JP2000265169A - Production of white light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an yellow light fluorescent powder capable of controlling a working wavelength by setting to have a specified compounding ratio and capable of keeping yellow light conversion rate at high efficiency by controlling the mole ratio of gadolinium. SOLUTION: This yellow light fluorescent powder is obtained by having a composition of the formula (Y1-p-xCepGdx)3Al5O12 [0<=p<=0.05; x is molar fraction of gadolinium and 0<=x<=1], making controllable a working wavelength generating yellow light with irradiating blue light of 430-470 nm and making keepable yellow light conversion rate at high efficiency by controlling gadolinium molar ratio x in changing the working wavelength of blue light. It is preferable that wavelength of the blue light λ (nm) and x satisfy the formula 3x=A +Bλ+Cλ2+Dλ3+Eλ4 (A=126268.8005±0.37666; B=-1145.0025±0.3766; C=3.89314±0.00126; D=-0.00588±1.85931×10-6; E=3.33290×10-6±1.03219×10-9).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a white light source, and more particularly, to a method of manufacturing a white light source using a blue light-emitting diode and a yttrium aluminum garnet material that emits yellow light when triggered by blue light. A blue light source having a wavelength of 430 to 470 can be easily obtained by adding a fixed amount of cerium to this yttrium aluminum garnet material and not including samarium, and adjusting the content of gadolinium therein. The present invention relates to a method for generating high-purity white light in combination.

[0002]

2. Description of the Related Art Lighting is indispensable in modern life, and the power used for lighting worldwide accounts for about 40% of the total power consumption. Therefore, development of energy-saving lighting fixtures is required. Recently (September 1996), Nichia Chemical of Japan has been promoting the use of yttrium aluminum garnet (Y ₃ A) which emits yellowish light.
l ₅ O ₁₂ , Yttrium Aluminum-Ga
rnet (YAG)) blue light-emitting diode containing fluorescent powder was developed, and a highly efficient white light source could be manufactured. Among them, the yttrium aluminum garnet fluorescent powder emits yellow light after the blue light emitting diode emits blue light. The yellow light is mixed with the blue light of the original diode to generate white light. This white light-emitting diode has a characteristic of emitting light under an extremely low current (20 mA), its color temperature (8000 K) is not inferior to that of a sunlight-colored daylight, and its color reproducibility is high-performance daylight. (Three-wavelength type). The average brightness per light is one watt or five luminants, two of which exceed the interior light of a car (eight luminants). Compared with the white light emitting diode device composed of traditional three primary color light emitting diode chips, its structure is simple, the manufacturing cost is halved, and the individual single color light emitting diode deteriorates and the color becomes non-uniform No problem. Lighting equipment using this white light-emitting diode consumes less power, saves energy resources, and will be used in the future in automotive meter board peripherals, liquid crystal backlights, indoor lighting, notebook computer displays, scanners, and fax machines. And it can be applied to applications such as military lighting.

[0003] The world patent of the Nichia Corporation (WO98 /
5078), the distribution of the fluorescent powder is (Re _1-r S
_{m r) 3 (Al 1-} s Ga s) is ₅ O _12, of which,
0 ≦ r <1, 0 ≦ s ≦ 1, and Re is yttrium (Y)
Alternatively, it is gadolinium (Gd). In this distribution, cerium (Ce) is added in an extrinsic manner, and according to the distribution shown in this patent, (Y _{1 -X} Gd
_x ) ₃ Al ₅ O ₁₂ (0 ≦ x ≦ 0.8). Among them, the number of moles of cerium (Ce) added is 0.003, that is, a solid solution of cerium (Ce) and yttrium (Y) or gadolinium (Gd) having a total measuring ratio of 3 before the addition of cerium (Ce). (Solid solution
n) is [(1-x) + x] × 3 + 0.003 =
It has a relationship of 3.003. The fluorescent powder formed by such a method often tends to form an impurity phase due to the deviation of the components, and the quality thereof has deteriorated. The sum of the measurement ratio is 3
To form a solid state solution, by adding a samarium (Sm) _{element, (Y 1-p- qr Gd} p Ce q Sm
_{r) 3 (Al 1-s} Ga s) 5 O 12 ( of which 0 ≦ p ≦
0.8, 0.003 ≦ q ≦ 0.2, 0.0003 ≦ r ≦
0.08, 0 ≦ s ≦ 1) must be formed. That is, it is necessary that cerium (Ce) and samarium (Sm) be present at the same time.
e), the total of the measurement ratios of yttrium (Y), gadolinium (Gd) and samarium (Sm) could be set to 3. That is, [(1-pq-r) + p + q + r] × 3 =
3, wherein q and r are not both 0. In addition, generally manufactured InGaN-type blue light emitting diodes require complicated growth conditions during manufacture, and the blue light generated thereby is controlled to a constant wavelength, but the control is difficult. Normally manufactured blue light has a wavelength of 430 to 470 nm, and fluctuates by about 40 nm. The fluorescent powder provided by Nichia Corporation is applied only to a certain specific wavelength, so that high-purity, high-brightness white light cannot be achieved in practical applications.

[0004]

SUMMARY OF THE INVENTION The present invention is a method for producing a white light source that produces high purity and high brightness white light combined with the existing blue light source wavelength range by simply adjusting a single component. The challenge is to provide

According to the present invention, in a method for manufacturing a white light source utilizing a blue light diode and a yttrium aluminum garnet material that emits yellow light when triggered by blue light, the yttrium aluminum garnet material is provided with a fixed amount of cerium. And does not contain samarium. According to the invention, the single-phase (Y _0.98
3-x Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ can be used, and there is no need to add expensive samarium (Sm) -containing rare earth material, that is, a function of generating white light triggered by blue light can be achieved. . The wavelength of 430 to 470 n can be obtained simply by adjusting the gadolinium (Gd) content.
m high blue light can be generated in combination with the m blue light.

[0006]

The invention of claim 1 is a yellow light fluorescent powder capable of adjusting the working wavelength, which emits yellow light after irradiating blue light having a working wavelength of 430 nm to 470 nm, and generates the yellow light. The distribution of the fluorescent powder is (Y _1-px Ce _p
Gd _x ) ₃ Al ₅ O _12, and when the working wavelength of blue light changes, adjusting the molar ratio x of gadolinium (Gd) allows the yellow light fluorescent powder to maintain a high efficiency yellow light conversion rate. The present invention is characterized in that it is a yellow light fluorescent powder. According to a second aspect of the present invention, 0 ≦ p ≦ 0.05, 0 ≦ x ≦ 1
The yellow light fluorescent powder according to claim 1, characterized in that: The third aspect of the present invention provides the wavelength λ of blue light.
(Nm) and the molar ratio x of gadolinium (Gd) are as follows: 3x = A + Bλ + Cλ ² + Dλ ³ + Eλ ⁴ where A = 1262688.805 ± 0.3766
6 B = -1145.0025 ± 0.37666 C = 3.89144 ± 0.00126 D = −0.00588 ± 1.85931 × 10 ⁻⁶ E = 3.3290 × 10 ⁻⁶ ± 1.03219 × 10 ^{− 9.} The yellow light fluorescent powder according to claim 1, wherein the yellow light fluorescent powder is the same as the yellow light fluorescent powder. The invention according to claim 4 includes the following steps: Y ₂ O ₃ , Ce (No ₃ ) ₃ , Gd ₂ O ₃ and Al
Using (NO ₃ ) ₃ , the molar ratio is Y: Ce: Gd: Al
= 2.949-3x: 0.051: 3x: T, where 0 ≦
Forming a mixture of x ≦ 1 and polishing and mixing, forging in air at 1000 ° C. for 24 hours. The material obtained in step 2.1 is further ground and mixed, and further baked in air at 1500 ° C. for 24 hours. Coupling Step 3.2 The material obtained in the step of 3.2 is further polished, mixed with silicon at a weight ratio of 0.24: 1, and further coated on a blue light source having a wavelength of 430 to 470 nm. And a method for manufacturing a white light source. According to a fifth aspect of the present invention, there is provided the white light source manufacturing method according to the fourth aspect, wherein a gel method can be adopted instead of the sintering step. According to a sixth aspect of the present invention, there is provided the white light source manufacturing method according to the fourth aspect, wherein a coprecipitation method can be adopted instead of the sintering step. According to a seventh aspect of the present invention, in the method for manufacturing a white light source of the fourth aspect, the blue light source is an InGaN blue light emitting diode. According to an eighth aspect of the present invention, in the method for manufacturing a white light source according to the fourth aspect, the wavelength λ (nm) of the blue light source and the molar ratio of gadolinium (Gd) are represented by the following relational expressions: 3x = A + Bλ + Cλ ² + Dλ ³ + Eλ ⁴ Of which, A = 126268.8005 ± 0.3766
6 B = -1145.0025 ± 0.37666 C = 3.89144 ± 0.00126 D = −0.00588 ± 1.85931 × 10 ⁻⁶ E = 3.3290 × 10 ⁻⁶ ± 1.03219 × 10 ^{− A} method for producing a white light source, characterized by matching ⁹ or more.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Please refer to FIG. According to a preferred embodiment of the method for manufacturing a white light source of the present invention, the white light source of the present invention includes a blue light emitting diode and a yttrium aluminum garnet fluorescent powder that is triggered by receiving blue light to generate yellow light. The manufacturing steps include: Step 100 is a forging step, in which the phosphor powder of the present invention is formed by a solid state reaction, that is, Y ₂ O ₃ , Ce
Using (No ₃ ) ₃ , Gd ₂ O ₃ and Al (NO ₃ ) ₃ , the molar ratio is Y: Ce: Gd: Al = 2.949-3.
A mixture of x: 0.051: 3x: T (0 ≦ x ≦ 1) is formed, and after polishing and mixing, the mixture is forged in air at 1000 ° C. for 24 hours. Step 102 is a sintering step, in which the material obtained in step 100 is further polished and mixed, and
The powder is sintered in the air at 500 ° C. for 24 hours to form the phosphor powder of the present invention. In addition, the powder of the present invention can be formed by a gel method or a coprecipitation method. Step 10
Step 4 is a step of combining the fluorescent powder obtained in step 102 with a blue light source. That is, after the phosphor powder is further polished, it is mixed with silicon at a weight ratio of 0.24: 1, and further mixed with InGaN blue light (wavelength 430 to 47).
0 nm), the structure is resin-sealed using conventional light emitting diode technology, and an appropriate current is applied to form a light emitting diode that produces white light.

The features of the manufacturing method of the present invention will be described below with reference to the drawings. FIG. 1 shows (Y
_0.983-x Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ fluorescent powder (0
≦ x ≦ 1) X-ray diffraction pattern. If the value of x is 0
When 0.6, a single-phase compound was formed, when x was 0.8, a small number of impurity phases were present, and when x> 0.8, the formed compound contained a large amount of impurity phases. Ia-3
The above YAG compound is indexed by a cubic structure having a space group of d and a lattice constant of 12 angstroms,
Therefore, the distribution of the present invention is an internal addition method that does not depend on the presence of the samarium (Sm) element, and forms a single phase or a compound approaching a single phase within the range of 0 ≦ x ≦ 0.8. It has been proved that the disadvantage of generating the impurity phase is improved.

FIG. 2 shows (Y _0.983-x Ce _0.017 G) of the present invention.
d _x ) Trigger spectrum of ₃ Al ₅ O ₁₂ fluorescent powder (0 ≦ x ≦ 0.6). Gadolinium (G
According to d), the yellow fluorescent powder was converted to blue light (wavelength 457n).
The absorption spectrum band triggered in m) shifts to longer wavelengths, i.e., produces a red shift, which means that, when properly combined with blue light of a different wavelength, it can produce pure white light. Show.

FIG. 3 shows (Y _0.983-x Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ blue light having a wavelength of 430 nm and gadolinium (Gd) contents (x) of 0, 0.2 and 0.4, respectively.
It is the spectrum which triggered the fluorescent powder. Among them, x in the curves 1, 2 and 3 is set to 0, 0.2 and 0.4.
As can be seen from the figure, when x = 0, white light with high purity can be generated. When x = 0.2 or 0.4, white-violet light is generated. That is, after the value of x increases, a red shift occurs and white light becomes impure. Therefore, when the wavelength of blue light is 430 nm, white light with high purity is combined with a value of x that is 0. (Y _0.983-x
Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ fluorescent powder.

FIG. 4 shows blue light having a wavelength of 470 nm and gadolinium (Gd) content (x) of 0.2 and 0.2, respectively.
8 is a spectrum triggered by (Y _0.983-x Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ fluorescent powder. Curve 4,
X in 5 is set to 0.2 and 0.8. As can be seen from the figure, when x = 0.2, white light including green light is generated, that is, white light with low purity is generated. Also, x = 0.8
At this time, white light with high purity is generated. From this, when the wavelength of blue light is 470 nm, the combination of the values of x is 0.8 (Y
_{0.983-x Ce 0.01 7 Gd x} ) must be a ₃ Al ₅ O ₁₂ phosphor powder.

FIG. 5 shows blue light having a wavelength of 460 nm.
(Y) each having a content of (n) (x) of 0.2
_0.983-x Ce_0.017 Gd_x )_Three Al_Five O₁₂Fluorescent powder
It is a rigged spectrum. As you can see from this figure,
High-purity white light is emitted when the wavelength of blue light is 460 nm.
Combined to produce (Y
_0.983-x Ce_0.017 Gd_x )_Three Al_Five O₁₂Fluorescent powder
It must be.

FIG. 6 shows the present invention, in which different gadolinium (Gd) contents (x) (Y _0.983-x
10 is a spectrum triggered by Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ fluorescent powder, and is a best curve diagram of white light generation;
This best curve corresponds to the following equation: 3x = A + Bλ + Cλ ² + Dλ ³ + Eλ ⁴ where A = 126268.8005 ± 0.3766
6 B = -1145.0025 ± 0.37666 C = 3.89144 ± 0.00126 D = −0.00588 ± 1.85931 × 10 ⁻⁶ E = 3.3290 × 10 ⁻⁶ ± 1.03219 × 10 ^{− 9} Among them, λ (nm) is the wavelength of blue light, and x is the content of gadolinium (Gd). If you combine blue light of different wavelengths, then substituting into this equation,
Combined (Y _0.983-x Ce _0.017 Gd _x ) ₃ Al ₅
The x value of the O ₁₂ fluorescent powder, that is, the content of gadolinium (Gd) is determined. In this way, the best distribution can be found, and the disadvantages of having to find the best distribution by numerous experiments in the conventional method can be improved.

[0014]

The method of manufacturing a white light source according to the present invention is a method of manufacturing a white light source using a blue light-emitting diode and an yttrium aluminum garnet material that emits yellow light when triggered by blue light. The aluminum garnet material has a fixed amount of cerium added and does not contain samarium, and by adjusting the content of gadolinium in it, a blue light source with a wavelength of 430 to 470 is easily combined to produce high-purity white light. This method has novelty and industrial utility value.

[Brief description of the drawings]

FIG. 1 shows (Y _0.983-x Ce _0.017 Gd _x ) ₃ A of the present invention.
FIG. 3 is an X-ray diffraction pattern of l ₅ O ₁₂ fluorescent powder (0 ≦ x ≦ 1), in which “O” indicates an impurity phase.

FIG. 2 shows (Y _0.983-x Ce _0.017 Gd _x ) ₃ A of the present invention.
₅ is a trigger spectrum of l ₅ O ₁₂ fluorescent powder (0 ≦ x ≦ 0.6).

FIG. 3 is a graph showing blue light having a wavelength of 430 nm and gadolinium (Gd) content (x) of 0, 0.2 and 0.4.
(Y _0.983-x Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ Fluorescent powder was triggered, wherein x in curves 1, 2 and 3 was 0, 0.2 and 0.4, respectively. .

FIG. 4 shows (Y _0.983-x Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ fluorescence having a gadolinium (Gd) content (x) of 0.2 and 0.8 with blue light having a wavelength of 470 nm. This is the spectrum when the powder was triggered, where x in curves 4 and 5 are 0.2 and 0.8, respectively.

FIG. 5 shows (Y _0.983-x ) in which blue light having a wavelength of 460 nm and gadolinium (Gd) content (x) of 0.2 is used.
It is a spectrum when Ce _0.017 Gd _x ) ₃ Al ₅ O ₁₂ fluorescent powder is triggered.

FIG. 6 shows (Y _0.983-x Ce _0.017 ) of different gadolinium (Gd) contents (x) for blue light of different wavelengths in the present invention.
FIG. 4 is a spectrum triggered by Gd _x ) ₃ Al ₅ O ₁₂ fluorescent powder, and is a best curve diagram of white light generation.

FIG. 7 is a flowchart illustrating a method of manufacturing a white light source according to the present invention.

[Explanation of symbols]

 100 Forging step 102 Sintering step 104 Coating step

Continuing on the front page (72) Inventor Wang Jinlong 20-2 No. 294, Ethnic Road, Sanlin Village, Santan Village, Longtan Town, Taoyuan County, Taiwan No. 72 (72) Inventor Jing Jin, No. 268, No. 268, Chongming-ri, Thongxiao-ri, Tainan City, Taiwan F Term (Reference) 4H001 XA08 XA13 XA39 XA58 XA64 YA58 YA64 5F041 AA11 CA40 CA46 CA77

Claims (8)

[Claims] 1. A yellow light fluorescent powder capable of adjusting the working wavelength, wherein yellow light is generated after irradiation of blue light having a working wavelength of 430 nm to 470 nm, and the distribution of the yellow light fluorescent powder is (Y _{1 -px).} Ce _p Gd _x ) ₃ Al ₅ O _12, and when the working wavelength of blue light changes, adjusting the molar ratio x of gadolinium (Gd) allows the yellow light fluorescent powder to maintain a high efficiency yellow light conversion rate. A yellow light fluorescent powder, characterized in that it is possible. 2. The yellow light fluorescent powder according to claim 1, wherein 0 ≦ p ≦ 0.05 and 0 ≦ x ≦ 1. 3. The relationship between the wavelength λ (nm) of blue light and the molar ratio x of gadolinium (Gd) is as follows: 3x = A + Bλ + Cλ ² + Dλ ³ + Eλ ^{4 wherein} A = 1262688.8005 ± 0.3766.
6 B = -1145.0025 ± 0.37666 C = 3.89314 ± 0.00126 D = −0.00588 ± 1.85931 × 10 ⁻⁶ E = 3.3290 × 10 ⁻⁶ ± 1.03219 × 10 ⁻ The yellow light fluorescent powder according to claim 1, wherein the yellow light fluorescent powder corresponds to ⁹ . 4. The following steps: Y ₂ O ₃ , Ce (No ₃ ) ₃ , Gd ₂ O ₃ and Al
Using (NO ₃ ) ₃ , the molar ratio is Y: Ce: Gd: Al
= 2.949-3x: 0.051: 3x: T, where 0 ≦
Forming a mixture of x ≦ 1 and polishing and mixing, forging in air at 1000 ° C. for 24 hours. The material obtained in step 2.1 is further ground and mixed, and further baked in air at 1500 ° C. for 24 hours. Coupling Step 3.2 The material obtained in the step of 3.2 is further polished, mixed with silicon at a weight ratio of 0.24: 1, and further coated on a blue light source having a wavelength of 430 to 470 nm. Method for producing a white light source. 5. The method for producing a white light source according to claim 4, wherein a gel method can be adopted instead of the sintering step. 6. The method for manufacturing a white light source according to claim 4, wherein a coprecipitation method can be used instead of the sintering step. 7. The method for manufacturing a white light source according to claim 4, wherein the blue light source is an InGaN blue light emitting diode. 8. The method according to claim 4, wherein the wavelength λ (nm) of the blue light source and the gadolinium (G)
The molar ratio of d) is expressed by the following relational expression: 3x = A + Bλ + Cλ ² + Dλ ³ + Eλ ⁴ where A = 1262688.8005 ± 0.3766
6 B = -1145.0025 ± 0.37666 C = 3.89144 ± 0.00126 D = −0.00588 ± 1.85931 × 10 ⁻⁶ E = 3.3290 × 10 ⁻⁶ ± 1.03219 × 10 ^{− A} method for producing a white light source, wherein the method satisfies ⁹ or more.