TWI486424B - Phosphor particle and light emitting device - Google Patents

Description

Phosphor particles and illuminating device

The present invention relates to a phosphor particle and a light-emitting device using the same, and more particularly to a phosphor particle having high luminance and a light-emitting device using the same.

In recent years, light-emitting devices using semiconductor light-emitting devices have been widely used, and in particular, light-emitting diodes have been successfully developed. Such light-emitting devices have higher luminous efficiency and small volume than conventional light-emitting devices such as cold cathode fluorescent tubes and incandescent lamps. Low power consumption and low cost, so it can be used as a variety of light sources. The semiconductor light-emitting device includes a semiconductor light-emitting element and a phosphor, and the phosphor absorbs and converts light emitted from the semiconductor light-emitting element, and is used by mixing both light emitted by the semiconductor light-emitting element and light converted by the phosphor. Such a light-emitting device can be used in various fields such as a fluorescent lamp, a vehicle illumination, a display, a liquid crystal backlight display, and the like, and a white light-emitting device is most widely used. The current white light-emitting device is composed of a YAG phosphor (Y ₃ Al ₅ O ₁₂ :Ce) which is an active center and is combined with a semiconductor light-emitting element that emits blue light. However, a Y ₃ Al ₅ O ₁₂ :Ce phosphor is used in combination with a mixed light emitted by a semiconductor light-emitting element that emits blue light, the chromaticity coordinates of which are at the color coordinates of the semiconductor light-emitting element that emits blue light and Y ₃ Al ₅ O ₁₂ : The color coordinates of the Ce phosphor are connected to the line. Therefore, the mixed light emitted is white light lacking red light, and the color rendering and color saturation are obviously insufficient. Further, the preferred excitation spectrum region of Y ₃ Al ₅ O ₁₂ :Ce and the light-emitting region of the semiconductor light-emitting element do not coincide with each other. Therefore, the conversion efficiency of the excitation light is not good, and a high-luminance white light source is not easily obtained. In order to solve such a phenomenon of poor color tone and low luminance, in recent years, the YAG:Ce phosphor has been actively incorporated into a phosphor that emits red light, and the quality of a phosphor that emits red light is improved to improve light emission. Brightness.

However, phosphors that absorb blue light and emit red light are rare. Currently, research and development in the industry mainly consists of nitride and oxynitride phosphors. It is known that Sr ₂ Si ₅ N ₈ :Eu phosphor, CaAlSiN ₃ :Eu phosphor, and M _z Si _12-(m+n) Al _m+n O using erbium (Eu) as an active center are known. _n N _16-n : Eu's Sialon phosphor. However, the Sr ₂ Si ₅ N ₈ :Eu phosphor has limited applicability due to poor luminance, and is not popular in recent years. The Sialon phosphor itself has no durability problem, but the phosphor luminance is obviously insufficient. Commercial use is not universal. Although the CaAlSiN ₃ :Eu phosphor has better durability and better brightness than the Sialon phosphor, the industry is still expecting to further increase the luminance of the phosphor to make the illuminating device higher. Luminous efficiency.

In view of the above problems, it is an object of the present invention to provide a high-luminance phosphor, a phosphor particle, and a high-luminance light-emitting device using the above-described phosphor in combination with a semiconductor light-emitting device.

According to an embodiment of the invention, a phosphor is proposed. The phosphor includes a composition having a composition formula of (Ba _a Sr _1-a ) _2-z Si ₅ O _b N _n :Eu _Z , wherein 0.03<a<0.75, 0<b<1,7<n<9 0.03 < z < 0.3, preferably 0.3 ≦ a ≦ 0.7, 0 < b < 1, 7 < n < 9, 0.04 ≦ z ≦ 0.2.

According to another embodiment of the invention, a phosphor particle is proposed. The phosphor particles include barium (Ba), barium (Sr), barium (Si), and nitrogen (N). Wherein, the phosphor particles have an average particle diameter (D50), and the average particle diameter (D50) is greater than 6.2 micrometers (μm) and less than 14.4 micrometers (μm).

According to still another embodiment of the present invention, a phosphor particle is proposed. The phosphor particles include barium (Ba), barium (Sr), barium (Si), and nitrogen (N). Wherein, the phosphor particles have a long axis and a short axis, and the long axis is the longest distance between any two points on the surface of the phosphor particles, and the short axis is the surface of the phosphor particles on the intersection line perpendicular to the long axis. The longest distance between points, wherein the ratio of the major axis to the minor axis is greater than 1.24 and less than 4.1.

According to still another embodiment of the present invention, a light emitting device is proposed. The light emitting device includes a semiconductor light emitting element and a phosphor as described above. The phosphor is excited by light emitted from the semiconductor light-emitting element and converted to emit light having a wavelength different from that of the semiconductor light-emitting element.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

11‧‧‧ cabinet

12‧‧‧ sample slot

13‧‧‧Light source

14‧‧‧Light guiding tube

15‧‧‧Mirror

16‧‧‧luminometer

21‧‧‧Semiconductor light-emitting elements

22‧‧‧Fluorescent layer

23‧‧‧Encapsulation layer

211‧‧‧Base

212‧‧‧ bearing surface

213‧‧‧Light-emitting diode grains

214‧‧‧Connecting line

221‧‧‧Fertior

c, d, e, f‧‧ points

x _max ‧‧‧ long axis

y _min ‧‧‧Short axis

Fig. 1 is a schematic view showing a phosphor particle according to an embodiment of the present invention.

Figure 2 illustrates a glow measuring device applied to the present invention.

Fig. 3 is a perspective view showing a light-emitting device according to an embodiment of the present invention.

In an embodiment of the present invention, the phosphor includes a barium element (Ba), a barium element (Sr), a barium element (Si), and a nitrogen element (N).

Please refer to FIG. 1 , which is a schematic view showing phosphor particles according to an embodiment of the present invention. In an embodiment, the fluorescent system comprises a plurality of phosphor particles, in other words, the phosphor has the form of phosphor particles. In one embodiment, the phosphor particles include germanium (Ba), germanium (Sr), germanium (Si), and nitrogen (N), and the phosphor particles have a major axis x _max and a short axis y _Min , the long axis x _max is the longest distance between any two points c and d on the surface of the phosphor particle, and the short axis y _min is any point on the surface of the phosphor particle on the intersection line perpendicular to the long axis x _max The longest distance between e and f, wherein the ratio of the major axis x _max to the minor axis y _min is greater than 1.24 and less than 4.1 (1.24 < x _max / y _min < 4.1).

In one embodiment, the average particle diameter of the phosphor particles is preferably 30 micrometers (μm) or less. The reason is that the luminescence of the phosphor particles mainly occurs on the surface of the particles, and the average particle diameter (the "average particle diameter" in the present invention means the volume median diameter (D50)) is 30 micrometers (μm) or less. It will ensure the surface area per unit weight of the phosphor particles and avoid the decrease in luminance. Further, when the phosphor particles are coated on the light-emitting element, the density of the phosphor particles can be increased, and from this viewpoint, the luminance can be prevented from being lowered. Further, from the viewpoint of luminous efficiency of the phosphor particles, the average particle diameter is preferably more than 1 micrometer (μm). According to the above, the average of the phosphor particles of the present invention The particle diameter is preferably 1 micrometer (μm) or more and 30 micrometers (μm) or less, and particularly preferably 3.0 micrometers (μm) or more and 20 micrometers (μm) or less. Here, the "average particle diameter (D50)" is a value measured by the Coulter method using MultiSizer-3 manufactured by Beckman Coulter Co., Ltd. D* represents the particle size accumulated to *%, taking D50 as an example: D50 represents a particle size (um), which is 50% of the total from the smallest particle accumulation to the total particle size. Generally speaking, D50 is the average particle size.

In one embodiment, the average particle diameter (D50) of the phosphor particles is preferably greater than 6.2 micrometers (μm) and less than 14.4 micrometers (μm) (6.2 μm < D50 < 14.4 μm).

In one embodiment, the 10% particle size (D10) of the phosphor particles is greater than 3.4 microns (μm) and less than 8.3 microns (μm) (3.4 μm < D10 < 8.3 μm).

In an embodiment of the invention, the phosphor particles may further comprise an oxygen element (O).

In one embodiment, the phosphor (or phosphor particles) comprises a composition having the composition formula (Ba _a Sr _1-a ) ₂ Si ₅ O _b N _n :Eu _Z when 0.03<a<0.75,0 When <b<1,7<n<9, 0.03<z<0.3, the phosphor having the same element ratio as not falling within the range has a higher luminance value after the reliability test than the wavelength. Presents a good brightness retention rate. The same wavelength means that the wavelength difference is within ±1 nm. The luminance retention ratio is the ratio of the luminance values before and after the reliability test of the phosphor, that is, (the luminance after the reliability test/the sensitivity before the test) *100%.

In the phosphor, 0.03 < z < 0.3. If the amount of europium (Eu) in the center of the phosphor of the phosphor is too small, the luminance of the phosphor is lowered. If the amount of Eu in the luminescent center of the phosphor is too high, the concentration is caused by mutual interference between Eu atoms. The phenomenon of extinction, so that the brightness is reduced. Preferably, when 0.04 < z < 0.2, the luminance of the light is better.

In one embodiment, the phosphor comprises a composition having the composition formula (Ba _a Sr _1-a ) ₂ Si ₅ O _b N _n :Eu _Z when 0.3≦a≦0.7,0<b<1,7< When n<9, 0.04≦z≦0.2, the luminance value after the reliability test is better than that of the phosphor whose wavelength ratio is not within the range.

When the phosphor of the present invention is irradiated with a light source having a wavelength of 455 nm, the phosphor is excited to emit a dominant wavelength of 580 to 680 nm, and the CIE 1931 chromaticity coordinate (x, y) of the luminescent color is 0.45. ≦x≦0.72, 0.2≦y≦0.5. The main wavelength of light emission refers to the wavelength at which the intensity of light emission is the largest in the light emission spectrum.

In the embodiment of the present invention, in the production of the phosphor, the raw material of the lanthanum element may use a nitrogen-containing compound, an oxygen-containing compound, a compound of any form or an elemental state of ruthenium. For example, a nitride (Si ₃ N ₄ )/oxide (SiO _x ) of a cerium element may be mixed. The "oxygen compound" may include a compound such as an oxide, a carbonate or an oxalate. In the case of a nitrogen-containing compound, it also means a compound having a ruthenium element and nitrogen.

The phosphor raw materials of the present invention may be precursors of various forms, and the nitride and oxide raw materials are described below as an embodiment for the sake of convenience. Although the oxide or nitride raw material of the lanthanum (Ba) element, the lanthanum (Sr) element, and the cerium (Si) element may be a commercially available raw material, the higher the purity, the better, so it is preferable to prepare 3N (99.9%) or more. Raw materials are preferred. The particle diameter of each raw material particle is preferably fine particles from the viewpoint of promoting the reaction, but the particle diameter and shape of the obtained phosphor vary depending on the particle diameter and shape of the raw material. Therefore, as long as the particles required for the final obtained phosphor are matched For the diameter, a nitride or oxide raw material having an approximate particle diameter may be prepared. The raw material of the Eu element is preferably a commercially available oxide, a nitride raw material or a metal, and the higher the purity, the better, and it is preferable to prepare 2N (99%) or more, particularly preferably 3N (99.9%) or more.

The mixing method of the raw materials may be a dry method or a wet method. Various embodiments, such as a dry ball milling method or a wet ball milling method in which a liquid is added, are not limited to a single mode. When Sr ₃ N ₂ , Si ₃ N ₄ , and Ba ₃ N ₂ are weighed and mixed, since these compounds are easily oxidized, it is appropriate to operate in a glove box in an inactive environment. Further, since the nitride of each raw material element is more susceptible to moisture, it is preferable to use a gas which is sufficiently dehydrated for the inert gas used for filling the glove box. Further, in the case of the wet mixing method, when the liquid to be used is pure water, the raw material is decomposed, and therefore, it is necessary to select an appropriate organic solvent. As the mixing device, a device generally used such as a ball mill or a mortar can be used.

When preparing the phosphor, the raw materials can be weighed and mixed according to a certain ratio, placed in a crucible, and then placed in a high temperature furnace for firing. In the high-temperature furnace used for firing, since the firing temperature is high, it is preferable to use a high-temperature furnace of a metal resistance heating method or a graphite resistance heating method. As a method of baking, a baking method in which no external mechanical pressure is applied, such as a normal pressure baking method or a gas pressure (gas pressurization) baking method, is preferable. The crucible is preferably a high-purity material having a very low impurity content, such as an Al ₂ O ₃ crucible, a Si ₃ N ₄ crucible, an AlN crucible, a Saron crucible, a BN (boron nitride) crucible, etc. The crucible used in the active environment, in which the BN crucible is best used, is best for avoiding the incorporation of impurities from the crucible. The firing atmosphere is a non-oxidizing gas, and may be, for example, nitrogen, hydrogen, ammonia, argon or the like or any combination of the foregoing gases. The firing temperature of the phosphor (or phosphor particles) is 1200 ° C or higher and 2200 ° C or lower, more preferably 1400 ° C or higher and 2000 ° C or lower, and the temperature rising rate is 3 to 15 ° C / min. At lower temperatures, the finer phosphor particles can be obtained by firing, and the larger-sized phosphor particles can be obtained by firing at a higher temperature. The firing time varies depending on the type of the raw material, and the reaction time is preferably from 1 to 12 hours. The pressure in an inert environment at the time of baking is, for example, 0.5 MPa or less (especially preferably 0.1 MPa or less). After the completion of the firing, the mixture is cooled to room temperature, and can be pulverized by a ball mill or an industrial pulverizing machine, and then subjected to water washing, filtration, drying, classification, and the like to obtain the phosphor of the present invention.

In order to obtain a high-luminance phosphor, the content of impurities contained in the phosphor composition should be as much as possible during the firing due to factors such as the addition of flux, impurities in the raw material, and contamination of the process. small. In particular, when a large amount of elements such as fluorine element, boron element, chlorine element, and carbon element are present, luminescence is suppressed. Therefore, a higher purity raw material can be selected, and the synthesis step can be controlled to avoid contamination, so that the contents of the fluorine, boron, chlorine, carbon and the like are less than 1000 ppm, respectively.

The phosphor of the present invention is suitable for use in a fluorescent display tube (VFD), a field emission display (FED), a plasma display (PDP), a cathode ray tube (CRT), a light emitting diode (LED), and the like. In particular, when the phosphor of the present invention is irradiated with a light source having a wavelength of 455 nm, the main wavelength of the luminescence is 580 to 680 nm, and the chromaticity coordinate of the CIE 1931 chromaticity coordinate (x, y) is 0.45 ≦ x ≦ 0.72. 0.2≦y≦0.5, and high luminance, it is especially suitable for light-emitting diodes.

In one embodiment, the light emitting device of the present invention comprises a semiconductor light emitting device and a phosphor of the present invention. The semiconductor light-emitting element preferably emits light having a wavelength of 300 to 550 nm, and particularly preferably an ultraviolet (or violet) optical semiconductor light-emitting element emitting 330 to 420 nm or a blue semiconductor light-emitting element of 420 to 500 nm. As such a light-emitting element, the semiconductor light-emitting element can be various semiconductors such as zinc sulfide or gallium nitride, and a gallium nitride semiconductor is preferable in terms of light-emitting efficiency. The gallium nitride light-emitting element can form a nitride semiconductor on the substrate by a method such as metalorganic chemical vapor deposition (MOCVD) or hydride vapor phase epitaxy (HVPE), using In _α Al _β Ga _1-α-β. The semiconductor light-emitting device formed by N (0 ≦ α, 0 ≦ β, α + β < 1) is preferable. The semiconductor structure may be a homogeneous structure such as MIS bonding, PIN bonding, or PN bonding, a heterojunction structure, or a double heterojunction structure. Further, the light-emitting wavelength can be controlled by adjusting the material of the semiconductor layer or its crystallinity.

In the light-emitting device of the present invention, in addition to the use of the phosphor of the present invention alone, it can be used together with a phosphor having other light-emitting characteristics to constitute a light-emitting device capable of emitting a desired color. For example, an ultraviolet light-emitting semiconductor light-emitting element having an emission wavelength of 330 to 420 nm is used in combination with a blue phosphor that emits light at a wavelength of 420 nm or more and 500 nm or less, and emits light at a wavelength of 500 nm or more and 570. A combination of a green phosphor of light below nm and a phosphor of the present invention. The blue phosphor may be BaMgAl ₁₀ O ₁₇ :Eu, and the green phosphor may be a β-Sialon phosphor. According to this configuration, when the ultraviolet light emitted from the semiconductor light-emitting device is irradiated onto the phosphor, three colors of red, green, and blue light are emitted, and the light is emitted as a white light-emitting device.

In addition, a blue semiconductor light-emitting element having an emission wavelength of 420 to 500 nm may be used in combination with a yellow phosphor that is excited at such a wavelength to emit light having a wavelength of 550 nm or more and 600 nm or less, and the phosphor of the present invention. The combination. The yellow phosphor may be, for example, Y ₃ Al ₅ O ₁₂ :Ce. According to this configuration, when the blue light emitted from the semiconductor light emitting element is irradiated onto the phosphor, two colors of red and yellow light are emitted, and the blue light of the semiconductor light emitting element itself is mixed to become white or light with a bulb color. appliance.

Further, a blue semiconductor light-emitting element having an emission wavelength of 420 to 500 nm may be used in combination with a green phosphor that is excited at this wavelength to emit light having a wavelength of 500 nm or more and 570 nm or less, and the phosphor of the present invention. combination. An example of such a green phosphor may be a β-Sialon phosphor. According to this configuration, when the blue light emitted from the semiconductor light-emitting element is irradiated onto the phosphor, two colors of red and green light are emitted, and these are mixed with the blue light of the semiconductor light-emitting element itself to become a white lighting fixture.

EXAMPLES AND COMPARATIVE EXAMPLES Hereinafter, examples of the invention will be described, but the invention is not limited thereto.

Measurement methods:

(1) Phosphor luminance and chromaticity coordinates: The phosphor was measured by TOPCON luminance meter SR-3A using light irradiation at a wavelength of 455 nm. The difference in luminance measurement is within ±0.3%.

(2) Phosphor emission main wavelength: measured by Jobon YVON's Fluoro Max-3. The main wavelength of light emission refers to the wavelength of the maximum luminous intensity of the phosphor when the phosphor is excited by light having a wavelength of 455 nm.

(3) Analysis of the constituent elements of the phosphor:

(3-1a) Apparatus: The elemental content was measured by a ULTIMA-2 inductively coupled plasma atomic emission spectrometer (ICP) of Jobin YVON.

(3-1b) Sample pretreatment: Accurately weigh 0.1 g of sample, mix it in a platinum crucible, add 1 g of Na ₂ CO _{3 and} mix it at a high temperature furnace at 1200 ° C (temperature condition: 2 hours from room temperature) Arrive at 1200 ° C, constant temperature at 1200 ° C for 5 hours), after the melt is cooled, add an acid solution, such as 25 mL of HCl (36%), and heat to dissolve to clarify, cool and place in a 100 mL PFA dosing bottle. Pure water is quantified to the mark.

(3-2a) Instrument: Horiba's nitrogen oxide analyzer. Model EMGA-620W.

(3-2b) Measurement: 20 mg of the phosphor was placed in a tin capsule and placed in a crucible for measurement.

(4) Reliability test: The phosphor was placed in the air for a long time high temperature baking (400 ° C, 12 hours).

(5) Brightness retention ratio: the ratio of the luminance values before and after the reliability test of the phosphor, that is, (the luminance after the reliability test/the sensitivity before the test) * 100%.

Synthesis Example 1

Prepare the desired base metals (3N, 99.9%) and base metals (3N, 99.9%), pulverize and then directly fire to form nitrides under a pure nitrogen atmosphere. The reaction conditions are 750 ° C and 700 ° C, respectively. 24 hours. Compounds of cerium nitride (Sr ₃ N ₂ ) and tantalum nitride (Ba ₃ N ₂ ) can be obtained, respectively.

Examples 1 to 11 and Comparative Examples 1 to 3

The phosphors of Examples 1 to 11 and Comparative Examples 1 to 3 were produced in the same manner, and the difference mainly lies in tantalum nitride (Ba ₃ N ₂ ), tantalum nitride (Sr ₃ N ₂ ), tantalum nitride (Si ₃ N _{4 ).} The amount of use of ruthenium oxide (Eu ₂ O ₃ ) is different. Hereinafter, a method for producing a phosphor will be described by way of Example 1.

Taking Example 1 as an example, 49.293 g of the synthetic yttrium nitride (Sr ₃ N ₂ ) compound synthesized in Synthesis Example 1, 42.094 g of a lanthanum nitride (Ba ₃ N ₂ ) compound, and 95.862 g of lanthanum nitride (Si ₃ ) were weighed. N ₄ , purity 3N) and 4.329 g of cerium oxide (Eu ₂ O ₃ , purity 4N) were mixed in a glove box using a mortar under a nitrogen atmosphere to form a phosphor starting material.

Then, the phosphor starting material is placed in a firing vessel made of boron nitride, and then the firing vessel containing the starting material is placed in a high-temperature furnace containing high-purity nitrogen gas, and the flow rate of the nitrogen gas is 80 liters. /min, the temperature was raised to 1700 ° C at a temperature increase rate of 10 ° C / min, and maintained at 1700 ° C for 2 hours, and the high-temperature furnace operating pressure was maintained at 0.1 MPa for firing. After the firing, the temperature is lowered to room temperature according to the temperature drop rate of 10 ° C / min, and then the phosphor is obtained by the steps of pulverization, ball milling, water washing twice, filtration, drying, and classification.

Taking Example 8 as an example, the result of analysis using an inductively coupled plasma atomic emission spectrometer (ICP) and a nitrogen oxide analyzer was that the phosphor had a composition formula of Ba _0.666 Sr _1.207 Si ₅ O _0.149 N _7.415 :Eu _0.04 .

Table 1 shows the preparation conditions of Examples 1 to 11 and Comparative Examples 1 and 2, including the types of the compounds used for the phosphor starting materials, the weight ratio of each compound, and the sintering conditions. Tables 2 and 3 show the results obtained in Examples 1 to 11 and Comparative Examples 1 and 2. The phosphor properties include the amount of each element, the illuminating wavelength, the luminance, the reliability after the test, and the luminance retention of each of the phosphors. The emission wavelength of the phosphor (the dominant wavelength of the emission spectrum) means the wavelength at which the emission intensity is the largest.

As shown in Table 3, the phosphors of the examples and the comparative examples all exhibited good luminance performance. However, after the reliability test, the phosphors of the examples exhibited better luminance performance than the comparative examples 1 and 2, and thus had better luminance retention. Among them, in Examples 6 to 10, a better luminance performance was exhibited after the reliability test.

Table 4 shows the preparation conditions and the obtained phosphor properties of Examples 1, 4, 6 to 10, and Comparative Example 3, including the sintering conditions, luminance, particle diameter, reliability, and luminance retention of each phosphor. rate. The phosphors of Examples 1, 4, 6-10 and Comparative Example 2 all had the same element feed composition, wherein Sr:Ba:Eu=1.24:0.7:0.06, and the emission wavelength was 620±1 nm. In Table 3, D10 represents a 10% particle diameter (D10) of the phosphor particles, D50 represents an average particle diameter (D50) of the phosphor particles, and D90 represents a 90% particle diameter (D90) of the phosphor particles.

As shown in Table 4, in Examples 1, 4, 6 to 10 and Comparative Example 2, when each of the phosphors had the same feed composition (Sr: Ba: Eu = 1.24: 0.7: 0.06), the average was When the particle diameter (D50) is more than 6.2 μm and less than 14.4 μm, and the 10% particle diameter (D10) is more than 3.4 μm and less than 8.3 μm (for example, Examples 6 to 10), the phosphor has a good luminance retention. When the average particle diameter (D50) and the 10% particle diameter (D10) of the phosphor are outside the above range (for example, Examples 1, 4 and Comparative Example 2), the phosphor has a luminance retention ratio of 49% or less. Further, as shown in Comparative Example 2, when the sintering temperature and the sintering time were simultaneously increased, the particle diameter of the phosphor was increased (D10, D50, and D90 were larger than those in the examples), but the phosphor was deteriorated. Further, the luminance retention rate of the phosphor is lowered.

Table 5 shows the preparation conditions of Comparative Examples 1, 3 and 11 and the properties of the obtained phosphor, including the sintering conditions of each phosphor, the composition of the element, the luminance, the luminance retention, and the long axis to the minor axis. proportion. The light emission wavelengths of Comparative Examples 1, 3 and 11 were both 620 ± 1 nm.

As shown in Table 5, in Comparative Examples 1, 3, and 11, when the ratio of the major axis x _max to the minor axis y _min is greater than 1.24 and less than 4.1 (1.24 < x _max / y _min < 4.1) (for example, Example 11), the phosphor has a better luminance retention.

As a result of the composition analysis of the above-described phosphor implementation type, it was found that the atomic ratio relationship of each element (Ba, Sr, Si, O, N, Eu) calculated from the composition analysis result was compared with the raw material used. There is a slight deviation in the composition of the input material calculated from the blending ratio. This phenomenon is considered to be caused by a small amount of raw materials being decomposed or evaporated or not entering the crystal lattice and being washed by water, or due to analysis errors. In particular, the deviation of the atomic ratio b of oxygen is considered to be, for example, oxygen contained in the raw material from the beginning, or oxygen attached to the surface, or oxidation of the raw material surface when the raw material is weighed, mixed, and fired. Oxygen mixed in, and moisture or oxygen adsorbed on the surface of the phosphor after firing. Furthermore, firing in an environment containing nitrogen and/or ammonia At the time, the oxygen in the raw material may be detached and replaced by nitrogen, and it is judged that b and n will undergo some deviation.

Please refer to FIG. 2, which illustrates a glow measuring device applied to the present invention. The luminance of any of the foregoing phosphors of the present invention is measured by a luminance measuring device. As shown in FIG. 2, the luminance measuring device comprises a black housing 11, a sample slot 12, and a light source 13. a light guiding tube 14, a mirror 15 and a luminance meter 16, wherein the sample slot 12 is placed in the housing 11, and the light source 13 is disposed at a height of about 5 cm for the vertical sample slot 12, and the diameter of the light guiding tube 14 It is about 2 cm and is disposed at an angle of 45° with the light source 13. The mirror 15 is disposed in the light guiding tube 14 and is spaced apart from the sample slot 12 by about 8 cm, and the distance between the luminance meter 16 and the mirror 15 is about 40 cm. After the phosphor placed in the sample tank 12 is irradiated through the light source 13, the fluorescent light emitted from the phosphor is guided to the luminance meter 16 via the light guiding tube 14 and the mirror 15 to perform the luminance measurement.

In detail, in the foregoing various embodiments and comparative examples of the present invention, the glow measurement of the phosphor is performed by placing 1.3 g of the sample to be tested into the sample tank 12, and flattening the sample evenly in the sample tank 12, followed by The sample tank 12 is placed in the casing 11, and the sample is vertically irradiated with a light source 13 having a light source wavelength of 455 nm, and the luminance meter 16 (Model TOPCON, model SR-3A) detects the phosphor using the field 1° detection mode. Fluorescent brightness emitted after illumination by a light source. In addition, in order to avoid affecting the measured luminance value due to the change of the intensity of the light source, it is generally customary to standardize the measured luminance value by a standard product, and the luminance values of the present invention are all standardized relative values.

Next, the phosphor samples and semi-guides of the foregoing various embodiments of the present invention are used. The light-emitting device of the present invention is obtained by packaging a bulk light-emitting device.

Referring to FIG. 3, a perspective view of a light emitting device according to an embodiment of the present invention is shown. As shown in FIG. 3, a light-emitting device according to an embodiment of the present invention includes a semiconductor light-emitting element 21, a phosphor layer 22, and an encapsulation layer 23.

The semiconductor light-emitting element 21 includes a pedestal 211 that is electrically conductive and has a concave bearing surface 212, a light-emitting diode die 213 disposed on the concave bearing surface 212 and electrically connected to the pedestal 211, a connecting line 214, and a The wire 215 is electrically connected to the light-emitting diode die 213 through the connecting wire 214. The base 211 and the wire 215 can be combined to supply electric energy from the outside to the light-emitting diode die 213, and the light-emitting diode die 213 can be The received electrical energy is converted into light energy and emitted outward. In this embodiment, a commercially available blue light-emitting diode die 213 (manufacturer: Kelly Optoelectronics) having an emission wavelength of 455 nm (InGaN) is used as a conductive silver paste (Model: BQ6886, manufacturer: UNINFWELL) (not drawn) The bonding surface 214 and the wire 215 electrically connected to the LED die 213 are extended from the top surface of the LED 213.

The phosphor layer 22 covers the light-emitting diode crystal grains 213. The phosphor 221 contained in the phosphor layer 22 is converted to emit light different from the wavelength of the excitation light after being excited by the light emitted from the light-emitting diode crystal 213. In the present embodiment, the phosphor layer 22 is used. A polydecane oxyresin containing 35 wt% of the phosphor 221 was applied to the outer surface of the luminescent diode 213 and dried and hardened.

The encapsulation layer 23 covers the susceptor 211 of the semiconductor light emitting element 21, the connection line 214, a portion of the wire 215, and the phosphor layer 22.

In summary, the phosphor of the embodiment has high luminance. Moreover, the phosphor is matched with the semiconductor light-emitting element, and a high-luminance light-emitting device can be obtained at the same time.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

c, d, e, f‧‧ points

x _max ‧‧‧ long axis

y _min ‧‧‧Short axis

Claims (10)

A phosphor particle comprising: a lanthanum element (Ba), a lanthanum element (Sr), a lanthanum element (Si), and a nitrogen element (N), wherein the phosphor particles have a long axis and a short axis, the length The axis is the longest distance between any two points on the surface of the phosphor particle, and the minor axis is the longest distance between any two points on the surface of the phosphor particle on the intersection line perpendicular to the long axis, wherein the long axis is relatively long The ratio of the minor axis is greater than 1.24 and less than 4.1, and the composition ratio Ba:Sr: is 0.1 to 1.45: 0.5 to 1.7. The phosphor particles as described in claim 1 further include an oxygen element (O). The phosphor particles according to claim 1, wherein the phosphor particles have an average particle diameter (D50) which is greater than 6.2 micrometers (μm) and less than 14.4 micrometers (μm). ). The phosphor particles according to claim 1, wherein the phosphor particles have a 10% particle diameter (D10), and the 10% particle diameter (D10) is greater than 3.4 micrometers (μm) and less than 8.3 micrometers. (μm). The phosphor particles according to claim 1, wherein the phosphor particles comprise a composition having a composition formula of (Ba _a Sr _1-a ) _2-z Si ₅ O _b N _n :Eu _Z , wherein , 0.03 < a < 0.75, 0 < b < 1, 7 < n < 9, and 0.03 < z < 0.3. The phosphor particles according to claim 5, wherein 0.3 ≦ a ≦ 0.7, 0 < b < 1, 7 < n < 9, 0.04 ≦ z ≦ 0.2. The phosphor according to claim 5, wherein Ba:Sr:Eu is 0.1~1.45: 0.5~1.7:0.05~0.2. For example, the phosphor described in claim 5, wherein Ba:Sr:Eu is 0.7 to 1.25:0.62 to 1.24:0.06 to 0.13. The phosphor particles according to claim 1, wherein the phosphor is irradiated with a light source having a wavelength of 455 nm, and the phosphor is excited to emit a main wavelength of 580 to 680 nm, and the luminescent color thereof is used. The CIE 1931 chromaticity coordinate (x, y) is 0.45 ≦ x ≦ 0.72, 0.2 ≦ y ≦ 0.5. A light-emitting device comprising: a semiconductor light-emitting element; and a phosphor layer, comprising the phosphor particles according to any one of claims 1 to 9, wherein the phosphor particles are subjected to the semiconductor The light emitted by the light-emitting element excites and converts light having a wavelength different from that of the semiconductor light-emitting element.