TW201608008A - A formulation of phosphor and synthesis method thereof - Google Patents

Abstract

The present invention discloses a formulation of phosphor and a synthesis method thereof; when the phosphor is excited by UV, the formulation and synthesis of such a phosphor can make the FWHM narrowed and reduce the thermal quenching property. In display applications, the gamut breadth can be further increased. Structurally, the phosphor contains M1-xSi6N8: Eux 2+, which is made using metal nitride (M3N2), silicon nitride (Si3N4), and europium nitride (EuN) as reactants, wherein M is an alkaline earth metal, and the of ratio of M: Si: Eu (in moles number) is 2-x: 5: x, 0.02 ≤ x ≤ 0.2; after these reactants are mixed and heated to a sintering temperature; and held at the sintering temperature for more than 6 hours, so as to obtain a phosphor having a FWHM smaller than 40nm for the emission wavelength, and the luminous intensity at 150 DEG C may reach more than 75% the luminous intensity at 25 DEG C.

Description

Fluorescent powder formula and synthesis method thereof

The invention relates to a formula of a phosphor powder and a synthesis method thereof, in particular to a UV-excited phosphor powder, the formula for narrowing the half-height width and the heat quenching property and the synthesis method thereof, and the display method thereof Can further increase the gamut breadth.

As light-emitting diode (LED) light sources have gradually been accepted by the public, traditional backlight sources such as Cold-Cathode fluorescent light (CCFL), and illumination sources such as incandescent bulbs or fluorescent lamps, due to color The problems of environmental protection, power consumption, and fever have long been criticized for a long time, and gradually withdrew from the market stage.

In recent years, in the major optoelectronic exhibition venues, various brands of TV (TV) manufacturers are committed to the introduction of LED thin TV, while emphasizing the concept of energy saving and environmental protection, it can be known that thinning and energy saving is the trend of TV development, especially with LED backlight The modules are the most eye-catching. Because LED has obvious four major technical advantages: First, it can achieve color saturation more than cold cathode fluorescent tube backlight; Second, the brightness of LED backlight can be actively adjusted with the brightness of the picture, so it can save energy More than 30%; third, LED backlights do not contain toxic and harmful substances such as lead and mercury, and have environmental benefits; fourth, LEDs can reach ultra-thin requirements, with an average of less than 10mm. These four points have prompted the LED backlight TV to replace the traditional backlight source cold cathode tube.

Fluorescent powder In white LED applications, the matching of the excitation band to the luminescent color is an important prerequisite, and the host material, activator or other dopant of the inorganic phosphor material is available. Excitation and luminescent materials that can affect fluorescent materials. Many conventional fluorescent materials are more suitable for excitation in the short-wavelength UV band, and the excitation efficiency in the long-wavelength UV or visible light band is poor, resulting in a light-converting material that cannot be applied as an LED.

According to the principle of fluorescent powder, the material belongs to the solid-state luminescent material, and the powder absorbs electromagnetic radiation and emits light, which is called photoluminescence, and the bulk of the powder is (SrBaMg) ₂ SiO ₄ :Eu ^{2+ .} It is composed of a host material, namely (SrBaMg) ₂ SiO ₄ , and the luminescent properties of the illuminant are obtained by doping a small amount of foreign ions into the host, such as Eu ²⁺ . When the ion is incorporated into the host lattice to form a center that can be excited to emit light, it is called an activator. A sensitizer or co-activator is said to be a sensitizer or co-activator when it is incorporated into the host lattice and can transfer its excitation energy to a nearby activator, causing the activator to illuminate. The illuminator has no significant absorption of the base energy, while the sensitive person absorbs the excitation energy and then transfers the energy to the activator to illuminate it. The photoexcitation process is that the material absorbs the energy of the external light source, and the electrons of the electronic ground state S ₀ are transitioned to the excited state. The electrons that then transition to the excited state relax to the lowest vibrational state in the electronically excited state.

After the emergence of solid-state semiconductor lighting, the backlight and lighting industry has undergone major changes, which have improved the shortcomings of the original light source, which also changed the user's habits. Because the LED light source is a kind of semiconductor light source, it is related to color and some photoelectric characteristics. The original light source is different, and therefore the characteristics are different, so that the LED light source must be changed in design, so as to cooperate with the original backlight and lighting applications. First of all, we must first understand that the requirements of the wide color gamut for the light source are red, green and blue, that is, the full width Width of Half Magnitude (FWHM) is narrow, and it is expected to be in accordance with the International Commission on Illumination (Commission International de 1). , Eclairage, CIE) published the Chromaticity diagram, which is surrounded by red, green and blue. The larger the angular area, the better. This type of light source will be suitable for backlight use. There are many ways to use LED to stimulate fluorescent powder to reach a wide color gamut. For example, if LED is mixed with red, green and blue as a backlight, the color gamut analog value (NTSC) can reach 105%, but its price is higher. high. Using a blue LED as a backlight, plus yellow phosphor powder, NTSC can reach about 70%, which is cheaper. Using a blue LED as a backlight, plus yellow phosphor and red phosphor, NTSC can reach about 85%, but the reliability of red phosphor is a big problem. Using blue LED as a backlight, plus red and green phosphor, NTSC can reach 90~100%, and the reliability of red phosphor is not high enough. Using blue LEDs as backlights, plus quantum dot phosphors, NTSC is about 100%, but quantum dot phosphors are expensive. The high degree of color gamut performance will make the LED TV color performance more realistic, showing a rich variety of colors. Considering the problem of price and actual mass production, the industry is still aiming to achieve a wide color gamut with LED-activated phosphor powder.

In general, the luminous efficiency of Luminous Efficacy decreases at high temperatures, and the effect of this phenomenon is called thermal quenching or thermal free effect, and the luminous efficiency represents the efficiency with which the light source converts the consumed electrical energy into light. It is expressed in terms of luminous flux and power consumption table, and its unit is lm/W. The consumed electric energy is measured by the actual power consumption of the input electric energy. The unit is watt, and the luminous flux is emitted from the light source in all directions. The sum of the luminous flux (total luminous flux) is measured in lumens (lm). The higher the luminous efficiency, the higher the efficiency with which electrical energy is converted into light, and the less energy is consumed by emitting the same luminous flux. When the LED is applied in practice, the ambient temperature rises due to heat generation, which leads to a decrease in efficiency.

In view of the above disadvantages of the prior art, the present invention provides a formulation of a phosphor powder and a method for synthesizing the same, which utilizes a UV-excited phosphor powder to narrow the FWHM and reduce the heat quenching property. The formulation and its synthesis method can further increase the gamut breadth in the display application.

According to the color scheme system published by the International Commission on Illumination (CIE) in the International Committee for Weights and Measures (CIPM), the system analyzes the results according to the relationship between vision and visible light. The phosphor powder prepared by the invention is ultraviolet (UV) light. After excitation, the blue coordinate and the red light coordinate can be connected in a straight line relationship on the xy chromaticity coordinate map of CIE. Among them, the CIE 1931 RGB color system, which uses red, green and blue light sources to match the equal energy spectrum between unknown wavelengths of 400 nm and 700 nm, and obtains the chromaticity coordinates, such as CIE xy chromaticity coordinates, by mathematical transformation. The x value is the horizontal axis and the y value is the vertical axis. This chromaticity value is used to quantify the color. The x chromaticity coordinate is equivalent to the ratio of the red primary color, and the y chromaticity coordinate is equivalent to the proportion of the green primary color. The figure is a horseshoe-shaped spectral trajectory. The red band of the spectrum is concentrated in the lower right part of the figure, and the green band is concentrated in the upper part of the figure. The bands are concentrated in the lower left of the trace map. The whiteness of the central white light is the lowest, and the saturation of the light source trajectory is the highest. Calculating the chromaticity coordinate x, y of a certain color can clearly determine its color characteristics in the chromaticity. In the chromaticity diagram, the position of the point represents Color characteristics of various colors.

The heat quenching effect is a phenomenon in which the light-emitting intensity of the fluorescent powder decreases with an increase in temperature. At a low temperature, the ground-state electron-absorbing photons are excited to an excited state, and the non-radiative mitigation process returns to the lowest vibrational energy level of the excited state. Then return to the ground state in the form of light. At high temperatures, electrons can be thermally energized and transitioned to higher vibrational energy levels. If they are vibrated to the intersection of the excited and ground state energy curves, the electrons will cross the intersection and be mitigated by non-radiative vibrations back to the ground state. The lowest energy level, whose energy is lost in the crystal lattice, returns to the ground state in a non-exposed form, and reduces the intensity of the fluorescent light.

The main object of the present invention is to provide a formula of a phosphor powder which is M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, and the formulation is made of metal nitride (M ₃ N ₂ ). Powder, tantalum nitride (Si ₃ N ₄ ) powder and tantalum nitride (EuN) powder, wherein M is an alkaline earth metal, 0.02≦x≦0.2, and the molar ratio of M:Si:Eu is 2- x:5:x.

One of the embodiments of the present invention provides a formula of a phosphor powder which is M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, and the formulation is composed of a metal nitride (M ₃ N _{2 ).} ) powder, silicon nitride (Si ₃ N ₄₎ powder, and europium nitride (EuN) powder, where M is an alkaline earth metal, 0.02 ≦ x ≦ 0.2, and M: Si: number of moles of Eu ratio of respectively 2 -x: 5: x, wherein M of the metal nitride (M ₃ N ₂ ) comprises one of calcium (Ca), strontium (Sr), barium (Ba) or a combination thereof.

One of the embodiments of the present invention provides a formula of a phosphor powder which is M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, and the formulation is composed of a metal nitride (M ₃ N _{2 ).} Powder, tantalum nitride (Si ₃ N ₄ ) powder and tantalum nitride (EuN) powder, wherein M is an alkaline earth metal, 0.02 ≦ x ≦ 0.2, and the molar ratio of M: Si: Eu is 2 -x: 5: x, wherein the metal nitride (M ₃ N ₂ ) is calcium nitride (Ca ₃ N ₂ ), tantalum nitride (Sr ₃ N ₂ ) or tantalum nitride (Ba ₃ N ₂ ).

A second object of the present invention is to provide a method for synthesizing a phosphor powder, which is a M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, the method comprising the steps of: providing a metal nitride (M ₃ N ₂ ) powder, cerium nitride (Si ₃ N ₄ ) powder and cerium nitride (EuN) powder as raw materials, wherein M is an alkaline earth metal, and the molar ratio of M:Si:Eu is 2 x: 5: x, 0.02 ≦ x ≦ 0.2; the reactants are mixed and heated to a sintering temperature; and the temperature is maintained at the sintering temperature for 6 hours or more.

One embodiment of the present invention provides a method for synthesizing a phosphor powder, the phosphor powder structure being M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, the method comprising the steps of: providing a metal nitride (M ₃ N ₂ ) powder, cerium nitride (Si ₃ N ₄ ) powder and cerium nitride (EuN) powder as raw materials, wherein M is an alkaline earth metal, and the molar ratio of M:Si:Eu is 2 x: 5: x, 0.02 ≦ x ≦ 0.2; after mixing the reactants, the temperature is raised to a sintering temperature of 1700 ° C to 2100 ° C; and the temperature is maintained at the sintering temperature for 6 hours or more.

One embodiment of the present invention provides a method for synthesizing a phosphor powder, the phosphor powder structure being M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, the method comprising the steps of: providing a metal nitride (M ₃ N ₂ ) powder, cerium nitride (Si ₃ N ₄ ) powder and cerium nitride (EuN) powder as raw materials, wherein M is an alkaline earth metal, and the molar ratio of M:Si:Eu is 2 x: 5: x, 0.02 ≦ x ≦ 0.2; after mixing the reactants, the temperature is raised to a sintering temperature, which further comprises a sintering gas pressure, the sintering gas pressure is between 1 atm and 10 atm; and the temperature is maintained at the sintering temperature for 6 hours. the above.

One embodiment of the present invention provides a method for synthesizing a phosphor powder, the phosphor powder structure being M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, the method comprising the steps of: providing a metal nitride (M ₃ N ₂₎ powder, silicon nitride (Si ₃ N ₄₎ powder, and europium nitride (EuN) powder as a raw material, where M is an alkaline earth metal, so M: Si: number of moles of Eu ratio were 2- x: 5: x, 0.02 ≦ x ≦ 0.2; the reactants are mixed and heated to a sintering temperature; the temperature is maintained at the sintering temperature for 6 hours or more, and the phosphor powder M _1-x Si ₆ N _{8 is} sintered during sintering: The Eu _x ²⁺ system is obtained by a crystal phase change of M _2-y Si ₅ N ₈ :Eu _y , wherein 0.02 ≦ y ≦ 0.2.

Another object of the present invention is to provide a fluorescent powder formulation and a synthesis method thereof. The phosphor powder obtained by using the formulation of the present invention and the synthesis method thereof has a half-height width of the light-emitting wavelength of less than 40 nm, and is 150 ° C. The luminous intensity can reach 75% or more at 25 °C.

SrSi ₆ N ₈ (tradition) ‧‧‧Functional Fluorescent Powder

SrSi ₆ N ₈ (258)‧‧‧Flame powder of the invention

Eu _x ²⁺ phosphor powder diffraction pattern of: a first embodiment FIG. Department of Sr _1-x Si ₆ N ₈ embodiment of the present invention.

The second figure is an excitation spectrum of a fluorescent powder of Sr _1-x Si ₆ N ₈ :Eu _x ^{2+ according to an} embodiment of the present invention.

The third embodiment of FIG lines Sr _1-x Si ₆ N ₈ embodiment of the present invention: Eu _x ²⁺ phosphor emission spectrum of FIG.

The fourth figure is a fluorescence spectrum of a fluorescent powder of Sr _1-x Si ₆ N ₈ :Eu _x ^{2+ according to an} embodiment of the present invention.

The fifth graph is a CIE chromaticity analysis diagram of Sr _1-x Si ₆ N ₈ :Eu _x ^{2+ according to an} embodiment of the present invention.

The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. M ₃ N ₂ (where M contains Ca, Sr and Ba), Si ₃ N ₄ and EuN as synthetic raw materials, wherein the molar ratio of M:Si:Eu is 2-x:5:x and under pressure When the temperature is 0.5 MPa, the temperature is maintained at 1980 ° C, and the temperature is maintained for 6 hours or more, the M _1-x Si ₆ N ₈ :Eu _x ²⁺ blue nitride phosphor powder having a narrow FWHM can be synthesized. In the present invention, the ratio of each element of M _1.98 Si ₅ N ₈ :Eu ²⁺ _0.02 (ie, x=0.02) is the initial ratio of the reactants, and M _1.98 Si ₅ N ₈ :Eu can be obtained by extending the sintering temperature holding time. ²⁺ _{0.02 is} converted to M _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ . In addition, the photoexcitation spectrum shows that the material can be excited by a 365 nm wavelength source and produces a blue light with a peak of 455 nm, which indicates that the present invention is suitable as a blue phosphor for a UV-excited white light-emitting diode, and the phase synthesis compared to conventional methods of _{M 0.08 Si 6 N 8: Eu} 0.02 2+ , the synthesis of the sintering process of the present invention _{M 0.08 Si 6 N 8: Eu} 0.02 2+ having the half width of the narrower, and by a temperature change The fluorescence spectrum shows that the heat resistance is improved. M _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ synthesized by the sintering method of the present invention by CIE software has a high color purity, and when applied to a display, the gamut can be improved.

The sintering system transforms the powdery material into a dense body. The sintered compact system is a polycrystalline material whose microstructure is composed of crystal, glass phase and pores. The sintering process directly affects the grain size and distribution in the microstructure, and the pore size And distribution and grain boundary volume fraction, etc., by controlling grain boundary movement to suppress abnormal growth of crystal grains or by controlling surface diffusion, grain boundary diffusion and lattice expansion The pores are filled and dispersed, and the properties of the material are improved by changing the microstructure. In general, macroscopically, one or more solid powders are shaped to begin to shrink upon heating to a certain temperature and to become a dense, hard sintered body below the melting point. From a microscopic point of view, since molecules or atoms in the solid state attract each other, by heating, the powder body is granulated, and the substance is transferred to cause strength and lead to densification and recrystallization.

In sintering, most of the green body is pressed by a crystalline powdery material, and recrystallization and grain growth occur between the body particles as the sintering progresses, so that the strength of the green body is increased. Therefore, two processes are simultaneously performed at a high temperature during the sintering process. Recrystallization and grain growth. Especially in the late stage of sintering and the high temperature kinetics of sintering directly affect the microstructure of the sintered body such as grain size, pore distribution and strength. Therefore, sintering is a process of thermal activation and diffusion, which must occur after a certain temperature is exceeded, which involves the formation and growth of inter-powder bonds. At the beginning, the neck is formed by surface diffusion, and the crystal grains are smaller than the powder at this stage; during the sintering, the neck continuously grows and loses the shape of the neck, and the pores begin to round. At the end of sintering, the pores no longer continuously shrink by the bulk diffusion mechanism and gradually separate and separate, and the grain growth is accompanied by densification.

According to the sintering, when the green embryo is heated below the melting point of the main component in the body, the powder is tightly bonded by various diffusion methods. When the green body exists in part or all of the time during sintering, it is called Liquid phase sintering. There is no liquid phase present during sintering, which is called solid phase sintering. In the process of shrinkage, the faster the temperature rise, the higher the relative temperature corresponding to the maximum shrinkage rate, which may be advantageous for densification, but it is also possible that the grain is coarsened. If the rate of temperature rise is slow, the atoms have sufficient time to diffuse during the temperature rise, and thus the quality and dimensional stability of the finished product are high. In the case of solid phase sintering, the driving force for densification is a reduction in surface energy caused by the disappearance of the interface between the solid and the gas, and sufficient atom diffusion can be caused at the sintering temperature. The results of the sintering method, spectral properties and CIE analysis for reducing the full width at half maximum of the M _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ emission peak are described in the examples of the present invention.

Embodiment 1

To Sr ₃ N ₂ powder, Si ₃ N ₄ powder and EuN powder as a starting material of particle size of 45 m are less than, where Sr: Si: number of moles of Eu ratios were 1.98: 5: 0.02, Sr _1.98 in the present compositions based Si ₅ N ₈ :Eu ²⁺ _0.02 is used as a product to weigh the synthetic raw materials, and is sintered at a pressure of 0.5 MPa, a temperature of 1980 ° C, and a holding time of 6 hours or more, so that the half-height width can be synthesized. Sr _1.98 Si ₅ N ₈ :Eu ²⁺ _0.02 , by extending the sintering temperature holding time, Sr _1.98 Si ₅ N ₈ :Eu ²⁺ _{0.02 can be} converted into Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ , so finally Pure phase of Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ . The following description shows the Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ obtained by the formulation and the synthesis method of the present invention, represented by SrSi ₆ N ₈ (258), and is obtained by the following spectrogram showing the formulation of the present example and its synthesis method. The fluorescent powder has an effect that the half-height width of the emission spectrum is narrowed and the heat quenching property is lowered.

Comparative example one

To _{Sr 3 N 2, Si 3 N} 4 and EuN as the starting materials by conventional methods Sr _0.08 Si ₆ N _8: Eu _0.02 ²⁺ as weighing product ratio, 1/3 mole of Sr ₃ N ₂ and 1 /3 MoSi Si ₃ N ₄ was mixed with a trace amount of EuN, and then sintered at a sintering pressure of 0.5 MPa at 1900 ° C for 6 hours. The following description shows the Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ obtained by a conventional formulation and a synthesis method, and is represented by SrSi ₆ N ₈ (tradition).

Referring to the first to fourth embodiments of the present invention, the phosphor powder SrSi ₆ N ₈ (258) and the conventional method for producing the phosphor powder SrSi ₆ N ₈ (tradition) on the powder diffraction pattern, Comparison of excitation spectrum, emission spectrum and temperature-dependent fluorescence spectrum.

Please refer to the first figure for Sr _0.08 Si ₆ N ₈ :Eu _0.02 ^{2 which is} sintered by the conventional method (SrSi ₆ N ₈ (tradition)) and by the method of the invention (SrSi ₆ N ₈ (258)). ⁺ Fluorescent powder diffraction pattern. After careful comparison, the two methods can synthesize the same product Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ . The most obvious difference between the two figures is that Sr _0.08 Si ₆ N ₈ synthesized by the conventional method. :Eu _0.02 ²⁺ has a stronger signal at 2 θ of about 30°, thus compressing the strength of other signals.

Please refer to the second figure for Sr _0.08 Si ₆ N ₈ :Eu _0.02 ^{2 which is} sintered by the conventional method (SrSi ₆ N ₈ (tradition)) and by the method of the invention (SrSi ₆ N ₈ (258)). ⁺ Excitation spectrum measured at an emission wavelength of 455 nm. It can be seen from Fig. 2 that the Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ sintered by the method of the present invention is the same as the conventional method, and can be excited by UV light of 291 nm and 365-375 nm to generate blue light of 455 nm. Therefore, it can be applied to a UV-excited white LED as its blue phosphor.

Please refer to the third figure for Sr _0.08 Si ₆ N ₈ :Eu _0.02 ^{2 which is} sintered by the conventional method (SrSi ₆ N ₈ (tradition)) and the method of the present invention (SrSi ₆ N ₈ (258)). ⁺ An emission spectrum at an excitation wavelength of 365 nm. After excitation by 365 nm UV light, Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ synthesized by the two methods shows blue light with a peak at 455 nm, and the luminescence intensity of the two is equivalent. The difference is the sintering method proposed by the present invention. The synthesized Sr _0.08 Si ₆ N ₈ :Eu _0.02 ^{2+ has a} full width at half maximum of 39 nm, and the Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ semi-averitude width synthesized by a conventional method is 42 nm, so the present invention The Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ synthesized by the sintering method can be applied to the display, and the gamut is wider because of its narrower half-width, narrower color and higher color purity.

Please refer to the fourth figure for Sr _0.08 Si ₆ N ₈ :Eu _0.02 ^{2 which is} sintered by the conventional method (SrSi ₆ N ₈ (tradition)) and by the method of the invention (SrSi ₆ N ₈ (258)). ⁺ variable temperature fluorescence spectrum. This picture shows the temperature change in the fluorescence spectrum of the changing conditions of temperature, 455nm emission peak tracking of the signal strength, and two methods of Sr _{0.08 Si 6 N 8: Eu 0.02} 2+ phosphor powder at 25 deg.] C the measured signal The strength is set to 100%. From the figure, it can be seen that the sintering method of the present invention and the 168-fluorescent powder synthesized by the formulation can increase the emission intensity at 150 ° C by about 10% compared with the conventional method. More applicable to higher power LED devices.

See Figure V is a _{(SrSi 6 N 8 (258)} ) sintering Sr _0.08 Si ₆ N ₈ using the method of the present invention: Eu _0.02 ²⁺ analysis of the CIE chromaticity diagram, whereby figure shows analysis using The Sr _0.08 Si ₆ N ₈ :Eu _0.02 ²⁺ synthesized by the present invention has a chromaticity coordinate of (0.1472, 0.051), which is a blue phosphor of high color purity.

The above-described embodiments are merely illustrative of the features and functions of the present invention, and are not intended to limit the scope of the technical scope of the present invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the scope of the claims described below.

SrSi ₆ N ₈ (tradition) ‧‧‧Functional Fluorescent Powder

SrSi ₆ N ₈ (258)‧‧‧Flame powder of the invention

Claims (13)

A formula of a phosphor powder, the phosphor powder structure being M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, the formulation consisting of metal nitride (M ₃ N ₂ ) powder, tantalum nitride (Si ₃ N ₄ ) powder and cerium nitride (EuN) powder, wherein M is an alkaline earth metal, and the molar ratio of M:Si:Eu is 2-x:5:x, 0.02≦x≦0.2, respectively. The formula of the phosphor powder according to claim 1, wherein the metal nitride (M ₃ N ₂ ) M comprises calcium (Ca), strontium (Sr), barium (Ba) or a combination thereof. one. The formulation of a phosphor powder according to claim 1, wherein the metal nitride (M ₃ N ₂ ) is calcium (Ca ₃ N ₂ ), tantalum nitride (Sr ₃ N ₂ ) or Barium nitride (Ba ₃ N ₂ ). The formula of the phosphor powder according to claim 1, wherein the phosphor powder has a half width and a width less than 40 nm. The formula of the phosphor powder according to claim 1, wherein the phosphor powder has a luminous intensity at 150 ° C of 75% or more at 25 ° C. A method for synthesizing a phosphor powder, the phosphor powder structure being M _1-x Si ₆ N ₈ :Eu _x ²⁺ phosphor powder, the method comprising the following steps: (1) providing a metal nitride (M ₃ N ₂ Powder, tantalum nitride (Si ₃ N ₄ ) powder and tantalum nitride (EuN) powder are used as raw materials, wherein M is alkaline earth metal, so that the molar ratio of M:Si:Eu is 2-x:5:x , 0.02 ≦ x ≦ 0.2; (2) mixing the raw materials and then raising the temperature to a sintering temperature; (3) maintaining the temperature at the sintering temperature for 6 hours or more. A method for synthesizing a phosphor according to claim 4, wherein the metal nitride (M ₃ N ₂ ) M comprises calcium (Ca), strontium (Sr), strontium (Ba) or a combination thereof One of the groups. The method for synthesizing a phosphor according to the fourth aspect of the invention, wherein the metal nitride (M ₃ N ₂ ) is calcium (Ca ₃ N ₂ ) or tantalum nitride (Sr ₃ N ₂ ). Or tantalum nitride (Ba ₃ N ₂ ). A method for synthesizing a phosphor according to claim 4, wherein the sintering temperature in the step (2) is between 1700 ° C and 2100 ° C. A method for synthesizing a phosphor according to claim 4, wherein the step (2) further comprises a sintering gas pressure of between 1 atm and 10 atm. A method for synthesizing a fluorescent powder according to claim 4, wherein the step (3) of the fluorescent powder M _1-x Si ₆ N ₈ :Eu _x ²⁺ is composed of M _2-y Si ₅ N ₈ : Eu _y ²⁺ produces a crystal phase change, of which 0.02 ≦ y ≦ 0.2. The method for synthesizing a phosphor powder according to the fourth aspect of the invention, wherein the phosphor powder has a half width and a width of less than 40 nm. A method for synthesizing a phosphor according to the invention of claim 4, wherein the phosphor has an emission intensity at 150 ° C of 75% or more at 25 ° C.