Scheelite matrix non-rare earth activated dark red fluorescent powder and preparation method thereof

Abstract

The invention relates to scheelite matrix non-rare earth activated dark red fluorescent powder. The composition of the material is M3A2 (W, Mo) (1-x-y) O9: xMn < 4 + >, yBi < 3 + >, in the formula, M is any one of alkaline earth metals Ca, Sr and Ba; a is any one of Y, Gd and La; 0 lt; 0 < = y < = 1%. The dark red fluorescent powder provided by the invention is stable in matrix structure and performance, relatively good in physical and chemical stability, stable in luminescence performance, firm and uniform in particle, and relatively high in crystallinity and purity. A tungsten molybdate solid solution is used as a matrix, Mn < 4 + > is used as a luminescence center, Bi < 3 + > is used as a sensitizer, the raw materials are easy to obtain and non-toxic, and the prepared product can effectively absorb near ultraviolet light in the range of 300-400 nm and emit dark red light in the range of 650-700 nm, and has a certain beneficial effect of supplementing red light in the field of current white light LEDs and plant illumination LEDs.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of inorganic luminescent functional materials, and particularly relates to a scheelite matrix non-rare earth activated deep red fluorescent powder and a preparation method thereof. BACKGROUND

[0002] At present, the luminescent efficiency of red fluorescent powder in the three primary color fluorescent powder for near-ultraviolet LED is still far lower than that of blue and green fluorescent powder. Therefore, it is necessary to further develop red fluorescent powder that can match the current commercial LED chip to supplement the red light component in LED lamps. At the same time, in recent years, LED lamps have also been widely used in the field of plant light supplement, especially the chlorophyll in plants can absorb blue-violet light (390-500 nm) and deep red light (600-680 nm), and the light in this band plays a leading and important role in plant growth. Obviously, traditional incandescent lamps and fluorescent lamps are difficult to continue to be used for plant lighting. Light-emitting diodes can overcome these shortcomings due to their high efficiency, long service life, environmental friendliness, controllable spectral composition and other advantages. However, the light-emitting diodes and fluorescent powder used for photosynthesis currently have problems such as low efficiency, poor thermal stability, unchanged emission wavelength or mismatched spectrum, which limit their application.

[0003] The transition metal Mn element has rich valence and good optical performance, for example, Mn 4+ has 3d 5 valence electron configuration, and the spectral transition originates from 3d-3d transition, which has large transition intensity. Mn 4+ can present effective red light emission in a six-coordinated matrix and is easily excited by near-ultraviolet and blue light. In recent years, non-rare earth Mn 4+ ion activated luminescent materials have attracted much attention due to their wide excitation spectrum, wide emission spectrum and cheap activator raw materials, especially Mn 4+ ion activated luminescent materials have an emission spectrum range in the deep red region, which has high research value in improving the color rendering of LED. First, the emission spectrum peak of Mn 4+ is in the red light region, so the selection of the matrix is relatively large; secondly, Mn 4+ emission transition 2 E → 4 A 2 is parity forbidden and spin forbidden transition, so the excited state lifetime is long; furthermore, Mn 4+ is a high valence state, which is more likely to gain electrons, so in many matrices, Mn 4+ has a strong charge transfer band in the near-ultraviolet region in addition to the 3d-3d excitation band (located in the near-ultraviolet and visible light region), and is more easily excited in the near-ultraviolet region. In addition, the electronic configuration of Mn 4+ is [Ar]3d3 , the higher the valence state, the stronger the crystal field on it. Therefore, Mn 4+ 's emission transition is always 2 E → 4 A 2, and the light emission color is deep red. Among the many matrix materials, the tungsten molybdate with a scheelite structure is a typical self-activated material, because it has a wide and strong excitation band in the near ultraviolet region, which can effectively transfer the absorbed excitation light energy to the light emission center to realize light emission, and has the advantages of good physical and chemical stability, low price, green and pollution-free. Therefore, it is necessary to study and prepare Mn 4+ doped tungsten molybdate red fluorescent powder. SUMMARY

[0004] The purpose of the present application is to provide a scheelite matrix non-rare earth activated deep red fluorescent powder, which uses tungsten molybdate as the matrix, has solid and stable particles, and a particle size of 2-5 μm, can effectively absorb near ultraviolet light in the range of 300-400 nm, and emit deep red light.

[0005] Another purpose of the present application is to provide a preparation method of the above-mentioned scheelite matrix non-rare earth activated deep red fluorescent powder, which does not use and generate toxic and harmful substances, is more environmentally friendly, and has more complete reaction, lower synthesis temperature, and energy saving.

[0006] The above-mentioned purpose of the present application is realized by the following technical scheme: A scheelite matrix non-rare earth activated deep red fluorescent powder, characterized in that it is composed of M3A2(W,Mo) 1-x-y O9: x Mn 4+ , y Bi 3+ , wherein M is any one of alkaline earth metals Ca, Sr and Ba; A is any one of Y, Gd and La; 0 x ≤1%, 0≤ y ≤1%.

[0007] The design idea of the above-mentioned scheelite matrix non-rare earth activated deep red fluorescent powder is to use Mn 4+ as the light emission center, use the scheelite solid solution synthesized by alkaline earth metals, rare earth metals and tungsten molybdenum metal oxides as the matrix, and then add Bi 3+ as a sensitizer to increase the defects in the matrix structure and improve the energy transfer efficiency between ions, so as to realize high-efficiency deep red light emission.

[0008] The preparation method of the above-mentioned scheelite matrix non-rare earth activated deep red fluorescent powder, characterized in that it comprises the following preparation steps in sequence: (1) according to the target fluorescent powder product formula M3A2(W, Mo) 1-x-y O9: x Mn 4+ , y Bi 3+ , the stoichiometric composition ratio is respectively weighed with appropriate amount of MCO3, A2O3, WO3, MoO3, MnO2 and Bi2O3 as the reaction raw material; (2) the weighed reaction raw material is loaded into the agate ball mill tank, the appropriate size and number of agate grinding balls are added, and an appropriate amount of ball milling agent is added, and the planetary ball mill is ball milled at room temperature; (3) the mixture in the ball mill tank after ball milling is filtered together with the washing liquid, dried, and then calcined in a high temperature furnace, and the target product is obtained after cooling, grinding and discharging.

[0009] As a further clarification, the weight ratio of the grinding ball and the reaction raw material in the above step (2) is 2:1;The ball milling time is 1-2 hours.

[0010] As a further clarification, the ball milling agent in the above step (2) is anhydrous ethanol.

[0011] As a further clarification, the calcination temperature in the above step (3) is 1200 ℃-1400 ℃, and the calcination time is 3-6 hours.

[0012] The present application has the following beneficial effects: 1. The present application provides a scheelite-based non-rare earth activated deep red fluorescent powder, which has stable matrix structure and performance, good physical and chemical stability, stable luminescent performance, solid and uniform particles, high crystallinity and purity. It uses tungstate-molybdate solid solution as the matrix, Mn 4+ as the luminescent center, and Bi 3+ as the sensitizer, and the raw materials are easy to obtain and non-toxic. The prepared product can effectively absorb near-ultraviolet light in the range of 300-400 nm and emit deep red light in the range of 650-700 nm, which has certain beneficial effects on supplementing the current white light LED and plant lighting LED field red light.

[0013] 2. The preparation method adopted in the present application is to synthesize the target fluorescent powder by anhydrous ethanol ball milling high temperature solid phase one-time calcination process, which utilizes the grinding effect of friction and extrusion force in ball milling, fully disperses the contact between reaction raw material particles, and helps the synthesis of product in the subsequent calcination process. There is no use and generation of toxic and harmful substances in the whole preparation process, which is more environmentally friendly. Compared with the traditional single high temperature solid phase method without ball milling, the reaction is more complete, the synthesis temperature is lower, and the energy is saved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1This is a process flow diagram of the method for preparing deep red phosphor with non-rare earth activation based on scheelite matrix as described in this invention.

[0015] Figure 2 The Ca3Y2(W,Mo) prepared in Example 4 of this invention is... 0.994 O9:0.3%Mn 4+ 0.3%Bi 3+ X-ray diffraction pattern of deep red phosphor.

[0016] Figure 3 The Ca3Y2(W,Mo) prepared in Example 4 of this invention is... 0.994 O9:0.3%Mn 4+ 0.3%Bi 3+ Fluorescence spectrum of deep red phosphor. Detailed Implementation

[0017] The present invention will now be described through specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0018] Example 1 A deep red phosphor with a scheelite matrix and non-rare earth activated composition, Ca3Y2(W,Mo). 0.999 O9:0.1%Mn 4+ The specific preparation steps are as follows: based on the molecular formula Ca3Y2(W,Mo) 0.999 O9:0.1%Mn 4+ Weigh appropriate amounts of CaCO3 (AR), Y2O3 (AR), WO3 (AR), MoO3 (AR), and MnO2 (99.95%), with 0.00005 mol of MnO2 (99.95%). Mix all the weighed raw materials and transfer them into an agate ball mill jar. Add agate grinding balls of appropriate size at a ball-to-material ratio of 2:1, and then add an appropriate amount of anhydrous ethanol. Mill the mixture at room temperature for 1 h. After milling, filter the material along with the washing liquid, wash, dry, and then calcine it in a resistance furnace at a sintering temperature of 1200 ℃ for 3 h. After grinding, the target product is obtained.

[0019] Example 2 A deep red phosphor with a scheelite matrix and non-rare earth activated composition, Ca3Y2(W,Mo). 0.998 O9:0.1%Mn 4+ 0.1%Bi 3+ The specific preparation steps are as follows: based on the molecular formula Ca3Y2(W,Mo)0.998 O9:0.1%Mn 4+ 0.1%Bi 3+ Weigh appropriate amounts of CaCO3(AR), Y2O3(AR), WO3(AR), MoO3(AR), MnO2(99.95%), and Bi2O3(AR), respectively, with 0.00005 mol of MnO2(99.95%). Mix all the weighed raw materials and transfer them into an agate ball mill jar. Add agate grinding balls of appropriate size at a ball-to-material ratio of 2:1, and then add an appropriate amount of anhydrous ethanol. Mill the mixture at room temperature for 2 h. After milling, filter the material and washing liquid, wash, dry, and then calcine it in a resistance furnace at a sintering temperature of 1300 ℃ for 3 h. After grinding, the target product is obtained.

[0020] Example 3 A deep red phosphor with a scheelite matrix and non-rare earth activated composition, Ca3Y2(W,Mo). 0.996 O9:0.3%Mn 4+ 0.1%Bi 3+ The specific preparation steps are as follows: based on the molecular formula Ca3Y2(W,Mo) 0.996 O9:0.3%Mn 4+ 0.1%Bi 3+ Weigh appropriate amounts of CaCO3(AR), Y2O3(AR), WO3(AR), MoO3(AR), MnO2(99.95%), and Bi2O3(AR), respectively, with MnO2(99.95%) being 0.00015 mol. Mix all the weighed raw materials and transfer them into an agate ball mill jar. Add agate grinding balls of appropriate size at a ball-to-material ratio of 2:1, and then add an appropriate amount of anhydrous ethanol. Mill the mixture at room temperature for 2 h. After milling, filter the material along with the washing liquid, wash, dry, and then calcine it in a resistance furnace at a sintering temperature of 1350 ℃ for 4 h. After grinding, the target product is obtained.

[0021] Example 4 A deep red phosphor with a scheelite matrix and non-rare earth activated composition, Ca3Y2(W,Mo). 0.994 O9:0.3%Mn 4+ 0.3%Bi 3+ The specific preparation steps are as follows: based on the molecular formula Ca3Y2(W,Mo) 0.994 O9:0.3%Mn 4+ 0.3%Bi 3+CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00015 mol; all the weighed raw materials were mixed and then moved into a corundum ball mill tank, and then appropriate corundum grinding balls were added according to a ball-to-material ratio of 2:1, and then appropriate anhydrous ethanol was added, and then the mixture was ball milled at room temperature for 2 h; the ball milled material was filtered, washed and dried, and then calcined in a resistance furnace, wherein the sintering temperature was 1300 ℃, the calcination time was 4 h, and the target product was obtained after grinding.

[0022] Example 5 A scheelite matrix non-rare earth activated deep red fluorescent powder, which is composed of Ca3Y2(W,Mo) 0.994 O9: 0.3% Mn 4+ , 0.3% Bi 3+ ; the specific preparation steps are as follows: according to the molecular formula Ca3Y2(W,Mo) 0.994 O9: 0.3% Mn 4+ , 0.3% Bi 3+ CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00015 mol; all the weighed raw materials were mixed and then moved into a corundum ball mill tank, and then appropriate corundum grinding balls were added according to a ball-to-material ratio of 2:1, and then appropriate anhydrous ethanol was added, and then the mixture was ball milled at room temperature for 2 h; the ball milled material was filtered, washed and dried, and then calcined in a resistance furnace, wherein the sintering temperature was 1200 ℃, the calcination time was 5 h, and the target product was obtained after grinding.

[0023] Example 6 A scheelite matrix non-rare earth activated deep red fluorescent powder, which is composed of Ca3Y2(W,Mo) 0.994 O9: 0.3% Mn 4+ , 0.3% Bi 3+ ; the specific preparation steps are as follows: according to the molecular formula Ca3Y2(W,Mo) 0.994 O9: 0.3% Mn 4+ , 0.3% Bi 3+CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00015 mol; all the weighed raw materials were mixed and then moved into a corundum ball mill tank, and then appropriate corundum grinding balls were added according to a ball-to-material ratio of 2:1, and then appropriate anhydrous ethanol was added, and then the mixture was ball milled at room temperature for 2 hours; the ball milled material was filtered, washed and dried, and then calcined in a resistance furnace, wherein the sintering temperature was 1400 ℃, the calcination time was 3 hours, and then the target product was obtained after grinding.

[0024] Example 7 A scheelite matrix non-rare earth activated deep red fluorescent powder, which is composed of Ca3Y2(W,Mo) 0.992 O9: 0.3% Mn 4+ , 0.5% Bi 3+ ; the specific preparation steps are as follows: according to the molecular formula Ca3Y2(W,Mo) 0.992 O9: 0.3% Mn 4+ , 0.5% Bi 3+ CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00015 mol; all the weighed raw materials were mixed and then moved into a corundum ball mill tank, and then appropriate corundum grinding balls were added according to a ball-to-material ratio of 2:1, and then appropriate anhydrous ethanol was added, and then the mixture was ball milled at room temperature for 2 hours; the ball milled material was filtered, washed and dried, and then calcined in a resistance furnace, wherein the sintering temperature was 1300 ℃, the calcination time was 4 hours, and then the target product was obtained after grinding.

[0025] Example 8 A scheelite matrix non-rare earth activated deep red fluorescent powder, which is composed of Ca3Y2(W,Mo) 0.992 O9: 0.5% Mn 4+ , 0.3% Bi 3+ ; the specific preparation steps are as follows: according to the molecular formula Ca3Y2(W,Mo) 0.992 O9: 0.5% Mn 4+ , 0.3% Bi 3+CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00025 mol; all the weighed raw materials were mixed and then moved into a corundum ball mill tank, and then appropriate corundum grinding balls were added according to a ball-to-material ratio of 2:1, and then appropriate anhydrous ethanol was added, and then the mixture was ball milled at room temperature for 2 h; the ball milled material was filtered, washed and dried, and then calcined in a resistance furnace, wherein the sintering temperature was 1300 ℃, the calcination time was 4 h, and then the target product was obtained after grinding.

[0026] Example 9 A scheelite matrix non-rare earth activated deep red fluorescent powder, which is composed of Ca3Y2(W,Mo) 0.99 O9: 0.5% Mn 4 + , 0.5% Bi 3+ ; the specific preparation steps are as follows: according to the molecular formula Ca3Y2(W,Mo) 0.99 O9: 0.5% Mn 4+ , 0.5% Bi 3+ CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00025 mol; all the weighed raw materials were mixed and then moved into a corundum ball mill tank, and then appropriate corundum grinding balls were added according to a ball-to-material ratio of 2:1, and then appropriate anhydrous ethanol was added, and then the mixture was ball milled at room temperature for 2 h; the ball milled material was filtered, washed and dried, and then calcined in a resistance furnace, wherein the sintering temperature was 1300 ℃, the calcination time was 4 h, and then the target product was obtained after grinding.

[0027] Example 10 A scheelite matrix non-rare earth activated deep red fluorescent powder, which is composed of Ca3Y2(W,Mo) 0.988 O9: 0.7% Mn 4+ , 0.5% Bi 3+ ; the specific preparation steps are as follows: according to the molecular formula Ca3Y2(W,Mo) 0.988 O9: 0.7% Mn 4+ , 0.5% Bi 3+CaCO3(A.R.), Y2O3(A.R.), WO3(A.R.), MoO3(A.R.), MnO2(99.95%) and Bi2O3(A.R.) were weighed respectively, wherein MnO2(99.95%) was 0.00035 mol; all the weighed raw materials were mixed and then moved into a agate ball mill jar, and then appropriate amount of agate grinding balls and anhydrous ethanol were added, and then ball milling was carried out at room temperature for 2 h; the ball-milled material was filtered, washed and dried, and then calcined in an electric resistance furnace, wherein the sintering temperature was 1300 ℃, the calcination time was 4 h, and the target product was obtained after grinding.

Claims

1. A scheelite host non-rare earth activated deep red phosphor, characterized by: Composition: M3A2(W, Mo) 1-x- y O9: x Mn 4+ , y Bi 3+ , wherein M is any one of alkaline earth metals Ca, Sr, and Ba; A is any one of Y, Gd, and La; 0 x ≤1%, 0≤ y ≤1%.

2. The method for preparing the non-rare earth activated deep red phosphor based on scheelite matrix as described in claim 1, characterized in that, The preparation steps include the following in sequence: (1) According to the molecular formula M3A2(W, Mo) of the target fluorescent powder product 1-x-y O9: x Mn 4+ , y Bi 3+ , the appropriate amount of MCO3, A2O3, WO3, MoO3, MnO2 and Bi2O3 was weighed according to the stoichiometric composition ratio as the reaction raw material; (2) The weighed reaction raw materials are loaded into a marbled ball mill tank, marbled grinding balls of appropriate size are added, and an appropriate amount of ball mill agent is added, and then the mixture is ball milled in a planetary ball mill at room temperature; (3) The mixture in the ball mill tank after ball milling is filtered together with the washing solution, dried, and then calcined in a high-temperature furnace, and cooled and ground after being taken out of the furnace.

3. The method of making scheelite host non-rare earth activated deep red phosphor of claim 2, wherein: The weight ratio of the grinding balls to the reaction raw materials in the step (2) is 2:1, and the ball milling time is 1-2 hours.

4. The method of producing scheelite-based non-rare earth activated deep red phosphor according to claim 2 or 3, characterized in that: The ball mill agent in the step (2) is anhydrous ethanol.

5. The method of producing scheelite-based non-rare earth activated deep red phosphor according to claim 2 or 3, characterized in that: The calcination temperature in the step (3) is 1200-1400 DEG C, and the calcination time is 3-6 hours.

6. The method of making scheelite host non-rare earth activated deep red phosphor of claim 4, wherein: The calcination temperature in the step (3) is 1200-1400 DEG C, and the calcination time is 3-6 hours.

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