WO2007148880A1 - Thulium-containing fluorescent substance for white light emitting diode and manufacturing method thereof - Google Patents
Thulium-containing fluorescent substance for white light emitting diode and manufacturing method thereof Download PDFInfo
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- WO2007148880A1 WO2007148880A1 PCT/KR2007/002723 KR2007002723W WO2007148880A1 WO 2007148880 A1 WO2007148880 A1 WO 2007148880A1 KR 2007002723 W KR2007002723 W KR 2007002723W WO 2007148880 A1 WO2007148880 A1 WO 2007148880A1
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- WIPO (PCT)
- Prior art keywords
- fluorescent substance
- thulium
- emitting diode
- white light
- light emitting
- Prior art date
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- 239000000126 substance Substances 0.000 title claims abstract description 84
- 229910052775 Thulium Inorganic materials 0.000 title claims abstract description 30
- FRNOGLGSGLTDKL-UHFFFAOYSA-N thulium atom Chemical compound [Tm] FRNOGLGSGLTDKL-UHFFFAOYSA-N 0.000 title claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 229910001940 europium oxide Inorganic materials 0.000 claims abstract description 20
- AEBZCFFCDTZXHP-UHFFFAOYSA-N europium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Eu+3].[Eu+3] AEBZCFFCDTZXHP-UHFFFAOYSA-N 0.000 claims abstract description 20
- ZIKATJAYWZUJPY-UHFFFAOYSA-N thulium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Tm+3].[Tm+3] ZIKATJAYWZUJPY-UHFFFAOYSA-N 0.000 claims abstract description 15
- 150000001768 cations Chemical class 0.000 claims abstract description 9
- 229910052751 metal Inorganic materials 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims abstract description 8
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 8
- 229910052788 barium Inorganic materials 0.000 claims abstract description 6
- 238000002156 mixing Methods 0.000 claims description 11
- 229910052909 inorganic silicate Inorganic materials 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 8
- 229910052744 lithium Inorganic materials 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims description 4
- 238000012805 post-processing Methods 0.000 claims description 4
- 238000010298 pulverizing process Methods 0.000 claims description 4
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 2
- 229910052772 Samarium Inorganic materials 0.000 claims description 2
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 2
- 150000002910 rare earth metals Chemical group 0.000 claims description 2
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 claims 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims 1
- 239000012190 activator Substances 0.000 abstract description 16
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 abstract description 11
- 229910052693 Europium Inorganic materials 0.000 description 19
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 13
- -1 carbonate compound Chemical class 0.000 description 11
- 230000000694 effects Effects 0.000 description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 238000000295 emission spectrum Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000013078 crystal Substances 0.000 description 4
- 230000001965 increasing effect Effects 0.000 description 4
- 238000005424 photoluminescence Methods 0.000 description 4
- 230000005284 excitation Effects 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 238000000695 excitation spectrum Methods 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- 229910000018 strontium carbonate Inorganic materials 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 229910012974 LiCo2 Inorganic materials 0.000 description 1
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- AAOVKJBEBIDNHE-UHFFFAOYSA-N diazepam Chemical compound N=1CC(=O)N(C)C2=CC=C(Cl)C=C2C=1C1=CC=CC=C1 AAOVKJBEBIDNHE-UHFFFAOYSA-N 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 229910001409 divalent cation oxide Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- 229940072690 valium Drugs 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
- C09K11/7783—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals one of which being europium
- C09K11/77922—Silicates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
- H01L33/50—Wavelength conversion elements
- H01L33/501—Wavelength conversion elements characterised by the materials, e.g. binder
- H01L33/502—Wavelength conversion materials
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
Definitions
- the present invention relates to a thulium-containing fluorescent substance for a
- M is a divalent cation metal including Sr or Ba, with 0.005 ⁇ x ⁇ 0.05 and
- the present invention is to provide a method of manufacturing a
- the method comprising the steps of adding europium oxide (Eu 2 O 3 ) and thulium
- a white LED is one of next-generation light-emitting elements which can replace
- the white light-emitting diode has been manufactured by mixing three-primary-colored light-emitting diodes since red, green and blue light-emitting
- silicate-based yellow fluorescent substance according to the present invention
- Eu 2 O 3 europium oxide
- Tm 2 O 3 thulium oxide
- Fig. 1 is a scanning electronic microscopic view of a yellow fluorescent substance
- Fig. 2 is a luminous intensity graph in case where an amount of added europium is
- Fig. 3 is a resultant emission spectrum graph in an Example 4 of the present
- Fig. 4 is a luminous intensity graph for a white LED obtained in an Example 5 of
- Fig. 5 is a resultant light excitation spectrum graph of a fluorescent substance
- M is a divalent cation metal including Sr or Ba, with 0.005 ⁇ x ⁇ 0.05 and
- the present invention is to provide a method of manufacturing a yellow
- Eu 2 O 3 europium oxide
- Tm 2 O 3 thulium oxide
- post-processing including a pulverizing process.
- the present invention is to provide a thulium-containing fluorescent substance for a white light emitting diode, characterized in that the fluorescent substance is
- M is a divalent cation metal including Sr or Ba
- A is a univalent cation
- R is a rare earth metal including Ce, Pr, Sm
- silicate-based yellow fluorescent substance according to the present invention
- Tm 2 O 3 thulium oxide
- carbonate compound containing a divalent cation and silicon oxide (SiO 2 ) is
- Eu 2 O 3 europium oxide
- Tm 2 O 3 thulium oxide
- the luminance may be reduced due to a
- thulium oxide which is a co-
- Tm 0.03 : 0.01.
- a mixer such as balling milling or
- thermal treatment temperature is higher than 1,300 0 C, there may be a problem that non ⁇
- the obtained material was placed into a distilled water and pulverized using
- Fig. 1 is a scanning electronic microscopic view of the yellow fluorescent
- substance according to the present invention is particles having a size of 10-30 ⁇ m.
- the yellow fluorescent substance has a superior emission luminance compared with an
- europium ion greatly contributes to a yellow emission of silicate fluorescent substance.
- Tm 2+ divalent thulium ion
- thulium is oxidized and this delays the oxidation of europium ion, thereby increasing the
- Example 4 a white LED is manufactured, and the result is shown in Fig. 4.
- thulium exists as two types, both in divalent and trivalent state within a silicate fluorescent substance, and it increases lifetime and stability
- luminous intensity can be enhanced and the stability of lifetime and crystal can be induced.
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Luminescent Compositions (AREA)
Abstract
The present invention relates to a thulium-containing fluorescent substance for a white light emitting diode represented by a following chemical formula 1, [Chemical Formula 1 ] (M1-X-J7EuxTnIy)2SiO4 where M is a divalent cation metal including Sr or Ba, with 0.005 < x < 0.05 and 0.005 < y < 0.05. The silicate-based yellow fluorescent substance according to the present invention is sufficiently excited by a blue light source generated by a blue LED to exhibit a yellow emission, with superior luminous intensity, due to the addition of europium oxide (Eu2O3) and thulium oxide (Tm2O3) as an activator, thereby being suitable for a white LED.
Description
THULIUM-CONTAINING FLUORESCENT SUBSTANCE FOR WHITE
LIGHT EMITTING DIODE AND MANUFACTURING METHOD THEREOF
[Technical Field]
The present invention relates to a thulium-containing fluorescent substance for a
white light emitting diode(LED) represented by a following chemical formula 1,
[Chemical Formula 1]
(Mi-x-yEuxTmy)2Si04
where M is a divalent cation metal including Sr or Ba, with 0.005<x<0.05 and
0.005<y<0.05.
Furthermore, the present invention is to provide a method of manufacturing a
fluorescent substance for a white light-emitting diode of the above chemical formula 1, that
is, for a yellow fluorescent substance, wherein a silicate-based compound is used as a host
material, the method comprising the steps of adding europium oxide (Eu2O3) and thulium
oxide (Tm2O3) to this substance and mixing them together; thermally treating a material
obtained in the mixing step in a temperature between 1,000-1,500 °C; and post-processing
including a pulverizing process.
[Background Art]
A white LED is one of next-generation light-emitting elements which can replace
the existing general lights, and the white light-emitting diode has been manufactured by
mixing three-primary-colored light-emitting diodes since red, green and blue light-emitting
diodes having a high luminance began to be commercialized.
Due to a remarkable development of technology, a yellow fluorescent substance
can be excited by a blue light source having a wavelength of 460 nm using a blue light-
emitting diode having sufficient excited energy, and thus a white light-emitting diode can
be manufactured by mixing blue and yellow.
[Disclosure]
[Technical Problem]
However, in order to implement a white light-emitting diode having high
luminance, it is required to provide a yellow fluorescent substance having high luminance
excited by a blue light source generated from a blue light-emitting diode to emit a light.
[Technical Solution]
Accordingly, the present invention is made by taking the problem mentioned
above into consideration, and a silicate-based fluorescent substance activated by europium,
having low luminous efficiency, is doped by thulium as a co-activator under blue light
source excitation, thereby providing a thulium-containing fluorescent substance for a white
light emitting diode and a manufacturing method thereof to enhance light-emitting
efficiency even under blue light source excitation.
[Advantageous Effects]
The silicate-based yellow fluorescent substance according to the present invention
is sufficiently excited by a blue light source generated by a blue LED to exhibit a yellow
emission, and especially the luminous intensity is superior, thereby having an effect
suitable for a white LED, and also an effect of superior yellow-emitting luminance can be
obtained by adding europium oxide (Eu2O3) and thulium oxide (Tm2O3) as an activator.
[Description of Drawings]
The above and other objects, features and advantages of the present invention will
become apparent from the following description of preferred embodiments given in
conjunction with the accompanying drawings, in which:
Fig. 1 is a scanning electronic microscopic view of a yellow fluorescent substance
obtained in an Example 2 of the present invention,
Fig. 2 is a luminous intensity graph in case where an amount of added europium is
changed in an Example 3 of the present invention,
Fig. 3 is a resultant emission spectrum graph in an Example 4 of the present
invention,
Fig. 4 is a luminous intensity graph for a white LED obtained in an Example 5 of
the present invention, and
Fig. 5 is a resultant light excitation spectrum graph of a fluorescent substance
obtained in an Example 6 of the present invention.
[Best Mode]
Hereinafter, the embodiments of the present invention will be described in detail
with reference to accompanying drawings.
In order to achieve the above-mentioned object, the present invention is
characterized to provide a thulium-containing fluorescent substance for a white light
emitting diode represented by a following chemical formula 1,
[Chemical Formula 1]
(M1-x-yEuχTmy)2Siθ4
where M is a divalent cation metal including Sr or Ba, with 0.005<x<0.05 and
0.005<y<0.05.
Also, the present invention is to provide a method of manufacturing a yellow
fluorescent substance of the above chemical formula 1, characterized in that a silicate-
based compound is used as a parent substance, the method comprising the steps of adding
europium oxide (Eu2O3) and thulium oxide (Tm2O3) to this substance and mixing them
together; thermally treating a material obtained in the mixing step in a temperature
between 1,000-1,500 °C; and post-processing including a pulverizing process.
Furthermore, the present invention is to provide a thulium-containing fluorescent
substance for a white light emitting diode, characterized in that the fluorescent substance is
represented by a following chemical formula 2,
[Chemical Formula 2]
(M1-x-y.z-αEuxTmyAzRα)2Siθ4
where M is a divalent cation metal including Sr or Ba, and A is a univalent cation
metal including Li or K with 0.00<z<0.05, and R is a rare earth metal including Ce, Pr, Sm
or Gd with 0.00<α<0.05.
The silicate-based yellow fluorescent substance according to the present invention
is sufficiently excited by a blue light source generated by a blue LED to exhibit a yellow
emission, and especially the luminous intensity is superior, thereby having an effect
suitable for a white LED.
According to the present invention, in particular, it is characterized to obtain an
effect of superior yellow-emitting luminance by adding europium oxide (Eu2O3) and
thulium oxide (Tm2O3) as an activator.
Such a yellow fluorescent substance according to the present invention will be
described in more detail as follows based on a manufacturing method thereof.
First, carbonate compound containing a divalent cation and silicon oxide (SiO2) is
added by europium oxide (Eu2O3) as an activator and thulium oxide (Tm2O3) as a co-
activator to mix them.
At this time, 0.005-0.04 mol of the europium oxide, which is used as an activator,
is added to a carbonate compound among fluorescent substance raw materials. There
occurs a problem that it may not be a sufficient amount to function as an activator if the
amount less than 0.005 mol is used, and the luminance may be reduced due to a
concentration quenching phenomenon if more than 0.04 mol is used.
According to the present invention, furthermore, thulium oxide, which is a co-
activator, is used together, and it will be an optimal amount when the molar ratio of Eu :
Tm is 0.03 : 0.01.
The fluorescent substance raw materials and co-activator as described above were
measured respectively to be a specific ratio according to a desired composition, and
sufficiently mixed to be a uniform composition using a mixer, such as balling milling or
agate mortar under ethanol solvent for an effective mixing. Then, the mixture was placed
into an oven and dried at a temperature between 100-150 °C for 24 hours. The dried
mixture was placed into a high-purity alumina boat and thermally treated at a temperature
between 1,000-1,300 °C using an electric furnace, and then sufficiently pulverized. If
thermal treatment temperature is higher than 1,300 0C, there may be a problem that non¬
uniform growth of particles is caused due to an oversintering phenomenon to reduce the
luminance, and if lower than 1,000 0C, it may be not good because the phase formation
property is inferior.
Photoluminescence (PL) was measured for this powder using a fluorescence
spectrophotometer, and as a result a yellow fluorescent substance represented by the
chemical formula 1, having a maximum emission peak at 560 nm, showing a strong
emission spectrum in a range between 475-680 nm, and exhibiting a superior emission
luminance, was obtained.
In this way, the thulium-containing silicate-based yellow fluorescent substance
manufactured according to the present invention is excited by a blue light source generated
by a blue LED to exhibit a yellow emission having superior luminous intensity, thereby
having high luminance suitable for a white LED.
Hereinafter, it will be described in more detail through examples.
Example 1: Manufacture of Fluorescent Substance
(Sro.75Bao.21Euo.o3Tmo.o1)2Siθ4
With a ratio of 0.75 mol strontium carbonate, 0.21 mol barium carbonate, 0.03 mol
europium oxide, 0.01 mol thulium oxide, and 1 mol silicon oxide, raw materials were
measured to be mixed uniformly using an agate mortar. The mixed specimen is dried at
130 °C for 24 hours using an oven. The obtained mixture was placed into a high-purity
alumina boat and the electric furnace was heated at 1,300 °C for 4 hours in a reducing
atmosphere. The obtained material was placed into a distilled water and pulverized using
ultra waves and a mixer, and then ball-milled to obtain a yellow fluorescent substance
represented by (Sro,75Bao.21Euo.o3Tm0.oi)2Siθ4.
Example 2: Surface Shape of Silicate-Based Yellow Fluorescent Substance to
Which Europium and Thulium are Added
Similarly implemented as in the Example 1, but 0.76 mol of strontium carbonate
and 0.03 mol of europium oxide were added respectively to obtain a yellow fluorescent
substance represented by (Sro.76Ba0.21Euo.02Tmo.oi)2Si04. Then, the obtained yellow
fluorescent substance was observed by a scanning electronic microscope, and the surface
shape is shown in Fig. 1.
Fig. 1 is a scanning electronic microscopic view of the yellow fluorescent
substance obtained in an Example 2 of the present invention.
As shown in Fig. 1, it is confirmed that the silicate-based yellow fluorescent
substance according to the present invention is particles having a size of 10-30 μm.
Example 3: Photoluminescence Intensity of Silicate-Based Yellow Fluorescent
Substance according to the Europium Content
For a yellow fluorescent substance represented by (Sro.79-xBao.2iEux)2Siθ4,
photoluminescence was measured for the specimens in which an amount of added
europium has been changed, and the result is shown in Fig. 2.
As shown in Fig. 2, it is confirmed that emission luminance gradually increased by
adding europium to the yellow fluorescent substance of the invention, but emission
luminance decreased due to a concentration quenching phenomenon in case where an
amount of added europium is more than 0.0035 mol. Accordingly, it is confirmed that a
range of added europium capable of exhibiting an especially superior emission luminance
is 0.025-0.035 mol.
Example 4: Comparison of Emission Spectrum of Fluorescent Substance
(Sro.76Bao.2iEuo.o3)2Si04 with Fluorescent Substance in Which Thulium is Added to
This Substance
Emission spectrum was measured for the fluorescent substance
(Sro.76Ba0.21Euo.03)2Siθ4 obtained in the Example 3 and the fluorescent substance (Sro.76-
yBa0.21Euo.o3Tmy)2Siθ4, and the result is shown in Fig. 3.
As shown in Fig. 3, as europium and thulium were added by 0.03 mol and 0.01
mol respectively, the yellow fluorescent substance according to the present invention
exhibits a yellow emission having a peak wavelength at 560 nm, and it is confirmed that
the yellow fluorescent substance has a superior emission luminance compared with an
emission spectrum of fluorescent substance (SrC76BaC21EUcOs)2SiO4. Consequently, it is
confirmed that europium ion (Eu ) works as an activator on fluorescent substance
(Sro.76Bao.21Euo.03)2Si04 to exhibit a yellow emission, and thulium ion (Tm2+), which has
been added together with the europium ion, as a co-activator for transferring energy to the
europium ion, greatly contributes to a yellow emission of silicate fluorescent substance.
Since divalent thulium ion (Tm2+) is a material which is unstable at room temperature and
in air as well as has a high oxidizing power, it has a tendency to be re-oxidized to trivalent
thulium ion (Tm3+) in silicate environment. Because oxidizing power at this time is greater
than the oxidizing power of europium ion from a divalent to a trivalent state, firstly
thulium is oxidized and this delays the oxidation of europium ion, thereby increasing the
lifetime as well as enhancing the stability of reduced europium ion due to this effect.
Furthermore, substitution, surface defect, or the like in europium are controlled to help its
crystal growth, and as a result it is expected to have an effect of increasing luminous
intensity.
Example 5: Manufacture of a White LED Using Fluorescent Substance
(SrC75BaO-21EUcOsTmO-Oi)2SiO4
Using fluorescent substance (Sro.75Bao.21Euo.o3Tmo.01)2Siθ4 obtained in the
Example 4, a white LED is manufactured, and the result is shown in Fig. 4.
As shown in Fig. 4, it is confirmed that the yellow fluorescent substance of the
invention exhibits a superior yellow emission at 560 nm in a blue excited light of 465 nm,
and the blue excited light and the yellow emission are combined to emit a white light.
Example 6: Manufacture of Fluorescent Substance
(SrO-72BaO-2IEUcOsTmCo1LiCo2GdO-Oi)ZSiO4
In case of the Example 4, thulium exists as two types, both in divalent and
trivalent state within a silicate fluorescent substance, and it increases lifetime and stability
when re-oxidizing from a divalent to a trivalent state. At this time, however, thulium
oxidized to a trivalent state may reduce luminous characteristics due to a charge valence
difference from strontium, which is a divalent cation. Accordingly, there may be a method
of adding univalent lithium for a method of reducing the charge quantity of thulium, which
has been re-oxidized to a trivalent state, again to a divalent state. Through transferring
electrons between thulium, which has been re-oxidized to a trivalent state, and univalent
lithium, the charge quantity of strontium, valium, europium, thulium, and lithium
consisting of a cationic group, is all controlled to a divalent level, thereby facilitating
energy transfer. Accordingly, through the site control, good crystal growth, and increased
energy transfer of europium by adding thulium and lithium in proportioning materials,
luminous intensity can be enhanced and the stability of lifetime and crystal can be induced.
Light excitation spectrum was measured for fluorescent substance
(Sro.72Bao.2iEuo.o3Tmo.oiLio.o2Gdo.oi)2Siθ4 obtained in the Example 6 and
(Sro.76Ba0.21Euo.o3)2Si04 to which co-activators such as thulium or the like is not added, and
the result is shown in Fig. 5.
As shown in Fig. 5, it can be seen that the luminous intensity of fluorescent
substance (a) (SrC72BaC21EUoOsTmCQ1LiO1O2GdCOi)2SiO4 increases more than 15 %
compared with fluorescent substance (b) to which a co-activator such as Tm or the like is
not added in vicinity of 450 nm, which is a blue LED light source.
[Industrial Applicability]
As stated above, according to the present invention, by adding europium as an
activator and thulium as a co-activator to a silicate-based fluorescent substance, it has high
luminance as well as exhibits a yellow emission under excitation of a blue light source
having a wavelength of 460 nm generated from a blue LED, and therefore it is useful as a
yellow fluorescent substance applicable to fluorescent substance for a white LED.
Moreover, by adding lithium, it can prevent the variation of charge quantity caused by the
re-oxidation of thulium, and increase lifetime, thereby enhancing the overall stability of
crystal.
Claims
[Chemical Formula 1]
(M 1-x-yEuxTmy)2 SiO4
where M is a divalent cation metal including Sr or Ba with 0.005<x<0.05 and
0.005<y<0.05.
[Claim 2]
The thulium-containing fluorescent substance for a white light emitting diode
according to claim 1, characterized in that the europium oxide and thulium oxide are used
to become l≤x/y<5.
[Claim 3]
A method of manufacturing a thulium-containing fluorescent substance for a white
light emitting diode as a manufacturing method of claim 1, characterized in that a silicate-
based compound is used as a parent substance, the method comprising the steps of:
adding europium oxide (Eu2O3) and thulium oxide (Tm2O3) to this substance and
mixing them together;
thermally treating a material obtained in the mixing step in a temperature between
1,000-1,500 °C; and
post-processing including a pulverizing process.
[Claim 4]
A thulium-containing fluorescent substance for a white light emitting diode,
characterized in that the fluorescent substance is represented by a following chemical
formula 2,
[Chemical Formula 2]
(M1-x-y-z-αEuχTmyAzRα)2Si04
where M is a divalent cation metal including Sr or Ba, and A is a univalent cation
metal including Li or K with 0.00<z<0.05, and R is a rare earth metal including Ce5 Pr, Sm
or Gd with 0.00≤α<0.05.
[Claim 5]
A method of manufacturing a thulium-containing fluorescent substance for a white
light emitting diode as a manufacturing method of claim 4, characterized in that a silicate-
based compound is used as a parent substance, the method comprising the steps of:
adding europium oxide (Eu2O3), thulium oxide (Tm2O3), lithium carbonate
(Li2CO3), and gadolinium oxide (Gd2O3) to this substance and mixing them together;
thermally treating a material obtained in the mixing step in a temperature between
1,000-1,500 0C; and
post-processing including a pulverizing process.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009516390A JP5391065B2 (en) | 2006-06-21 | 2007-06-05 | Thulium-containing yellow fluorescent material for white light emitting diode and method for producing the same |
| CN2007800230976A CN101473013B (en) | 2006-06-21 | 2007-06-05 | Thulium-containing fluorescent substance for white light emitting diode and manufacturing method thereof |
| US12/305,735 US8119030B2 (en) | 2006-06-21 | 2007-06-05 | Thulium-containing fluorescent substance for white light emitting diode and manufacturing method thereof |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20060055876 | 2006-06-21 | ||
| KR10-2006-0055876 | 2006-06-21 | ||
| KR10-2007-0036378 | 2007-04-12 | ||
| KR1020070036378A KR100939936B1 (en) | 2006-06-21 | 2007-04-13 | Thullium Containing Fluorescent Substance For White Light Emitting Diode And Manufacturing Method Thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2007148880A1 true WO2007148880A1 (en) | 2007-12-27 |
Family
ID=38833593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/KR2007/002723 WO2007148880A1 (en) | 2006-06-21 | 2007-06-05 | Thulium-containing fluorescent substance for white light emitting diode and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2007148880A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010026297A (en) * | 1999-09-04 | 2001-04-06 | 박호군 | New Silicates Phosphors for Lamp |
| WO2004056939A1 (en) * | 2002-12-20 | 2004-07-08 | Toyoda Gosei Co., Ltd. | Luminescent body and optical device including the same |
| WO2004097949A1 (en) * | 2003-04-25 | 2004-11-11 | Luxpia Co. Ltd. | White semiconductor light emitting device |
-
2007
- 2007-06-05 WO PCT/KR2007/002723 patent/WO2007148880A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010026297A (en) * | 1999-09-04 | 2001-04-06 | 박호군 | New Silicates Phosphors for Lamp |
| WO2004056939A1 (en) * | 2002-12-20 | 2004-07-08 | Toyoda Gosei Co., Ltd. | Luminescent body and optical device including the same |
| WO2004097949A1 (en) * | 2003-04-25 | 2004-11-11 | Luxpia Co. Ltd. | White semiconductor light emitting device |
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