A bismuth-doped yellow phosphor, its preparation method and application

Abstract

The present invention discloses a bismuth-doped yellow phosphor, a preparation method thereof and an application thereof. Among them, the chemical general formula of the bismuth-doped yellow phosphor is Ba 3‑x SbAl3Ge2O 14 :xBi 3+ , where x is the doping concentration, and the range is: 0 < x ≤ 0.3. It is prepared by the following steps: weighing raw materials according to stoichiometric ratios, grinding and mixing evenly; pre-calcining at 400 - 800 °C for 4 - 8 h, naturally cooling to room temperature, grinding and mixing evenly to obtain an intermediate product; then calcining the intermediate product at 1200 - 1600 °C for 4 - 8 h, and after naturally cooling to room temperature, grinding to obtain the bismuth-doped yellow phosphor. The yellow phosphor prepared by the present invention has an excitation range of 280 - 400 nm, an emission range of 400 - 800 nm, a peak at 545 nm, and a quantum efficiency as high as 95.3%, and has potential application value in the field of LED lighting.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and particularly relates to a bismuth-doped yellow phosphor, a preparation method thereof, and an application thereof. Background Art

[0002] Since Holonyak, N. et al. fabricated the world's first red-light-emitting semiconductor light-emitting diode (LED) using gallium phosphoarsenide (GaAsP), LEDs have received unprecedented attention. As a new technology for high efficiency and energy saving, the main application of LEDs is lighting. Currently, the lighting technology based on LEDs is becoming increasingly mature and is widely used in indoor lighting, public lighting, architectural decoration, agricultural supplementary lighting, display backlights and other fields. However, with the continuous development of society and economy, people's quality of life has been greatly improved, and correspondingly, the requirements for the lighting quality of LEDs have also been further improved. Especially in indoor lighting, people's focus has shifted from simply pursuing "high brightness" at the beginning to "high quality" that takes into account light color properties such as color temperature and color rendering index, and even to full-spectrum lighting similar to sunlight.

[0003] Currently, there are mainly two ways to achieve full-spectrum LEDs: ① combining multiple LED chips in the visible light band; ② using a single blue / ultraviolet LED chip + multi-color phosphors. Among them, the full-spectrum LEDs obtained by scheme ① are not ideal and are generally only used for making small-size lighting devices. For scheme ②, because of its advantages such as simple manufacturing method, low cost, and more continuous spectrum, it has become the mainstream method for current full-spectrum LEDs. However, the full-spectrum LED devices based on blue LED chips + multi-color phosphors have serious spectral deficiencies in the blue-green and red regions, resulting in problems such as color distortion, high color temperature, and low color rendering index. In addition, the devices also have deficiencies in the ultraviolet and blue regions smaller than the emission wavelength of the blue LED chip. Therefore, the corresponding spectrum is really unable to rival the sunlight spectrum. Obviously, the full-spectrum LED technology excited by blue LED chips does not belong to full-spectrum lighting in the strict sense. With the gradual maturity of the ultraviolet / near-ultraviolet chip technology in the third-generation semiconductors that China has focused on deploying and developing, and the continuous decline of chip costs, the full-spectrum LED technology based on ultraviolet / near-ultraviolet LED chips + multi-color phosphors conforms to the trend of the times and has broad development prospects. Phosphors, as the key materials in scheme ②, play a crucial role in full-spectrum LEDs, directly determining the lumen efficiency, light color performance, manufacturing cost, and service life of the final devices. Currently, the research on high-efficiency phosphors excited by ultraviolet / near-ultraviolet light for full-spectrum LEDs continues to be intense, but the relevant work mainly focuses on rare earth Eu 2+ , Ce 3+ -doped phosphors. Eu 2+ , Ce 3+The excitation spectra of doped phosphors usually cover the ultraviolet, blue, green, and even red light regions, which means that they have strong and broad absorption in the visible light region. When used in combination with other phosphors, luminescence reabsorption between phosphors is inevitable, so it is difficult to meet the requirements of full-spectrum lighting. Therefore, the development of phosphors that can be efficiently excited by ultraviolet / near-ultraviolet light, emit broadband light, have high quantum efficiency, and low mutual absorption between phosphors has become the research focus in the industry and an important breakthrough point for China to obtain intellectual property rights in the field of full-spectrum lighting. Summary of the Invention

[0004] The main object of the present invention is to provide a bismuth-doped yellow phosphor, its preparation method and application, aiming to solve the technical problem of luminescence reabsorption between existing phosphors.

[0005] To achieve the above object, the present invention provides a bismuth-doped yellow phosphor, and the chemical general formula of the bismuth-doped yellow phosphor is Ba 3-x SbAl3Ge2O 14 :xBi 3+ , where x is the doping concentration, and the range is: 0 < x ≤ 0.3.

[0006] Optionally, the excitation range of the bismuth-doped yellow phosphor is 280 - 400 nm, the emission range is 400 - 800 nm, and the peak is located at 545 nm.

[0007] To achieve the above object, the present invention also provides a preparation method of a bismuth-doped yellow phosphor, and the method includes the following steps:

[0008] Step 1, weigh the compounds containing Ba element, the compounds containing Sb element, the compounds containing Al element, the compounds containing Ge element, and the compounds containing Bi element according to the stoichiometric ratios of the elements in Ba 3-x SbAl3Ge2O 14 :xBi 3+ , grind and mix them evenly to obtain a mixed raw material;

[0009] Step 2, pre-calcine the obtained mixed raw material at 400 - 800 °C for 4 - 8 h, naturally cool it to room temperature, grind and mix it evenly to obtain an intermediate product;

[0010] Step 3, calcine the intermediate product at 1200 - 1600 °C for 4 - 8 h, and after naturally cooling it to room temperature, grind it to obtain the bismuth-doped yellow phosphor.

[0011] Optionally, the compound containing Ba element is one or more of barium carbonate, barium nitrate, barium acetate, barium oxalate, and barium oxide.

[0012] Optionally, the compound containing Sb element is one or more of antimony acetate, antimony trioxide, and antimony pentoxide.

[0013] Optionally, the compound containing Al element is one or more of aluminum nitrate, aluminum acetate, aluminum hydroxide, and aluminum trioxide.

[0014] Optionally, the compound containing Ge element is one or more of germanium acetate and germanium dioxide.

[0015] Optionally, the compound containing Bi element is one or more of bismuth nitrate, bismuth acetate, and bismuth trioxide.

[0016] Optionally, the Ba 3-x SbAl3Ge2O 14 :xBi 3+ The molar ratio of each element in

[0017] The molar ratio of Ba:Sb:Al:Ge:Bi is 2.997:1:3:2:0.003, and x is 0.003;

[0018] Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.985:1:3:2:0.015, and x is 0.015;

[0019] Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.970:1:3:2:0.030, and x is 0.030;

[0020] Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.940:1:3:2:0.060, and x is 0.060;

[0021] Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.910:1:3:2:0.090, and x is 0.090;

[0022] Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.880:1:3:2:0.120, and x is 0.120.

[0023] To achieve the above object, the present invention provides an application of the above-mentioned bismuth-doped yellow phosphor, and the bismuth-doped yellow phosphor is used for encapsulating an ultraviolet / near-ultraviolet LED chip to prepare an LED lighting device.

[0024] Beneficial effects:

[0025] (1) The emission peak of the bismuth-doped yellow phosphor of the present invention is located at 545 nm, and the full width at half maximum is 129 nm.

[0026] (2) The bismuth-doped yellow phosphor of the present invention has no absorption in the visible light region. When used in combination with other phosphors, it can avoid the reabsorption of luminescence between phosphors.

[0027] (3) The bismuth-doped yellow phosphor of the present invention has only one Bi 3+ luminescence center. Under the excitation of light with different wavelengths, the emission peak position and full width at half maximum remain unchanged.

[0028] (4) The quantum efficiency of the bismuth-doped yellow phosphor of the present invention is as high as 95.3%.

[0029] (5) The preparation method of the bismuth-doped yellow phosphor of the present invention is simple, the preparation conditions are easy to control, and it is conducive to industrial production.

[0030] (6) The bismuth-doped yellow phosphor of the present invention can be used for the encapsulation of ultraviolet / near-ultraviolet LED chips to prepare LED lighting devices. Description of the Drawings

[0031] Figure 1 It is the X-ray diffraction pattern and standard card of the samples corresponding to the ratios (1)-(6) in Examples 1-6.

[0032] Figure 2 It is the emission spectrum of the samples corresponding to the ratios (1)-(6) in Examples 1-6, and the excitation wavelength is 340 nm.

[0033] Figure 3 It is the excitation spectrum of the samples corresponding to the ratios (1)-(6) in Examples 1-6, and the monitoring wavelength is 545 nm.

[0034] Figure 4 It is the normalized excitation spectrum of the sample corresponding to the ratio (3) in Example 3, and the monitoring wavelength is 310-370 nm.

[0035] Figure 5 It is the normalized emission spectrum of the sample corresponding to the ratio (3) in Example 3, and the excitation wavelength is 480-740 nm.

[0036] Figure 6 It is the quantum efficiency diagram of the sample corresponding to the ratio (3) in Example 3, and the inset is a partial enlarged view. Detailed Embodiments

[0037] To make the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the following examples. However, the embodiments of the present invention are not limited thereto.

[0038] Since the test conditions of the following examples are the same, the conditions are listed below:

[0039] (1) All are carried out at room temperature.

[0040] (2) The X-ray diffraction pattern was collected by a Rigaku Ultima IV X-ray powder diffractometer in Japan. The radiation source was Cu target Kα ray. The test voltage was 40 kV, the test current was 40 mA, the scanning step was 0.02° / step, and the scanning speed was 0.12 s / step.

[0041] (3) The excitation spectrum, emission spectrum and quantum efficiency were measured by an Edinburgh FLS980 fluorescence spectrometer in the UK. The excitation light source was a 450 W xenon lamp, equipped with a time-correlated single photon counting card, a thermoelectrically cooled red-sensitive photomultiplier tube, and an integrating sphere lined with BaSO4.

[0042] The present invention provides a method for preparing a bismuth-doped yellow phosphor, and the method comprises the following steps:

[0043] Step 1, according to Ba 3-x SbAl3Ge2O 14 :xBi 3+ Weigh the compounds containing Ba element, the compounds containing Sb element, the compounds containing Al element, the compounds containing Ge element and the compounds containing Bi element according to the stoichiometric ratio of each element in it, grind and mix them evenly to obtain a mixed raw material.

[0044] Specifically, the range of x is: 0 < x ≤ 0.3. The compound containing Ba element is one or more of barium carbonate, barium nitrate, barium acetate, barium oxalate and barium oxide. The compound containing Sb element is one or more of antimony acetate, antimony trioxide and antimony pentoxide. The compound containing Al element is one or more of aluminum nitrate, aluminum acetate, aluminum hydroxide and aluminum trioxide. The compound containing Ge element is one or more of germanium acetate and germanium dioxide. The compound containing Bi element is one or more of bismuth nitrate, bismuth acetate and bismuth trioxide.

[0045] Preferably, control Ba 3-x SbAl3Ge2O 14 :xBi 3+The molar ratios of Ba:Sb:Al:Ge:Bi in each element are 2.997:1:3:2:0.003, where x is 0.003; or, the molar ratios of Ba:Sb:Al:Ge:Bi are 2.985:1:3:2:0.015, where x is 0.015; or, the molar ratios of Ba:Sb:Al:Ge:Bi are 2.970:1:3:2:0.030, where x is 0.030; or, the molar ratios of Ba:Sb:Al:Ge:Bi are 2.940:1:3:2:0.060, where x is 0.060; or, the molar ratios of Ba:Sb:Al:Ge:Bi are 2.910:1:3:2:0.090, where x is 0.090; or, the molar ratios of Ba:Sb:Al:Ge:Bi are 2.880:1:3:2:0.120, where x is 0.120.

[0046] Step 2: Pre-calcine the obtained mixed raw materials at 400 - 800 °C for 4 - 8 h, naturally cool to room temperature, grind and mix evenly to obtain an intermediate product; specifically, after grinding and mixing the mixed raw materials obtained in Step 1 evenly, load them into a corundum crucible, place the corundum crucible in a corundum boat, and put it into a high-temperature box furnace for pre-calcination at 400 - 800 °C for 4 - 8 h.

[0047] Step 3: Calcinate the intermediate product at 1200 - 1600 °C for 4 - 8 h, naturally cool to room temperature, and then grind to obtain bismuth-doped yellow phosphor.

[0048] Specifically, the luminescence principle of the bismuth-doped yellow phosphor prepared by the above steps: Bi 3+ luminescence depends on the surrounding crystal field and the coordination environment in the matrix lattice, and shows a broad spectral band of different colors from ultraviolet to red in different matrices. According to the crystallographic data, Ba3SbAl3Ge2O 14 the matrix belongs to the trigonal system, space group P321 (No.150), and the unit cell parameters are: Ba3SbAl3Ge2O 14 There are four different cation lattice sites in the matrix crystal structure, and each lattice site is occupied by a single atom, namely the Ba lattice site with eight coordination, the Sb lattice site with six coordination, the Al lattice site with four coordination, and the Ge lattice site with four coordination. According to the formula D r =(R m -R d ) / R m ×100% (where D r is the percentage of radius difference, and R m and R d are the radii of the matrix ion and the doped ion respectively), when the doped ion replaces the matrix ion, the value of D r should be less than 30%. Bi 3+ replaces Ba2+ , Sb 5+ , Al 2+ , Ge 4+ 's D r values are 17.6%, -86.67%, -138.30%, -138.30% respectively. Therefore, Bi 3+ preferentially occupies the Ba lattice site to form a Bi 3+ luminescence center. It should be particularly noted that Ba3SbAl3Ge2O 14 matrix does not emit light at room temperature, and the luminescence of the phosphor all originates from Bi 3+ .

[0049] Furthermore, in order to better illustrate the crystal structure and luminescence properties of the bismuth-doped yellow phosphor prepared by the above steps, the following specific examples are used to illustrate:

[0050] Example 1

[0051] 1) Select barium carbonate, antimony trioxide, aluminum hydroxide, germanium dioxide, and bismuth trioxide as raw materials, and weigh the five raw materials according to the molar ratio of each element. Among them, Ba:Sb:Al:Ge:Bi = 2.997:1:3:2:0.003, corresponding to x = 0.003, denoted as formulation (1);

[0052] 2) After the mixture is ground and mixed evenly, it is loaded into a corundum crucible; the corundum crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 600 °C for 4 h. Naturally cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0053] 3) Calcinate the intermediate product at 1350 °C for 6 h, and after naturally cooling to room temperature, grind to obtain the bismuth-doped yellow phosphor.

[0054] Example 2

[0055] On the basis of Example 1, modify Ba:Sb:Al:Ge:Bi = 2.985:1:3:2:0.015, corresponding to x = 0.015, denoted as formulation (2), and the others are basically the same.

[0056] Example 3

[0057] On the basis of Example 1, modify Ba:Sb:Al:Ge:Bi = 2.970:1:3:2:0.030, corresponding to x = 0.030, denoted as formulation (3), and the others are basically the same.

[0058] Example 4

[0059] On the basis of Example 1, modify Ba:Sb:Al:Ge:Bi = 2.940:1:3:2:0.060, corresponding to x = 0.060, denoted as formulation (4), and the others are basically the same.

[0060] Example 5

[0061] On the basis of Example 1, modify Ba:Sb:Al:Ge:Bi = 2.910:1:3:2:0.090, corresponding to x = 0.090, denoted as formulation (5), and the others are basically the same.

[0062] Example 6

[0063] On the basis of Example 1, modify Ba:Sb:Al:Ge:Bi = 2.880:1:3:2:0.120, corresponding to x = 0.120, denoted as formulation (6), and the others are basically the same.

[0064] Furthermore, the samples corresponding to formulations (1)-(6) in Examples 1-6 were tested and analyzed to determine the crystal structure and luminescence properties of the prepared samples.

[0065] Crystal structure:

[0066] According to the X-ray diffraction patterns of the samples corresponding to formulations (1)-(6), as Figure 1 shown, the diffraction peaks of all samples can be indexed to the Ba3SbAl3Ge2O 14 standard card. XRD pattern analysis shows that all samples are of the Ba3SbAl3Ge2O 14 phase, and bismuth doping does not introduce other phases or impurities.

[0067] Luminescence properties:

[0068] According to the emission spectra of the samples corresponding to formulations (1)-(6), the excitation wavelength is 340 nm, as Figure 2 shown, under 340 nm excitation, all samples emit yellow light, the emission peak is located at 545 nm, and the full width at half maximum is 129 nm, attributed to the 3+ of Bi 3 P1→ 1 S0 transition.

[0069] And according to the excitation spectra of the samples corresponding to formulations (1)-(6), the monitoring wavelength is 545 nm, as Figure 3 shown, all samples have absorption in the range of 280 - 400 nm, and as the Bi 3+ doping concentration increases, the position of the absorption peak does not change significantly.

[0070] And according to the normalized excitation spectrum of the sample corresponding to formulation (3), the monitoring wavelength is 480 - 740 nm, asFigure 4 As shown, as the monitoring wavelength increases, the position of the excitation peak does not change, indicating that there is only one Bi 3+ luminescence center.

[0071] And the normalized emission spectra of the samples corresponding to formulation (3), with the excitation wavelength being 310 - 370 nm, as Figure 5 shown, as the excitation wavelength increases, the position of the emission peak does not change, indicating that there is only one Bi 3+ luminescence center.

[0072] And the quantum efficiency graph of the samples corresponding to formulation (3), with the inset being a partial enlarged view, as Figure 6 shown, the calculated quantum efficiency is 95.3%.

[0073] Furthermore, on the basis of Example 1, modifications are made to prepare bismuth-doped yellow phosphors by replacing the compound types containing various elements in Examples 2 - 5. The details of the examples are as follows.

[0074] Example 7

[0075] 1) Select barium oxalate, antimony pentoxide, aluminum hydroxide, germanium dioxide, and bismuth nitrate as raw materials, with the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.910:1:3:2:0.090, corresponding to x = 0.090;

[0076] 2) Weigh the above five raw materials respectively. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 400 °C for 8 h. Naturally cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0077] 3) Calcinate the intermediate product at 1250 °C for 5 h. After naturally cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0078] The molar ratio in this example is the same as that in Example 5. The finally obtained phosphor is Ba3SbAl3Ge2O 14 phase, and bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 5.

[0079] Example 8

[0080] 1) Select barium acetate, antimony trioxide, aluminum trioxide, germanium dioxide, and bismuth acetate as raw materials, with the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.985:1:3:2:0.015, corresponding to x = 0.015;

[0081] 2) Weigh the above five raw materials separately. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 600 °C for 8 h. Naturally cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0082] 3) Calcinate the intermediate product at 1450 °C for 8 h. After naturally cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0083] The molar ratio in this example is the same as that in Example 2, and the finally obtained phosphor is Ba3SbAl3Ge2O 14 phase. Bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 2.

[0084] Example 9

[0085] 1) Select barium acetate, antimony acetate, aluminum hydroxide, germanium acetate, and bismuth trioxide as raw materials, with the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.940:1:3:2:0.060, corresponding to x = 0.060;

[0086] 2) Weigh the five raw materials separately. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 450 °C for 5 h. Naturally cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0087] 3) Calcinate the intermediate product at 1300 °C for 8 h. After naturally cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0088] The molar ratio in this example is the same as that in Example 4, and the finally obtained phosphor is Ba3SbAl3Ge2O 14 phase. Bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 4.

[0089] Example 10

[0090] 1) Select barium oxide, antimony trioxide, aluminum nitrate, germanium dioxide, and bismuth nitrate as raw materials, with the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.970:1:3:2:0.030, corresponding to x = 0.030;

[0091] 2) Weigh the five raw materials separately. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 550 °C for 6 h. Naturally cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0092] 3) Calcinate the intermediate product at 1350 °C for 4 h. After naturally cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0093] The molar ratio in this example is the same as that in Example 3, and the finally obtained phosphor is Ba3SbAl3Ge2O 14 phase. Bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 3.

[0094] Example 11

[0095] 1) Select barium carbonate, antimony trioxide, aluminum hydroxide, germanium acetate, and bismuth acetate as raw materials. According to the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.940:1:3:2:0.060, corresponding to x = 0.060;

[0096] 2) Weigh the five raw materials separately. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 800 °C for 8 h. Naturally cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0097] 3) Calcinate the intermediate product at 1300 °C for 6 h. After naturally cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0098] The molar ratio in this example is the same as that in Example 4, and the finally obtained phosphor is Ba3SbAl3Ge2O 14 phase. Bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 4.

[0099] Example 12

[0100] 1) Select barium nitrate, antimony acetate, aluminum acetate, germanium dioxide, and bismuth trioxide as raw materials. According to the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.910:1:3:2:0.090, corresponding to x = 0.090;

[0101] 2) Weigh the five raw materials separately. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-calcine at 400 °C for 8 h. Cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0102] 3) Calcinate the intermediate product at 1200 °C for 7 h. After naturally cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0103] The molar ratio in this example is the same as that in Example 5, and the finally obtained phosphor is Ba3SbAl3Ge2O 14 phase. Bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 5.

[0104] Example 13

[0105] 1) Select barium carbonate, antimony pentoxide, aluminum hydroxide, germanium acetate, and bismuth trioxide as raw materials, with the molar ratio of each element Ba:Sb:Al:Ge:Bi = 2.970:1:3:2:0.030, corresponding to x = 0.030;

[0106] 2) Weigh the five raw materials separately. After the mixture is ground and mixed evenly, it is loaded into a corundum crucible. The crucible is placed in a corundum boat and then put into a high-temperature box furnace. Pre-burn at 500 °C for 8 h. Cool to room temperature, grind and mix evenly to obtain an intermediate product;

[0107] 3) Calcinate the intermediate product at 1400 °C for 6 h. After natural cooling to room temperature, grind to obtain bismuth-doped yellow phosphor.

[0108] The molar ratio in this example is the same as that in Example 3, and the finally obtained phosphor is Ba3SbAl3Ge2O 14 phase. Bismuth doping does not introduce other phases or impurities, and the luminescence properties are similar to those in Example 3.

[0109] In summary, it should be noted that the above are only the preferred embodiments of the present invention, but the implementation manners of the present invention are not limited by the described embodiments. It should be pointed out that for those of ordinary skill in the art, any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principle of the present invention should be equivalent replacement methods and all fall within the protection scope of the present invention.

Claims

1. A bismuth-doped yellow phosphor, characterized in that, The chemical general formula of the bismuth-doped yellow phosphor is Ba 3- x SbAl3Ge2O 14 :xBi 3+ , where x is the doping concentration, and the range is: 0 < x ≤ 0.

3.

2. The bismuth-doped yellow phosphor according to claim 1, wherein The excitation range of the bismuth-doped yellow phosphor is 280-400 nm, the emission range is 400-800 nm, and the peak is located at 545 nm.

3. A method for preparing the bismuth-doped yellow phosphor according to claim 1 or 2, characterized in that, The method includes the following steps: Step 1, according to Ba 3-x SbAl3Ge2O 14 :xBi 3+ Weigh the compounds containing Ba element, Sb element, Al element, Ge element and Bi element according to the stoichiometric ratios of the elements in it, grind and mix them evenly to obtain a mixed raw material; Step 2, pre-calcine the obtained mixed raw materials at 400-800 °C for 4-8 h, naturally cool to room temperature, grind and mix evenly to obtain an intermediate product; Step 3, calcine the intermediate product at 1200-1600 °C for 4-8 h, naturally cool to room temperature, and then grind to obtain the bismuth-doped yellow phosphor.

4. The preparation method of the bismuth-doped yellow phosphor according to claim 3, wherein, The compound containing Ba element is one or more of barium carbonate, barium nitrate, barium acetate, barium oxalate and barium oxide.

5. The preparation method of the bismuth-doped yellow phosphor according to claim 3, wherein, The compound containing Sb element is one or more of antimony acetate, antimony trioxide and antimony pentoxide.

6. The preparation method of the bismuth-doped yellow phosphor according to claim 3, wherein, The compound containing Al element is one or more of aluminum nitrate, aluminum acetate, aluminum hydroxide and aluminum oxide.

7. The preparation method of the bismuth-doped yellow phosphor according to claim 3, characterized in that, The compound containing Ge element is one or more of germanium acetate and germanium dioxide.

8. The preparation method of the bismuth-doped yellow phosphor according to claim 3, wherein, The compound containing Bi element is one or more of bismuth nitrate, bismuth acetate and bismuth trioxide.

9. The preparation method of the bismuth-doped yellow phosphor according to any one of claims 3 to 8, characterized in that, The Ba 3-x SbAl3Ge2O 14 :xBi 3+ The molar ratio of each element in The molar ratio of Ba:Sb:Al:Ge:Bi is 2.997:1:3:2:0.003, and x is 0.003; Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.985:1:3:2:0.015, and x is 0.015; Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.970:1:3:2:0.030, and x is 0.030; Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.940:1:3:2:0.060, and x is 0.060; Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.910:1:3:2:0.090, and x is 0.090; Or, the molar ratio of Ba:Sb:Al:Ge:Bi is 2.880:1:3:2:0.120, and x is 0.

120.

10. Use of the bismuth-doped yellow phosphor according to claim 1 or 2, characterized in that, The bismuth-doped yellow phosphor is used for encapsulating ultraviolet / near-ultraviolet LED chips to prepare LED lighting devices.

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