TWI695061B - Phosphors and light-emitting device including the same - Google Patents

Abstract

The present invention relates to a phosphor and an light-emitting device including the same. The phosphor is of the following general formula 1:         A_1-x [Mg₂ Al₂ N₄ ]：Ce_x ³⁺ [1] , wherein A is Ca, Sr or Ba, Ce_x ³⁺ is activator, and 0 ＜ x ≤ 0.08.

Description

Fluorescent material and light-emitting device containing fluorescent material

The present invention relates to a light-emitting device in which fluorescent materials include fluorescent materials, and particularly to a magnesium-aluminum-nitrogen compound fluorescent material and its application in a light-emitting device.

In the nineteenth century, Edison invented the electric lamp and changed the history of mankind. Since then, the development of lighting equipment has changed rapidly. In recent years, light-emitting diodes (LEDs) have developed vigorously, and such solid-state devices have been used as light sources with the improvement of technology. The light-emitting diode can not only efficiently convert electrical energy into light energy, but also has the advantages of power saving, environmental protection (mercury-free), small size, and good color rendering. Under the trend of rising environmental awareness, developing renewable energy and promoting energy saving, traditional incandescent bulbs, halogen lamps and other lighting equipment have been gradually replaced by white light-emitting diodes.

One of the principles of white light-emitting diodes is to use a light-emitting diode chip as a light source, such as an ultraviolet chip or a blue light chip, to excite the fluorescent material, so that the fluorescent material emits visible light of other wavelengths (such as green light, red light, etc.) ), thereby mixing out white light with different color temperatures and color rendering.

At present, the most commonly used method is to use the blue light emitted by the blue light-emitting diode chip to excite the yellow phosphor to convert to yellow light, and the unconverted blue light is mixed with the converted yellow light to form white light, but its color rendering is not good. Therefore, to this day, the development of phosphors is still an important issue in the development of light-emitting diodes.

One object of the present invention is to provide a fluorescent material having the following general formula 1: A _1-x [Mg ₂ Al ₂ N ₄ ]: Ce _x ³⁺ [1] where A is Ca, Sr or Ba, Ce ³⁺ is the activator, and 0 <x ≤ 0.08.

In some embodiments of the present invention, the fluorescent material may be excited by excitation light having a peak in the wavelength range of 400 nm to 540 nm to emit a radiated light.

In some embodiments of the present invention, 0.005 <x ≤ 0.08, and the fluorescent material can be excited by excitation light with a peak in the wavelength range of 490 nm to 540 nm, and emit a maximum emission intensity of 570 nm to 585 Radiated light in the nm wavelength range.

In some embodiments of the present invention, 0.01 <x ≤ 0.08, and the fluorescent material can be excited by excitation light with a peak in the wavelength range of 450 nm to 540 nm, and emit a maximum emission intensity of 570 nm to 585 Emitted light in the nm range.

In some embodiments of the present invention, 0 <x ≤ 0.01, and the fluorescent material can be excited by excitation light with a peak in the wavelength range of 450 nm to 470 nm, and emit a maximum emission intensity of 610 nm to 625 The emitted light in the wavelength range of nm, and can be excited by the excitation light with a peak in the wavelength range of 510 nm to 540 nm, emits a emitted light with the maximum emission intensity in the wavelength range of 570 nm to 585 nm.

In some embodiments of the present invention, when the fluorescent material can be excited by excitation light with a peak in the wavelength range of 500 nm to 520 nm, its emission spectrum includes a saddle structure.

In some embodiments of the present invention, A in Formula 1 is strontium (Sr).

Another object of the present invention is to provide a light-emitting device including a first excitation light source with a peak in the wavelength range of 400 nm to 540 nm, and the fluorescent material as described above.

In some embodiments of the present invention, the first excitation light source can emit light with a peak in the wavelength range of 490 nm to 540 nm or light with a peak in the wavelength range of 450 nm to 470 nm.

In some embodiments of the present invention, the light-emitting device further includes a second excitation light source, wherein the first excitation light source can emit light with a peak in the wavelength range of 450 nm to 470 nm, and the second excitation light source can emit a peak Light in the wavelength range of 490 nm to 540 nm, and in Formula 1, 0 <x ≤ 0.01.

In order to make the above objects, technical features and advantages of the present invention more obvious and understandable, the following is a detailed description with some specific implementations.

The following will specifically describe some specific implementations according to the present invention; however, without departing from the spirit of the present invention, the present invention can be practiced in many different forms, and the scope of protection of the present invention should not be interpreted as being limited to the specification The stated. In addition, unless otherwise stated in the text, "a", "the" and similar terms used in this specification (especially in the scope of patent applications described below) should be understood to include both singular and plural forms.

The invention is a magnesium aluminum nitrogen compound fluorescent material using cerium (Ce) as an activator. The fluorescent material of the present invention can use excitation light with a peak in the wavelength range of 400 nm to 540 nm as the excitation light source, and can pass through the change of the concentration of the activator cerium and the wavelength of the excitation light to obtain different emission light bands, and the applicable range It is wide and can provide a wide emission spectrum with a saddle, which helps to improve the color rendering of the applied light-emitting device, as detailed below.

In particular, the present invention provides a fluorescent material having the following general formula 1: A _1-x [Mg ₂ Al ₂ N ₄ ]: Ce _x ³⁺ [1]

A in Formula 1 may be Ca, Sr or Ba, and Sr is used in the specific implementation of the following examples. In the fluorescent material of the present invention, Ce ³⁺ is an activator of the fluorescent material, and its content (that is, the value of "x") is not 0; generally speaking, it is calculated as the total moles of A and Ce ³⁺ , The content ratio of the activator Ce ³⁺ is not more than 8%, that is, 0 <x ≤ 0.08. In the specific implementation of the following embodiment, x is controlled to be in the range of greater than 0.005 to not more than 0.08 (0.005 <x ≤ 0.08).

The fluorescent material of the present invention can use light with a peak in the wavelength range of 400 nm to 540 nm as the excitation light, and can obtain different emission bands by changing the wavelength of the excitation light, in particular, an emission spectrum including a saddle structure can be obtained. The wavelengths of the two peaks that constitute the saddle structure can differ by more than 30 nm, which can contribute to the improvement of color rendering in the application of light-emitting devices.

Specifically, in the fluorescent material of the general formula 1 of the present invention, in the case of 0 <x ≤ 0.08, for example, 0.005 <x ≤ 0.08, the fluorescent material can be subjected to a peak in the wavelength range of 490 nm to 540 nm The excitation light is excited, in one embodiment, the excitation light is green light, which produces an emission spectrum with a saddle, wherein the peak of the maximum emission intensity is in the wavelength range of 570 nm to 585 nm, and the peak of the next highest emission intensity is 610 In the wavelength range from nm to 625 nm, in one embodiment, the emitted light is yellow light and/or orange light. If x is greater than 0.01, that is, 0.01 <x ≤ 0.08, under the excitation of excitation light with a peak in the wavelength range of 450 nm to 540 nm, in one embodiment, the excitation light is blue light, all of which will cause the maximum emission as above An emission spectrum with a saddle having an intensity in the range of 570 nm to 585 nm and a sub-highest emission intensity in the range of 610 nm to 625 nm, in one embodiment, the emitted light includes yellow light, orange light, and/or orange light. If x is less than or equal to 0.01, that is, 0 <x ≤ 0.01, then only under the excitation of excitation light with a peak in the wavelength range of 510 nm to 540 nm, in one embodiment, the excitation light is green light, which will be obtained as above Emission spectrum with a saddle; under excitation of excitation light with a peak in the wavelength range of 450 nm to 470 nm, in one embodiment, the excitation light is blue light, resulting in an emission spectrum with a maximum emission intensity in the wavelength range of 610 nm to 625 nm In one embodiment, the emitted light is orange light and/or orange-red light.

Taking the green light with the peak at 510 nm or the blue light with the peak at 460 nm as the excitation light, the radiation performance of the fluorescent material of Formula 1 of the present invention under different Ce contents is shown in Table 1 below:

Table 1

Since the fluorescent material of the present invention has the above-mentioned special properties of radiated light, it will be more flexible when applied to a light-emitting device. For example, in the case of 0 <x ≤ 0.01, by adjusting the excitation light to green light or blue light, the light with the maximum emission intensity at different wavelengths can be generated, and the application range is wider due to different light emission requirements; And through the activator concentration (x) adjustment and excitation light arrangement as shown in Table 1, an emission spectrum with a saddle portion can be provided. This emission spectrum with a wide emission wavelength has a significant benefit for the improvement of color rendering. The above special radiation performance will be clearly presented in the following examples.

The present invention also provides a light-emitting device which includes the fluorescent material of Formula 1 of the present invention and a first excitation light source. The peak of the excitation light of the first excitation light source is in the wavelength range of 400 nm to 540 nm to excite the fluorescent light material. In one embodiment, the excitation light source is a blue light-emitting device, such as a blue LED chip. The blue light emitting element can emit excitation light with a peak in the wavelength range of 440 nm to 480 nm. In addition, the blue light emitting element may also be a blue laser. In another embodiment, the excitation light source is a green light-emitting element, wherein the green light-emitting element can emit excitation light with a peak in the wavelength range of 490 nm to 540 nm.

In addition, in view of the diversity of the light emitting performance of the fluorescent material, the light-emitting device of the present invention does not exclude the case of using multiple excitation light sources. For example, the light-emitting device may include a first excitation light source and a second excitation light source with different wavelength ranges. The first excitation light source may emit light with a peak in the wavelength range of 450 nm to 470 nm, and the second excitation light source may emit light with a peak in the range of 490 nm to In the 540 nm wavelength range, under this configuration, when the fluorescent material satisfies the condition of 0.010 <x ≤ 0.01, it will be excited by the first excitation light and the second excitation light respectively, emitting different emission spectra, providing applications. Diversity. In one embodiment, the excitation light source is a blue light-emitting element, and cooperates with other phosphors that can emit green wavelength bands, such as (Ba, Sr, Ca) ₂ SiO ₄ : Eu ²⁺ . In another embodiment, the excitation light source includes a first excitation light source as a blue light emitting element and a second excitation light source as a green light emitting element.

The present invention also provides a manufacturing method for manufacturing the fluorescent material of Formula 1 of the present invention. The manufacturing method is prepared by a solid-state sintering method, which has the advantages of simple steps and mass production. Taking the method of preparing magnesium aluminum nitride compound fluorescent material (Sr _1-x [Mg ₂ Al ₂ N ₄ ]: Ce _x ³⁺ ) as an example, the reactants Sr ₃ N ₂ , Mg ₃ N ₂ , AlN and After the CeN is weighed separately, it is put into a mortar and grinded to be uniformly mixed, and then sintered at a high temperature under an inert atmosphere (such as a nitrogen atmosphere) to obtain the product. The sintering conditions are, for example, a temperature of 1550 ^o C and a pressure of 0.9 Pa.

The following examples further illustrate the invention. These embodiments are only provided as illustrations, rather than to limit the protection scope of the present invention. The protection scope of the present invention is as shown in the appended patent application scope.

Examples

1. Fluorescent material 1 to 7 Preparation

In the glove box, weigh Sr ₃ N ₂ , Mg ₃ N ₂ , AlN and CeN at the weight ratios (weight %) shown in Table 2 and put them in a mortar and grind for 20 minutes, then at 0.9 Pa High-temperature sintering under nitrogen, sintering temperature 1550 ^o C, sintering time four hours (4h), to obtain fluorescent materials 1 to 7: Sr _1-x [Mg ₂ Al ₂ N ₄ ]: Ce _x ³⁺ , x respectively It is 0.005, 0.01, 0.015, 0.02, 0.04, 0.06, and 0.08.

Table 2

2. Crystal phase test of fluorescent materials

The crystal phase purity of fluorescent materials 1 to 7 was analyzed with an X-ray powder diffractometer (Bruker; model: D2 phaser). The results are shown in Figure 1. As shown in the figure, the crystal phases of the prepared fluorescent materials are all pure phases, no impurity phases are generated, and the purity is good.

3. Excitation spectrum of fluorescent materials

The excitation spectra of fluorescent materials 1 to 7 were analyzed with a spectrophotometer (Horiba; model: FluoroMax-3), where the peaks of the emitted light were set to 580 nm and 620 nm, respectively, and the results are shown in Figure 2a and Figure 2b.

As shown in the figure, regardless of whether the peak of the emitted light is set at 580 nm (Figure 2a) or 620 nm (Figure 2b), the fluorescent materials 1 to 7 can be excited by light with a peak in the wavelength range of 400 nm to 550 nm .

4. Ce Effect of content ratio on emission spectrum

Using a spectrophotometer (Horiba; model: FluoroMax-3) to excite fluorescent materials 1 to 7 with green light with a peak at 510 nm and blue light with a peak at 460 nm, respectively, to analyze the activator (Ce) The influence of the content ratio (x value) on the emission spectrum of fluorescent materials. The test results of the emission spectrum are shown in Figure 3a and Figure 3b, respectively, and the corresponding color coordinate spectrum (showing the change in the position of the emitted light) is displayed separately. In Figure 4a and Figure 4b.

Specifically, as shown in the figure, when the fluorescent material is excited with green light with a peak at 510 nm (Figure 3a; the corresponding color coordinate spectrum is Figure 4a), regardless of the Ce content ratio, the fluorescent material 1 All of them produce an emission spectrum with a saddle, and the maximum emission intensity is in the wavelength range of about 570 nm to 585 nm, and the next highest emission intensity is in the wavelength range of about 610 nm to 625 nm. When the fluorescent material is excited with blue light with a peak at 460 nm (Figure 3b; the corresponding color coordinate spectrum is Figure 4b), the proportion of Ce content is not higher than 0.01 (fluorescent materials 1 and 2, x are 0.005 respectively) And 0.01), the fluorescent material produces an emission spectrum with a maximum emission intensity in the wavelength range of approximately 610 nm to 625 nm; when the Ce content ratio is higher than 0.01 (fluorescent materials 3 to 7, x is 0.015, 0.02, 0.04, 0.06, respectively) And 0.08), the fluorescent material produces an emission spectrum with a saddle, and the maximum emission intensity is approximately in the wavelength range of 570 nm to 585 nm, and the second highest emission intensity is in the wavelength range of approximately 610 nm to 625 nm. The above results show that the fluorescent material of the present invention can provide a variety of light emission options, can increase the breadth of application, and can provide a wide range of emitted light wavelength spectrum formed by the saddle, which helps to improve the application of the light-emitting device Color rendering.

5. Effect of excitation light wavelength on emission spectrum

Use spectrophotometer (Horiba; model: FluoroMax-3) to test the emission spectrum of fluorescent materials 1 and 2, in which the peak wavelength of the excitation light is gradually changed from 460 nm to 510 nm (at intervals of 10 nm) In order to test the effect of excitation light wavelength on the emission spectrum, the results are shown in Figure 5a and Figure 5b, respectively.

Figure 5a is the test result of the change of the emission spectrum of the fluorescent material 1 (x = 0.005) with the peak wavelength of the excitation light, and Figure 5b is the change of the emission spectrum of the fluorescent material 2 (x = 0.01) with the peak wavelength of the excitation light Test results. As shown in the figure, under the excitation of excitation light with a peak wavelength of 460 nm, the peak wavelength position of the radiated light of the fluorescent materials 1 and 2 mainly falls in the wavelength range of 610 nm to 625 nm, and the excitation wavelength becomes longer As the wavelength band moves, the emission spectrum gradually produces a saddle, the maximum emission intensity shifts to a wavelength range of about 570 nm to 585 nm, and the next highest emission intensity is about 610 nm to 625 nm. This result verifies the light emitting diversity of the fluorescent material of the present invention again.

The above-mentioned embodiments are only illustrative of the principles and effects of the present invention, and explain the technical features of the present invention. The purpose is to enable those with ordinary knowledge in the field to which the present invention belongs to understand the content of the present invention and implement it accordingly, not Used to limit the protection scope of the present invention. Any change or arrangement that can be easily completed by anyone familiar with the technology without violating the technical principles and spirit of the present invention falls within the scope claimed by the present invention. Therefore, the protection scope of the present invention is as listed in the appended patent application scope.

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Figure 1 shows the results of crystal phase diffraction analysis of several embodiments of the fluorescent material of the present invention.

Figure 2a is the excitation spectrum of several embodiments of the fluorescent material of the present invention (the peak of the emitted light is set at a wavelength of 580 nm).

Figure 2b is the excitation spectrum of several embodiments of the fluorescent material of the present invention (the peak of the emitted light is set at a wavelength of 620 nm).

FIG. 3a is an emission spectrum diagram excited by excitation light with a peak of 510 nm at several specific embodiments of the fluorescent material of the present invention.

Fig. 3b is a graph of the emission spectrum excited by the excitation light with a peak wavelength of 460 nm at several specific embodiments of the fluorescent material of the present invention.

FIG. 4a is a color coordinate spectrum corresponding to the emission spectrum excited by the excitation light with a peak of 510 nm at several specific embodiments of the fluorescent material of the present invention.

FIG. 4b is a color coordinate spectrum corresponding to the emission spectrum excited by the excitation light with a peak of 460 nm at several embodiments of the fluorescent material of the present invention.

Figure 5a is a test result of the variation of the emission spectrum of the fluorescent material according to one embodiment of the present invention with wavelength.

FIG. 5b is a test result of the variation of the emission spectrum of the fluorescent material according to another embodiment of the present invention with wavelength.

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Claims (8)

A fluorescent material having the following general formula 1: A _1-x [Mg ₂ Al ₂ N ₄ ]: Ce _x ³⁺ [1] where A is Ca, Sr or Ba, and Ce ³⁺ is an activator, and 0<x

0.08; when 0<x

0.01, and when the peak of the excitation is in the wavelength range of 450nm to 470nm, the maximum emission intensity of the emitted light is in the wavelength range of 610nm to 625nm; and when 0.01<x

0.08, and when the peak of the excitation light is in the wavelength range of 450 nm to 470 nm, the maximum emission intensity of the emitted light is in the wavelength range of 570 nm to 585 nm, and the next highest emission intensity is in the wavelength range of 610 nm to 625 nm. A fluorescent material having the following general formula 1: A _1-x [Mg ₂ Al ₂ N ₄ ]: Ce _x ³⁺ [1] where A is Ca, Sr or Ba, and Ce ³⁺ is an activator, and 0<x

0.08; when the peak of the excitation is in the wavelength range of 490nm to 540nm, the peak of the maximum emission intensity of the emitted light is in the wavelength range of 570nm to 585nm, and the next highest emission intensity is in the wavelength range of 610nm to 625nm. The fluorescent material according to claim 1 or 2, wherein the emission spectrum of the emitted light includes a saddle structure. The fluorescent material according to claim 3, wherein the wavelengths of the two peaks constituting the saddle structure differ by more than 30 nm. The fluorescent material according to claim 1 or 2, wherein A is Sr. A light-emitting device includes a first excitation light source that can emit light with a peak in the wavelength range of 400 nm to 540 nm, and the fluorescent material according to any one of claims 1 to 5. The light-emitting device according to claim 6, wherein the first excitation light source can emit light with a peak in the wavelength range of 490nm to 540nm or light with a peak in the wavelength range of 450nm to 470nm. The light-emitting device according to claim 7, further comprising a second excitation light source, wherein the first excitation light source can emit light having a peak in the wavelength range of 450nm to 470nm, and the second excitation light source can emit a peak in 490nm Light in the wavelength range up to 540nm.

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