pat. Nos. 5,376,303, 5,424,006 and 5,686,022. However, according to the results of these studies, the synthesis temperature of the strontium aluminate (SrAl ₂ O ₄ ) -based phosphor is very high heating temperature of more than 1400 ℃ in the reducing atmosphere containing hydrogen (H ₂ ) gas is preferred.

Accordingly, the present invention is a phosphor containing aluminum (Al) in the elements constituting various compounds, more specifically strontium aluminate (SrAl ₂ O ₄ ) series phosphor, YAG (Yttrium Aluminum Garnet) phosphor and It is designed to lower the high temperature synthesis temperature of multi-component metal oxide phosphors in which aluminum (Al) is a component of metal oxide, such as TAG (Terbium Aluminum Garnet) series phosphor, and aluminum (Al) is a component of metal oxide Aluminum (Al) -containing compounds having different physical and chemical properties in the synthesis of multi-component metal oxide phosphors, more specifically, three kinds of aluminum oxides (alpha-aluminum oxide [α-Al ₂ O ₃ ], gamma-). aluminum oxide _{[γ-Al 2 O 3]} , an amorphous aluminum-oxide _{[amorphous-Al 2 O 3]} ) and aluminum hydroxide [Al (OH) _3] powder) only bar The straight-selected by a number of the properties of the phosphor, especially in the range that does not affect the light emission properties lower the synthesis temperature of the phosphor to the preparation method that can reduce the manufacturing cost and the investment cost of the phosphor.

DETAILED DESCRIPTION In order to achieve the above object, the present invention will be described in more detail with reference to the accompanying drawings.

A method for producing a strontium aluminate (SrAl ₂ O ₄ ) -based phosphor according to a preferred embodiment of the present invention is a strontium (Sr) compound, an aluminum (Al) -containing compound and an activator (Eu) After weighing the containing compound at a constant composition ratio, the mixture was mixed using a solvent selected from acetone and alcohol, and then dried in a high purity aluminum oxide boat at 100 to 150 ° C. in a reducing atmosphere containing hydrogen (H ₂ ) gas. It bakes at -1500 degreeC.

The composition ratios and various firing conditions of the raw materials were based on what is disclosed in US Pat. Nos. 5,376,303, 5,424,006 and 5,686,022.

However, in view of the following points, the present invention is designed to lower the synthesis temperature of the multi-component metal oxide phosphor in which aluminum (Al) is a constituent of metal oxide.

In general, aluminum oxide (Al ₂ O ₃ ) has the same chemical composition and crystal structure, physical and chemical properties of different alpha-aluminum oxide (α-Al ₂ O ₃ ) phase and gamma-aluminum oxide (γ-Al ₂ O ₃ ) phase homomorphic (dimorphism) material, and aluminum oxide also has an amorphous (amorphous) phase, depending on the powder production method, there is also an aluminum hydroxide [Al (OH) ₃ ] material.

Referring to the action during the firing according to the type of the various aluminum (Al) -containing compound as described above is as follows. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the following description, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood that.

FIG. 1A illustrates a strontium compound (SrCO ₃ ), amorphous-Al ₂ O ₃ , and an activator at a constant composition ratio in order to synthesize SrAl ₂ O ₄ : Eu ^{+ 2-} based phosphors according to the present invention. After preparing a mixed powder of the europium-containing compound (Eu ₂ O ₃ ), and shows the weight change rate (TG) according to the temperature change of the mixed powder in a reducing atmosphere containing hydrogen (H ₂ ) gas, the weight loss at about 661 ℃ begins as was correction of the most rapid weight loss at 932 ℃, which start the pyrolysis reactions SrCO ₃ is CO ₂ component in the SrCO ₃ in the vicinity of 661 ℃ of the mixed powder is discharged in gaseous form Due to weight loss.

In addition, FIG. 1B is a difference in that the aluminum (Al) -containing compound used in comparison with FIG. 1A was an alpha-aluminum oxide (α-Al ₂ O ₃ ) powder. As shown in the figure, in the case of alpha-aluminum oxide (α-Al ₂ O ₃ ), weight loss starts at about 740 ° C., which is about 80 ° C. higher than amorphous-Al ₂ O ₃ , and starts at 932 ° C. The most rapid weight loss was shown in.

Table 1 summarizes the results of the thermal analysis according to the type of aluminum (Al) -containing compounds, the thermal decomposition temperature of SrCO ₃ is different depending on the type of aluminum (Al) -containing compound in the mixed powder for SrAl ₂ O ₄ matrix crystal synthesis Particularly, in the case of the amorphous-aluminum oxide (amorphous-Al ₂ O ₃ ) added sample, the pyrolysis reaction started at the lowest temperature, and the pyrolysis reaction of SrCO ₃ occurred in the following order as a whole.

amorphous-Al ₂ O ₃ <γ-Al ₂ O ₃ <Al (OH) ₃ <α-Al ₂ O ₃

Therefore, it is possible to lower the formation temperature of the SrAl ₂ O ₄ matrix crystal by selecting only the kind of the aluminum (Al) -containing compound, and the above results were also confirmed in the XRD analysis results of FIGS. 2A and 2B. .

FIG. 3 shows representative excitation and emission spectra of SrAl ₂ O ₄ : Eu ⁺² -based phosphors synthesized using amorphous-Al ₂ O ₃ according to the present invention. The emission spectrum of 520nm (2.384eV) as the maximum emission wavelength was shown, and the excitation spectrum measured by fixing the emission wavelength at 520nm showed the maximum absorption peak of 360nm and the absorption spectrum in the wide range of 250nm to 480nm. Able to know. However, the light emission characteristics were the same regardless of the type of the aluminum (Al) -containing compound.

4 shows three kinds of aluminum oxides (alpha-aluminum oxide [α-Al ₂ O ₃ ], gamma-aluminum oxide [γ-Al ₂ O ₃ ], amorphous-aluminum oxide [amorphous-Al ₂ O _{3]) according to the present invention.} ]) Change of afterglow intensity of 520 nm emission spectrum according to time variation of phosphor prepared by solid phase reaction of powder and aluminum hydroxide [Al (OH) ₃ ] powder As a result of the measurement, the decay rate of the light emission, which is the most important characteristic of the long afterglow phosphor, was different depending on the type of the aluminum (Al) -containing compound, and in particular, even though the same firing temperature and firing time, amorphous-aluminum oxide ( When amorphous-Al ₂ O ₃ ) was used, it was possible to produce phosphors having various properties as phosphors, in particular, excellent light emission characteristics.

As described above, according to the present invention, a multi-component metal oxide phosphor in which aluminum (Al) is a part of a metal oxide, more specifically, strontium aluminate (SrAl ₂ O ₄ ) series phosphor, YAG (Yttrium Aluminum Garnet) In the synthesis of a) series phosphor and a TAG (Terbium Aluminum Garnet) series phosphor, the kind of aluminum-containing compound to be added during the manufacturing process, more specifically, amorphous-alumina (amorphous-Al ₂ O ₃ ) to select these phosphors In addition to lowering the optimal synthesis temperature, the manufacturing cost and investment cost of the phosphor can be reduced, and the existing phosphor manufacturing process as well as the advantages that the phosphors do not affect various properties, in particular, light emission characteristics, can be reduced. It can be used.

Claims (2)

In the production of various types of oxide-based phosphors used for displays, lamp phosphors and photoluminescent phosphors, An oxide-based phosphor manufacturing method, characterized in that the phosphor manufacturing temperature is lowered by selecting the type of aluminum (Al) -containing compound to be added during the manufacturing process, more specifically, amorphous-Al ₂ O ₃ . The method of claim 1, The oxide-based phosphor includes strontium aluminate (SrAl ₂ O ₄ ) -based phosphors, YAG (Yttrium Aluminum Garnet) -based phosphors, and TAG (Terbium Aluminum Garnet) -based phosphors. Multi-component metal oxide phosphor.

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