CN100449803C - Phosphor and white light emitting diode thereof - Google Patents

Abstract

The invention relates to a fluorescent body and a white light-emitting diode thereof. The white light LED at least comprises a light emitting element, a coating layer coated around the light emitting element and at least two fluorescent books uniformly dispersed in the coating layer. The light emitting device can provide a blue light with a wavelength ranging from 410 to 500 nm; the fluorescent body comprises a first fluorescent body and a second fluorescent body, and can absorb part of blue light generated by the light-emitting element and respectively excite yellow green light with a wavelength range of 500-550 nm and red light with a wavelength range of 590-650 nm. By mixing the blue light, the yellow-green light and the red light, a white light can be generated.

Description

Phosphor and its white light emitting diode

technical field

The present invention relates to a fluorescent body and its white light emitting diode, in particular to a fluorescent body with high color rendering and its white light produced by using a yellow-green fluorescent body with an adjustable wavelength in combination with a red fluorescent body and a blue light source. led.

Background technique

Since the development of light-emitting diode (LED) in the 1970s, many key technologies have matured day by day. Especially in recent years, the technical bottleneck of white light-emitting diodes has been broken through, coupled with its advantages of environmental protection and energy saving, white light-emitting diodes are expected to replace traditional white light sources and become the main lighting source in the 21st century.

There are two methods of traditional white light-emitting diodes. One is to use blue light to excite yellow phosphors to generate white light. The efficiency of white light generation is high, but the disadvantage is that the color rendering index (CRI) is not good. Another way is to use ultraviolet light to mix with several phosphors that can produce different colors of light to produce white light, which can solve the above-mentioned problem of poor color rendering. However, there are still many insurmountable degradation problems in the technology of applying ultraviolet light to light-emitting diodes at present, so it is difficult to precisely control its luminous efficiency and luminous characteristics.

At present, researchers from all over the world are devoting themselves to the development of lighting equipment with higher efficiency, that is to say, when the light emitted by the excitation light source is almost without loss, the phosphor is excited to generate light with high conversion efficiency. The light source and phosphor are controlled under the most appropriate conditions to enhance the luminous ability of both. In addition, in order to improve the luminous quality of LEDs, in addition to requiring low power consumption and high brightness, their color performance is also the focus of consideration, so as to continuously improve the quality of white LEDs.

It can be seen that the above-mentioned existing phosphors and white light emitting diodes obviously still have inconveniences and defects in structure and use, and need to be further improved urgently. In order to solve the problems of phosphors and white light emitting diodes, relevant manufacturers have tried their best to find a solution, but no suitable design has been developed for a long time, and there is no suitable structure for general products. The above-mentioned problem is obviously a problem that relevant industry players are eager to solve. Therefore, how to create a new type of structure with high luminous efficiency, high brightness and high color rendering, and suitable for general and high power conditions of phosphors and white light emitting diodes, has become a goal that the industry needs to improve. .

Contents of the invention

The purpose of the present invention is to overcome the defects of existing white light emitting diodes and provide a white light emitting diode with a new structure. The problem of poor color rendering of white light emitting diodes makes them more suitable for practical use.

Another object of the present invention is to overcome the defects of existing phosphors and provide a phosphor with a new structure. The technical problem to be solved is to make it possible to adjust the ratio of metal elements in the phosphor And combination, to get the color light of the ideal wavelength range, which is more suitable for practical use.

Another purpose of the present invention is to overcome the defects of existing phosphors and provide a phosphor with a new structure. The purpose of the wavelength, and increase the radiation intensity of the phosphor, which is more suitable for practical use.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. A white light-emitting diode proposed according to the present invention comprises: a light-emitting element capable of generating blue light with a wavelength range of 410-500 nm; a cladding layer wrapped around the light-emitting element; a first phosphor, It is a trivalent europium ion-activated silicate compound with the formula ((2-xyz)Sr(x)Ca(y)Mg)·(1-a)SiO ₄ ·aGa ₂ O ₃ :(z)Eu , and its element contents x, y, z, and a are not equal to zero, the first phosphor is dispersed in the coating layer, and can absorb the blue light generated by the light-emitting element to generate yellow-green light with a wavelength range of 500-550nm; And a second phosphor, which is an alkaline earth metal sulfide activated by trivalent europium ions, the chemical formula is (xAyBzC)S:Eu, wherein the three elements of A, B and C are selected from beryllium, magnesium , calcium, strontium, barium, sodium, potassium, lithium or a group thereof, and its element content x, y and z are not equal to zero, the second phosphor is dispersed in the coating layer and can absorb the light-emitting element The blue light generated is to generate red light with a wavelength range of 590-650nm, and the yellow-green light and red light respectively emitted by the first phosphor and the second phosphor are mixed with the blue light generated by the light-emitting element. Produces white light.

The purpose of the present invention and the solution to its technical problems also adopt the following technical measures to further realize.

In the aforementioned white light emitting diode, the material of the light emitting element is gallium indium nitride, gallium nitride/silicon carbide or any combination thereof.

In the aforementioned white light emitting diode, the mixing ratios of the first phosphor and the second phosphor are respectively 3% and 1.5%.

The purpose of the present invention and the solution to its technical problem also adopt the following technical solutions to achieve. A phosphor according to the present invention, which comprises: a silicate compound whose chemical formula is ((2-xyz)Sr(x)Ca(y)Mg)·(1-a)SiO ₄ ·aGa ₂ O ₃ : (z)Eu, wherein the ratio of the element content x, y, z and a contained in the silicate compound is in the following ranges: 0.1≤x≤0.6, 0.1≤y≤0.6, 0.01≤z≤ 0.15, 0.02≤a≤0.1, wherein, x, y, z and a are not equal to zero, and the phosphor emits yellow-green light with a wavelength range of 500-550 nm after being excited.

The purpose of the present invention and the solution to its technical problems also adopt the following technical measures to further realize.

The aforementioned phosphor further includes a sensitizer selected from the group consisting of manganese, cerium, gadolinium, terbium or a combination thereof.

The purpose of the present invention and the solution to its technical problem also adopt the following technical solutions to achieve. A phosphor proposed according to the present invention comprises: an alkaline earth metal sulfide, whose chemical formula is (xAyBzC)S:Eu, wherein the three elements A, B, and C are selected from beryllium, magnesium, calcium , Strontium, Barium, Sodium, Potassium, Lithium and any combination of the above groups, the ratio of the element content x, y and z contained in the alkaline earth metal sulfide is in the following range: 0.1≤x≤0.6, 0.1≤ y≤0.6, 0.01≤z≤0.15. Wherein, x, y and z are not equal to zero, and the phosphor emits red light with a wavelength range of 590-650nm after being excited.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. As can be seen from above technical scheme, main technical content of the present invention is as follows:

In order to achieve the above object, the present invention provides a phosphor, which proposes a silicate compound activated by trivalent europium (Eu) ions, which can be excited by blue light to generate yellow-green light with a wavelength range of 500-550nm. According to a preferred embodiment of the present invention, the chemical formula of the silicate compound is ((2-xyz)Sr(x)Ca(y)Mg)·(1-a)SiO ₄ ·aGa ₂ O ₃ :(z ) Eu, the purpose of adjusting the wavelength can be achieved by adding different substitution amounts of metals x, y, z and a. In addition, a sensitizer, such as manganese or lanthanide metal elements, can be used to increase the radiation intensity of the phosphor.

In addition, in order to achieve the above object, the present invention also provides a phosphor, which proposes an alkaline earth metal sulfide activated by trivalent europium (Eu) ions, which can be excited by blue light to generate red light with a wavelength range of 590-650nm . According to a preferred embodiment of the present invention, the chemical formula of the alkaline earth metal sulfide is (xAyBzC)S:Eu. The main elements A, B or C that make up the alkaline earth metal sulfide can be selected from any three of divalent metal elements or monovalent alkali metal elements, such as beryllium, magnesium, calcium, strontium, barium, sodium, potassium, lithium, etc. , by adjusting the ratio and combination of the aforementioned metal elements, an ideal wavelength range can be obtained.

In addition, in order to achieve the above object, the present invention also provides a white light emitting diode, which has a light emitting element, a coating layer and at least two phosphors.

According to a preferred embodiment of the present invention, the material of the above-mentioned light-emitting element is a multi-component composite compound of the VA group, which can emit blue light with a wavelength range of 410-500 nm. The cladding layer wraps around the light-emitting element and is a transparent packaging material, such as inorganic transparent glue, which can improve the light extraction efficiency of the white light-emitting diode package. Two phosphors are evenly dispersed in the cladding layer, including a first phosphor, which can absorb part of the blue light generated by the light-emitting element, and convert it into yellow-green light with a wavelength range of 500-550nm; and a second phosphor, which can Absorb part of the blue light generated by the light-emitting element and convert it into red light with a wavelength range of 590-650nm. By properly controlling the wavelength ranges of the blue light, yellow-green light and red light, white light with high luminous efficiency and a color rendering of over 88 can be produced.

With the above-mentioned technical solution, the phosphor and its white light emitting diode of the present invention have at least the following advantages:

1. The alkaline earth metal sulfide-based phosphor of the present invention can obtain color light in an ideal wavelength range by adjusting the ratio and combination of metal elements in the phosphor, which is more suitable for practical use.

2. The silicate compound-based phosphor of the present invention can adjust the wavelength by adding different amounts of metals, and increase the radiation intensity of the phosphor, so it is more suitable for practical use.

3. The light-emitting diode of the present invention can produce white light with high luminous efficiency and a color rendering of 88 or more by properly controlling the wavelength ranges of blue light, yellow-green light and red light.

Therefore, according to the above, the present invention uses a yellow-green phosphor with an adjustable wavelength to match red phosphor and blue light, and the color rendering of white light emitting diodes can be significantly improved by mixing the three colors of light.

To sum up, the present invention relates to a fluorescent body and a white light emitting diode thereof. The white light emitting diode at least includes a light-emitting element, a cladding layer wrapped around the light-emitting element, and at least two phosphors uniformly dispersed in the cladding layer. The light-emitting element can provide a blue light with a wavelength range of 410-500nm; the phosphor includes a first phosphor and a second phosphor, which can absorb part of the blue light generated by the light-emitting element, and respectively excite them with a wavelength range of 500-550nm Yellow-green light and red light with a wavelength range of 590-650nm. A white light can be produced by mixing the above mentioned blue light, yellow-green light and red light. The present invention can improve the problem of poor color rendering of white light-emitting diodes made by traditional photoluminescence methods; in addition, by adjusting the ratio and combination of metal elements in the phosphor, the color light in an ideal wavelength range can be obtained; The purpose of adjusting the wavelength can also be achieved by adding different substitution amounts of metals, and the radiation intensity of the phosphor can be increased. It has the above-mentioned many advantages and practical value, both in the structure and function of the product have been greatly improved, the technology has made great progress, and has produced easy-to-use and practical effects, and compared with the existing fluorescent The body and the white light-emitting diode thereof have enhanced multiple effects, thereby being more suitable for practical use, and having extensive industrial application value, which is a novel, progressive and practical new design.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments are specifically cited below, and are described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a cross-sectional view of a packaging structure of a white light emitting diode according to a preferred embodiment of the present invention.

Fig. 2 is an excitation spectrum diagram of blue light, yellow-green light and red light according to a preferred embodiment of the present invention.

100: LED packaging structure 110: Substrate

120: Light-emitting element 130: Covering layer

131: The first phosphor 132: The second phosphor

210: crest 220: crest

230: Crest

Detailed ways

In order to further explain the technical means and effects of the present invention to achieve the intended purpose of the invention, the specific implementation, structure, Features and their functions are described in detail below.

The white light emitting diode provided by the present invention can produce white light with high brightness and high color rendering. Therefore, the advantages of the technology provided by the present invention can be used to solve the problem of poor color rendering of the existing traditional white light emitting diode.

Please refer to FIG. 1 , which is a cross-sectional view of a packaging structure of a white light emitting diode according to a preferred embodiment of the present invention. The white light emitting diode packaging structure 100 of the preferred embodiment of the present invention includes a substrate 110, a light emitting element 120, a cladding layer 130, a first phosphor 131 and a second phosphor 132, wherein:

The substrate 110 is a base for carrying the light-emitting element 120 , which can be made of heat-conducting materials (such as metal or organic polymer materials). In addition, the substrate 110 can also be a printed circuit board.

The light emitting element 120 is attached on the substrate 110 and is a blue light emitting chip. The light-emitting element 120 can be made of semiconductor materials, such as multi-component composite compounds of group VA, including indium gallium nitride (InGaN), gallium nitride/silicon carbide (GaN/SiC), or any combination thereof. The light-emitting element 120 is produced by a general light-emitting semiconductor element manufacturing method, and can emit blue light with a wavelength range of 410nm-500nm under the operation of a current of 20 milliamps (mA).

The cladding layer 130 wraps around the light-emitting element 120 and can be a transparent encapsulation material, such as a high refractive index inorganic material. The refractive index of the above-mentioned inorganic material is greater than 1.40, such as silica gel or silica gel composite material, which is used to improve the light extraction efficiency of the white light emitting diode package.

In the coating layer 130 , more than two kinds of phosphors are also mixed, and the two or more kinds of phosphors are uniformly dispersed in the coating layer 130 . The aforementioned phosphors at least include a first phosphor 131 and a second phosphor 132 , wherein the mixing ratios of the first phosphor 131 and the second phosphor 132 are 3% and 1.5%, respectively.

According to a preferred embodiment of the present invention, the host of the first phosphor 131 is a silicate compound whose chemical formula is ((2-xyz)Sr(x)Ca(y)Mg)·( 1-a) SiO ₄ ·aGa ₂ O ₃ : (z)Eu. Where x, y, z, and a are not equal to zero, and the value of a is 0.02≤a≤0.1. Trivalent europium (Eu) metal ion is an activator that can be incorporated into the host lattice to form an excitable light-emitting center. In addition, the purpose of adjusting the wavelength can still be achieved by adjusting the ratio of the host metal elements strontium (Sr), calcium (Ca) or magnesium (Mg). When the content of strontium and calcium is low, the fluorescent powder should be greenish. When more strontium and calcium are added, the difference in energy level will be caused by the smaller atoms, and the light color will gradually change from the wavelength of green light to that of green light. Long wavelength shift, so the wavelength range of the light emitted by the first phosphor can be adjusted by the ratio of strontium and calcium metal added. However, the addition ratio of strontium and calcium metals has no proportional increase relationship with the wavelength shift. Wherein, the content ratio of main metal elements is in the following ranges:

x: 0.1≤x≤0.6

y: 0.1≤y≤0.6

z: 0.01≤z≤0.15

In addition, a metal element, such as manganese or lanthanide metal elements, such as cerium (Ce), gadolinium (Gd), terbium (Tb) and other elements can be used as a sensitizer (sensitizer) to absorb the excitation light The energy is then transferred to the activation element of the first phosphor 131 to increase the light intensity of the first phosphor 131 . The first phosphor 131 can absorb part of the blue light and emit yellow-green light with a wavelength range of 500-550 nm.

The main body of the second phosphor 132 is an alkaline earth metal sulfide, and its chemical formula is (xAyBzC)S:Eu. Among them, none of x, y, and z is equal to zero. Trivalent europium (Eu) metal ions are active elements that can be incorporated into the host lattice to form a center that can be excited to emit light. The three elements A, B and C that make up the alkaline earth metal sulfide can be selected from divalent metal elements, such as beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) Any three kinds; monovalent alkali metal elements, such as sodium (Na), potassium (K), lithium (Li), etc. can also be added for adjustment. With proper ratio and combination, an ideal wavelength range can be obtained. The content ratio of the main metal element of the alkaline earth metal sulfide is in the following range:

x: 0.1≤x≤0.6

y: 0.1≤y≤0.6

z: 0.01≤z≤0.15

The second phosphor 132 can absorb part of the blue light and emit red light with a wavelength range of 590-650 nm.

Therefore, the preferred embodiment of the present invention is to use the above-mentioned light-emitting element 120 to generate blue light, and use the first phosphor 131 and the second phosphor 132 that can adjust the wavelength to absorb part of the blue light to generate yellow-green light and red light, and use By mixing the blue light, yellow-green light and red light, a white light-emitting diode with high color rendering property is obtained.

Please refer to FIG. 2 , which is an excitation spectrum diagram of a white light emitting diode according to a preferred embodiment of the present invention, wherein the vertical axis is luminous intensity (intensity, %), and the horizontal axis is wavelength (wavelength, nm). Under the condition of color rendering 88, analyze the wavelength range of the light emitted by the white light emitting diode of the preferred embodiment of the present invention, the peak 210 is the blue light generated by the light emitting element 120, its luminous intensity is the strongest, and the wavelength range is between 410~ Between 500nm. The peak 220 is the emission wavelength of the yellow light excited by the blue light from the first phosphor 131 mainly composed of silicate compound, and the wavelength range may be between 500-550 nm. The peak 230 is the emission wavelength of red light excited by the blue light from the second phosphor 132 mainly composed of alkaline earth metal sulfide, and the wavelength range may be between 500nm and 550nm. The white light emitting diode of the preferred embodiment of the present invention can produce white light with high luminous efficiency and a color rendering ratio of 88 or higher by properly controlling the blue light, yellow-green light and red light.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the structure and technical content disclosed above to make some changes or modifications to equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention, Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solutions of the present invention.

Claims (6)

1, a kind of white light emitting diode is characterized in that it comprises:

One light-emitting component can produce the blue light that wave-length coverage is 410～500nm;

One coating layer, be coated on this light-emitting component around;

One first phosphor body, it is the silicate compound of trivalent europium ion activation, its chemical formula is ((2-x-y-z) Sr (x) Ca (y) Mg) (1-a) SiO ₄AGa ₂O ₃: (z) Eu, and its constituent content x, y, z, a is neither equals zero, and this first phosphor body is scattered in this coating layer, can absorb the blue light that this light-emitting component produces, and is the green-yellow light of 500～550nm to produce wave-length coverage; And

One second phosphor body, it is the alkaline earth sulfide of trivalent europium ion activation, chemical formula is (xAyBzC) S:Eu, wherein said A, three kinds of elements of B and C are to be selected from by beryllium, magnesium, calcium, strontium, barium, sodium, potassium, lithium or its group that forms, and its constituent content x, y and z are neither to equal zero, this second phosphor body is scattered in this coating layer, can absorb the blue light that this light-emitting component produces, to produce wave-length coverage is the ruddiness of 590～650nm, by green-yellow light and ruddiness that this first phosphor body and this second phosphor body are emitted respectively, the blue light that is produced with this light-emitting component produces white light.

2, white light emitting diode according to claim 1, the material that it is characterized in that wherein said light-emitting component are nitrogen indium gallium, gallium nitride/carborundum or above-mentioned combination in any.

3, white light emitting diode according to claim 1 is characterized in that the mixed proportion of wherein said first phosphor body and this second phosphor body is respectively 3% and 1.5%.

4, a kind of phosphor body is characterized in that it comprises: a silicate compound, its chemical formula are ((2-x-y-z) Sr (x) Ca (y) Mg) (1-a) SiO ₄AGa ₂O ₃: (z) Eu, wherein, the ratio of constituent content x, y, z and a that this silicate compound is contained is between following scope:

0.1≤x≤0.6、

0.1≤y≤0.6、

0.01≤z≤0.15、

0.02≤a≤0.1，

Wherein, x, y, z and a all are not equal to zero, and this phosphor body emit wavelength scope after exciting is the green-yellow light of 500～550nm.

5, phosphor body according to claim 4 is characterized in that it more comprises a sensitizer, is to be selected from by manganese, cerium, gadolinium, terbium or its group that forms.

6, a kind of phosphor body is characterized in that it comprises:

One alkaline earth sulfide, its chemical formula is (xAyBzC) S:Eu, wherein this A, B, three kinds of elements of C are to be selected from the group that is made up of beryllium, magnesium, calcium, strontium, barium, sodium, potassium, lithium and above-mentioned combination in any, and constituent content x, y that this alkaline earth sulfide is contained and the ratio of z are between following scope:

0.1≤x≤0.6、

0.1≤y≤0.6、

0.01≤z≤0.15；

Wherein, x, y and z all are not equal to zero, and this phosphor body emit wavelength scope after exciting is the ruddiness of 590～650nm.

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