KR20180061837A - Oxyide phosphor - Google Patents

Abstract

The present invention relates to an oxide-based fluorescent substance which generates light in a wavelength range of 550-800 nm through ultraviolet ray excite light in a wavelength range of 200-400 nm; and to a light emitting device including the same. The oxide-based fluorescent substance comprises: a base body which includes Li, Ta, Ge, and O; and a rare earth element which is used as an activator in the base body. In addition, the base body includes an image as a main image, which shows a diffraction peak with a relative intensity of 5% or higher in a range where Bragg angle (2θ) of an X-ray diffraction pattern is 16.6-18.1°, 21.2-22.7°, 25.5-27.0°, 26.2-27.7°, and 35.0-36.5° when the relative intensity of the diffraction peak with the highest intensity is 100% in the powder X-ray diffraction pattern. Furthermore, the rare earth element is composed of one or more kinds selected from a group which is composed of Mn, Ce, and Eu. Therefore, the oxide-based fluorescent substance is able to be chemically stabilized by being composed of oxides, is able to have excellent luminous brightness because of light emission in a red wavelength range by using ultraviolet rays as excite light, and is able to have a new crystal structure that has not been known yet.

Description

OXYIDE PHOSPHOR [0002]

The present invention relates to a phosphor having a novel crystal structure, and more particularly to a novel oxide-based phosphor capable of emitting light in a red range when an ultraviolet light emitting diode is excited by an oxide having excellent durability.

BACKGROUND ART [0002] A white LED light emitting device, which has recently been spotlighted for illumination, LCD backlighting, automobile lighting, etc., has an LED light emitting device that emits blue or ultraviolet rays, and a light source that emits light from the light emitting device, And a phosphor.

These white as how to implement the LED using a conventional blue light emitting diode with an InGaN-based material having a wavelength of 450 ~ 550nm as a light emitting element and phosphor is (Y, Gd) as the _{3 (Al, Ga) 5 O} 12 composition formula In this white LED, the blue light emitted from the light emitting device is incident on the phosphor layer, and absorption and scattering are repeated several times in the phosphor layer. In this process, the blue light absorbed by the phosphor A part of the yellow light whose wavelength is converted into yellow and the blue light which is incident is mixed to make the white light appear to the human eye.

However, the white LED of such a structure has a problem that only red light is less in red component, color temperature is high, and red and green components are insufficient, so that only an illumination light with poor color rendering is obtained.

In addition, when visible light is used as the excitation light, it is difficult to realize a high-luminance light source. In order to overcome this problem, a red phosphor capable of being excited by ultraviolet rays and being material stable is developed, For the purpose of supplementation, various phosphors such as the following patent documents are presented.

However, while the developed materials each have certain merits, they have disadvantages such as lack of material stability, complicated manufacturing process, low brightness, low color rendering, etc. Therefore, in order to diversify the color rendering property, A phosphor having various emission wavelengths is required.

1. Korean Published Patent Application No. 2009-0069773 2. Korean Patent Publication No. 2010-0104896 3. Korean Patent Publication No. 2009-0049712

The present invention relates to a phosphor which is composed of an oxide and is chemically stable and emits light in a red wavelength range by using ultraviolet light as excitation light, has excellent luminescence brightness, and has a phosphor having a new crystal structure which has not been known yet, And a light emitting device including the light emitting device.

A first aspect of the present invention for solving the above problems is a phosphor comprising a matrix containing Li, Ta, Ge and O and a phosphor obtained by solidifying the matrix with a rare earth element as an activator and the matrix is a powder X- Ray diffraction pattern has a Bragg angle (2?) Of 16.6 ° to 18.1 °, 21.2 ° to 22.7 °, 25.5 ° to 27.0 °, and 26.2 ° to 27.2 °, where the relative intensity of the diffraction peak having the highest intensity is 100% 27.7 DEG and 35.0 DEG to 36.5 DEG in terms of diffraction peaks with a relative intensity of 5% or more, wherein the rare earth element is at least one selected from the group consisting of Mn, Ce and Eu will be.

According to a second aspect of the present invention, there is provided a light emitting device including a light emitting device that emits excitation light, and a wavelength converting unit that absorbs the excitation light to emit visible light, Ray diffraction pattern and a relative intensity of a diffraction peak having the highest intensity in a powder X-ray diffraction pattern as 100%, wherein the matrix has a rare earth element as an activator, The phase exhibiting diffraction peaks of 5% or more in relative intensity in the range of Bragg angle (2?) Of 16.6 ° to 18.1 °, 21.2 ° to 22.7 °, 25.5 ° to 27.0 °, 26.2 ° to 27.7 ° and 35.0 ° to 36.5 °, , And the rare earth element includes at least one oxide selected from the group consisting of Mn, Ce and Eu.

As a phosphor composition using a Li, Ta, Ge, O as a matrix and using an activator, there is no known phosphor composition in which the Bragg angle (2?) Of the X-ray diffraction pattern shows a peak in the above angular range. Therefore, It is a substance.

In addition, the phosphor composition according to the present invention can be used as a red phosphor and has excellent light efficiency, and can be suitably used as a phosphor for LED and a phosphor for display.

Further, the phosphor according to the present invention can change the emission wavelength and the light efficiency by adjusting the molar ratio of the constituent elements constituting the matrix, by substituting a substance having the same oxidation number in the Li or Ge site or by adjusting the doping concentration of the activator , And as a phosphor for tuning.

1 shows an X-ray diffraction pattern of a phosphor prepared according to an embodiment of the present invention.
2 shows PL characteristics of a phosphor prepared according to an embodiment of the present invention.
FIG. 3 is a graph showing the X-ray diffraction patterns of the phosphors prepared according to the embodiment of the present invention, in which Bragg angles are in a range of 16.6 to 18.1, 21.2 to 22.7, 25.5 to 27.0, 26.2 to 27.7, Lt; RTI ID = 0.0 > 36.5. ≪ / RTI >

Although the present invention is made of an oxide, is a red phosphor, has excellent luminescence brightness, is out of the composition range of a conventional red phosphor, and crystal information is known, it is not used as a phosphor by using an activator, And the present invention has been achieved.

The phosphor composition according to the present invention is a phosphor composition comprising a matrix containing Li, Ta, Ge and O and a rare earth element as an activator in the matrix, wherein the matrix has a diffraction peak with the highest intensity in the powder X- Of the X-ray diffraction pattern is 16.6 to 18.1 deg., 21.2 to 22.7 deg., 25.5 to 27.0 deg., 26.2 to 27.7 deg. 35.0 deg. To 36.5 deg. And the rare earth element is composed of at least one element selected from the group consisting of Mn, Ce and Eu.

The phosphor composition may specifically be composed of the following [formula 1].

[Formula 1]

Li _a Ta _b Ge _C O _x : Ln _z

(0.5? A? 1.5, 0.5? B? 1.5, 0.5? C? 1.5, 2.5? X? 7.5, 0.001? Z / a? 0.2)

It is preferable that the molar ratio of Ta to Ge is in the range of 0.05 to 1 in terms of b / c in the preparation of the composition having the crystal structure according to the present invention.

If the molar ratio of the activator (RE) is less than 0.001, the luminance is insufficient due to the shortage of the luminescent element, and if the molar ratio exceeds 0.2, the luminance is decreased due to the effect of so- , It is preferable to obtain a high luminance in the range of 0.001 to 0.2, and more preferably 0.005 to 0.03 in terms of the molar ratio. As the activator, Mn is the most preferable, and Mn can be co-doped with at least one element selected from Ce and Eu.

Further, the Li may be partially substituted with K within a range in which the crystal structure of the matrix is maintained.

Further, the Ge may be partially substituted with Si within the range of maintaining the crystal structure of the matrix.

Further, the rare earth element may be replaced by the molar ratio of 20% or less to the Ge (or a part of Si when a part of Ge is replaced with Si).

In addition, the matrix of the phosphor composition according to the present invention may have a monoclinic crystal structure.

The lattice constant of the phosphor composition according to the present invention is a = 7.589 Å, b = 8.130 Å, and c = 7.509 Å, and the lattice constant may be 10% or less, preferably 5% or less, Also in this case, the characteristics of the phosphor according to the present invention can be shown.

Further, the ratio of Li, Ta, and Ge contained in the matrix of the phosphor composition according to the present invention is most preferably 1: 1: 1.

The ratio (Li :( Ta) :( Ge) :( O) of Li (K), Ta, Ge (Si), and O contained in the matrix of the phosphor composition is a: b: c: d , The ratio is most preferably 1: 1: 1: 5.

Further, the phosphor composition may exhibit an emission peak wavelength range of 550 to 800 nm for ultraviolet excitation light having a peak wavelength range of 200 to 400 nm.

In addition, the phosphor may exhibit an emission peak wavelength of 600 to 800 nm with respect to the excitation light of 200 to 400 nm (preferably 200 to 350 nm).

The phosphor of the composition according to the present invention is ideally composed of a single phase. However, a small amount of unavoidable amorphous or monoclinic other crystal phase may be included in the manufacturing process, and such an amorphous phase or other crystalline phase may be included. May be included as long as they do not affect the properties.

The average particle size of the phosphor according to the present invention is preferably in the range of 1 탆 to 20 탆. If the average particle size is smaller than 1 탆, the light absorptance due to scattering decreases and the uniform dispersion of the resin sealing the LED If the average particle size exceeds 20 mu m, the light emission intensity and color tone may be uneven.

The present invention provides a light emitting device comprising: a light emitting element that emits excitation light; And a wavelength converter for absorbing the excitation light to emit visible light, wherein the wavelength converter converts the excitation light having an emission wavelength of 200 to 400 nm to a light emitting device comprising the phosphor composition, And may be an ultraviolet light emitting diode that can emit light.

Hereinafter, the oxide-based fluorescent material of the present invention will be described in detail with reference to more specific examples.

[Example]

(Li ₂ CO ₃ ), tantalum pentoxide (Ta ₂ O ₅ ), germanium dioxide (GeO ₂ ) and manganese carbonate (MnCO ₃ ) powders in the case of Li, Ta, Ge, Were used.

When the main components Li, Ta, Ge and Mn are synthesized, the raw materials are weighed and mixed with Li ₂ CO ₃ , Ta ₂ O ₅ , GeO ₂ and MnCO ₃ so as to have a predetermined composition. The amount was 1 g, and the mixing of the raw materials was carried out in an atmospheric environment.

In this way, the mixture sample thus obtained composed mainly of oxygen and nitrogen gas under atmospheric pressure at least 20 atm performed in an oxygen and a nitrogen gas atmosphere that contains the O ₂ of 25% by volume or less, so that the sintering in an oxygen and a nitrogen gas atmosphere, It is possible to prevent or suppress the decomposition of the oxides synthesized during firing and to reduce the compositional deviation of the resulting oxides, thereby making it possible to produce a phosphor composition having excellent performance.

In the embodiment of the present invention, a gas atmosphere containing 21% of oxygen gas and 78% or more of nitrogen gas relative to the total gas was used.

The firing temperature is preferably 1000 to 1200 DEG C, and more preferably 1100 DEG C or more to obtain a high-quality phosphor. The firing time may be in the range of 30 minutes to 100 hours, preferably 2 hours to 24 hours, considering the quality and productivity. In this embodiment, firing was performed at a firing temperature of 1100 DEG C for 4 hours in an atmosphere of atmospheric air gas, and then crushed to produce a phosphor.

Specifically, 0.1012 g of Li ₂ CO _3, 0.6054 g of Ta ₂ O ₅ , 0.2866 g of GeO ₂ and 0.0067 g of MnCO ₃ were weighed respectively and then mixed manually using induction in an air atmosphere 1 g of a raw material powder mixture was obtained.

1 g of the raw material powder mixture thus mixed was charged into the crucible and fired by heating the mixture at a temperature of 1100 占 폚 for 4 hours by flowing an oxygen and nitrogen mixed gas at a rate of 500 cc / minute into the firing furnace, followed by pulverization to obtain a phosphor composition. When this phosphor composition was excited by a 254 nm ultraviolet light source, it was confirmed that red light emission was obtained as shown in Table 1 below.

Raw material mixing ratio and emission peak wavelength Raw material (g) Revival
Mole ratio Emission wavelength
(nm) Li ₂ CO Ta ₂ O ₅ GeO ₂ MnCO ₃ Example 0.1012 0.6504 0.2866 0.0067 0.01 650

As shown in FIG. 2, the phosphor compositions prepared above were analyzed for luminescence characteristics using a PL apparatus, and the crystal structure was analyzed by XRD as shown in FIG.

FIG. 1 shows the X-ray diffraction result of the phosphor composition according to the embodiment, and the PL measurement result of FIG. 2 also supports this.

The Bragg angle (2?) Of the X-ray diffraction pattern is 16.6 to 18.1, 21.2 to 22.7, 25.5 to 27.0, and 26.2 as shown in Fig. 3 based on Li, Ta, Ge, There is no known phosphor having a crystal structure having a crystal structure showing a diffraction peak with a relative intensity of 5% or more in the range of? 27.7 ° 35.0 ° to 36.5 °.

The present invention is not limited to the above-described embodiments and the accompanying drawings, but is intended to be limited only by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

Claims (12)

Li, Ta, Ge, and O, and a phosphor having a rare earth element dissolved therein as an activator,
The matrix preferably has a Bragg angle (2?) Of 16.6 to 18.1 deg., 21.2 to 22.7 deg. (Where X is the Bragg angle of the X-ray diffraction pattern) when the relative intensity of the diffraction peak having the highest intensity in the powder X- , 25.5 DEG to 27.0 DEG, 26.2 DEG to 27.7 DEG, and 35.0 DEG to 36.5 DEG.
Wherein the rare earth element is at least one selected from the group consisting of Mn, Ce and Eu. The method according to claim 1,
The matrix is composed of the following [Formula 1].
[Formula 1]
Li _a Ta _b Ge _C O _x : Ln _z
(0.5? A? 1.5, 0.5? B? 1.5, 0.5? C? 1.5, 2.5? X? 7.5, 0.001? Z / a? 0.2) 3. The method of claim 2,
and b / c is 0.05 to 1. 3. The method of claim 2,
and z is 0.001 to 0.2. The method according to claim 1,
Wherein a ratio of Li, Ta, and Ge contained in the mother body is 1: 1: 1. The method according to claim 1,
Wherein the oxide-based fluorescent material exhibits an emission peak wavelength range of 550 to 800 nm with respect to excitation light having a peak wavelength range of 200 to 400 nm. The method according to claim 1,
The matrix is a monoclinic crystal structure. The method according to claim 1,
Wherein the lattice constant of the matrix is a = 7.589 A, b = 8.130 A, c = 7.509 A, and the lattice constant can be changed to 10% or less based on the above numerical value. The method according to claim 1,
Wherein the oxide-based fluorescent material has an average particle size of 1 to 20 占 퐉. A light emitting element that emits excitation light; And
And a wavelength converter for absorbing the excitation light to emit visible light,
Wherein the wavelength converting portion comprises a matrix containing Li, K, Ta, Ge, Si and O, and a phosphor obtained by solid-solving a rare earth element as an activator in the matrix,
The matrix preferably has a Bragg angle (2?) Of 16.6 to 18.1 deg., 21.2 to 22.7 deg. (Where X is the Bragg angle of the X-ray diffraction pattern) when the relative intensity of the diffraction peak having the highest intensity in the powder X- , 25.5 DEG to 27.0 DEG, 26.2 DEG to 27.7 DEG, and 35.0 DEG to 36.5 DEG.
Wherein the rare earth element comprises an oxide phosphor composed of at least one selected from the group consisting of Mn, Ce and Eu. 11. The method of claim 10,
Wherein the light emitting element is an ultraviolet light emitting diode. 11. The method of claim 10,
Wherein the ratio of Li, Ta, and Ge contained in the matrix is 1: 1: 1.

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