High-purple-light-absorption yellow fluorescent powder as well as preparation method and application thereof

Abstract

The invention relates to high-purple-light-absorption yellow fluorescent powder as well as a preparation method and application thereof, the chemical expression of the high-purple-light-absorption yellow fluorescent powder is (CaSrBa) 2-xSiO4: xEu < 2 + >, and x is more than or equal to 0.01 and less than or equal to 0.5. The preparation method comprises the following steps: (1) weighing a Ca-containing compound, a Sr-containing compound, a Ba-containing compound, a Si-containing compound and an Eu-containing compound according to a stoichiometric ratio, grinding and uniformly mixing, and placing in a crucible; (2) calcining the powder obtained in the step (1) in an air atmosphere, and cooling to obtain a precursor; and (3) uniformly grinding the precursor synthesized in the step (2) again, sintering in a reducing atmosphere, and cooling to obtain the purple light high-absorption yellow fluorescent powder. Compared with the prior art, the yellow fluorescent powder covers a wider emission spectrum range, and the prepared yellow fluorescent powder is stable in physical and chemical performance and can be combined with a purple light chip to prepare a glare-free LED (light-emitting diode).

Description

Technical Field

[0001] The invention relates to the technical field of fluorescent material preparation, and in particular to a purple light high-absorption yellow fluorescent powder and a preparation method and application thereof. Background Art

[0002] With the development of society, people's demand for electricity is increasing. At the same time, people's awareness of protecting the environment is also increasing. Based on this, more and more research is being conducted on high-efficiency and low-consumption lighting. Compared with typical lighting technologies such as incandescent lamps, fluorescent lamps and high-pressure sodium lamps, light-emitting diodes (LEDs) have many advantages. LEDs are known as the fourth generation of green and environmentally friendly lighting sources. Due to their advantages of energy saving, environmental protection, long life and low heat generation, they have been widely used in display screens, traffic lights, car headlights and other places, becoming the preferred lighting source in the 21st century. However, with the continuous changes in people's living standards and the continuous improvement of their requirements for quality of life and living environment health, people's demand for healthy lighting is also increasing. There are currently two commonly used methods for achieving white light LEDs in business. One is to mix yellow light phosphors and blue light chips to achieve white light emission. However, the current commercial yellow phosphors lack the cyan region under blue excitation, which limits its application in the field of high-quality lighting, and this method has blue light hazards. Another method is to combine three primary color phosphors (green, blue and red) with n-UV LED chips to achieve white light LEDs. Currently, commercial white light LED chips are mainly ultraviolet chips, purple chips, and blue chips. Among them, phosphor is the core component of fluorescent conversion type solar-like LED, and its performance directly determines the performance of the device such as luminous efficiency, color temperature, color rendering index and life. However, the emission area of ​​LED is much smaller than that of traditional light sources. Therefore, as the luminous efficiency increases, its brightness will increase excessively, resulting in uncomfortable glare, affecting people's visual health and work efficiency. Therefore, it is crucial to design and develop new high-efficiency phosphor materials to meet people's visual, physiological and psychological needs. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a purple light highly absorbing yellow phosphor and its preparation method and application to cover a wider emission spectrum range. The prepared yellow phosphor has stable physical and chemical properties and can be combined with a purple light chip to make a glare-free LED lighting device.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] One of the technical solutions of the present invention is to provide a purple light highly absorbing yellow phosphor, the chemical expression of which is (CaSrBa) 2-x SiO4:xEu 2+, where 0.01≤x≤0.5. Where (CaSrBa) 2-x SiO4 is the matrix material, Eu 2+ As rare earth doping ions replacing part of Ba ions, x represents the molar content of doping ion Eu, and the total molar amount of Ca, Sr, Ba and Eu in the matrix is ​​2.

[0006] Furthermore, the excitation wavelength band of the purple light highly absorbing yellow phosphor is 220 to 520 nm, which is located in the ultraviolet, purple and blue light regions;

[0007] The violet light highly absorbing yellow phosphor has an emission band of 420-830 nm and a central wavelength of 555-560 nm.

[0008] Furthermore, the purple light highly absorbing yellow phosphor is a light yellow powdery material.

[0009] Furthermore, the emission intensity of the violet light highly absorbing yellow phosphor under 400nm violet light excitation is 85% to 95% of the optimal emission intensity, preferably 88% to 92%;

[0010] The emission intensity of the yellow phosphor under 410nm violet light excitation is 80% to 90% of the optimal emission intensity, preferably 84% to 88%.

[0011] Furthermore, the purple light highly absorbing yellow phosphor can achieve strong yellow light emission with the emission center at 558 nm under the excitation of ultraviolet, purple and blue light of 220 to 520 nm.

[0012] Furthermore, the absorption coefficient of the purple light highly absorbing yellow phosphor is 80% to 100%.

[0013] Furthermore, the purple light highly absorbing yellow phosphor is a silicate system, which has the advantages of simple preparation process, low cost, and broad application prospects.

[0014] The second technical solution of the present invention is to provide a method for preparing a purple light highly absorbing yellow phosphor, comprising the following steps:

[0015] (1) weighing a Ca-containing compound, a Sr-containing compound, a Ba-containing compound, a Si-containing compound, and a Eu-containing compound according to a stoichiometric ratio, grinding and mixing them uniformly, and placing them in a crucible;

[0016] (2) calcining the powder obtained in step (1) in an air atmosphere, and obtaining a precursor after cooling;

[0017] (3) Grinding the precursor synthesized in step (2) again to obtain a uniform surface, sintering the precursor in a reducing atmosphere, and cooling the precursor to obtain the yellow phosphor with high violet light absorption.

[0018] Furthermore, in step (1), the Ca-containing compound is CaCO3, the Sr-containing compound is SrCO3, the Ba-containing compound is BaCO3, the Eu-containing compound is Eu2O3, and the Si-containing compound is SiO2.

[0019] Furthermore, in step (2), the calcination temperature in air atmosphere is 800-1600° C., and the calcination time is 2-10 hours.

[0020] Furthermore, the reducing atmosphere is a mixture of hydrogen and nitrogen, and the calcination temperature in the reducing atmosphere is 900-1400°C.

[0021] Furthermore, the volume content of hydrogen in the hydrogen and nitrogen mixture is 2% to 20%.

[0022] Furthermore, the specific steps of sintering in step (3) are: placing the evenly ground precursor in a crucible, placing the crucible in a vacuum tube furnace, first evacuating the vacuum, and then introducing a reducing atmosphere. During the sintering process, the reducing atmosphere is continuously introduced for 1 to 10 hours.

[0023] Furthermore, in steps (1) and (3), the grinding time is 10 to 60 minutes.

[0024] The purple light high absorption yellow fluorescent powder obtained by the preparation method of the present invention has a light yellow appearance and is a powdery material.

[0025] The third technical solution of the present invention is to provide an application of a purple light highly absorbing yellow phosphor, wherein the purple light highly absorbing yellow phosphor is combined with a chip to prepare a glare-free LED lighting device, which has a wide range of applications in the glare-free aspect.

[0026] A fourth technical solution of the present invention is to provide an LED lighting device, wherein the LED lighting device comprises the purple light highly absorbing yellow phosphor.

[0027] Furthermore, the LED lighting device can be applied to healthy lighting fields such as violet-excited white light LEDs, violet-excited solar-like LEDs, and violet-excited full-spectrum LEDs, and has huge development potential.

[0028] Compared with the prior art, the present invention provides a new, unreported, purple light high absorption yellow phosphor and its preparation method and application, which is a wide excitation yellow phosphor, and its innovation lies in:

[0029] (1) The phosphor of the present invention has a wide excitation band, and its effective absorption range covers 220 to 520 nm. It can be excited by ultraviolet light, purple light, and blue light to achieve bright and dazzling yellow light emission, and the emission center is at 558 nm. It is a completely new material that has not been reported before.

[0030] (2) Compared with the prior art, the phosphor of the present invention is a broad excitation yellow phosphor with a light yellow appearance and a powdery material. It has the advantage of stable physical and chemical properties. At the same time, the phosphor can be prepared by a solid phase reaction method, has a simple preparation process, and is conducive to industrial production. It can become a good candidate material for preparing white light LEDs and has a wide application prospect in terms of glare reduction.

[0031] (3) The phosphor of the present invention can be well matched with various existing ultraviolet, purple, blue and other chips. It can maintain about 90% of the optimal emission intensity under excitation at 400nm, and the luminous intensity can still be maintained at more than 86% under excitation at 410nm. It has excellent luminous performance and has great development prospects in the fields of healthy lighting such as purple light-excited white light LEDs, purple light-excited solar light LEDs, and purple light-excited full-spectrum LEDs, as well as in glare suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a photoexcitation-emission spectrum of the purple light highly absorbing yellow phosphor of Example 1 of the present invention. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments. Based on the given embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0034] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art.

[0035] n-UV LED chips refer to LED chips with a central wavelength of light below 400nm, but sometimes the light-emitting wavelengths greater than 380nm are called near-ultraviolet LED chips, and those shorter than 300nm are called deep ultraviolet LED chips.

[0036] Example 1

[0037] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0038] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, and SiO2 as starting materials, with a mass ratio of Ca:Sr:Ba:Si:Eu=0.1859:0.2743:0.3666:0.1683:0.0049, corresponding to the chemical formula (CaSrBa) 2-xSiO4:xEu 2+ Where x=0.01, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0039] 2. Grind the above raw material mixture in an agate mortar for 30 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible, place it in an air atmosphere, calcine it at 1300°C for 6 hours, cool it to room temperature to synthesize a precursor, then grind the precursor evenly again, place it in a reducing atmosphere, sinter it at 1000°C for 4 hours, and obtain the target product after cooling.

[0040] 3. Use fluorescence spectrometer (HITACHI F-7500) to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band, covering the ultraviolet, purple and blue light regions, with a peak value near 371nm, and a high spectral peak, indicating that it can be effectively excited by ultraviolet, purple and blue light chips, and matches well with a variety of commercial chips. It has a large Stokes shift and a high absorption coefficient, and can be used for glare suppression of white light LEDs. Under the excitation of a near-ultraviolet light source of 371nm, the phosphor emits a dazzling yellow light, and the emission spectrum consists of a wide emission band (420-830nm) with a peak at 558nm.

[0041] Example 2

[0042] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0043] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, and SiO2 as starting materials, with a mass ratio of Ca:Sr:Ba:Si:Eu=0.1849:0.2727:0.3645:0.1681:0.0098, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.02, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0044] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0045] Example 3

[0046] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0047] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, and SiO2 as starting materials, with a mass ratio of Ca:Sr:Ba:Si:Eu=0.1742:0.2569:0.3434:0.1669:0.0586, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.12, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0048] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0049] Example 4

[0050] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0051] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, and SiO2 as starting materials, with a mass ratio of Ca:Sr:Ba:Si:Eu=0.1657:0.2445:0.3268:0.1658:0.0971, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.2, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0052] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0053] Example 5

[0054] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0055] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, SiO2 as starting materials, the mass ratio is Ca:Sr:Ba:Si:Eu=0.1574:0.2322:0.3104:0.1648:0.1352, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.28, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0056] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0057] Example 6

[0058] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0059] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, SiO2 as starting materials, the mass ratio is Ca:Sr:Ba:Si:Eu=0.1492:0.2201:0.2942:0.1638:0.1727, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.36, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0060] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0061] Example 7

[0062] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0063] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, and SiO2 as starting materials, with a mass ratio of Ca:Sr:Ba:Si:Eu=0.1411:0.2081:0.2781:0.1629:0.2099, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.44, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0064] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0065] Example 8

[0066] This embodiment provides a purple light highly absorbing yellow phosphor and a preparation method thereof, the preparation method comprising the following steps:

[0067] 1. Select CaCO3, SrCO3, BaCO3, Eu2O3, SiO2 as starting materials, the mass ratio is Ca:Sr:Ba:Si:Eu=0.1350:0.1992:0.2662:0.1621:0.2374, corresponding to the chemical formula (CaSrBa) 2-x SiO4:xEu 2+ Where x=0.5, five raw materials are weighed separately to control the total mass of the raw material mixture to be 1 g of mixed raw material.

[0068] 2. The raw material mixture was placed in an agate mortar and ground for 30 minutes. After the materials were mixed evenly, the mixture was loaded into an alumina crucible, placed in an air atmosphere, calcined at 1300°C for 6 hours, cooled to room temperature to synthesize a precursor, and then the precursor was ground evenly again, placed in a reducing atmosphere, sintered at 1000°C for 4 hours, and cooled to obtain the target product. The photoluminescence performance of the luminescent material is similar to that in Example 1.

[0069] The raw material composition and process parameters of the preparation of the purple light highly absorbing yellow phosphors of Examples 1 to 8 provided above are specifically shown in Table 1.

[0070] Table 1 Preparation process parameters of Examples 1 to 8

[0071]

[0072] The data in the above table show the different Eu 2+ The sample with the highest concentration showed an excitation position of 369-373 nm and an emission position of 556-558 nm. 2+ As the concentration increases, the sample always maintains bright yellow light. Under 400nm excitation, the sample intensity remains at about 90% under optimal excitation, and under 410nm excitation, the sample intensity remains at about 86% under optimal excitation, which is suitable for violet light excitation, and the absorption coefficient is about 90%, indicating that the sample has a high external quantum efficiency while having a high internal quantum efficiency. The sample has a wide spectrum and can be combined with a violet light chip to make a glare-free LED lighting device.

[0073] Comparative Example 1

[0074] Compared with Example 1, most of the aspects are the same, except that Eu2O3 is not added and the target product does not emit light.

[0075] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A yellow phosphor with high violet light absorption, characterized in that: The chemical formula of the purple light highly absorbing yellow phosphor is (CaSrBa) 2-x SiO4:xEu 2+ , where 0.01≤x≤0.

5.

2. The yellow phosphor with high violet light absorption according to claim 1, characterized in that: The excitation wavelength band of the purple light high absorption yellow phosphor is 220-520nm, which is located in the ultraviolet, purple and blue light regions; The violet light highly absorbing yellow phosphor has an emission band of 420 to 830 nm and a central wavelength of 555 to 560 nm.

3. The yellow phosphor with high violet light absorption according to claim 1, characterized in that: The purple light highly absorbing yellow fluorescent powder is a light yellow powdery material.

4. The yellow phosphor with high violet light absorption according to claim 1, characterized in that: The emission intensity of the purple light highly absorbing yellow phosphor under 400nm purple light excitation is 85% to 95% of the optimal emission intensity; The emission intensity of the yellow phosphor under 410nm violet light excitation is 80% to 90% of the optimal emission intensity; The absorption coefficient of the purple light high absorption yellow phosphor is 80% to 100%.

5. The method for preparing a yellow phosphor with high violet light absorption as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: (1) weighing a Ca-containing compound, an Sr-containing compound, a Ba-containing compound, a Si-containing compound, and a Eu-containing compound according to a stoichiometric ratio, grinding and mixing them uniformly, and placing them in a crucible; (2) calcining the powder obtained in step (1) in an air atmosphere, and obtaining a precursor after cooling; (3) Grinding the precursor synthesized in step (2) again to obtain a uniform surface, sintering the precursor in a reducing atmosphere, and cooling the precursor to obtain the yellow phosphor with high violet light absorption.

6. The method for preparing a yellow phosphor with high purple light absorption according to claim 5, characterized in that: In step (1), the Ca-containing compound is CaCO3, the Sr-containing compound is SrCO3, the Ba-containing compound is BaCO3, the Eu-containing compound is Eu2O3, and the Si-containing compound is SiO2.

7. The method for preparing a purple light highly absorbing yellow phosphor according to claim 5, characterized in that: In step (2), the calcination temperature in air atmosphere is 800-1600°C.

8. The method for preparing a purple light highly absorbing yellow phosphor according to claim 5, characterized in that: The reducing atmosphere is a mixture of hydrogen and nitrogen, and the calcination temperature in the reducing atmosphere is 900-1400°C.

9. The use of a yellow phosphor with high violet light absorption as claimed in any one of claims 1 to 4, characterized in that: The purple light highly absorbing yellow fluorescent powder is combined with a chip to prepare a glare-free LED lighting device.

10. An LED lighting device, characterized in that: The LED lighting device comprises the purple light highly absorbing yellow phosphor according to any one of claims 1 to 4.

Images