A red light emitting fluorescent material and a preparation method thereof

Abstract

The application discloses a red light emitting fluorescent material and a preparation method thereof, and belongs to the technical field of visible light photoluminescence fluorescence. 3+ and Ln 3+ co-doped Ca5Ga6O 14 , a chemical formula of which is Ca 5‑x‑y Ga6O 14 : xBi 3+ , yLn 3+ , wherein 0 < x <= 0.05, 0 < y <= 0.03, Ln 3+ is Pr 3+ , Dy 3+ , Sm 3+ or Tb 3+ . The solid phase method is adopted, no strong acid solvent pollutes the environment, no harmful waste is generated, and the synthesized sample does not need to be further purified; the obtained red light emitting fluorescent material has good crystallinity and stability to light, heat and humidity; and the excitation spectrum of the obtained red light emitting fluorescent material is located in an n-UV region; therefore, spectral overlap can be effectively avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of visible light photoluminescence fluorescence, and particularly relates to a red light emitting fluorescent material and a preparation method thereof. BACKGROUND

[0002] Traditional activator-doped phosphors have some inherent problems due to their luminescence properties. For Eu 2+ Longer wavelength phosphors, Eu 2+ Usually located in a higher covalent crystal site, such as nitride or oxynitride, the strong crystal field around it will further split the 5d energy level, resulting in red emission. The extension of the 5d energy level extends the excitation to the red spectral range. Longer wavelength excitation inevitably leads to reabsorption of the device emission, thus reducing the luminous efficiency of the device. These problems are due to the luminescence transition properties of these phosphors, which cannot be solved under the traditional doped base phosphor framework. This limits the future development of phosphor conversion technology.

[0003] In recent years, Bi 3+ Activated phosphors have been widely studied due to their unique luminescence properties, and their excitation spectrum is located in the n-UV region, so spectral overlap can be effectively avoided. However, Bi 3+ Ions usually emit blue and green light, rarely red light. SUMMARY

[0004] In view of the above shortcomings of the prior art, the application provides a red light emitting fluorescent material and a preparation method thereof.

[0005] To achieve the above purpose, the technical scheme adopted by the application is as follows: a red light emitting fluorescent material is Bi 3+ And Ln 3+ Co-doped Ca5Ga6O 14 , and the chemical formula is Ca 5-x-y Ga6O 14 : xBi 3+ , yLn 3+ , wherein 0 3+ Pr 3+ , Dy 3+ , Sm 3+ Or Tb 3+ .

[0006] The application also claims the preparation method of the red light emitting fluorescent material, which comprises: weighing CaCO3, Ga2O3, Bi2O3 and Ln oxide according to the stoichiometric ratio of the chemical formula, mixing, adding anhydrous ethanol, grinding, and then calcining to obtain the red light emitting fluorescent material.

[0007] As a preferred embodiment of the present application, the molar ratio of CaCO3, Ga2O3, Bi2O3 and the oxide of Ln is according to Ca 5-x- y Ga6O 14 : xBi 3+ , yLn 3+ The stoichiometric ratio is calculated.

[0008] The oxide of Ln is Pr6O 11 , Dy2O3, Sm2O3 or Tb4O7.

[0009] As a preferred embodiment of the present application, the volume ratio of the total mass of CaCO3, Ga2O3, Bi2O3 and the oxide of Ln to anhydrous ethanol is 1 g / (4-7) ml.

[0010] As a preferred embodiment of the present application, the temperature of the calcination is 1100-1300℃, the time is 5-10 h, and the heating rate is 5℃ / min.

[0011] As a preferred embodiment of the present application, the grinding time is 20-60 min.

[0012] The present application constructs an adapted crystal structure by introducing Pr 3+ , Dy 3+ , Sm 3+ or Tb 3+ , regulates the oxygen vacancy around Bi 3+ ion, makes the electron around Bi 3+ ion localized, and thus realizes the red or orange-red light emission of Bi 3+ ion.

[0013] Compared with the prior art, the present application has the beneficial effects that the red light emission fluorescent material has good crystallinity and stability to light, heat and humidity. And the solid phase method is adopted, there is no strong acid solvent to pollute the environment, no harmful waste, and the synthesized sample does not need further purification, and the excitation spectrum of the obtained red light emission fluorescent material is located in the n-UV region; therefore, the spectral overlap can be effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The emission spectrum diagram of the red light emission fluorescent material prepared in Example 1 of the present application is excited by a xenon lamp with a wavelength of 365 nm at room temperature.

[0015] Figure 2 The excitation spectrum diagram of the red light emission fluorescent material prepared in Example 1 of the present application is excited by a xenon lamp with a wavelength of 365 nm at room temperature.

[0016] Figure 3The emission spectrum of the fluorescent material prepared in Comparative Example 1 of this invention after being excited by a xenon lamp with a wavelength of 286 nm at room temperature is shown. Detailed Implementation

[0017] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0018] In the examples and comparative examples, CaCO3, Ga2O3, Bi2O3 and Pr6O 11 The purity of all of them is 99.99%.

[0019] Example 1

[0020] A red-light-emitting fluorescent material is prepared by weighing CaCO3: 498 mol, Ga2O3: 300 mol, Bi2O3: 0.5 mol, and Pr6O3 in the following proportions. 11 After mixing 0.167 mol, the mixed powder was placed in an agate mortar and anhydrous ethanol was added dropwise. The mixture was then ground for 30 min (the mass ratio of the mixed powder to the volume of anhydrous ethanol was 1 g: 4 mL) until the material was powdery. The material was then transferred to a corundum crucible and placed in a box furnace at 1300℃ for high-temperature sintering for 6 h at a heating rate of 5℃ / min. Finally, the material was allowed to cool naturally to room temperature to obtain the red light emitting fluorescent material.

[0021] The emission spectrum of the red-emitting fluorescent material prepared in Example 1 was measured at room temperature using an F7000 fluorescence spectrophotometer. A xenon lamp source of 365 nm was selected. The results are shown below. Figure 1 ,from Figure 1 As can be seen, under 365nm xenon lamp excitation, the material exhibits broadband emission in the 500-800nm ​​region, with the emission peak centered at 610nm, thus emitting red light.

[0022] Further, by detecting the 610 nm wavelength, the excitation spectrum (PLE) of this red-emitting fluorescent material can be measured, and the results are shown below. Figure 2 The excitation spectrum shows four excitation peaks at 345 nm, 451 nm, 472 nm, and 486 nm.

[0023] Example 2

[0024] A red-light-emitting fluorescent material is prepared by weighing CaCO3: 492 mol, Ga2O3: 300 mol, Bi2O3: 2.5 mol, and Pr6O3 in the following proportions. 11: 0.5 mol After mixing, the mixed powder was placed in an agate mortar, and then absolute ethanol was added dropwise and ground for 30 min (the mass of the mixed powder to the volume of absolute ethanol was 1 g: 7 mL). The material was ground into a powder, and then transferred to a corundum crucible and placed in a 1100°C box furnace for high-temperature sintering. The sintering time was 10 h, the heating rate was 5°C / min, and finally the temperature was naturally lowered to room temperature to obtain the red light emitting fluorescent material.

[0025] The red light emitting fluorescent material prepared in Example 2 has a broadband emission in the range of 500-800 nm under 365 nm xenon lamp excitation, and the emission peak center is located at 610 nm, thereby emitting red light.

[0026] Example 3

[0027] A red light emitting fluorescent material was prepared by weighing CaCO3: 484 mol, Ga2O3: 300 mol, Bi2O3: 0.05 mol and Pr6O 11 : 0.01 mol After mixing, the mixed powder was placed in an agate mortar, and then absolute ethanol was added dropwise and ground for 30 min (the mass of the mixed powder to the volume of absolute ethanol was 1 g: 5 mL). The material was ground into a powder, and then transferred to a corundum crucible and placed in a 1200°C box furnace for high-temperature sintering. The sintering time was 5 h, the heating rate was 5°C / min, and finally the temperature was naturally lowered to room temperature to obtain the red light emitting fluorescent material.

[0028] The red light emitting fluorescent material prepared in Example 3 has a broadband emission in the range of 500-800 nm under 365 nm xenon lamp excitation, and the emission peak center is located at 610 nm, thereby emitting red light.

[0029] Example 4

[0030] A red light emitting fluorescent material was prepared by weighing CaCO3: 492 mol, Ga2O3: 300 mol, Bi2O3: 2.5 mol and Dy2O3: 1.5 mol After mixing, the mixed powder was placed in an agate mortar, and then absolute ethanol was added dropwise and ground for 30 min (the mass of the mixed powder to the volume of absolute ethanol was 1 g: 7 mL). The material was ground into a powder, and then transferred to a corundum crucible and placed in a 1100°C box furnace for high-temperature sintering. The sintering time was 10 h, the heating rate was 5°C / min, and finally the temperature was naturally lowered to room temperature to obtain the red light emitting fluorescent material.

[0031] The red light emitting fluorescent material prepared in Example 4 has a broadband emission in the range of 500-800 nm under 365 nm xenon lamp excitation, and the emission peak center is located at 578 nm, thereby emitting orange-red light.

[0032] Example 5

[0033] A red light emitting fluorescent material is prepared by mixing CaCO3: 492 mol, Ga2O3: 300 mol, Bi2O3: 2.5 mol and Sm2O3: 1.5 mol in the following proportions, placing the mixed powder in an agate mortar, adding anhydrous ethanol dropwise, grinding for 30 min (the mass of the mixed powder to the volume of anhydrous ethanol is 1 g: 7 mL), grinding until the material is in powder form, transferring the material to a corundum crucible, placing it in a box furnace at 1100°C for high-temperature sintering, sintering for 10 h at a heating rate of 5°C / min, and finally naturally cooling to room temperature.

[0034] The red light emitting fluorescent material prepared in Example 5 has broadband emission in the range of 500-800 nm under excitation by a 365 nm xenon lamp, with the emission peak center at 607 nm, thereby emitting red light.

[0035] Example 6

[0036] A red light emitting fluorescent material is prepared by mixing CaCO3: 492 mol, Ga2O3: 300 mol, Bi2O3: 2.5 mol and Tb4O7: 0.75 mol in the following proportions, placing the mixed powder in an agate mortar, adding anhydrous ethanol dropwise, grinding for 30 min (the mass of the mixed powder to the volume of anhydrous ethanol is 1 g: 7 mL), grinding until the material is in powder form, transferring the material to a corundum crucible, placing it in a box furnace at 1100°C for high-temperature sintering, sintering for 10 h at a heating rate of 5°C / min, and finally naturally cooling to room temperature.

[0037] The red light emitting fluorescent material prepared in Example 6 has broadband emission in the range of 500-800 nm under excitation by a 365 nm xenon lamp, with the emission peak center at 598 nm, thereby emitting orange-red light.

[0038] Comparative Example 1

[0039] A fluorescent material is prepared by mixing CaCO3: 499 mol, Ga2O3: 300 mol, Bi2O3: 0.5 mol in the following proportions, placing the mixed powder in an agate mortar, adding anhydrous ethanol dropwise, grinding for 30 min (the mass of the mixed powder to the volume of anhydrous ethanol is 1 g: 4 mL), grinding until the material is in powder form, transferring the material to a corundum crucible, placing it in a box furnace at 1300°C for high-temperature sintering, sintering for 6 h at a heating rate of 5°C / min, and finally naturally cooling to room temperature.

[0040] From Figure 1As can be seen from the data, the fluorescent material obtained in Comparative Example 1 has the strongest emission peak at 373 nm when excited by 286 nm light, and does not emit red or orange-red light.

[0041] Comparative Example 2

[0042] A fluorescent material is prepared by weighing CaCO3: 498 mol, Ga2O3: 300 mol, and Pr6O in the following proportions. 11 After mixing 0.167 mol, the mixed powder was placed in an agate mortar and anhydrous ethanol was added dropwise. The mixture was then ground for 30 min (the mass ratio of the mixed powder to the volume of anhydrous ethanol was 1 g: 4 mL) until the material was powdery. The material was then transferred to a corundum crucible and placed in a box furnace at 1300℃ for high-temperature sintering for 6 h at a heating rate of 5℃ / min. Finally, the material was allowed to cool naturally to room temperature to obtain the fluorescent material.

[0043] The fluorescent material obtained in Comparative Example 2 exhibits the strongest emission peak at 630 nm under 365 nm light excitation, but its red light emission is significantly weaker compared to Examples 1-6. Furthermore, the fluorescent material prepared in Comparative Example 2 emits light through Pr ions, resulting in narrow-band emission, while the red-emitting fluorescent material of this invention utilizes the influence of Pr ions on the electrons surrounding Bi ions, making Bi ions the luminescent centers for broadband emission, emitting red or orange-red light.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for producing a red light emitting fluorescent material, characterized by, The application relates to a red light emitting fluorescent material, and a preparation method thereof. The red light emitting fluorescent material is prepared by mixing CaCO3, Ga2O3, Bi2O3 and Ln2O3, adding anhydrous ethanol, grinding, and calcining. The molar ratio of CaCO3, Ga2O3, Bi2O3, the oxide of Ln is calculated as Ca 2+ : Ga 3+ : Bi 3+ : Ln 3+ = (5-x-y): 6: x: y, wherein 0 < x < 0.05, 0 < y < 0.03, Ln 3+ is Pr 3+ , Dy 3+ , Sm 3+ or Tb 3+ .

2. The method for preparing the red-emitting fluorescent material as described in claim 1, characterized in that, The total mass of CaCO3, Ga2O3, Bi2O3 and Ln2O3 is 1g, and the volume of anhydrous ethanol is (4-7)ml.

3. The method for preparing the red-emitting fluorescent material as described in claim 1, characterized in that, The calcining temperature is 1100-1300 DEG C, the time is 5-10h, and the temperature increasing rate is 5 DEG C / min.

4. The method for preparing the red-emitting fluorescent material as described in claim 1, characterized in that, The grinding time is 20-60min.

Images