A high-light-efficiency full-spectrum semiconductor light-emitting device

Abstract

The present invention relates to a high-light-efficiency and high-stability full-spectrum semiconductor light-emitting device, and the combination mode of the device is: a high-light-efficiency and high-stability full-spectrum semiconductor light-emitting device, characterized in that the device includes any two or more blue light chips with different peak wavelengths in the range of 420-480nm, and a first phosphor with a peak wavelength of 480-520nm, a second phosphor with a peak wavelength of 530nm-540nm, a third phosphor with a peak wavelength of 640-660nm, and a fourth phosphor with a peak wavelength of 680nm-700nm. The present invention combines and matches the main wavelength and phosphor of the chip combination, and the phosphor system can be suitable for efficient excitation of long- and short-wave blue light, and the obtained light-emitting device has the advantages of high light efficiency, high color rendering index, good stability, and a spectrum closer to natural light.

Description

Technical Field

[0001] The present invention relates to the field of healthy lighting technology, and in particular to a high-light-efficiency full-spectrum light-emitting device. Background Art

[0002] Healthy lighting mainly refers to lighting technology, lighting forms, lighting facilities and usage methods that have beneficial effects on people's vision, vision, physiology, psychology and other physical and mental health needs. The main technical focus of current healthy lighting is to make the spectrum of LED light sources as close to the visible spectrum of the sun (sunlight-like), reduce the relative energy of blue light to prevent blue light hazards; increase the relative energy of red light to promote the physical and mental health of the human body. The core of achieving healthy lighting at present is to develop a continuous spectrum with a solar-like spectrum in the visible light band. However, at this stage, the implementation method of conventional full-spectrum white light LEDs is to use a single blue light chip to excite fluorescent materials, and the obtained white light has the characteristics of high light efficiency and high color rendering index. However, the spectrum of this method has two obvious differences compared with the solar spectrum: first, its spectral continuity is poor, especially in the 480-500nm band. The loss is more serious. This part of light plays an important role in regulating human rhythms. In addition, the energy in the long-wave red light part is insufficient; second, its blue light has a relatively high relative intensity, and long-term use is easy to fatigue, and even cause vision loss. Based on different wavelengths of blue light chips to excite fluorescent materials to achieve continuous spectrum, it can achieve the advantages of low blue light, high CRI, and good spectrum continuity. However, the commonly used yellow-green powder and red powder have low luminous efficiency under long-wave blue light excitation, which cannot meet the market demand for high-light-efficiency products; and in order to improve the CRI, it is still necessary to use cyan powder with a peak wavelength of about 495nm. The conventional cyan phosphor BaSi 2 O 2 N 2 :Eu 2+ The system phosphor has poor thermal stability and cannot be used in large and medium-sized power devices. More importantly, the optimal excitation current and radiation power of long-wave and short-wave chips are different. The excitation effect of the phosphors is also different due to the difference in wavelength and radiation. The stability and light efficiency of the obtained white light lamp beads need to be improved.

[0003] Therefore, achieving high luminous efficiency and high stability based on the excitation of phosphors by blue light chips in different bands is of great significance to the promotion of healthy lighting. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is:

[0005] (1) Provides a high-efficiency and high-stability phosphor system suitable for excitation of blue light chips in different bands;

[0006] (2) A full-spectrum semiconductor light-emitting device with high light efficiency and high stability is proposed.

[0007] The technical solution of the present invention provides a high-light-efficiency and high-stability full-spectrum semiconductor light-emitting device, specifically:

[0008] A high-light-efficiency and high-stability full-spectrum semiconductor light-emitting device, characterized in that the device comprises any two or more blue light chips with different peak wavelengths whose peak wavelengths are in the range of 420-480nm, and a first phosphor with a peak wavelength of 480-520nm, a second phosphor with a peak wavelength of 530nm-540nm, a third phosphor with a peak wavelength of 640-660nm and a third phosphor with a peak wavelength of 680nm-700nm.

[0009] Preferably, after any two or more blue light chips with different peak wavelengths in the 420-480nm range are combined, the main wavelength of the chip is in the range of 447-457nm. After any two or more chips are combined, the main wavelength of the chip is in the range of 447-457nm, and the color rendering index can be improved and can reach above 98 after exciting the combined spectrum of phosphors. When the main wavelength of the chip after combination is lower than 447nm or higher than 457nm, the color rendering index of the device will decrease, and the color rendering index will not reach 95.

[0010] Preferably, the peak wavelength of the first phosphor is 495-500nm, the peak wavelength of the second phosphor is 530-535nm, the peak wavelength of the third phosphor is 645-650nm, and the peak wavelength of the fourth phosphor is 680-690nm. Based on the optimization of the peak wavelengths of the above phosphors, the spectrum of the combined device is more continuous, closer to the solar spectrum of the same color temperature, and the color rendering index and device light efficiency are higher.

[0011] Preferably, the chemical formula of the first phosphor is Lu 3 (Al 1-x ,Ga x ) 5 O 12 :zCe, the structure of the phosphor is a modification of the garnet structure phosphor, the stability is relatively conventional nitrogen oxide (BaSi 2 O 2 N 2 :Eu) is high. Preferably, 0.1≤x≤0.3, 0.003≤z≤0.008. In the chemical formula, a small amount of Ga is substituted for Al, which can make the peak wavelength of the phosphor blue-shifted. 3+ Al 3+The radius is large, and a small amount of Ga replacing Al can make the peak wavelength of the phosphor blue-shifted and reduce the half-wave width of the phosphor. If the x value is too low, the peak wavelength of the spectrum will not be obviously blue-shifted and cannot be below 500nm; if the x value is too high, it will cause the phosphor impurities to be generated, resulting in low brightness of the phosphor. The z value represents the content of the phosphor activator. As the z value increases, the activator concentration increases, the number of luminescence centers increases, and the phosphor shows a red-shift phenomenon; but if the z value is too small, it will lead to fewer luminescence centers and lower phosphor brightness; if the z value is too large, the peak wavelength of the phosphor will exceed 500nm, and it is easy to cause quenching of the luminescence center concentration and reduce thermal stability. Through the combined effect of x and z values, the stability, peak wavelength, half-peak width and brightness of the phosphor are optimized.

[0012] Preferably, the chemical formula of the second phosphor is Lu 3 Si 5 N 11 :Ce. This structure phosphor has higher thermal stability than garnet structure phosphor and is suitable for high-power excitation. And the excitation spectrum of this system phosphor can be efficiently excited in the range of 440-480nm, especially in the left and right bands of 460nm, the excitation efficiency can be balanced. This system phosphor and La 3 Si 5 N 11 :Ce has a different structure, is more stable in high temperature excitation, and has a narrower half-peak width. After the device is applied, the combined spectrum is more continuous, and the color rendering index and light efficiency are relatively higher. Therefore, based on the excellent emission spectrum, excitation spectrum and stability of the phosphor of this system, it has higher photoelectric parameters and spectral performance after the full-spectrum device is applied.

[0013] Preferably, the third phosphor is K having a core-shell structure. 2 TiF 6 :Mn@(Ca,Sr)AlSiN 3 :Eu, of which K2TiF 6 :Mn and (Ca,Sr)AlSiN 3 The molar ratio of (Ca, Sr)AlSiN is between 1 and 3. 3 :Eu nitride phosphor has high excitation efficiency in ultraviolet and short-wave blue light, but its excitation efficiency in long-wave phosphor is relatively low. In this technical solution, we use long- and short-wave blue light synergistic excitation. However, the nitride phosphor using this system has a good excitation effect in short-wave blue light, but the excitation efficiency is low under long-wave blue light excitation conditions, resulting in low overall excitation efficiency of the device. K 2 TiF 6:Mn is a fluoride phosphor activated by Mn4+, and its spectrum is linear narrow-band emission, which is suitable for long-wave blue light chip excitation; this technical solution proposes a core-shell structure K 2 TiF 6 :Mn@(Ca,Sr)AlSiN 3 :Eu combination, in (Ca, Sr)AlSiN 3 :Eu is coated with fluoride to form a multi-phase mixed combination. The core-shell structure phosphor is suitable for long- and short-wave synergistic excitation to achieve higher light efficiency. 6 :Mn and (Ca,Sr)AlSiN 3 The molar ratio of :Eu is between 1 / 3-1. Mainly K2TiF 6 :Mn ratio (Ca, Sr)AlSiN 3 :Eu has higher excitation efficiency, and K2TiF 6 :Mn is coated on the outer layer, and the ratio should be low. If it is too high, it will cause spectral imbalance, and it will be difficult to improve the optoelectronic parameters and spectrum. If the ratio is too low, it may lead to incomplete absorption of long-wave blue light, which will also cause device spectrum imbalance. Based on the above combination, the optoelectronic parameter performance of the spectrum is the best, and the relative blue light intensity will be lower with the addition of K2TiF6:Mn.

[0014] Preferably, the fourth phosphor is Eu 2+ The activated dual-phase structure of Sr 2 Si 5 N 8 and CaAlSiN 3 Phosphor. Specifically, the above two-phase structure is uniformly presented in a powder, which is made by solid phase method. The specific preparation method is as follows: according to a certain molar ratio, the corresponding Sr3N2, Ca3N2, Si3N4, AlN and EuN raw materials are configured, stirred evenly, and placed in a high-temperature furnace for sintering at 1400-1500℃ for 8h. After the obtained phosphor is crushed and washed, the desired two-phase structure phosphor is obtained. The phosphor has a relatively high half-wave width of about 150-170nm, and the peak wavelength is between 680nm-700nm.

[0015] Preferably, in the mixed phase, Sr2Si5N8 is the main phase, and the molar ratio of the two is between 1 and 3. If the Sr2Si5N8 phase is too low, the half-wave width of the phosphor will be low, which will easily cause discontinuity of long-wave red light after the device spectrum is applied, and the photoelectric parameters will be reduced. If the ratio is too high, the peak wavelength will be too low, and it will be difficult to reach between 680-700nm, which will cause the device spectrum to lack long waves.

[0016] The technical solution of the present invention also discloses a method for preparing the core-shell structure phosphor, which is prepared by a high-temperature solid phase method and a hydrothermal method. The preparation steps are as follows: weigh the corresponding element or compound according to the chemical formula, grind and mix them evenly, and sinter them at 1600°C to 1800°C for 4 to 10 hours to obtain (Ca, Sr)AlSiN 3 :Eu intermediate, the intermediate is crushed and post-processed as a hydrothermal precursor; the precursor is used as a raw material, by adding some K 2 TiF 6 :Mn corresponding element reagent, stir and react fully for 1 to 5 hours at a certain temperature, and finally dry to obtain K 2 TiF 6 :Mn@(Ca,Sr)AlSiN 3 :Eu products.

[0017] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0018] The present invention uses multi-band blue light to excite phosphors of the corresponding system, and at the same time limits the structure and component ratio of the phosphors. The full-spectrum light-emitting device obtained through the synergy of the chip and the phosphors has higher luminous efficiency, higher stability, and is also suitable for high-power excitation.

[0019] Additional aspects and advantages of the present invention will be partially given in the following description, and some synergistic enhancement solutions will become apparent from the following description or be learned through the practice of the present invention. It should be understood that the above general description and the detailed description below are only exemplary and explanatory and cannot limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0021] Figure 1 is a spectrum diagram of the device of Example 1;

[0022] Figure 2 The excitation and emission spectra of the narrow-band red powder of Example 1;

[0023] Figure 3 This is the XRD pattern of Lu3Si5N11:Ce; DETAILED DESCRIPTION

[0024] The following further examples are given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values ​​​​exemplified below.

[0025] Example 1

[0026] A high-light-efficiency and high-stability full-spectrum semiconductor light-emitting device, specifically, the typical peak wavelengths of the chip include 442nm, 450nm and 465nm, the above chips are controlled by chip optical power, and the main wavelength of the chip after combination is located at 452nm; the phosphor includes the following system: Lu3(Al1-x, Gax)5O12:zCe, x=0.2, z=0.003, the peak wavelength is 498nm; Lu3Si5N11:Ce, the peak wavelength is 535nm; K2TiF6:Mn@(Ca,Sr)AlSiN3:Eu, the molar ratio of the two is 1 / 2; Eu2+ activated Sr2Si5N8 and CaAlSiN3 are mixed in a uniform phase, and the molar ratio of the two is 1; the photoelectric parameters of the device obtained after combining the above chips and the phosphors in appropriate proportions are shown in Table 2, and the emission spectrum is shown in Figure 1 .

[0027] Examples 2 to 10, Comparative Examples 1 to 4

[0028] Different chip combinations and different phosphor combinations are used. The phosphor system is the same as in Example 2, the peak wavelength is the same as in Example 1, and the preparation process is the same as in Example 1. The specific combination of the prepared device is shown in Table 1, and the optoelectronic parameters are shown in Table 2.

[0029] Table 1: Chip and phosphor combination solutions of Examples 2-10 and Comparative Examples 1-5

[0030]

[0031]

[0032] Table 2: Photoelectric parameters of the devices in the embodiments and comparative examples

[0033]

[0034]

[0035] Note: 85℃@85%humidity light maintenance rate refers to the luminous flux maintenance rate of the device after aging for 1000h under double 85 conditions; spectral similarity refers to the similarity between the device spectrum and the solar spectrum of the same color temperature in the visible spectrum. The rated power of the above device is 3W, and the package is EMC5050 package.

[0036] From the above photoelectric parameter data comparison, it can be seen that the wavelength combination based on the excitation of phosphors by multiple bands of blue light chips has a great influence on the spectrum, color rendering index and light efficiency. The photoelectric parameter performance of the main wavelength in the range of 447-457nm is the best; the photoelectric parameters of the spectrum of the traditional blue powder BaSi2O2N2:Eu, green powder Lu3Al5O12:Ce, red powder Sr2Si5N8:Eu, (Ca,Sr)AlSiN3:Eu or K2SiF6:Mn are relatively poor, while the phosphor system suitable for the synergy of long- and short-wave blue light has higher light efficiency, higher stability and better spectral similarity.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A full-spectrum semiconductor light-emitting device with high light efficiency and high stability, characterized in that: The device comprises any two or more blue light chips with different peak wavelengths and peak wavelengths in the range of 420-480nm, and a first phosphor with a peak wavelength in the range of 480-520nm, a second phosphor with a peak wavelength in the range of 530nm-540nm, a third phosphor with a peak wavelength in the range of 640-660nm, and a fourth phosphor with a peak wavelength in the range of 680nm-700nm; The chemical formula of the first phosphor is Lu3(Al 1-x ,Gax)5O 12 :zCe, where 0.1≤x≤0.3, 0.003≤z≤0.008; The second phosphor is Lu3Si5N 11 :Ce; The third phosphor is K2TiF6:Mn@(Ca,Sr)AlSiN3:Eu with a core-shell structure, wherein the molar ratio of K2TiF6:Mn to (Ca,Sr)AlSiN3:Eu is between 1 / 3 and 1; The fourth phosphor is Eu 2+ Activated dual-phase structured Sr2Si5N8 and CaAlSiN3 phosphors; In the dual-phase structure, Sr2Si5N8 is the main phase, and the molar ratio of the two phases is between 1 and 3.

2. The light emitting device according to claim 1, characterized in that: When any two or more blue light chips with different peak wavelengths in the 420-480nm range are combined, the main wavelength is between 447-457nm.

3. The light emitting device according to claim 1, characterized in that: The peak wavelength of the first phosphor is 495-500nm, the peak wavelength of the second phosphor is 530-535nm; the peak wavelength of the third phosphor is 645-650nm; and the peak wavelength of the fourth phosphor is 680-690nm.

4. A healthy lighting fixture, characterized in that: The healthy lighting fixture comprises at least the light-emitting device according to any one of claims 1-3.

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