Eu < 3 + >-doped aluminoborate red-orange luminescent material as well as preparation method and application thereof

Abstract

The invention provides an Eu < 3 + >-doped aluminoborate red-orange luminescent material as well as a preparation method and application thereof, and belongs to the technical field of luminescent materials. Wherein the chemical formula of the Eu < 3 + >-doped boron aluminate red and orange luminescent material is Li4Al2B4O11: 4xEu < 3 + >, x is the mole number of Eu < 3 + > replacing Li < + >, and x is more than or equal to 0.005 and less than or equal to 0.04. The material can be effectively excited by light with near ultraviolet and blue light wavelengths, and emits a sharp spectrum with a wavelength peak value at 593 nanometers, and the red and orange light has pure chromaticity, high luminous intensity and good thermal stability. The Eu < 3 + >-doped aluminoborate red-orange luminescent material can be combined with a near-ultraviolet or blue-light semiconductor chip to prepare a corresponding white-light LED (light-emitting diode) lighting device.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials and specifically relates to a Eu 3+ Doped boroaluminate red-orange luminescent material, preparation method and application thereof. Background Art

[0002] Today, white LED solid-state lighting based on semiconductor chips is the most eye-catching green light source, and its application market is very broad. White LEDs that use near-ultraviolet light (350-410nm) and InGaN semiconductor chips and three-primary color phosphor packaging have become one of the hot spots in the field of research and development, and are considered to be the leading new generation of white LED lighting. High-efficiency near-ultraviolet light-excited phosphors are also one of the hot spots in the research and development of luminescent materials. At present, InGaN-based light-emitting diodes with a wavelength of 350-470nm are commonly used as excitation light sources for white LEDs internationally, so the excitation spectrum of the phosphor must also be within this wavelength range. In addition, high-quality phosphors must also have the following characteristics: the emission peak should be concentrated in a specific wavelength range, high chromaticity, high quantum efficiency, good excitation light absorption rate, excellent thermal stability, and small and uniform particles. There is no doubt that among the luminescent materials that combine such conditions, rare earth ion-activated phosphors are the most important candidates. Rare earth ion-activated phosphors can emit spectra of different wavelengths and produce colorful luminescence effects, playing an important role in the fields of luminescence and display.

[0003] At present, traditional phosphors such as Y2O2S:Eu 3+ 、Y2O3:Eu 3+ , etc., have weak excitation light in the near-ultraviolet and blue light regions, poor high-temperature stability and luminous efficiency. For example, the traditional red phosphor Y2O3:Eu 3+ 、YVO4:Eu 3+ During the preparation process, there are still problems such as emission of toxic waste gas and high sintering temperature. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art and provide a Eu 3+ Doped boroaluminate red-orange luminescent material, preparation method and application thereof.

[0005] In one aspect of the present disclosure, there is provided a Eu 3+ Doped boroaluminate red-orange luminescent material, the chemical formula of the red-orange luminescent material is Li4Al2B4O 11 :4xEu 3+ , where x is Eu 3+ Li + The number of moles, and 0.005≤x≤0.04.

[0006] Optionally, the red-orange luminescent material can emit orange-red light with a sharp characteristic peak at 593 nanometers under the excitation of light in the ultraviolet-blue light band.

[0007] Another aspect of the present disclosure is to provide a method for preparing the Eu 3+ A method for doping a red-orange luminescent material of boroaluminate, the method comprising:

[0008] According to the chemical formula Li4Al2B4O 11 :4xEu 3+ The stoichiometric ratio of each element in the mixture is 0.005≤x≤0.04, and a compound containing lithium ions, a compound containing aluminum ions, a compound containing boron ions, and a compound containing europium ions are weighed respectively, and then 1wt% to 5wt% of the complexing agent of each of the above raw materials is weighed respectively;

[0009] Dissolve the weighed reagents in deionized water or nitric acid respectively, then add 1-5wt% of the complexing agent to each reagent, stir for 1-2 hours, and obtain transparent precursor solutions of various raw materials;

[0010] Slowly mix the transparent precursor solutions of the above raw materials, stir for 1 to 5 hours at a temperature of 40 to 95° C., let stand, and dry to obtain a precursor powder;

[0011] The above precursor powder is placed in a muffle furnace and calcined at a temperature of 720-800°C for 1-10 hours. After naturally cooling to room temperature, a Eu 3+ Doped boroaluminate red-orange luminescent material.

[0012] Optionally, the compound containing lithium ions is one or more of lithium oxide, lithium nitrate, lithium carbonate and lithium hydroxide.

[0013] Optionally, the compound containing aluminum ions is one or more of aluminum oxide, aluminum nitrate, and aluminum hydroxide.

[0014] Optionally, the compound containing boron ions is one or more of boron trioxide and boric acid.

[0015] Optionally, the compound containing europium ions is one or more of europium oxide and europium nitrate.

[0016] Optionally, the complexing agent is citric acid or oxalic acid.

[0017] Another aspect of the present disclosure provides a Eu 3+ The application of doped boroaluminate red-orange luminescent material adopts the Eu 3+The doped boroaluminate red-orange luminescent material is used in white-light emitting LEDs based on near-ultraviolet and blue-light semiconductor chip excitation.

[0018] The present disclosure proposes a Eu 3+ Doped boroaluminate red-orange luminescent material and its preparation method and application. The chemical formula of the red-orange luminescent material is Li4Al2B4O 11 :4xEu 3+ , where x is Eu 3+ Li + The molar number of , and 0.005≤x≤0.04. The material can be effectively excited by light of near-ultraviolet and blue wavelengths, and emits a sharp spectrum with a wavelength peak at 593 nanometers. The red-orange luminescence has pure chromaticity, high luminous intensity and good thermal stability. 3+ The doped boroaluminate red-orange luminescent material can be combined with a near-ultraviolet or blue light semiconductor chip to prepare a corresponding white light LED lighting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 For this disclosure 3+ A flowchart of a method for preparing a doped boroaluminate red-orange luminescent material;

[0020] Figure 2 The XRD diffraction patterns of the samples prepared in Examples 1, 2, 3, and 4 of the present disclosure are compared with the X-ray diffraction standard card PDF#28-0548;

[0021] Figure 3 This is a SEM image of the sample prepared in Example 1 of the present disclosure;

[0022] Figure 4 is the excitation spectrum of the sample prepared in Example 1 of the present disclosure;

[0023] Figure 5 The luminescence spectrum of the sample prepared in Example 1 of the present disclosure;

[0024] Figure 6 is the luminescence decay curve of the sample prepared in Example 1 of the present disclosure;

[0025] Figure 7 is the excitation spectrum of the sample prepared in Example 2 of the present disclosure;

[0026] Figure 8 The luminescence spectrum of the sample prepared in Example 2 of the present disclosure;

[0027] Fig. 9 is the luminescence decay curve of the sample prepared in Example 2 of the present disclosure;

[0028] Fig.10is the excitation spectrum of the sample prepared in Example 3 of the present disclosure;

[0029] Fig.11 The luminescence spectrum of the sample prepared in Example 3 of the present disclosure;

[0030] Fig.12 is the luminescence decay curve of the sample prepared in Example 3 of the present disclosure;

[0031] Fig.13 is the excitation spectrum of the sample prepared in Example 4 of the present disclosure;

[0032] Fig.14 The luminescence spectrum of the sample prepared in Example 4 of the present disclosure;

[0033] Fig.15 This is the luminescence attenuation curve of the sample prepared in Example 4 of the present disclosure. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0035] In one aspect of the present disclosure, a Eu 3+ Doped boroaluminate red-orange luminescent material, the chemical formula of the red-orange luminescent material is Li4Al2B4O 11 :4xEu 3+ , where x is Eu 3+ Li + The number of moles, and 0.005≤x≤0.04.

[0036] In this embodiment, the boroaluminate matrix Li4Al2B4O 11 The crystal lattice is composed of Al-O and BO strong covalent bonds, and the smallest metal ion Li is filled in the crystal lattice. The luminescence spectrum of this phosphor is very sharp, the chromaticity of the red-orange luminescence is pure, and the luminescence efficiency and thermal stability of the luminescence are good. Compared with traditional phosphors such as Y2O2S:Eu 3+ 、Y2O3:Eu 3+ Compared with other luminescent materials, the phosphor of the present invention has stronger excitation in the near-ultraviolet (near 400nm) and blue light regions (near 450nm), and is very compatible with the luminescent wavelength of commercial InGaN-based light-emitting diodes.

[0037] In some preferred embodiments, the red-orange luminescent material can emit orange-red light with a sharp characteristic peak at 593 nanometers under the excitation of light in the ultraviolet-blue light band.

[0038] like Figure 1 As shown, one aspect of the present disclosure provides a method for preparing Eu as described above. 3+ The method S100 for preparing a doped boroaluminate red-orange luminescent material specifically comprises the following steps S110 to S140:

[0039] S110, according to the chemical formula Li4Al2B4O 11 :4xEu 3+ The stoichiometric ratio of each element is 0.005≤x≤0.04, and a compound containing lithium ions, a compound containing aluminum ions, a compound containing boron ions, and a compound containing europium ions are weighed respectively, and then 1wt% to 5wt% of the complexing agent of each of the above raw materials is weighed respectively.

[0040] In some preferred embodiments, the lithium ion (Li + ) is one or a combination of lithium oxide, lithium nitrate, lithium carbonate, and lithium hydroxide.

[0041] In other preferred embodiments, aluminum ions (Al 3+ ) is one or a combination of aluminum oxide, aluminum nitrate, and aluminum hydroxide.

[0042] In other preferred embodiments, the boron ion (B 3+ ) is: boron trioxide, boric acid or a combination thereof.

[0043] In other preferred embodiments, the 3+ ) is one of europium oxide and europium nitrate or a combination thereof.

[0044] In other preferred embodiments, the complexing agent is citric acid or oxalic acid.

[0045] S120, dissolving the weighed reagents in deionized water or nitric acid respectively, and then adding 1-5 wt% of the complexing agent to each reagent respectively, stirring for 1-2 hours to obtain transparent precursor solutions of various raw materials.

[0046] It should be noted that in step S120, the weighed reagents are dissolved in deionized water or nitric acid, and a complexing agent is added to each reagent to form various transparent precursor solutions, wherein the amount of the complexing agent added to each reagent is 1-5wt% of the mass of each raw material, for example, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%.

[0047] S130, slowly mix the transparent precursor solutions of the above raw materials, stir for 1 to 5 hours at a temperature of 40 to 95° C., let stand, and dry to obtain a precursor powder.

[0048] In some preferred embodiments, the temperature is 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 95°C, and the stirring time is 1 hour, 2 hours, 3 hours, 4 hours, 5 hours.

[0049] S140, calcining the above precursor powder in a muffle furnace at a temperature of 720-800°C for 1-10 hours, and cooling naturally to room temperature to obtain a Eu 3+ Doped boroaluminate red-orange luminescent material.

[0050] In some preferred embodiments, the calcination temperature is 720°C, 750°C, 780°C, 800°C, etc., and the calcination time is 1 hour, 3 hours, 5 hours, 7 hours, 10 hours, etc.

[0051] Compared with the traditional red luminescent powder Y2O3:Eu 3+ 、YVO4:Eu 3+ Compared with the above, the present embodiment uses a chemical sol-gel method to synthesize and prepare the phosphor powder. The preparation method is simple, the physical phase of the preparation material is single, the particle size is fine, the raw materials are easily available, the repeatability is good, there is no pollution, no waste gas or waste liquid emissions, the sintering temperature is low, it saves energy consumption, and it is easy to produce.

[0052] Another aspect of the present disclosure provides a Eu 3+ The application of doped boroaluminate red-orange luminescent material adopts the Eu 3+ The doped boroaluminate red-orange luminescent material is used in white-light emitting LEDs based on near-ultraviolet and blue-light semiconductor chip excitation.

[0053] The following will further illustrate Eu 3+ Preparation method and properties of doped boroaluminate red-orange luminescent materials:

[0054] Embodiment 1:

[0055] According to the chemical formula Li 3.98 Eu 0.02 Al2B4O 11The stoichiometric ratio of each element is as follows: 13.72 g lithium nitrate, 37.51 g aluminum nitrate, 12.37 g boric acid, and 0.446 g europium nitrate are weighed respectively. The weighed lithium nitrate is dissolved in ionized water, and 0.69 g citric acid is added; aluminum nitrate is dissolved in ionized water, and 1.88 g citric acid is added; boric acid is dissolved in ionized water, and 0.62 g citric acid is added; europium nitrate is dissolved in ionized water, and 0.03 g citric acid is added; the above solutions are stirred for 1 hour to obtain transparent precursor solutions of the raw materials; the above four precursor solutions are slowly mixed, stirred at 95°C for 1 hour, allowed to stand, and dried to obtain fluffy precursor powders; the above precursor powders are placed in a muffle furnace for calcination at a temperature of 800°C for 1 hour, and naturally cooled to room temperature to obtain a Eu 3+ Doped boroaluminate red-orange luminescent material.

[0056] See attached Figure 2 , is a comparison of the X-ray powder diffraction pattern of the sample prepared according to this Example 1 with the standard card PDF#28-0548, and the result shows that the sample is a pure phase material.

[0057] See attached Figure 3 , is a SEM picture of the sample prepared according to Example 1. The result shows that the sample is fine particles with uniform particle size, and the particle size is 100-300 nanometers.

[0058] See attached Figure 4 , is the excitation spectrum of the sample prepared according to Example 1. It can be seen that the sample exhibits good excitation in the ultraviolet light-blue light range.

[0059] See attached Figure 5 , is the luminescence spectrum of the sample prepared according to Example 1. It can be seen that the strongest luminescence peak is located at 593 nanometers, and the luminescence peak is sharp, and the chromaticity of the red-orange luminescence is pure;

[0060] See attached Figure 6 , is the luminescence decay curve of the sample prepared according to Example 1, and its luminescence lifetime is 1.47 milliseconds, which is Eu 3+ The characteristic luminescence decay of ions can meet the needs of luminescence display without the afterglow phenomenon.

[0061] Example 2

[0062] According to the chemical formula Li 3.96 Eu 0.04 Al2B4O 11The stoichiometric ratio of each element is as follows: 14.47 g lithium nitrate, 39.76 g aluminum nitrate, 13.11 g boric acid, and 0.95 g europium nitrate are weighed respectively. The weighed lithium nitrate is dissolved in ionized water, and 0.58 g citric acid is added; aluminum nitrate is dissolved in ionized water, and 1.59 g citric acid is added; boric acid is dissolved in ionized water, and 0.53 g citric acid is added; europium nitrate is dissolved in ionized water, and 0.04 g citric acid is added; the above solutions are stirred for 2 hours to obtain transparent precursor solutions of the raw materials; the above four precursor solutions are slowly mixed, stirred at 40°C for 5 hours, allowed to stand, and dried to obtain fluffy precursor powders; the above precursor powders are placed in a muffle furnace for calcination at a temperature of 720°C for 10 hours, and naturally cooled to room temperature to obtain a Eu 3+ Doped boroaluminate red-orange luminescent material.

[0063] See attached Figure 2 , is a comparison of the X-ray powder diffraction pattern of the sample prepared according to this Example 2 with the standard card PDF#28-0548, and the result shows that the sample is a pure phase material.

[0064] See attached Figure 7 , is the excitation spectrum of the sample prepared according to Example 2. It can be seen that the sample exhibits good excitation in the ultraviolet light-blue light range.

[0065] See attached Figure 8 , is the luminescence spectrum of the sample prepared according to Example 2. It can be seen that the strongest luminescence peak is located at 593 nanometers, and the luminescence peak is sharp, and the chromaticity of the red-orange luminescence is pure;

[0066] See attached Fig. 9 , is the luminescence decay curve of the sample prepared according to Example 2, and its luminescence lifetime is 1.32 milliseconds, which is Eu 3+ The characteristic luminescence decay of ions can meet the needs of luminescence display without the afterglow phenomenon.

[0067] Example 3

[0068] According to the chemical formula Li 3.88 Eu 0.12 Al2B4O 11The stoichiometric ratio of each element is as follows: 12.84 g lithium nitrate, 36.01 g aluminum nitrate, 11.87 g boric acid, and 2.57 g europium nitrate are weighed respectively. The weighed lithium nitrate is dissolved in ionized water, and 0.26 g citric acid is added; aluminum nitrate is dissolved in ionized water, and 0.72 g citric acid is added; boric acid is dissolved in ionized water, and 0.24 g citric acid is added; europium nitrate is dissolved in ionized water, and 0.05 g citric acid is added; the above solutions are stirred for 2 hours to obtain transparent precursor solutions of the raw materials; the above four precursor solutions are slowly mixed, stirred at 60°C for 2 hours, allowed to stand, and dried to obtain fluffy precursor powders; the above precursor powders are placed in a muffle furnace for calcination at a temperature of 780°C for 5 hours, and naturally cooled to room temperature to obtain a Eu 3+ Doped boroaluminate red-orange luminescent material.

[0069] See attached Figure 2 , is a comparison of the X-ray powder diffraction pattern of the sample prepared according to this Example 3 with the standard card PDF#28-0548, and the result shows that the sample is a pure phase material.

[0070] See attached Fig.10 , is the excitation spectrum of the sample prepared according to Example 3. It can be seen that the sample exhibits good excitation in the ultraviolet light-blue light range.

[0071] See attached Fig.11 , is the luminescence spectrum of the sample prepared according to Example 3. It can be seen that the strongest luminescence peak is located at 593 nanometers, and the luminescence peak is sharp, and the chromaticity of the red-orange luminescence is pure;

[0072] See attached Fig.12 , is the luminescence decay curve of the sample prepared according to Example 3, and its luminescence lifetime is 1.25 milliseconds, which is Eu 3+ The characteristic luminescence decay of ions can meet the needs of luminescence display without the afterglow phenomenon.

[0073] Example 4

[0074] According to the chemical formula Li 3.84 Eu 0.16 Al2B4O 11The stoichiometric ratio of each element is as follows: 10.59 g lithium nitrate, 30.01 g aluminum nitrate, 9.89 g boric acid, and 2.85 g europium nitrate are weighed respectively. The weighed lithium nitrate is dissolved in ionized water, and 0.53 g oxalic acid is added; aluminum nitrate is dissolved in ionized water, and 1.51 g oxalic acid is added; boric acid is dissolved in ionized water, and 0.49 g oxalic acid is added; europium nitrate is dissolved in ionized water, and 0.14 g oxalic acid is added; the above solutions are stirred for 2 hours to obtain transparent precursor solutions of the raw materials; the above four precursor solutions are slowly mixed, stirred at 60°C for 2 hours, allowed to stand, and dried to obtain fluffy precursor powders; the above precursor powders are placed in a muffle furnace for calcination at a temperature of 780°C for 5 hours, and naturally cooled to room temperature to obtain a Eu 3+ Doped boroaluminate red-orange luminescent material.

[0075] See attached Figure 2 , is a comparison of the X-ray powder diffraction pattern of the sample prepared according to Example 4 with the standard card PDF#28-0548, and the result shows that the sample is a pure phase material.

[0076] See attached Fig.13 , is the excitation spectrum of the sample prepared according to Example 4. It can be seen that the sample exhibits good excitation in the ultraviolet light-blue light range.

[0077] See attached Fig.14 , is the luminescence spectrum of the sample prepared according to Example 4. It can be seen that the strongest luminescence peak is located at 593 nanometers, and the luminescence peak is sharp, and the chromaticity of the red-orange luminescence is pure;

[0078] See attached Fig.15 , is the luminescence decay curve of the sample prepared according to Example 4, and its luminescence lifetime is 1.13 milliseconds, which is Eu 3+ The characteristic luminescence decay of ions can meet the needs of luminescence display without the afterglow phenomenon.

[0079] The present disclosure proposes a Eu 3+ The doped boroaluminate red-orange luminescent material and its preparation method and application have the following beneficial effects compared with the prior art:

[0080] First, boroaluminate matrix Li4Al2B4O 11 The crystal lattice is composed of Al-O and BO with strong covalent bonds, and the smallest metal ion Li is filled in the crystal lattice. The luminescence spectrum of the phosphor is very sharp, the chromaticity of the red-orange luminescence is pure, and the luminescence efficiency and thermal stability of the luminescence are good.

[0081] Second, compared with traditional phosphors such as Y2O2S:Eu 3+ 、Y2O3:Eu 3+Compared with other luminescent materials, the phosphor prepared by the technical solution of the present invention has stronger excitation in the near-ultraviolet (near 400nm) and blue light regions (near 450nm), which is very compatible with the emission wavelength of commercial InGaN-based light-emitting diodes.

[0082] Third, the red phosphor prepared by the technical solution of the present invention has strong high-temperature stability, small quenching of luminescence at high temperature, and no shift in the main peak of luminescence at high temperature, maintaining chromaticity stability, which is conducive to the preparation of high-power LEDs.

[0083] Fourth, compared with the traditional red luminescent powder Y2O3:Eu 3+ 、YVO4:Eu 3+ Compared with other methods, the preparation method of the phosphor provided by this patent is simple, the prepared material has fine particle size, no pollution, no waste gas and waste liquid emissions, low sintering temperature, energy saving, and easy production.

[0084] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. Eu 3+ The doped boroaluminate red-orange luminescent material is characterized in that: The chemical formula of the red-orange luminescent material is Li4Al2B4O 11 :4xEu 3+ , where x is Eu 3+ Li + The number of moles, and 0.005≤x≤0.

04.

2. Eu according to claim 1 3+ The doped boroaluminate red-orange luminescent material is characterized in that: The red-orange luminescent material can emit orange-red light with a sharp characteristic peak at 593 nanometers under the excitation of light in the ultraviolet-blue light band.

3. A method for preparing Eu as claimed in claim 1 or 2 3+ The method of doping a red-orange luminescent material of boroaluminate is characterized in that The method comprises: According to the chemical formula Li4Al2B4O 11 :4xEu 3+ The stoichiometric ratio of each element in the mixture is 0.005≤x≤0.04, and a compound containing lithium ions, a compound containing aluminum ions, a compound containing boron ions, and a compound containing europium ions are weighed respectively, and then 1wt% to 5wt% of the complexing agent of each of the above raw materials is weighed respectively; Dissolve the weighed reagents in deionized water or nitric acid respectively, then add 1-5wt% of the complexing agent to each reagent, stir for 1-2 hours, and obtain transparent precursor solutions of various raw materials; Slowly mix the transparent precursor solutions of the above raw materials, stir for 1 to 5 hours at a temperature of 40 to 95° C., let stand, and dry to obtain a precursor powder; The above precursor powder is placed in a muffle furnace and calcined at a temperature of 720-800°C for 1-10 hours. After naturally cooling to room temperature, a Eu 3+ Doped boroaluminate red-orange luminescent material.

4. The method according to claim 3, characterized in that The compound containing lithium ions is one or more of lithium oxide, lithium nitrate, lithium carbonate and lithium hydroxide.

5. The method according to claim 3, characterized in that: The compound containing aluminum ions is one or more of aluminum oxide, aluminum nitrate, and aluminum hydroxide.

6. The method according to claim 3, characterized in that The compound containing boron ions is one or more of boron trioxide and boric acid.

7. The method according to claim 3, characterized in that The compound containing europium ions is one or more of europium oxide and europium nitrate.

8. The method according to claim 3, characterized in that The complexing agent is citric acid or oxalic acid.

9. Eu 3+ Application of doped boroaluminate red-orange luminescent material, characterized in that: Using the Eu described in claim 1 or 2 3+ The doped boroaluminate red-orange luminescent material is used in white-light emitting LEDs based on near-ultraviolet and blue-light semiconductor chip excitation.

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