KR102048678B1 - Oxide phosphor, preparing mehtod thereof and light emitting diode comprising the oxide phosphor - Google Patents

Abstract

The present invention relates to an oxide-based phosphor represented by the following formula (1-4), a manufacturing method thereof and a light emitting diode device using the same.
[Formula 1]
Sr ₃ WO ₆ : xMn ^{4 +}
[Formula 2]
Ba ₃ WO ₆ : x Mn ^{4 +}
[Formula 3]
^{_{Sr 3 WO 6: xMn 4 +}} , yZn 2 +
[Formula 4]
Ba ₃ WO ₆ : xMn ^{4 +,} yZn ^{2 +}
(In the above, 0.001 <x <0.2 and 0 <y <2.)

Description

OXIDE PHOSPHOR, PREPARING MEHTOD THEREOF AND LIGHT EMITTING DIODE COMPRISING THE OXIDE PHOSPHOR}

The present invention relates to an oxide-based phosphor represented by the following formula (1-4), a manufacturing method thereof and a light emitting diode (hereinafter abbreviated as "LED") device using the same.

[Formula 1]

Sr ₃ WO ₆ : xMn ^{4 +}

[Formula 2]

Ba ₃ WO ₆ : x Mn ^{4 +}

[Formula 3]

_{^{Sr 3 WO 6: xMn 4 +}} , yZn 2 +

[Formula 4]

Ba ₃ WO ₆ : xMn ^{4 +,} yZn ^{2 +}

(In the above, 0.001 <x <0.2 and 0 <y <2.)

Phosphors serve as a medium for converting the energy of the excitation source into the energy of visible light, and are essential for realizing the image of various display devices, and at the same time, the efficiency of the phosphor is directly related to the efficiency of the display product.

Currently, a method of realizing white light is to mix a blue light and yellow light by applying a yellow phosphor having blue light as an excitation light source to a GaN LED device emitting blue light in a wavelength region of 465 nm. However, it is pointed out that the color rendering of the color is degraded due to the lack of light in the red region. This drawback is fatal in the display field. Therefore, alternatively, a method of realizing white light including all three primary colors of light by applying green and red phosphors instead of yellow light has been proposed. In order to realize this method, development of a red phosphor with high light efficiency is required. Therefore, the present inventors newly invented a red phosphor that absorbs blue light and exhibits red light.

Most phosphors have a disadvantage that they are difficult to apply to displays or white LEDs due to their wide color emission and high color contamination. The reason why the light emission width is widened is due to the overlap of lattice vibration and transition. When the energy level in the excited state and the energy level in the ground state are shifted according to the lattice vibration, the emission wavelength band spreads and the wavelength width becomes wider. In addition, the splitting of the active ion energy level according to the crystal field has the same effect as the emission wavelength range is increased due to the overlap of transitions. To overcome this problem, it is reasonable to select a new luminescent phosphor in the direction of selecting a solid crystal structure capable of suppressing lattice vibrations and replacing ions with ions having a coordination environment where the energy level of electrons is small. can do. Therefore, we focused on finding a structure that meets the above mentioned conditions using ICSD (Inorganic Crystal Structure Database), and thus double perovskite type structure having the formula of M ₃ WO ₆ (divalent cation such as M = Sr, Ba, Zn). I was able to find out.

An object of the present invention is to provide a red oxide-based phosphor having an excitation source in a 300-550 nm wavelength region.

In order to achieve the above object, the present invention provides an oxide-based phosphor comprising at least one of the above formulas (1) to (4) that have not been utilized previously.

[Formula 1]

Sr ₃ WO ₆ : xMn ^{4 +}

[Formula 2]

Ba ₃ WO ₆ : x Mn ^{4 +}

[Formula 3]

_{^{Sr 3 WO 6: xMn 4 +}} , yZn 2 +

[Formula 4]

Ba ₃ WO ₆ : xMn ^{4 +,} yZn ^{2 +}

(In the above, 0.001 <x <0.2 and 0 <y <2.)

In the oxide-based phosphor of the present invention, Mn ions are substituted for W ion sites, which are the central elements of the phosphor, thereby activating fluorescent properties. At this time, Mn has a range of 0.001 to 0.2 molar concentration.

The oxide phosphor of the present invention is a red phosphor that emits visible light of 680 to 700 nm with a wavelength range of 300 to 550 nm as an excitation source.

The present invention also provides a method for producing the oxide-based phosphor.

Ions containing alkaline earth metals (Sr, Ba); Zn ions; W ions; Quantifying and mixing a metal salt containing Mn ions; And

Heat treating the mixed raw material salt at 500 to 1400 ° C. for 5 to 12 hours.

Specifically, the heat treatment of the mixed raw material salt at 500 ~ 1400 ℃ 5-12 hours,

The mixed raw material salt is heat treated at 500 to 700 ° C. for 5 to 12 hours, and then calcined at 1000 to 1400 ° C. for 5 to 24 hours, or

The mixed raw salt can be carried out by firing for 5 to 24 hours in the 800 ~ 1400 ℃ range.

In addition, the present invention provides a light emitting diode including the oxide-based phosphor described above.

The oxide-based phosphor of the present invention can provide an oxide-based red phosphor useful for a white LED device by emitting red light of 680-700 nm using the 300-550 nm wavelength region as an excitation source.

In addition, the present invention can be utilized in a white LED device having excellent color purity and excellent color rendering properties by using the oxide-based red phosphor of the present invention in a conventional method of implementing white.

Figure 1 shows the crystal structure of Sr ₃ WO ₆ , the figure on the right shows a light emitting mechanism.
Figure 2 shows the XRD results for the results of Example 1, Mn concentration from below corresponds to 0.2, 0.4, 0.5, 0.8, 1.0 mol%, respectively.
FIG. 3 shows the fluorescence spectrum of the results of Example 1, before 650 nm shows a fluorescence excitation spectrum emitting 694 nm fluorescence, and after 650 nm is a fluorescence spectrum obtained by excitation at 334 nm.
Figure 4 is a graph showing the maximum fluorescence intensity according to Mn concentration for Example 1.
Figure 5 shows the XRD pattern for the result of Example 2, it shows when doped ZnO by 0, 1.0, 0.6, 0.75 compared to tungsten from below.
Figure 6 shows the fluorescence excitation spectrum of the fluorescent light emitting 694nm before 650nm for the result of Example 2, after 650nm is a fluorescence spectrum obtained by excitation at 334nm.
FIG. 7 is a photograph of Example 2 in daylight and under UV lamp. FIG.

The present invention provides an oxide-based phosphor comprising at least one of the following formulas (1) to (4).

[Formula 1]

Sr ₃ WO ₆ : xMn ⁴⁺

[Formula 2]

Ba ₃ WO ₆ : xMn ⁴⁺

[Formula 3]

Sr ₃ WO ₆ : xMn ^4+, yZn ²⁺

[Formula 4]

Ba ₃ WO ₆ : xMn ^4+, yZn ²⁺

(In the above, 0.001 <x <0.2 and 0 <y <2.)

Oxide-based phosphors according to the present invention includes a case of the phosphor represented by the structure of any one of the above formulas (1) to (4). In some cases, a mixture of two or more of the components represented by the above formula (1) is also included.

When considering the size and charge, and the fluorescent spectrum of the ions, the ions of Mn ^{+ 4} is estimated that it contacts with W ⁶⁺ place. The structure is shown in FIG.

M ₃ WO ₆ has the same structure as double perovskite, and the unit cell is composed of monoclinic system. As shown on the left side of FIG. 1, the WO ₆ octahedral structure is independently located inside the unit cell, and a divalent cation is located around the octahedron.

Recently, the research to develop new phosphors are reported by doping Mn ^{4 +} W ⁶⁺ in place. We predicted that if Mn ^{4 +} could be doped to a highly symmetrical W ⁶⁺ site, the orbital behavior along the Tanabe-Sugano diagram could be observed. The advantage of this case is that the energy level that contributes to the red colored light emission of Mn ^{+ 4} does not substantially affect the field around the ligand. Therefore, although three types of W are found crystallographically in the Sr ₃ WO 6 structure, their emission wavelengths will almost coincide, so that the emission wavelengths can be prevented from being extended by overlapping the emission wavelengths. That the selected light on the basis of these predictions were the experiment, the increase and decrease doped Zn ^{2 +} ions in the (sensitizer) to absorb visible light as shown in Fig. 1 to the right was investigated by the performance of the phosphor.

PXRD (powder X-ray diffraction) taken after synthesizing Sr ₃ WO ₆ : Mn ^{4 +} having Mn concentrations of 0.2, 0.4, 0.5, 0.8, and 1.0 mol% as in Example 1 is shown in FIG. 2. Since all five XRD patterns show the same shape, it can be confirmed that Mn was successfully doped. The result of investigating the fluorescence property is shown in FIG. Data before 650 nm is photoluminescence excitation spectrum (PLE) and data after it is photoluminescence spectrum (PL). According to FIG. 3, Sr ₃ WO ₆ : Mn ^{4 +} has absorption bands of 335 nm and 480 nm, that is, absorbs UV and blue light regions, and emits light of 694 nm magenta region. Maximum emission intensity according to Mn concentration is shown in FIG. 4. As a result, it can be seen that Mn concentration is the most efficient at 0.5 mol%.

The Mn concentration was fixed at 0.5 mol%, and Zn, a sensitizer, was added to carry out synthesis as in Example 2. XRD for this is shown in Figure 5, when Zn is added, it can be seen that other than the Sr ₃ WO ₆ phase is formed, this phase was found to be SrZnO ₂ . SrZnO ₂ fluoresces blue light when Mn is doped, and thus does not significantly affect red light implementation, which is an object of the present invention. It can be seen that the effect of Zn as a sensitizer is very large, referring to FIG. It is adjusted to absorb green light strongly. In addition, it can be seen that the emission intensity is about 2 to 2.5 times stronger even at the same Mn ⁴⁺ concentration. Thus it can be seen that Zn acted as a very good sensitizer in Sr ₃ WO ₆ .

The present invention provides a method of manufacturing the oxide-based phosphor described above.

In one example, the manufacturing method according to the present invention,

Alkaline earth metal ions; Zn ions; Quantifying and mixing a metal salt containing W ions; And

Heat treating the mixed raw material salt at 500 to 1400 ° C. for 5 to 12 hours.

Specifically, the step of heat treatment the mixed raw material salt at 500 ~ 1400 ℃ 5-12 hours,

The mixed raw material salt is heat treated at 500 to 700 ° C. for 5 to 12 hours, and then calcined at 1100 to 1400 ° C. for 5 to 24 hours.

In addition, a mixture containing Mn ions in the mixed raw salt is contained at a molar concentration of 0.001 to 0.2.

The shape of the alkaline earth metal capable of forming the oxide of the embodiment of the present invention at this stage is not particularly limited, but acetates, nitrates, hydroxides, oxides, carbonates, etc., in which residues remain after the reaction, are suitable, but in terms of cost It is more preferable to use carbonate in terms of purity. The shape of the tungsten to form an oxide of an embodiment of the present invention preferably is not particularly restricted but the use of WO _3. Oxide, carbonate, etc. can be used in order to add manganese which is a light emission center ion. Since it synthesize | combines at high temperature in air, the oxidation number of manganese does not need to consider especially. The shape of zinc used as a sensitizer can be used halides such as chlorides, nitrates, oxides, and the like, and more preferably, oxides that do not dissolve at the reaction temperature with other samples.

The present invention also provides a light emitting diode device comprising the oxide-based phosphor described above. For example, the light emitting diode device is a white light emitting diode device.

Hereinafter, the present invention will be described in more detail with reference to Examples.

EXAMPLE

SrCO ₃ , WO ₃ , MnCO ₃ were quantified and mixed well with a mortar. Pellets were prepared to allow the reaction to proceed well and placed in an alumina crucible. This crucible was placed in an electric furnace and heat treated at a temperature of 1100 to 1300 ° C. for 6 hours to obtain Sr ₃ WO ₆ : Mn ^{4 +} phosphor.

2. SrCO ₃ , ZnO, WO ₃ , MnCO ₃ was quantified and mixed well with a mortar. Pellets were made to allow the reaction to proceed well and placed in an alumina crucible. Place the crucible in an electric furnace, heat treatment for 6 hours at a temperature of 1100 ~ 1300 ℃ to ^{_{Sr 3 WO 6: Zn 2 +}} , Mn 4 + to obtain a phosphor.

Claims (11)

An oxide-based phosphor containing at least one of the following Chemical Formulas 1 to 4:
[Formula 1]
Sr ₃ WO ₆ : xMn ⁴⁺
[Formula 2]
Ba ₃ WO ₆ : xMn ⁴⁺
[Formula 3]
Sr ₃ WO ₆ : xMn ^4+, yZn ²⁺
[Formula 4]
Ba ₃ WO ₆ : xMn ^4+, yZn ²⁺
(In the above, 0.001 <x <0.2 and 0 <y <2.)
The method of claim 1, wherein the oxide phosphor is an oxide phosphor, characterized in that the structure of Formula 1:
[Formula 1]
Sr ₃ WO ₆ : xMn ⁴⁺
(In the range 0.001 <x <0.2).
The method of claim 1, wherein the oxide phosphor is an oxide phosphor, characterized in that the structure of Formula 2:
[Formula 2]
Ba ₃ WO ₆ : xMn ⁴⁺
(In the range 0.001 <x <0.2).
The method of claim 1, wherein the oxide phosphor is an oxide phosphor, characterized in that the structure of Formula 3:
[Formula 3]
Sr ₃ WO ₆ : xMn ^4+, yZn ²⁺
(In the range 0.001 <x <0.2, 0 <y <2).
According to claim 1, wherein the oxide phosphor is an oxide phosphor, characterized in that the structure of formula (4):
[Formula 4]
Ba ₃ WO ₆ : xMn ^4+, yZn ²⁺
(In the range 0.001 <x <0.2, 0 <y <2).
The method of claim 1,
The oxide-based phosphor is a red phosphor that emits visible light in the 680-700nm band using a 300-550nm wavelength region as an excitation source.
Alkaline earth metal ions; Zn ions; Quantifying and mixing a metal salt containing W ions; And
Method of producing an oxide-based phosphor comprising the step of heat-treating the mixed raw material salt at 500 ~ 1400 ℃ for 5 to 12 hours.
The method of claim 7, wherein
Heat-treating the mixed raw material salt at 500-1400 ° C. for 5-12 hours,
The mixed raw material salt is heat treated at 500 to 700 ° C. for 5 to 12 hours and then calcined at 1100 to 1400 ° C. for 5 to 24 hours.
The method of manufacturing a phosphor according to claim 7, wherein the mixed raw material salt contains a mixture containing Mn ions at a molar concentration of 0.001 to 0.2.
A light emitting diode device comprising the oxide phosphor according to any one of claims 1 to 6.
The method of claim 10,
The light emitting diode device is a light emitting diode device, characterized in that the white light emitting diode device.

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