Sodium terbium gallium indium germanium garnet-based red light fluorescent powder and preparation method thereof

Abstract

The invention discloses red light NaTb2Ga2InGe2O12: Sm < 3 + > fluorescent powder and a preparation method thereof. The invention relates to red light NaTb2Ga2InGe2O12: Sm < 3 + > fluorescent powder, the chemical composition expression formula of the fluorescent powder is NaTb2-2xGa2InGe2O12: 2xSm < 3 + >, x is the doping amount of Sm < 3 + > ions, x is not less than 0.90 and not more than xlt; 1. The red light NaTb2Ga2InGe2O12: Sm < 3 + > fluorescent powder provided by the invention can be efficiently excited by near ultraviolet light with the wavelength of 365 to 385 nm, 400 to 410 nm and blue light with the wavelength of 475 to 500 nm, and can emit red light with the strongest main peak of 616 nm, meanwhile, the fluorescent powder is accompanied with multi-peak narrow-band light emission in a range from 565 to 660 nm to dark red light, and the color coordinate of the fluorescent powder can reach (0.5939, 0.4028).

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a red light emitting NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor and preparation method thereof. Background Art

[0002] There are two main categories of designs for mainstream white light LED devices: those based on the combination of near-ultraviolet LED chips and three-primary color (blue, green, and red) phosphors, and those based on the combination of visible blue LED chips and yellow YAG phosphors. The former can obtain high-quality white light by selecting three-primary color phosphors. However, the latter often requires the addition of red phosphors to compensate for the lack of red light components in YAG phosphors. Therefore, no matter which design is chosen, red phosphors are still crucial to obtaining high-quality LED white light.

[0003] Sm 3+ It is an activator of common inorganic red phosphors. In different inorganic compound systems, it can obtain narrow-band luminescence in the spectral region from orange to red. 3+ of 4 G 5 / 2 - 6 H 7 / 2 The transition luminescence (corresponding to a wavelength of 615±10nm) will be extremely intense, and is a high-quality red light that can effectively improve the color rendering index of white light LED devices. 3+ The main excitation peak (generally located around 405nm) that can be provided by its own energy level is relatively narrow, and its half-peak width is often less than 10nm, resulting in a low effective utilization rate of the excitation light. 3+ Get extra Tb 3+ The excitation spectrum characteristics of will solve the above problems. In the prior art, there are reports on terbium and samarium energy transfer, such as Ba 3 MgSi 2 O 8 :Tb 3+ ,Sm 3+ , Ba 3 La(PO 4 ) 3 :Tb 3+ ,Sm 3+ However, the terbium in the phosphor exists in the form of doped ions, and the total amount in the phosphor is limited. 3+It exists as a role of the matrix constituent elements, and its high content ensures that the material has sufficient absorption and utilization efficiency for near-ultraviolet light in the 365 - 385 nm and 400 - 410 nm regions and blue light in the 475 - 500 nm region, and finally obtains high-brightness Sm 3+ Characteristic red light. Summary of the Invention

[0004] The present invention provides a red-light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ phosphor and its preparation method. The red-light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ phosphor material can be efficiently excited by near-ultraviolet light of 365 - 385 nm, 400 - 410 nm and blue light of 475 - 500 nm, emit red light with the strongest main peak at 616 nm, and at the same time be accompanied by multi-peak narrow-band luminescence in the orange to deep red light region of 565 - 660 nm, and its color coordinates can reach (0.5939, 0.4028).

[0005] The purpose of the present invention is to propose a red-light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ phosphor, and its chemical composition formula is: NaTb 2-2x Ga 2 InGe 2 O 12 :2xSm 3+ , where x is the doping amount of Sm 3+ ions, and 0 < x ≤ 0.05.

[0006] Another purpose of the present invention is to propose a preparation method of the above-mentioned red-light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ phosphor, including the following steps: Weigh raw materials containing sodium, terbium, gallium, indium, germanium and samarium elements according to the chemical composition respectively. Among them, the molar ratio of the elements is Na:Tb:Ga:In:Ge:Sm = 1:2 - 2x:2:1:2:2x, where 0 < x ≤ 0.05. Then, according to the high or low experimental temperature, an additional amount of Ga 2 O 3 and In 2 O3 It is used to compensate for the loss of Ga and In during the high-temperature reaction. The mixture is fully ground to make it uniform and placed in a reaction container. It is sintered in a normal pressure air atmosphere and then cooled to room temperature. The product is ground to obtain the red light NaTb. 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor.

[0007] The red light NaTb proposed by the present invention 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor uses terbium and samarium energy transfer to make Sm 3+ Additional Tb 3+ The excitation spectrum characteristics of Tb 3+ As a matrix component, its high content ensures that the material has sufficient absorption utilization rate for near-ultraviolet light in the 365-385nm, 400-410nm region and blue light in the 475-500nm region, and finally obtains high-brightness Sm 3+ Characteristic red light.

[0008] Preferably, the raw material containing sodium element is selected from one or more of sodium carbonate, sodium bicarbonate and sodium oxalate.

[0009] Preferably, the raw material containing terbium element is selected from at least one of terbium oxide, terbium oxalate, terbium carbonate and terbium nitrate.

[0010] Preferably, the raw material containing gallium element is selected from gallium oxide.

[0011] Preferably, the raw material containing the indium element is selected from indium oxide.

[0012] Preferably, the raw material containing germanium element is selected from germanium oxide.

[0013] Preferably, the raw material containing samarium element is selected from at least one of samarium oxide, samarium oxalate, samarium carbonate and samarium nitrate.

[0014] Preferably, the sintering steps are as follows: sintering in one step, at a temperature of 1100-1300°C, for 4-6 hours, at a heating rate of 5°C / min, and during the reaction, Ga 2 O 3 WithIn 2 O 3 The use of requires a superstoichiometric ratio to compensate for the loss of Ga and In during the high-temperature reaction.

[0015] The present invention also protects the above-mentioned red light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Application of phosphor in light-emitting devices: The orange-yellow phosphor proposed in the present invention has a wide effective excitation range and a wide emission coverage range, and can be applied in the field of solid-state white light LED lighting and display.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) Red light NaTb proposed in the present invention 2 Ga 2 InGe 2 O 12 :Sm 3+ The phosphor only needs one step of sintering to be completed. The reaction process does not require a reducing atmosphere. The reaction temperature is low, the phase formation time is short, the production and preparation threshold is low, and it is easy to industrialize.

[0018] (2) Red light NaTb proposed in the present invention 2 Ga 2 InGe 2 O 12 :Sm 3+ The phosphor material can be efficiently excited by 365-385nm, 400-410nm near-ultraviolet light and 475-500nm blue light, emitting red light with the strongest main peak at 616nm, accompanied by multi-peak narrow-band emission in the 565-660nm orange to deep red region, and its color coordinates can reach (0.5939, 0.4028). Due to its wide excitation range and excellent red light peak position, it can be used in solid-state white light LED lighting and display fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The red light NaTb prepared in Example 1 2 Ga 2 InGe 2 O 12 :Sm 3+ X-ray powder diffraction pattern of phosphor;

[0020] Figure 2 The red light NaTb prepared in Example 1 2 Ga 2 InGe 2 O 12 :Sm 3+ Fluorescence emission spectrum of phosphor;

[0021] Figure 3 The red light NaTb prepared in Example 12 Ga 2 InGe 2 O 12 :Sm 3+ Fluorescence excitation emission spectrum of phosphor;

[0022] Figure 4 The red light NaTb prepared in Example 1 2 Ga 2 InGe 2 O 12 :Sm 3+ Chromaticity coordinates of phosphor. DETAILED DESCRIPTION

[0023] The following examples are provided to further illustrate the present invention, but are not intended to limit the present invention. Unless otherwise specified, the equipment and reagents used in the present invention are conventional commercial products in the art.

[0024] Example 1

[0025] Weigh sodium carbonate (Na 2 CO 3 )0.0265g, terbium oxide (Tb 4 O 7 )0.1832g, gallium oxide (Ga 2 O 3 )0.1031g, indium oxide (In 2 O 3 )0.0763g, germanium oxide (GeO 2 )0.1046g, samarium oxide (Sm 2 O 3 )0.0035g, grind the above raw materials in an agate mortar, grind them evenly, and then conduct solid phase reaction. In a normal pressure air atmosphere, heat the temperature from room temperature to 1200℃ at a rate of 5℃ / min, keep the temperature constant for 4h, and then cool it naturally. Grind it evenly to obtain red light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor.

[0026] Example 2

[0027] Weigh sodium carbonate (Na 2 CO 3 )0.0265g, terbium oxide (Tb 4 O 7 )0.1776g, gallium oxide (Ga 2 O 3 )0.1031g, indium oxide (In 2O 3 )0.0763g, germanium oxide (GeO 2 )0.1046g, samarium oxide (Sm 2 O 3 )0.0087g, grind the above raw materials in an agate mortar, grind them evenly, and then conduct solid phase reaction. In a normal pressure air atmosphere, heat the temperature from room temperature to 1200℃ at a rate of 5℃ / min, keep the temperature constant for 4h, and then cool it naturally. Grind it evenly to obtain red light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor.

[0028] Example 3

[0029] Weigh sodium carbonate (Na 2 CO 3 )0.0265g, terbium oxide (Tb 4 O 7 )0.1850g, gallium oxide (Ga 2 O 3 )0.1031g, indium oxide (In 2 O 3 )0.0763g, germanium oxide (GeO 2 )0.1046g, samarium oxide (Sm 2 O 3 )0.0017g, grind the above raw materials in an agate mortar, grind them evenly, and then conduct solid phase reaction. In a normal pressure air atmosphere, heat the temperature from room temperature to 1200℃ at a rate of 5℃ / min, keep the temperature constant for 4h, and then cool it naturally. Grind it evenly to obtain red light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor.

[0030] Example 4

[0031] Weigh sodium bicarbonate (NaHCO 3 )0.0420g, terbium oxide (Tb 4 O 7 )0.1832g, gallium oxide (Ga 2 O 3 )0.1031g, indium oxide (In 2 O 3 )0.0763g, germanium oxide (GeO 2 )0.1046g, samarium oxide (Sm 2 O3 )0.0035g, grind the above raw materials in an agate mortar, grind them evenly, and then conduct solid phase reaction. In a normal pressure air atmosphere, heat the temperature from room temperature to 1100°C at a rate of 5°C / min, keep the temperature constant for 6h, and then cool it naturally. Grind it evenly to obtain red light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor.

[0032] Example 5

[0033] Weigh sodium bicarbonate (NaHCO 3 )0.0420g, terbium oxide (Tb 4 O 7 )0.1832g, gallium oxide (Ga 2 O 3 )0.1031g, indium oxide (In 2 O 3 )0.0763g, germanium oxide (GeO 2 )0.1046g, samarium oxide (Sm 2 O 3 )0.0035g, grind the above raw materials in an agate mortar, grind them evenly, and then conduct solid phase reaction. In a normal pressure air atmosphere, heat the temperature from room temperature to 1300℃ at a rate of 5℃ / min, keep the temperature constant for 4h, and then cool it naturally. Grind it evenly to obtain red light NaTb 2 Ga 2 InGe 2 O 12 :Sm 3+ Phosphor.

[0034] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A red light NaTb2Ga2InGe2O 12 :Sm 3+ Phosphor, its chemical composition is expressed as: NaTb 2-2x Ga2InGe2O 12 :2xSm 3+ , x is Sm 3+ Ion doping amount, where: 0<x≤0.05。 2. The red light NaTb2Ga2InGe2O according to claim 1 12 :Sm 3+ The method for preparing phosphor is characterized in that: It includes the following steps: Weigh the raw materials containing sodium, terbium, gallium, indium, germanium and samarium respectively according to their chemical compositions. Among them, the molar ratio of the elements is Na:Tb:Ga:In:Ge:Sm = 1:2 - 2x:2:1:2:2x, where 0 < x ≤ 0.

05. Then, according to the temperature of the experiment, an appropriate amount of Ga2O3 and In2O3 are additionally added to compensate for the loss of Ga and In during the high-temperature reaction. Grind them充分研磨使其混合均匀 and put them into a reaction vessel, sinter them in an atmospheric air atmosphere, and then cool them to room temperature. Grind the product to obtain the red-light NaTb2Ga2InGe2O 12 :Sm 3+ phosphor.

3. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The method for preparing phosphor is characterized in that: The raw material containing sodium element is selected from at least one of sodium carbonate, sodium bicarbonate and sodium oxalate.

4. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The preparation method is characterized in that The raw material containing terbium element is selected from at least one of terbium oxide, terbium oxalate, terbium carbonate and terbium nitrate.

5. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The method for preparing phosphor is characterized in that: The raw material containing gallium element is selected from gallium oxide.

6. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The method for preparing phosphor is characterized in that: The raw material containing indium element is selected from indium oxide.

7. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The method for preparing phosphor is characterized in that: The raw material containing germanium element is selected from germanium oxide.

8. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The method for preparing phosphor is characterized in that: The raw material containing samarium element is selected from at least one of samarium oxide, samarium oxalate, samarium carbonate and samarium nitrate.

9. The red light NaTb2Ga2InGe2O according to claim 2 12 :Sm 3+ The method for preparing phosphor is characterized in that: The specific sintering steps are: only one-step sintering, the temperature is 1150-1250°C, the time is 4-6h, the heating rate is 5°C / min, and the use of Ga2O3 and In2O3 in the reaction process requires a superstoichiometric ratio to compensate for the loss of Ga and In during the high-temperature reaction.

10. The red light NaTb2Ga2InGe2O according to claim 1 12 :Sm 3+ Application of phosphors in light-emitting devices.

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