Preparation method of ultraviolet-excited niobate white light emitting fluorescent powder

Abstract

The invention belongs to the technical field of luminescent materials, and particularly relates to a preparation method of ultraviolet excited niobate white light emitting fluorescent powder. The chemical expression of the fluorescent powder is Sr2La1-x-yNbO6: xDy < 3 + >, yEu < 3 + >, 1% < = x < = 5%, and 0.1% < = y < = 0.5%. The Dy < 3 + > and Eu < 3 + > co-doped niobate fluorescent powder Sr2La1-x-yNbO6: xDy < 3 + >, yEu < 3 + > is synthesized by a high-temperature solid-phase method. Under excitation of near ultraviolet light, white light can be directly emitted, the emission peak covers 450-650 nm in a visible light area, the peak positions are 485 nm, 580 nm and 612 nm, and finally white light emission is achieved in a single component. The preparation process is simple, and harsh preparation conditions are not adopted; and an excitation wave band is located in an ultraviolet region, so that overlapping with excitation light is avoided, and the problem of reabsorption does not exist.

Description

Technical Field

[0001] The invention belongs to the technical field of luminescent materials, and in particular relates to a method for preparing a luminescent material used in semiconductor lighting. Background Art

[0002] Due to their unique spectral characteristics, fluorescent materials are widely used in light-emitting diodes (LEDs), plant growth, field emission displays (FEDs), anti-counterfeiting, and temperature measurement. White light-emitting diodes have attracted widespread attention due to their durability, high efficiency, and energy saving, and are considered to be the next generation of solid-state light sources.

[0003] Commercial white LEDs are mainly composed of InGaN blue chips and Y3A l5 O 12 :Ce 3+ (YAG:Ce 3+ ) yellow phosphor. However, due to the lack of red components, it has the disadvantages of low color rendering and high color temperature. The best solution is to combine the three primary color phosphors (red, green, and blue) with UV chips. UV LED chips can also solve the impact of blue light produced by blue LED chips on the human eye. This method can achieve white output, but there are also problems such as strong reabsorption, mismatched aging rates, and unbalanced concentration quenching. So far, the development of new single-element phosphors excited by NUV chips to achieve high-quality white light is a good alternative.

[0004] Perovskite materials are widely used in phosphors, white light emitters and other fields due to their ferroelectricity, photoluminescence and other properties. Double perovskite is a cubic structure with good rigidity and chemical stability. Rare earth ions are widely used in luminescent materials due to their unique spectral characteristics. 3+ , Eu 3 + Commonly used to prepare white light LED phosphor. 3+ As a luminescent center, it can emit light in the blue and yellow bands. 3+ As a luminescent center, it can emit light in the red band. At present, there is no method to make the Sr2LaNbO6 matrix achieve white light emission with a single-element phosphor. 3+ and Eu 3+ The amount of addition is regulated to achieve Sr2LaNbO6:Dy 3+ , Eu 3+ The white light emission of the phosphor provides a good theoretical basis for the preparation of new commercial phosphors. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a Sr2LaNbO6:Dy 3+ , Eu 3+ A method for preparing phosphor.

[0006] The technical solution of the present invention is: a method for preparing ultraviolet excited niobate white light emitting phosphor, characterized in that: by using rare earth Dy 3+ and Eu 3+ Ions are used as luminescent activators, double perovskite strontium lanthanum niobate is used as the luminescent material matrix, and a series of Sr2La 1-x-y NbO6:xDy 3+ , yEu 3+ The phosphor comprises the following steps:

[0007] S1), according to the chemical formula Sr2La 1-x-y NbO6:xDy 3+ , yEu 3+ According to the stoichiometric ratio, a compound containing Sr, a compound containing La, a compound containing Nb, a compound containing Dy and a compound containing Eu are weighed as raw materials respectively;

[0008] S2), appropriately weighing the compounds in step S1), grinding the mixture consisting of the five compounds for 20 min to fully mix the mixture;

[0009] S3), putting the mixed material ground in step S2) into a crucible, and calcining the crucible containing the mixed material in an air atmosphere using a Ma Furnace, the calcination temperature is 1400°C, and the temperature is kept for 5 hours;

[0010] S4), the mixture calcined in step S3) is naturally cooled to room temperature and then taken out from the furnace, and the taken out mixture is ground again to obtain white light Sr2LaNbO6:Dy 3+ , Eu 3+ Phosphor.

[0011] Furthermore, in step S1), the Sr-containing compound raw material is strontium carbonate.

[0012] Furthermore, in step S1), the La-containing compound raw material is lanthanum oxide.

[0013] Furthermore, in step S1), the Nb-containing compound raw material is niobium pentoxide.

[0014] Furthermore, in step S1), the Dy-containing compound raw material is dysprosium oxide.

[0015] Furthermore, in step S1), the Eu-containing compound raw material is europium oxide.

[0016] Furthermore, in step S1), the x value is 1%≤x≤5%, and the y value is 0.1%≤y≤0.5%.

[0017] Further, in step S4), the prepared white light Sr2LaNbO6:Dy 3+ , Eu 3+ When the phosphor is excited at 350 nm, there are three main emission wavelengths in the emission spectrum, located at 485 nm (blue light), 580 nm (yellow light) and 612 nm (red light). These three wavelengths together constitute the white light emission.

[0018] Furthermore, the white light Sr2LaNbO6:Dy prepared in step S4) 3+ , Eu 3+ Phosphor and 365 nm ultraviolet chip are used to prepare white light emitting LED devices.

[0019] The beneficial effects of the present invention are as follows:

[0020] The white light Sr2LaNbO6:Dy obtained by the high temperature solid phase method of the present invention 3+ , Eu 3+ When the phosphor luminescent material is used in LED light source devices, it can have three emission peaks in the blue band, yellow band and red band under ultraviolet light excitation, and finally realize white light emission in the new single-substance phosphor; the three emission peaks cover 450 nm to 650 nm, and the peak values ​​are respectively located at 485 nm, 580 nm and 612 nm. The preparation method of the invention has simple process and mature technology, and has good industrialization and application prospects. The excitation band is located in the ultraviolet region, avoiding overlap with the emitted light, and there is no reabsorption problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is Sr2LaNbO6:Dy 3+ , Eu 3+ XRD pattern of the product prepared by phosphor.

[0022] Figure 2 The present invention is Sr2LaNbO6:Dy 3+ , Eu 3+ Excitation spectra of products prepared from phosphors.

[0023] Figure 3 The present invention is Sr2LaNbO6:Dy 3+ , Eu 3+(1%≤x≤5%) Emission spectrum of products prepared from phosphors.

[0024] Figure 4 The present invention is Sr2LaNbO6:2%Dy 3+ , yEu 3+ (0.1%≤y≤0.5%) Emission spectrum of products prepared from phosphor.

[0025] Figure 5 Invented Sr2LaNbO6:Dy 3+ ,Eu 3+ CIE spectrum of products prepared from phosphors.

[0026] Figure 6 Invented Sr2LaNbO6:Dy 3+ ,Eu 3+ A white light LED device made from phosphor and UV chip. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0028] Example Sr2LaNbO6:xDy 3+ (1%≤x≤5%)

[0029] A method for preparing ultraviolet excited niobate white light emitting phosphor comprises the following steps:

[0030] S1), according to the chemical formula Sr2La 1-x NbO6:xDy 3+ The stoichiometric ratio is 1%≤x≤5%, and strontium carbonate, lanthanum oxide, niobium pentoxide and dysprosium oxide are weighed as raw materials, and the sample after calcination is 5g;

[0031] S2), appropriately weighing the compounds in step S1), grinding the mixture consisting of the four compounds for 20 min to fully mix the mixture;

[0032] S3), putting the mixed material ground in step S2) into a crucible, and calcining the crucible containing the mixed material in an air atmosphere using a Ma Furnace, the calcination temperature is 1400° C., and the temperature is kept for 5 hours;

[0033] S4), the mixture calcined in step S3) is naturally cooled to room temperature and then taken out from the furnace, and the taken out mixture is ground again to obtain white light Sr2LaNbO6:Dy 3+ Phosphor.

[0034] Example Sr2LaNbO6:2%Dy 3+ , yEu3+ (0.1%≤y≤0.5%)

[0035] A method for preparing ultraviolet excited niobate white light emitting phosphor comprises the following steps:

[0036] S1), according to the chemical formula Sr2La 1-x-y NbO6:2%Dy 3+ , yEu 3+ The stoichiometric ratio is 0.1%≤y≤0.5%, and strontium carbonate, lanthanum oxide, niobium pentoxide, dysprosium oxide and europium oxide are weighed as raw materials respectively, and the sample after calcination is 5g;

[0037] S2), appropriately weighing the compounds in step S1), grinding the mixture consisting of the five compounds for 20 min to fully mix the mixture;

[0038] S3), putting the mixed material ground in step S2) into a crucible, and calcining the crucible containing the mixed material in an air atmosphere using a Ma Furnace, the calcination temperature is 1400° C., and the temperature is kept for 5 hours;

[0039] S4), the mixture calcined in step S3) is naturally cooled to room temperature and then taken out from the furnace, and the taken out mixture is ground again to obtain white light Sr2LaNbO6:Dy 3+ , Eu 3+ Phosphor.

[0040] Figure 1 Sr2LaNbO6:Dy 3+ , Eu 3+ XRD pattern of phosphor. Figure 1 It can be seen that the phases fired according to the above steps are Sr2LaNbO6, rare earth Dy 3+ and Eu 3+ Ion doping has no effect on the matrix double perovskite structure.

[0041] Figure 2 Sr2LaNbO6:2%Dy 3+ Excitation spectrum of phosphor. When the emission wavelength is controlled at 485 nm, the strongest excitation peak is located at 350 nm, and the strongest excitation peak is located in the ultraviolet region. 3+ Phosphors can be excited using near-UV chips.

[0042] Figure 3 Sr2LaNbO6:xDy 3+(1%≤x≤5%) emission spectrum of phosphor. When the excitation spectrum is controlled at 350 nm, the emission spectrum has emission peaks in the blue band and the yellow band, with peak wavelengths at 485 nm and 580 nm, respectively. When x = 2%, the fluorescence intensity is the highest.

[0043] Figure 4 Sr2LaNbO6:2%Dy 3+ , yEu 3+ (0.1%≤y≤0.5%) Emission spectrum of phosphor. When the excitation spectrum is controlled at 350 nm, the emission spectrum has emission peaks in the blue band, yellow band and red band, and the peak wavelengths are located at 485 nm, 580 nm and 612 nm respectively. 3+ With the increase of doping concentration, the luminous intensity in the red band (612nm) is constantly increasing.

[0044] Figure 5 Sr2LaNbO6:xDy 3+ (1%≤x≤5%) and Sr2LaNbO6:2%Dy 3+ , yEu 3+ (0.1%≤y≤0.5%) CIE spectrum of phosphor. All examples are within the white light region, doped with Eu 3+ After reaching the matrix, the color temperature is significantly reduced.

[0045] Figure 6 Sr2LaNbO6:2%Dy 3+ and Sr2LaNbO6:2%Dy 3+ , 0.3%Eu 3+ Phosphor for white LED devices. Sr2LaNbO6:2%Dy 3+ and Sr2LaNbO6:2%Dy 3+ , 0.3%Eu 3+ The phosphor is combined with a 365nm UV chip to make a white light LED. When the white light LED device is turned on with a 30mA current and a 3V voltage, it can emit bright white light.

[0046] The above embodiments are preferred implementations of the present invention and cannot be used to limit the protection scope of the present invention. Any equivalent changes or equivalent modifications made to the present invention by those skilled in the art without being detrimental to the spirit and essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a UV-excited niobate white light emitting phosphor, characterized in that: By using rare earth Dy 3+ and Eu 3+ Ions are used as luminescent activators, and double perovskite strontium lanthanide niobate is used as the luminescent material matrix, with the chemical formula of Sr2LaNbO6: Dy 3+ , Eu 3+ , a series of Sr2La 1-x-y NbO6:xDy 3+ , yEu 3+ Phosphor.

2. The method for preparing a UV-excited niobate white light emitting phosphor according to claim 1, wherein a series of Sr2La 1-x-y NbO6:xDy 3+ , yEu 3+ The phosphor comprises the following steps: S1), according to the chemical formula Sr2La 1-x-y NbO6:xDy 3+ , yEu 3+ According to the stoichiometric ratio, a compound containing Sr, a compound containing La, a compound containing Nb, a compound containing Dy and a compound containing Eu are weighed as raw materials respectively; S2), appropriately weighing the compounds in step S1), grinding the mixture consisting of the five compounds for 20 minutes to fully mix the mixture; S3), putting the mixed material ground in step S2) into a crucible, and calcining the crucible containing the mixed material in an air atmosphere using a Ma furnace, the calcination temperature is 1400°C, and the temperature is kept for 5 hours; S4), the mixture after burning in step S3) is naturally cooled to room temperature and then taken out from the furnace, and the taken out mixture is ground again to obtain white light Sr2LaNbO6:Dy 3+ , Eu 3+ Phosphor.

3. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: In step S1), the Sr-containing compound raw material is strontium carbonate.

4. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: In step S1), the compound raw material containing La is lanthanum oxide.

5. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: In step S1), the compound raw material containing Nb is niobium pentoxide.

6. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: In step S1), the Dy-containing compound raw material is dysprosium oxide.

7. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: In step S1), the Eu-containing compound raw material is europium oxide.

8. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: In step S1), the x value is 1%≤x≤5%, and the y value is 0.1%≤y≤0.5%.

9. A method for preparing a UV-excited niobate white light emitting phosphor according to claim 2, characterized in that: The white light Sr2LaNbO6:Dy prepared in step S4) 3+ , Eu 3+ Phosphor and 365 nm ultraviolet chip are used to prepare white light emitting LED devices.

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