KR100668796B1 - Huntite phosphor and white light emitting device using there - Google Patents

Abstract

Provided is a huntite-based phosphor, which has a high light emitting efficiency in a short wavelength region such as blue light or UV rays, shows excellent luminance and color purity, and is useful for the production of a white light emitting device. The huntite-based phosphor is represented by the formula of Y1-x-x'Al3B4O12:xCe,x'Tb, wherein each of x and x' represents a number corresponding to 0.01-0.5 moles per mole of Y. The huntite-based phosphor shows an absorption peak in a range of 420nm-480nm and an emission peak in a range of 500nm-620nm. The huntite-based phosphor is obtained by mixing Y2O3, Al2O3, B2O3, Ce2(C2O4)3 and Tb4O7 to form a mixture, and by firing the mixture.

Description

Huntite Phosphor and White Light Emitting Device using there}

1 is the emission spectrum at 469.5 nm of a phosphor having no Tb as the activator;

2 is an absorption spectrum at 544.3 nm of the phosphor of Formula 1 according to a preferred embodiment of the present invention;

3 is an emission spectrum at 469.5 nm of the phosphor of Formula 1 according to a preferred embodiment of the present invention;

4 is an emission spectrum at 365.8 nm of the phosphor of Formula 1 according to a preferred embodiment of the present invention;

5 is an absorption spectrum at 544.3 nm of of the phosphor of Formula 2 according to a preferred embodiment of the present invention;

6 is an emission spectrum at 469.5 nm of the phosphor of Formula 2 according to a preferred embodiment of the present invention;

7 is an emission spectrum at 365.8 nm of the phosphor of Formula 2 according to a preferred embodiment of the present invention;

8A is a SEM photograph of the phosphor of formula 1 according to a preferred embodiment of the present invention;

8b is a SEM photograph of the phosphor of formula 2 according to a preferred embodiment of the present invention;

9A is a graph of an XRD result of the phosphor of Formula 1 according to a preferred embodiment of the present invention;

9B is an XRD result graph of the phosphor of Chemical Formula 2 according to the preferred embodiment of the present invention;

10 is a light emission spectrum of a white light emitting diode manufactured using the phosphor of Chemical Formula 1 according to a preferred embodiment of the present invention;

11 is a light emission spectrum of a white light emitting diode manufactured using the phosphor of Chemical Formula 2 according to a preferred embodiment of the present invention.

12 is an emission spectrum at 469.5 nm of the phosphor of Formula 3 according to a preferred embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to huntite-based phosphors, and more particularly to phosphors that can be used in white light emitting devices.

Light Emitting Diode (LED) is a futuristic display device that is one of the most recently researched fields due to its application to flat panel displays as well as various instrument panels and TVs. Known. In the electroluminescence, when an electric field is applied to a light emitting material that emits light, electrons injected from the cathode and holes formed in the anode are combined in the emission layer to form a so-called "single excition". This single excitons form an excited state and emit a variety of light when it transitions to the ground state. The light emitting device of this principle is a semiconductor device having higher luminous efficiency, lower power consumption, and better thermal safety than the conventional ones, and has excellent characteristics with long life and good response.

Among these LEDs, white LEDs have various applicability and marketability, such as home lighting, liquid crystal display (LCD) panel backlighting, and interior lighting of automobiles.

In this regard, a method of making a white light emitting device by combining a yttrium aluminum garnet (Y ₃ AL ₅ O ₁₂ ) -based fluorescent material with a light emitting diode in a short wavelength region such as blue or ultraviolet light has been studied (S. Nakamura, The Blue Laser Diode, See Springer-Verlag, pp 216-219 (1997). In general, white light-emitting phosphors for white light-emitting diodes that are currently practically used are (Re _{1 - r S m r} ) ₃ (Al _{1 - s} Ga _s ) ₅ O ₁₂ : Ce (where 0≤r <1, 0≤s < 1, Re: Y or Gd) is a YAG-based phosphor (Nichia, U.S. Patent No. 6069440) (hereinafter referred to as the '440 patent'). There is also a TAG-based phosphor represented by Tb ₃ (Al, Ga) ₅ O ₁₂ : Ce, in which Tb is added to the phosphor to cause a shift in the long wavelength so as to have a positive effect on the red component (Osram, US Pat. (Hereinafter referred to as '' 179 patents ''). In addition, a fluorescent material (Philips, U.S. Patent No. 4,215,289) for a low pressure mercury vapor discharge lamp having a huntite structure of yttrium-aluminum-borate (YAl ₃ B ₄ O ₁₂ ) as a matrix has been disclosed (hereinafter, '' 289 ''). Patents'). However, as a phosphor for white light emitting diodes, phosphors based on a hunite structure other than YAG or TAG have not been disclosed. Furthermore, no phosphor for white light emitting diodes using a huntite structure as a parent and using Ce and Tb as activators has not been developed.

The above-mentioned '440 patent has a drawback in that the emission color is limited, the reproduction range of white as a white light emitting diode is narrow, and the phosphor itself has a strong yellow color to absorb a part of the blue emission as white. The '179 patent also has a drawback of low luminous intensity. In addition, the '289 patent discloses at least one of Y or La as the active agent; At least one of Pb Ti Sb Pr and Bi; Since it is made of at least one of Mn, Tb, Eu, and Dy, and is excited only in the ultraviolet region having a short wavelength of 270 nm or less, it is not suitable for use as a phosphor for white light emitting diodes because it is not excited in blue wavelength as in the present invention.

The present invention has been made to solve the above-mentioned problems and provides a hunite-based phosphor having high luminous efficiency by being excited in a short wavelength region such as blue or ultraviolet light. In another aspect, the present invention provides a method for producing a huntite-based phosphor having excellent brightness and color purity. The present invention also provides a white light emitting device having a wide range of white reproduction, including the above-described huntite-based phosphor.

According to an aspect of the present invention, it is possible to provide a huntite-based phosphor having the formula (1).

<Formula 1>

Y _1-X- X'Al ₃ B ₄ O ₁₂ : x Ce, x'Tb (x and x 'in Formula 1 are 0.01 to 0.5 mol per mol of Y.)

According to a preferred embodiment, the huntite phosphor exhibits an absorption peak in a range of 420 nm to 480 nm, an emission peak in a range of 500 nm to 620 nm, an absorption peak in a range of 325 nm to 385 nm, and a range of 540 nm to 560 nm. The emission peak can be represented by.

According to another aspect of the invention, the step of weighing and mixing Y ₂ 0 ₃ , Al ₂ 0 ₃ , B ₂ 0 ₃ , Ce ₂ (C ₂ O ₄ ) ₃ and Tb ₄ O ₇ and calcining the mixture It may include a method of producing a phosphor represented by the formula (1). According to a preferred embodiment, the step of firing may be performed at 1000 to 1600 ℃ 1 to 48 hours.

According to another aspect of the present invention, it is possible to provide a huntite-based phosphor having the formula (2).

<Formula 2>

(Y _{1 -aX- X '} A _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb (in Formula 2, 0 <a ≦ 0.2, a + x + x'<0.5, and A is Bi, Mn At least one element selected from the group consisting of Eu, and Gd, and X and X 'are 0.01 to 0.5 mol per mol of Y.)

According to a preferred embodiment, the huntite phosphor exhibits an absorption peak in a range of 420 nm to 480 nm, an emission peak in a range of 490 nm to 650 nm, an absorption peak in a range of 320 nm to 390 nm, and a range of 540 nm to 560 nm. The emission peak can be represented by.

According to another aspect of the invention, Y ₂ 0 ₃ , Al ₂ 0 ₃ , B ₂ 0 ₃ , Ce ₂ (C ₂ O ₄ ) ₃ , Tb ₄ O ₇ and Bi ₂ O ₃ , MnCO ₃ , Eu ₂ O _A method of preparing the phosphor represented by Chemical Formula 2 may be provided, comprising: weighing and mixing one or more elements selected from the group consisting of ₃ and Gd ₂ O ₃ and calcining the mixture.

In addition, according to another aspect of the present invention, it is possible to provide a huntite-based phosphor having the formula

<Formula 3>

(Gd _{1 -aX- X '} Y _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb (0 <a≤0.4 in Formula 3, a + x + x'<1, and X is per mole of Y 0.01 to 0.3 mol, X 'is 0.01 to 0.2 mol per mol of Y.)

According to a preferred embodiment, the huntite-based phosphor exhibits an absorption peak in the range of 420 nm to 480 nm, an emission peak in the range of 500 nm to 650 nm, an absorption peak in the range of 320 nm to 390 nm, and light emission in the range of 540 nm to 560 nm. Peaks may be indicated.

In addition, according to another aspect of the present invention, it is possible to provide a white light emitting device including the above-described huntite-based phosphor and a blue light emitting diode having a peak emission wavelength of 450 to 470 nm.

Hereinafter, the huntite-based phosphor according to the present invention, a manufacturing method thereof, and a white light emitting device will be described in detail with preferred embodiments.

As a phosphor having a yttrium-aluminum-borate according to the present invention as a parent, more specifically, has the following general formula (1):

<Formula 1>

Y _{1-X-X '} Al ₃ B ₄ O ₁₂ : xCe, x'Tb

In Formula 1, x and x 'are 0.01 to 0.5 moles per 1 mole of Y, preferably x is 0.03 to 0.2 moles, and x' is 0.03 to 0.4 moles.

Phosphor having a yttrium-aluminum-borate huntite structure is composed of a BO ₃ -based matrix, a trigonal structure (R32), a Y element at a triangular prism site, and a cation replacing Al is octahedral ( octahedral) occupy a structure that occupies a place. This is a yellow phosphor, which is a normal garnet phosphor having a yttrium-aluminum-garnet structure as its parent, and the cations at Y site are located at the octahedral site based on oxygen, and the cations at Al site occupy tetrahedral sites. centered-cubic (BCC) structure and the parent structural difference.

Ce and Tb were used here as activators. An activator refers to an element that can play a role in actually generating light emission. Although not intended to be limited to a specific luminescence mechanism, Ce and Tb or Ce and Tb ions substituted in the basic host represented by YAl ₃ B ₄ O ₁₂ in Formula 1 may transfer between their base level and the excitation level. By absorbing or emitting energy by the light emission can be made. Furthermore, Tb ³⁺ is used as the activator to increase the crystallinity of the formed phosphor and to increase the luminescence brightness. Also it may represent a near white in color if the Tb ³⁺ ion with the emission wavelength to the charge transfer to Tb ^{+ 3} df by orbital transition from Ce ^{3 +} is added to the wavelength of the sulfur used in the green-blue light-emitting diode.

As a phosphor having another yttrium-aluminum-borate as a parent in the present invention, more specifically, it has the following Chemical Formula 2:

<Formula 2>

(Y _{1-aX-X '} A _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb

In Formula 2, X and X 'are 0.01 to 0.5 moles per 1 mole of Y, preferably x is 0.03 to 0.2 moles, and x' is 0.03 to 0.4 moles. This means the number of moles in which the addition amount of each Ce and Tb is substituted on the basis of 1 mole of the Y element.

The A increases the light emission luminance and color purity of the prepared phosphor used as a study agent. At least one A may be selected from the group consisting of Bi, Mn, Eu and Gd. For example, various modifications are possible, such as Bi, Mn, Eu, Gd may be used alone, and Bi and Mn may be used together. At this time, the molar ratio of A is 0 <a≤0.2, provided that a + x + x '<0.5. Preferably a + x + x '≦ 0.4. That is, Y must be included, and preferably 0.6 mol or more.

As a phosphor having another yttrium-aluminum borate of the present invention as a parent, more specifically, the following general formula (3).

<Formula 3>

(Gd _{1-aX-X '} Y _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb

In Formula 3, 0 <a ≦ 0.4, a + x + x ′ <1, X is 0.01 to 0.3 mol per mol of Y, and X 'is 0.01 to 0.2 mol per mol of Y.

The composition of the phosphor does not replace the Y element with Gd, but the Y element is substituted with the Gd matrix to increase the crystallinity of the phosphor, and improve the luminous efficiency to improve luminance and color purity. It is preferable that the molar ratio of Y added at this time is more than 0 and 0.4 or less, a + x + x '<1, and a + x + x' <0.9. That is, Y must be included and preferably 0.1 mol or more.

As described above, the phosphors according to the present invention are huntite-based phosphors having excellent luminance and color purity. Phosphors according to the present invention can be excited in the blue wavelength around 460nm and the ultraviolet region of 360 to 370nm can be utilized as a blue light LED or UV LED. Furthermore, the phosphors of the present invention emit a wide range of light at wavelengths around 470 nm, resulting in rich colors and more natural whites. In addition, when the light emitting area is wide, color fear may be reduced when mixed with blue light, thereby forming a white light emitting diode having no secondary concern.

In the case of phosphors such as Chemical Formula 2 using Bi, Mn, Eu, and Gd activators, the emission efficiency at blue wavelength was increased by about 50% based on the spectral intensity and the area ratio, compared with the absence of the activators. Can emit light in a wider wavelength range. Therefore, when the phosphor of Formula 2 is used in a white light emitting device, the most important color rendering property of the back light property is improved, so that the color is richer and the white color is closer to the natural color.

In addition, in the case of phosphors such as Chemical Formula 3 using Gd as a activator, the maximum value of the emission peak when emitted at blue wavelength is shifted to a longer wavelength than that of the phosphor of Chemical Formula 1, thereby obtaining a better phosphor in terms of color purity.

In addition, the huntite-based phosphor according to the present invention is characterized by emitting light in the blue region around 480 to 500 and the yellow region around 550 nm by infrared rays of 340 nm to 380 nm. In particular, when using the active agent of Bi, Mn, Eu, Gd can be obtained a white light emitting device with high luminous efficiency improved color rendering.

Therefore, the huntite-based phosphors of the present invention can manufacture a white light emitting device by coating phosphors on a blue LED, and replace the variable mixed color of the color by replacing blue, green, and red phosphors with an energy source of ultraviolet wavelength as a light source. The used white light emitting device can also be manufactured.

The method for producing the phosphor according to the present invention comprises a Y-containing compound; Al-containing compound; B-containing compound; Ce-containing compounds; And weighing and mixing at least one compound selected from the group consisting of a Tb-containing compound and optionally a Bi-containing compound, a Mn-containing compound, an Eu-containing compound, and a Gd-containing compound with a solvent and the mixture obtained from the step. And placing in a high purity alumina crucible and firing.

The Y-containing compound may be selected from compounds which form coprecipitation compounds of Y ₂ O ₃ , Y ₂ (CO ₃ ) ₃ , Y (OH) ₃ , Y (NO ₃ ) ₃ and Y, but are not limited thereto. It is not. Of these, Y ₂ O ₃ is preferred. The Al-containing compound may be selected from compounds which form coprecipitation compounds of Al ₂ O ₃ , Al ₂ (CO ₃ ) ₃ , Al (OH) ₃ , Al (NO ₃ ) ₃ and Al elements, but are not limited thereto. no. Of these, Al ₂ O ₃ is preferred.

The B-containing compound may be selected from B ₂ O ₃ , H ₃ BO ₃ , B ₂ (CO ₃ ) ₃ , B (OH) ₃ , and B (NO ₃ ) ₃ , but is not limited thereto. Of these, B ₂ O ₃ and H ₃ BO ₃ are preferred.

The Ce-containing compound may be selected from, but not limited to, a compound forming a coprecipitation compound of CeO ₂ , Ce ₂ (C ₂ O ₄ ) ₃ and Ce element. CeO ₂ , which can enhance the double reducing atmosphere, Ce ₂ (C ₂ O ₄ ) ₃ is preferred. The Tb-containing compound may be selected from, but is not limited to, a compound forming a coprecipitation compound of Tb ₄ O ₇ , Tb ₂ (C ₂ O ₄ ) _3, and Tb element. Tb ₄ O ₇ and Tb ₂ (C ₂ O ₄ ) ₃ capable of enhancing the double reducing atmosphere are preferred, and Tb ₂ (C ₂ O ₄ ) ₃ is particularly preferred.

Bi-containing compounds that can be used as a study agent may be selected from Bi ₂ O ₃ , Bi (CO ₃ ) ₃ , Bi (OH) ₃ , Bi (NO ₃ ) ₃ , but are not limited thereto. Of these, Bi ₂ O ₃ is preferred. The Mn-containing compound may include, but is not limited to, MnCO ₃ . The Eu-containing compound may be selected from, but is not limited to, a compound forming a coprecipitation compound of Eu ₂ O ₃ , Eu (CO ₃ ) ₃ , Eu (OH) ₃ , Eu (NO ₃ ) _3, and an Eu element. . Of these, Eu ₂ O ₃ is preferred. And the Gd-containing compound may be selected from Gd ₂ O ₃ , Gd (CO ₃ ) ₃ , Gd (OH) ₃ , and Gd (NO ₃ ) ₃ , but is not limited thereto. Of these, Gd ₂ O ₃ is preferred.

In the case of using CeO ₂ to prepare a phosphor activated with Ce, a reducing gas is required for this purpose because the oxidation number of Ce must be reduced from +4 to +3. Therefore, the reaction should take place in an open reaction vessel. In this case, a reaction occurs better than a portion in contact with the reducing gas, and a non-uniform reaction may occur. As a result, there was a limit in controlling the crystallinity of the phosphor.

Here, Ce ₂ (C ₂ O ₄ ) ₃ may be used as a starting material to perform a manufacturing process having high crystallinity, easy crystallinity control, and no reducing atmosphere for reducing Ce ions upon firing. In a preferred embodiment of the present invention by using Ce ₂ (C ₂ O ₄ ) ₃ (Ce oxalate) as a starting material, a separate reducing atmosphere is not required in the reaction. Therefore, the reaction is possible in a closed reaction vessel. Accordingly, sufficient reaction occurs with the gas generated from the inside instead of using a reducing gas supplied from the outside during the reaction, so that the desired crystallinity can be obtained only by controlling the reaction time and temperature. In addition, by using a closed reaction vessel, it is possible to alleviate the rate of generation of CO ₂ gas generated during firing, thereby sufficiently maintaining the equilibrium state of the decomposition reaction of Ce oxalate.

According to an exemplary embodiment of the present invention, starting materials for preparing the phosphor of Formula 1 may include Y ₂ 0 ₃ , Al ₂ 0 ₃ , B ₂ 0 ₃ , Ce ₂ (C ₂ O ₄ ) _3, and Tb ₄ O ₇ . use. According to another preferred embodiment of the present invention the starting material for preparing the phosphor of formula 2 is Y ₂ 0 ₃ , Al ₂ 0 ₃ , B ₂ 0 ₃ , Ce ₂ (C ₂ O ₄ ) ₃ , Tb ₄ O ₇ containing and Bi ₂ O _3, MnCO _3, further comprising at least one element selected from the group consisting of Eu ₂ O ₃ and Gd ₂ 0 _3. According to another preferred embodiment of the present invention, the starting material for preparing the phosphor of Chemical Formula ₃ further includes Gd ₂ O ₃ in Chemical Formula 1. The starting materials of each of these phosphors are mixed in the appropriate molar ratio.

Fluorine is used as a flux to the mixture. Examples of the fluorine compound are aluminum fluoride (AlF ₃ ), barium fluoride (BaF ₂ ), and ammonium fluoride (NH ₄ F). The mixture and fluoride are mixed in an appropriate amount. In this case, the appropriate amount refers to mixing a flux such as ammonium fluoride with the mixture at 3 to 5% by weight, preferably at 4% by weight. The flux-mixed mixture is placed in an organic solvent such as acetone or ethanol, separated by a sieve through a ball mill, and dried. The dried powder is placed in a sealed container and fired at 1000 to 1600 ° C for 1 to 48 hours. At this time, a high purity alumina crucible is preferable as a sealed container. When this firing process is carried out in the atmosphere, the firing conditions are preferably 2 to 5 hours at 1200 to 1450 ° C, and when the H ₂ / N ₂ mixed gas is used to increase the efficiency, it is 2 to 1100 to 1300 ° C. It is preferable to carry out for 5 hours. At this time, it is preferable to include 5% by weight of H ₂ in the mixed gas. Through this firing process, desired fluorescent powders can be obtained.

According to a preferred embodiment of the present invention, when Ce ₂ (C ₂ O ₄ ) ₃ and Tb ₄ O ₇ are included in the above-described starting material, the following reaction occurs.

Tb ₄ O ₇ (s) ------------ → 2Tb ₂ O ₃ (s) + O (g)

The generator oxygen produced by this reaction causes an initiation reaction of the decomposition reaction of Ce ₂ (C ₂ O ₄ ) ₃ .

1 / 2Ce ₂ (C ₂ O ₄ ) ₃ (s) + O (g) ------------ → CeO (s) + 3CO ₂ (g)

This initiation reaction causes the reaction between oxygen in the air and Ce ₂ (C ₂ O ₄ ) ₃ to occur sufficiently to remove unreacted intermediates that may occur during decomposition of organic acid salts that act as an activator in the starting material. Exclude and increase the crystallinity of the resulting phosphor.

The fluorescent powder obtained by the calcination process may be pulverized, washed with aqueous hydrochloric acid solution or distilled water to remove a flux such as alumina fluoride, filtered with filter paper, and then dried.

Hereinafter, the present invention will be described in more detail with reference to more specific embodiments. However, the technical idea of the present invention is not limited thereto.

Example 1 Preparation of Huntite-Based Phosphors of <Formula 1>

Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O ₇ were mixed in a molar ratio of 0.94: 3.00: 4.00: 0.03: 0.015 and aluminum fluoride as a flux to the mixture Was mixed with 4 wt% and zirconia balls were added to a sealed Teflon container in acetone. After 12 hours of mixing, the zirconia balls and the mixture were separated by a sieve and dried in an electric oven at 80 ° C. for 6 hours. The dried material was placed in a sealed high purity alumina crucible and calcined at 1450 ° C. for 2 hours in an air using an electric furnace to obtain a fluorescent powder. The fluorescent powder was pulverized well using alumina induction, washed with 3 wt% aqueous hydrochloric acid solution to remove aluminum fluoride, filtered with filter paper and dried in an electric oven at 80 ° C., (Y _0.94 Tb _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.03Ce was prepared.

Examples 2 to 10: Huntite-based phosphor of <Formula 1>

Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ and Tb ₄ O ₇ were mixed while changing the molar ratios as shown in [Table 1] and variously changed in the same manner as in Example 1 A phosphor having a composition was prepared.

TABLE 1

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ Tb ₄ O ₇ One 0.94 3.00 4.00 0.03 0.015 Y _0.94 Al ₃ B ₄ 0 ₁₂ : 0.03Ce0.03Tb 2 0.92 3.00 4.00 0.05 0.015 Y _0.92 Al ₃ B ₄ 0 ₁₂ : 0.05Ce0.03Tb 3 0.90 3.00 4.00 0.07 0.015 Y _0.90 Al ₃ B ₄ 0 ₁₂ : 0.07Ce0.03Tb 4 0.87 3.00 4.00 0.10 0.015 Y _0.87 Al ₃ B ₄ 0 ₁₂ : 0.10Ce0.03Tb 5 0.82 3.00 4.00 0.15 0.015 Y _0.82 Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb 6 0.77 3.00 4.00 0.20 0.015 Y _0.77 Al ₃ B ₄ 0 ₁₂ : 0.20Ce0.03Tb 7 0.67 3.00 4.00 0.30 0.015 Y _0.67 Al ₃ B ₄ 0 ₁₂ : 0.30Ce0.03Tb 8 0.57 3.00 4.00 0.40 0.015 Y _0.57 Al ₃ B ₄ 0 ₁₂ : 0.40Ce0.03Tb 9 0.47 3.00 4.00 0.50 0.015 Y _0.47 Al ₃ B ₄ 0 ₁₂ : 0.50Ce0.03Tb 10 0.57 3.00 4.00 0.03 0.20 Y _{0 .57} Al ₃ B ₄ 0 ₁₂ : 0.03Ce0.4Tb

Examples 11 to 16: The manufacture of the huntite-based phosphor of <Formula 2>

Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O _{7 ,} MnCO ₃ were mixed while changing the molar ratio as shown in [Table 2] and the same as in Example 1 Phosphors having various compositions were prepared by the method.

TABLE 2

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ MnCO ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ Tb ₄ O ₇ 11 0.89 0.06 3.00 4.00 0.03 0.015 (Y _0.91 Mn _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.03Ce0.03Tb 12 0.89 0.06 3.00 4.00 0.05 0.015 (Y _0.89 Mn _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.05Ce0.03Tb 13 0.87 0.10 3.00 4.00 0.05 0.015 (Y _0.87 Mn _0.05 ) Al ₃ B ₄ 0 ₁₂ : 0.07Ce0.03Tb 14 0.85 0.14 3.00 4.00 0.05 0.015 (Y _0.85 Mn _0.07 ) Al ₃ B ₄ 0 ₁₂ : 0.10Ce0.03Tb 15 0.82 0.20 3.00 4.00 0.05 0.015 (Y _0.82 Mn _0.10 ) Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb 16 0.77 0.30 3.00 4.00 0.05 0.015 (Y _{0 .77} Mn _{0 .15} ) Al ₃ B ₄ 0 ₁₂ : 0.20Ce0.03Tb

Examples 17 to 18: Huntite-based phosphor of <Formula 2> Preparation

Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O _{7 ,} Bi ₂ O ₃ were mixed while changing the molar ratio as shown in [Table 3] Example Phosphors having various compositions were prepared in the same manner as in Example 1.

TABLE 3

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ Bi ₂ O ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ Tb ₄ O ₇ 17 0.81 0.03 3.00 4.00 0.01 0.075 (Y _0.81 Bi _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.01Ce0.15Tb 18 0.81 0.01 3.00 4.00 0.15 0.015 _{(Y 0 .81 Bi 0 .01)} Al 3 B 4 0 12: 0.15Ce0.03Tb

Examples 19 to 21: Preparation of the huntite-based phosphor of <Formula 2>

Example 1 by mixing Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O _7, Gd ₂ 0 ₃ while changing the molar ratio as shown in [Table 4] Phosphors having various compositions were prepared in the same manner as described above.

TABLE 4

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ Gd ₂ 0 ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ Tb ₄ O ₇ 19 0.79 0.03 3.00 4.00 0.15 0.015 (Y _0.79 Gd _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb 20 0.77 0.05 3.00 4.00 0.15 0.015 (Y _0.77 Gd _0.05 ) Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb 21 0.72 0.10 3.00 4.00 0.15 0.015 (Y _{0 .72} Gd _{0 .10} ) Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb

Example  22 to 23: of <Formula 2> Huntite system  Phosphor manufacturing

Example 1 by mixing Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O _{7 ,} Eu ₂ O ₃ while changing the molar ratio as shown in [Table 5] Phosphors having various compositions were prepared in the same manner.

TABLE 5

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ Eu ₂ O ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ Tb ₄ O ₇ 22 0.79 0.03 3.00 4.00 0.15 0.015 (Y _0.79 Eu _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb 23 0.77 0.05 3.00 4.00 0.15 0.015 _{(Y 0 .77 Eu 0 .05)} Al 3 B 4 0 12: 0.15Ce0.03Tb

Example  24 to 27: <Formula 2> Huntite system  Phosphor manufacturing

Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O _7, MnCO ₃ were mixed with varying molar ratios as shown in [Table 6] and as a flux to the mixture. 4% by weight of aluminum fluoride was mixed and zirconia balls were added and placed in a sealed Teflon container in acetone. After mixing these for 12 hours, the zirconia ball and the mixture were separated by a sieve and dried in an electric oven at 80 ° C. for 6 hours. The dried material was placed in a high purity alumina crucible and calcined for 5 hours at a temperature of 1100 ° C. in a reducing atmosphere of a nitrogen gas mixture containing 5 wt% hydrogen gas using an electric furnace to obtain a fluorescent powder. The fluorescent powder was pulverized well using alumina induction, washed with distilled water, filtered with filter paper, and dried in an electric oven at 80 ° C. to prepare fluorescent powders having various compositions.

TABLE 6

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ MnCO ₃ Al ₂ 0 ₃ H ₂ BO ₃ CeO ₂ Tb ₄ O ₇ 24 0.89 0.10 3.00 8.00 0.06 0.015 (Y _0.89 Mn _0.05 ) Al ₃ B ₄ 0 ₁₂ : 0.03Ce0.03Tb 25 0.87 0.10 3.00 8.00 0.10 0.015 (Y _0.87 Mn _0.05 ) Al ₃ B ₄ 0 ₁₂ : 0.05Ce0.05Tb 26 0.799 0.002 3.00 8.00 0.10 0.075 (Y _0.799 Mn _0.001 ) Al ₃ B ₄ 0 ₁₂ : 0.07Ce0.15Tb 27 0.799 0.002 3.00 8.00 0.30 0.025 _{(Y 0 .799 Mn 0 .001)} Al 3 B 4 0 12: 0.10Ce0.05Tb

Example  28 to 32: <Formula 3> Huntite system  Phosphor manufacturing

Example 1 by mixing Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Tb ₄ O _7, Gd ₂ 0 ₃ while changing the molar ratio as shown in [Table 7] Phosphors having various compositions were prepared in the same manner as described above.

TABLE 7

Example Molar ratio Phosphor Composition Y ₂ 0 ₃ Gd ₂ 0 ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ Tb ₄ O ₇ 28 0.0 0.92 3.00 4.00 0.05 0.015 Gd _0.92 Al ₃ B ₄ 0 ₁₂ : 0.05Ce0.03Tb 29 0.34 0.58 3.00 4.00 0.05 0.015 (Gd _0.58 Y _0.34 ) Al ₃ B ₄ 0 ₁₂ : 0.05Ce0.03Tb 30 0.24 0.58 3.00 4.00 0.15 0.015 (Gd _0.58 Y _0.24 ) Al ₃ B ₄ 0 ₁₂ : 0.15Ce0.03Tb 31 0.14 0.58 3.00 4.00 0.25 0.015 (Gd _0.58 Y _0.14 ) Al ₃ B ₄ 0 ₁₂ : 0.25Ce0.03Tb 32 0.24 0.58 3.00 4.00 0.05 0.065 (Gd _{0 .58} Y _{0 .24} ) Al ₃ B ₄ 0 ₁₂ : 0.05Ce0.13Tb

Comparative example  1 to 2: Tb Phosphor Preparation Without

Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (CeO ₄ ) ₃ , Eu ₂ O ₃ were mixed while changing the molar ratios as shown in [Table 8] and variously prepared in the same manner as in Example 1 A phosphor having a composition was prepared.

TABLE 8

Comparative example Molar ratio Phosphor Composition Y ₂ 0 ₃ Eu ₂ O ₃ Al ₂ 0 ₃ B ₂ 0 ₃ Ce ₂ (C ₂ O ₄ ) ₃ One 0.96 0.03 3.00 4.00 0.03 (Y _0.96 Eu _0.03 ) Al ₃ B ₄ 0 ₁₂ : 0.01Ce 2 0.94 0.03 3.00 4.00 0.03 _{(Y 0 .94 Eu 0 .03)} Al 3 B 4 0 12: 0.03Ce

Fabrication of White Light Emitting Diode Using Phosphor According to the Present Invention

A white light emitting diode was manufactured using the phosphor obtained according to the above embodiment. GaN nucleation layer 25nm, n-GaN layer (metal: Ti / Al) 1.2㎛, 5cm InGaN / GaN multi-quantum well layer, InGaN layer 4nm, GaN layer 7nm and p-GaN layer on sapphire substrate Ni / Au) 0.11 μm was formed in order to prepare a blue light LED. Subsequently, a phosphor was dispersed in an epoxy on the surface of the blue light LED to prepare a white light emitting diode. The emission spectra of the manufactured white light emitting diodes are illustrated in FIGS. 10 and 11, respectively.

Hereinafter, the accompanying drawings will be described in detail.

1 is an emission spectrum at 469.5 nm of a phosphor having no Tb as an activator. Referring to FIG. 1, emission spectra at blue wavelengths of a phosphor having a huntite structure obtained in a comparative example and a Eu active agent but not having Tb as an activator are illustrated. This phosphor was hardly excited at a wavelength of 469.5 nm, so that no peak appeared at 500 nm to 550 nm, and peaks around 550 nm showed small and narrow emission characteristics. From this, it can be seen that Tb as an activator is an essential component for Ce activator to emit light in the yellow region.

Absorption and Emission Spectrum of the Huntite Phosphor of Formula 1

2 shows an absorption spectrum at 544.3 nm of the phosphor of Formula 1 according to Preferred Example 5 of the present invention. Referring to FIG. 2, it was found that the huntite-based phosphor of the present invention is excited in an ultraviolet region around 325 nm to 385 nm and a blue wavelength around 420 nm to 480 nm.

Figure 3 shows the emission spectrum at 469.5nm of the phosphor of formula 1 according to a preferred embodiment 5 of the present invention, Figure 4 shows the emission spectrum at 365.8nm of the phosphor of formula 1 according to a preferred embodiment 5 of the present invention It was. Referring to FIG. 3, the phosphor showed a broad and broad emission spectrum of 500 nm to 620 nm with a peak around 525 nm at a wavelength of 469.5 nm. This means that it can emit light in a wavelength range of various colors ranging from yellow to yellow to green. In addition, it was found that the phosphor was also excellent in luminous efficiency proportional to the area of the emission spectrum. Referring to FIG. 4, the phosphor showed an emission peak of greenish yellow in a narrow region at 540 nm to 560 nm at an absorption wavelength of 365.8 nm. That is, the phosphor of Formula 1 of the present invention is excited by a blue wavelength and has a high brightness and rich color to induce white light close to a natural color, and is excited by ultraviolet rays to emit light in green and yellow wavelengths.

Absorption and Emission Spectrum of the Huntite Phosphor of Formula 2

5 shows an absorption spectrum at 544.3 nm of of the phosphor of Chemical Formula 2 according to Example 19 of the present invention. Referring to FIG. 5, it can be seen that the phosphor is excited in an ultraviolet region around 320 nm to 390 nm and a blue wavelength around 420 nm to 480 nm.

6 shows an emission spectrum at 469.5 nm of the phosphor of Formula 2 according to a preferred embodiment 19 of the present invention, and FIG. 7 shows an emission spectrum at 365.8 nm of the phosphor of Formula 2 according to a preferred embodiment 19 of the present invention. . Referring to FIG. 6, this phosphor exhibited a broad and broad emission spectrum of 490 nm to 650 nm with the peak of a wide region of 520 nm to 550 nm by blue wavelength. It can be emitted in a wavelength range of a wider color than the phosphor 1, and the luminous efficiency is also increased by 50% more than the phosphor 1, it was found that the phosphor with improved color rendering properties. In addition, it is possible to obtain a phosphor having superior characteristics improved from phosphor 1 in terms of luminance and color. Referring to FIG. 4, it was found that the phosphor also exhibits an emission peak in a narrow region at 540 nm to 560 nm at an absorption wavelength of 365.8 nm, and is excited by ultraviolet rays to emit light at green and yellow wavelengths.

SEM picture of phosphor

FIG. 8A is a SEM photograph of the phosphor of formula 1 according to a preferred embodiment 5 of the present invention, and FIG. 8B is a SEM photograph of the phosphor of formula 2 according to a preferred embodiment 19 of the present invention.

8A and 8B, in the case of the phosphor for the light emitting device, the particle size affects the luminous efficiency and the manufacturing process of the light emitting device. When the particle size is too large, the light conversion efficiency through the large particles is lower than when using small particles, the settling speed is faster in the epoxy resin, it is difficult to apply uniformly when applied on the chip. In addition, if the particle size is too small, the luminous efficiency of the phosphor itself is reduced due to the mutual scattering of light-converted light. Therefore, a suitable size for the phosphor to be coated on the light emitting device chip is about 10㎛, it can be seen that the phosphors of the present invention have a suitable particle size for use in the light emitting device.

Furthermore, referring to FIG. 8B, compared to FIG. 8A, small particles adhering to the particle surface are removed to further improve luminous efficiency. The overall size of the particles was also 10 µm or less and more uniform.

XRD Results Graph

Figure 9a is a graph of the XRD results of the phosphor of formula 1 according to a preferred embodiment of the present invention, Figure 9b is a graph of the XRD results of the phosphor of formula 2 according to a preferred embodiment of the present invention.

9A and 9B, the peaks marked with ★ in the spectrum of FIG. 9B using the study agent appear as new peaks or show differences in diffraction intensity. The peaks appearing at about 29 ° and 37 ° are the new peaks, and the peaks at 34 ° and 55 ° are increased in intensity.

Emission Spectrum of White Light Emitting Diode Using Huntite Phosphor

10 is a light emission spectrum of a white light emitting diode manufactured using the phosphor of Chemical Formula 1 according to a preferred embodiment of the present invention, and FIG. 11 is a white light emission manufactured using the phosphor of Chemical Formula 2 according to a preferred embodiment of the present invention. The emission spectrum of the diode.

Referring to FIG. 10, the hunite-based phosphor of Chemical Formula 1 of the present invention shows a stable yellow region showing a main emission peak in a range of 550 nm to 600 nm in a white light emitting diode using a blue LED having various wavelengths. Accordingly, the phosphor has a feature that the wavelength is converted on the blue light LED to induce white light close to the natural color. Referring to FIG. 11, the white light emitting diode using the hunite-based phosphor of Chemical Formula 2 of the present invention exhibits a main emission peak in a range of 500 nm to 550 nm to show green and yellow regions, thereby converting wavelengths on a blue light LED and close to natural colors. There is a characteristic that can induce white light.

Emission Spectrum of the Huntite-Based Phosphor of Formula 3

12 is an emission spectrum at 469.5 nm of the phosphor of Formula 3 according to Example 28 of the present invention. Referring to FIG. 12, when the phosphor of Formula 3 of the present invention emits light at a blue wavelength, a maximum value of the emission peak is formed at 550 nm to 580 nm, which is shifted to a long wavelength when compared to the phosphor of Formula 1. As a result, phosphors having better color purity can be obtained. In addition, as in the other huntite-based phosphors of the present invention, a boarded emission spectrum is formed over a wide area.

The absorption spectrum at 544.3 nm of the phosphor of Formula 3 is similar to the absorption spectrum of FIG. 5 showing the absorption spectrum of the phosphor of Formula 2. In addition, the emission spectrum of the white light emitting diode manufactured using the phosphor of Formula 3 is similar to that of the phosphor of Formula 2 shown in FIG. 11.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, according to the phosphor according to the present invention and a method of manufacturing the same, a huntite-based phosphor having a completely new structure can be used in a phosphor area for a blue light emitting diode in which a phosphor of a garnet-based structure is conventionally used. Such huntite-based phosphors are excited by wavelengths such as blue or ultraviolet rays, and thus have high luminous efficiency. In addition, the method of manufacturing the huntite-based phosphor of the present invention can produce a phosphor having excellent brightness and color purity. The white light-emitting device including the above-described huntite-based phosphor is rich in color and obtains natural white light, and there is no fear of color change and luminance deterioration due to the generation of secondary phases.

Claims (11)

Huntite-based phosphors having the following Chemical Formula 1: <Formula 1> Y _{1-X-X '} Al ₃ B ₄ O ₁₂ : xCe, x'Tb In Formula 1, x and x 'are 0.01 to 0.5 moles per mole of Y. The method according to claim 1, A huntite-based phosphor that exhibits an absorption peak in a range of 420 nm to 480 nm and a light emitting peak in a range of 500 nm to 620 nm. The method according to claim 1, A huntite-based phosphor that exhibits an absorption peak in the range of 325 nm to 385 nm and exhibits an emission peak in the range of 540 nm to 560 nm. Weighing and mixing Y ₂ O ₃ , Al ₂ O ₃ , B ₂ O ₃ , Ce ₂ (C ₂ O ₄ ) ₃ and Tb ₄ O ₇ ; And Method for preparing a phosphor represented by the following formula 1, comprising the step of firing the mixture: <Formula 1> Y _{1-X-X '} Al ₃ B ₄ O ₁₂ : xCe, x'Tb In Formula 1, x and x 'are 0.01 to 0.5 moles per mole of Y. Huntite-based phosphors having the following Chemical Formula 2: <Formula 2> (Y _{1-aX-X '} A _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb In Formula 2, 0 <a ≦ 0.2, a + x + x '<0.5, A is one or more elements selected from the group consisting of Bi, Mn, Eu, and Gd, and X and X' are per mole of Y 0.01 to 0.5 mole. The method according to claim 5, A huntite-based phosphor that exhibits an absorption peak in the range of 420 nm to 480 nm, and exhibits an emission peak in the range of 490 nm to 650 nm. The method according to claim 5, A huntite-based phosphor that exhibits an absorption peak in the range of 320 nm to 390 nm, and an emission peak in the range of 540 nm to 560 nm. Group consisting of Y ₂ 0 ₃ , Al ₂ 0 ₃ , B ₂ 0 ₃ , Ce ₂ (C ₂ O ₄ ) ₃ , Tb ₄ O ₇ and Bi ₂ O ₃ , MnCO ₃ , Eu ₂ O ₃ and Gd ₂ 0 ₃ Weighing and mixing one or more elements selected from; And Method for producing a phosphor represented by the formula (2) comprising the step of firing the mixture: <Formula 2> (Y _{1-aX-X '} A _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb In Formula 2, 0 <a ≦ 0.2, a + x + x '<0.5, A is one or more elements selected from the group consisting of Bi, Mn, Eu, and Gd, and X and X' are per mole of Y 0.01 to 0.5 mole. Huntite-based phosphors having the formula <Formula 3> (Gd _{1-aX-X '} Y _a ) Al ₃ B ₄ O ₁₂ : xCe, x'Tb In Formula 3, 0 <a≤0.4, a + x + x '<1, X is 0.01 to 0.3 mol per mol of Y, and X' is 0.01 to 0.2 mol per mol of Y. The method according to claim 9, A huntite-based phosphor that exhibits an absorption peak in a range of 420 nm to 480 nm and a light emitting peak in a range of 500 nm to 650 nm. Claims 1 to 3, 5 to 7, a white light emitting device comprising the huntite-based phosphor according to any one of claims 9 and 10 and a blue light emitting diode having a peak emission wavelength of 450 to 470nm.

Images