An ultranarrow-band purple light fluorescent powder, a preparation method and application thereof

Abstract

The application discloses a kind of super narrow band purple light fluorescent powder, its chemical general formula is A2M (PO3) 4:zEu 2+ Wherein, A is one or more of Na, K, M is one or more of Ca, Sr, Ba;Super narrow band refers to the half-height width of fluorescent powder emission spectrum is less than 25nm.The application also discloses the preparation method of the super narrow band purple light fluorescent powder, including the following steps: raw material ball milling, slow pre-calcination, multi-section heat preservation and finally increase to 200~350 DEG C, cooling grinding;Finally, under reducing atmosphere, 550~700 DEG C is synthesized, after cooling grinding.The application further discloses the application of the super narrow band purple light fluorescent powder in display device and temperature sensing.The fluorescent powder obtained in the application is super narrow band purple light emission under near ultraviolet light excitation, high color purity, high luminous efficiency, good chemical stability;The production process of fluorescent powder is simple, synthesis temperature is low, green and environmental protection.

Description

Technical Field

[0001] This invention belongs to the field of rare earth luminescent materials technology, specifically an ultra-narrow band violet phosphor and its preparation method and application. Background Technology

[0002] With the development of technology, fluorescent materials are being used more and more widely in lighting, display technology, and biomarking. As an important optical material, the performance of phosphors directly affects the luminous efficacy, color reproduction, and lifespan of the final product. The demand for phosphors is particularly increasing in high-performance display technologies and high-efficiency lighting equipment.

[0003] Currently, various types of phosphors exist on the market, and these phosphors can be widely used in different fields based on their different excitation and emission spectra. Ultra-narrow-band violet phosphors, due to their high color purity and specific emission wavelengths, are considered materials with great potential in high-quality displays and special lighting. However, despite the obvious advantages of these materials, many challenges remain in practical applications. Existing violet phosphors (emission spectral range 380–450 nm, emission peak position 390–425 nm) have relatively wide half-widths (HWHMs), generally greater than 33 nm. These mainly include: α-Sr₂SiO₄:Ce 3+ / K + The emission peak is at 425 nm, and the full width at half maximum (FWHM) is 65.5 nm; NaSrBO3:Ce 3+ The emission peak is at 422 nm, and the full width at half maximum (FWHM) is 70 nm; KSrPO4:Eu 2+ The emission peak is at 428 nm, and the full width at half maximum (FWHM) is 35 nm; KBaPO4:Eu 2+ The emission peak is at 425 nm, and the full width at half maximum (FWHM) is 45 nm; K2BaSr(PO4)2:Eu 2+ The emission peak is at 428 nm, and the full width at half maximum (FWHM) is 38 nm; Na2BaSr(PO4)2:Eu 2+ The emission peak is at 428 nm, and the full width at half maximum (FWHM) is 62 nm; Ca3(PO4)2:Eu 2+ The emission peak is at 413 nm, and the full width at half maximum (FWHM) is 39 nm; Sr3(PO4)2:Eu 2+ The emission peak is at 416 nm, and the full width at half maximum (FWHM) is 41 nm; Ca8Mg7Si9N 22 Eu 2+ The emission peak is at 400nm, and the full width at half maximum (FWHM) is 34nm.

[0004] However, ultra-narrowband violet phosphors with a half-width at half-maximum (HWHM) of less than 25 nm are rarely reported. On the one hand, the wider the emission spectrum of a phosphor, the lower its color purity, limiting its application in high-end displays and precision lighting. On the other hand, the synthesis temperature of existing violet phosphors is generally high; orthophosphate phosphors typically require 1000–1500°C, while nitride phosphors require even higher temperatures exceeding 1700°C, resulting in high costs, high energy consumption, and demanding production equipment requirements. To address these issues, this invention aims to solve the problems of poor violet display capability, low color purity, high synthesis temperature, and high energy consumption in existing technologies through the development of a novel ultra-narrowband violet phosphor. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide an ultra-narrowband violet phosphor with high luminous efficiency, good chemical stability, high color purity and excellent temperature sensitivity. Another purpose of this invention is to provide a simple, convenient, low-cost and environmentally friendly method for preparing ultra-narrowband violet phosphor. A further purpose of this invention is to provide an application of ultra-narrowband violet phosphor in display devices and temperature sensors.

[0006] Technical solution: The present invention provides an ultra-narrow band ultraviolet phosphor with the general chemical formula A2M(PO3)4:zEu 2+ Where A is one or more of Na and K, M is one or more of Ca, Sr, and Ba, and the value of z ranges from 0.001 to 0.12; ultra-narrow band refers to the full width at half maximum (FWHM) of the phosphor emission spectrum being less than 25 nm. More preferably, 0.01 ≤ z ≤ 0.03.

[0007] Preferably, its general chemical formula is (K 1-x Na x )2(Sr 1-y Ca y (PO3)4:zEu 2+ Where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1. More preferably, 0 ≤ x ≤ 0.5, 0 ≤ y ≤ 0.8. More preferably, 0 ≤ x ≤ 0.2, 0.1 ≤ y ≤ 0.4, 0.01 ≤ z ≤ 0.03.

[0008] Preferably, its general chemical formula is (K 1-x Na x )2(Sr 1-y Ba y (PO3)4:zEu 2+ Where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1. More preferably, 0 ≤ x ≤ 0.5, 0 ≤ y ≤ 0.8, 0.001 ≤ z ≤ 0.12. More preferably, 0 ≤ x ≤ 0.2, 0.2 ≤ y ≤ 0.6, 0.01 ≤ z ≤ 0.03.

[0009] Preferably, its general chemical formula is (K 1-x Na x )2Sr(PO3)4:0.015Eu 2+ , 0.1≤x≤0.5.

[0010] Furthermore, the emission spectrum of the phosphor has a wavelength range of 390–450 nm, with a peak position at 415–420 nm.

[0011] The preparation method of the above-mentioned ultranarrowband violet phosphor includes the following steps:

[0012] Step 1, according to the general formula A2M(PO3)4:zEu 2+ The raw materials, including potassium-containing compounds, sodium-containing compounds, calcium-containing compounds, strontium-containing compounds, barium-containing compounds, phosphorus-containing compounds, and europium-containing compounds, were weighed according to the stoichiometric ratio and then ball-milled to mix them thoroughly and evenly.

[0013] Step 2: Transfer the contents obtained in Step 1 into a crucible and slowly pre-calcine it in an air atmosphere. Hold it at multiple temperature ranges of 70-200°C, and finally raise it to the pre-calcine temperature of 200-350°C and hold it thereafter. After cooling down, grind it to make it evenly mixed.

[0014] Step 3: The product obtained in Step 2 is synthesized in a reducing atmosphere at 550-700℃, kept at this temperature, and then taken out and ground after natural cooling to obtain ultra-narrow band violet phosphor.

[0015] In step one, the potassium-containing compound is one or more of potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium dihydrogen phosphate, or potassium nitrate; the sodium-containing compound is one or more of sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium dihydrogen phosphate, or sodium nitrate; the strontium-containing compound is one or more of strontium hydroxide, strontium carbonate, strontium phosphate, strontium hydrogen phosphate, or strontium nitrate; the calcium-containing compound is one or more of calcium hydroxide, calcium oxide, calcium carbonate, calcium phosphate, calcium hydrogen phosphate, or calcium nitrate; the barium-containing compound is one or more of barium hydroxide, barium oxide, barium carbonate, barium phosphate, barium hydrogen phosphate, or barium nitrate; the phosphorus-containing compound is one or more of diammonium hydrogen phosphate or diammonium dihydrogen phosphate; and the europium-containing compound is europium oxide or europium nitrate.

[0016] Preferably, the potassium-containing compound is K2CO3 or KOH, the sodium-containing compound is NaCO3 or NaOH, the strontium-containing compound is SrCO3 or Sr(NO3)2, the calcium-containing compound is Ca(OH)2 or CaCO3, the barium-containing compound is Ba(NO3)2 or BaCO3, the phosphorus-containing compound is NH4H2PO4, and the europium-containing compound is Eu2O3 or Eu(NO3)3.

[0017] Furthermore, in step two, the pre-calcination heating rate is 0.1–1 °C / min, and the temperature is maintained at each of the multiple holding stages for 10–60 minutes. Finally, the temperature is raised to the pre-calcination temperature of 200–350 °C and held for 2–24 hours.

[0018] Preferably, in step two, the final pre-calcination temperature is 250–300°C, and the calcination time is 4–8 hours.

[0019] Furthermore, in step three, the reducing atmosphere is one or more of nitrogen, hydrogen, argon, ammonia, and carbon monoxide. The holding time is 2–24 hours.

[0020] Preferably, in step three, the synthesis is carried out at 600–650°C for 4–8 hours.

[0021] Applications of the aforementioned ultra-narrowband violet phosphor in display devices and temperature sensors.

[0022] The application of display devices includes the following steps: mixing phosphor with high-purity green phosphor and red phosphor evenly, and then encapsulating it with a near-ultraviolet LED chip with an emission peak wavelength in the range of 330-385nm to produce a white LED device.

[0023] Furthermore, green phosphors can be used for Sr3Si 13 Al3O2N 21 Eu 2+ Red phosphors can be CaAlSiN3:Eu 2+ and K2SiF6:Mn 4+ .

[0024] When using the same green and red phosphors, white LED devices obtained by using the phosphors described in this invention as backlights for liquid crystal displays have a significantly wider color gamut.

[0025] Temperature sensing applications include the following steps: mixing a phosphor with another phosphor that has excellent fluorescent thermal stability and whose emission spectrum has little overlap with the emission spectrum of the phosphor described in this invention, thereby obtaining a fluorescent material with excellent temperature sensing performance.

[0026] Temperature measurement principle: The emission spectrum of the phosphor is collected at different temperatures (T), and the luminescence intensity value I at two peak positions (x nm and y nm) is directly read. x Value and I y The fluorescence intensity ratio (FIR = I) at various temperatures was obtained. x / I y This allows us to obtain a curve showing the fitting relationship between fluorescence intensity ratio (FIR) and temperature (T).

[0027] Temperature measurement method: Acquire spectral data of the fluorescent temperature sensing material under the conditions of the environment to be tested, and read the peak intensity (I0). x and I y The FIR value can be obtained, and temperature measurement and sensing can be performed based on the relationship curve.

[0028] Based on the temperature response characteristics of the phosphor described in this invention, its application in fluorescence temperature sensing not only features a simple testing method, eliminating the need for reference calibration and exhibiting self-calibrating temperature measurement characteristics, but also high accuracy and excellent sensitivity. Its application is unaffected by the ratio and amount of the two phosphors, as well as by environmental electromagnetic fields, the model of the testing instrument, and the intensity of the light source.

[0029] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0030] 1. The obtained phosphor exhibits ultra-narrow band violet light emission under near-ultraviolet light excitation, with high color purity, high luminous efficiency, and good chemical stability;

[0031] 2. The production process of phosphors is simple, the synthesis temperature is low, it is green and environmentally friendly, and the energy consumption is low;

[0032] 3. Phosphors have good application effects in display devices and temperature sensing fields. Attached Figure Description

[0033] Figure 1 These are the powder diffraction patterns of the ultranarrow band violet phosphors obtained in Examples 1-7 of this invention;

[0034] Figure 2 These are the excitation and emission spectra of the ultranarrowband violet phosphor obtained in Example 1 of this invention;

[0035] Figure 3 These are the emission spectra of the ultranarrowband violet phosphors obtained in Examples 1 to 7 of this invention;

[0036] Figure 4 These are the powder diffraction patterns of the ultranarrow band violet phosphors obtained in Examples 8-13 of this invention;

[0037] Figure 5 These are the emission spectra of the ultranarrowband violet phosphors obtained in Examples 8-13 of this invention;

[0038] Figure 6 The emission spectra of the ultranarrowband violet phosphors obtained in Examples 14-18 of this invention are shown.

[0039] Figure 7 The emission spectra of the ultranarrowband violet phosphors obtained in Examples 19-23 of this invention are shown.

[0040] Figure 8This is a color gamut comparison diagram of the white LED devices in Application Example 1 and Comparative Example 1 of the present invention;

[0041] Figure 9 This is a color gamut comparison diagram of the white LED devices in Application Example 3 and Comparative Example 2 of the present invention;

[0042] Figure 10 This is the temperature measurement curve of the fluorescent temperature sensing material in Application Example 4 of the present invention;

[0043] Figure 11 These are the relative and absolute sensitivity curves of the fluorescent temperature sensing material in Application Example 4 of this invention. Detailed Implementation

[0044] Unless otherwise specified, the experimental methods described in the examples are conventional methods; reagents and materials, unless otherwise specified, are commercially available. In the following examples, high purity refers to the purity of the raw materials being not less than 99.5%.

[0045] Example 1

[0046] An ultra-narrowband violet phosphor, the chemical composition of which is K2Sr(PO3)4:zEu 2+ The z-value is 0.005, and its preparation method includes the following steps:

[0047] (1) Accurately weigh high-purity raw material powders of K2CO3, SrCO3, NH4H2PO4 and Eu2O3 according to the stoichiometric ratio, and use planetary ball milling to fully mix the raw materials.

[0048] (2) Transfer the raw material mixture to a corundum crucible, place it in a muffle furnace, and slowly pre-calcine it in an air atmosphere. Slowly raise the temperature to 100, 150 and 200°C and hold for 30 minutes each time. Then, hold it at the final pre-calcine temperature of 300°C for 4 hours. The heating rate is 0.5°C / minute. After cooling, take out the sample and grind it evenly again.

[0049] (3) The ground powder was transferred to a high-temperature atmosphere reactor and synthesized at 650°C for 4 hours under a mixture of hydrogen and argon. After natural cooling, it was taken out and ground to obtain ultra-narrow band purple phosphor.

[0050] Example 2

[0051] The remaining steps in this embodiment are the same as in Embodiment 1, except that the z value is 0.01.

[0052] Example 3

[0053] The remaining steps in this embodiment are the same as in Embodiment 1, except that the z value is 0.025.

[0054] Example 4

[0055] The remaining steps in this embodiment are the same as in Embodiment 1, except that the z value is 0.04.

[0056] Example 5

[0057] The remaining steps in this embodiment are the same as in Embodiment 1, except that the z value is 0.06.

[0058] Example 6

[0059] The remaining steps in this embodiment are the same as in Embodiment 1, except that the z value is 0.09.

[0060] Example 7

[0061] The remaining steps in this embodiment are the same as in Embodiment 1, except that the z value is 0.12.

[0062] The phase structure of the phosphor was analyzed using a D2 Phaser X-ray diffractometer (Bruker, Germany). The powder diffraction patterns of the ultranarrow-band violet phosphors obtained in Examples 1-7 are shown below. Figure 1 The ultranarrowband violet phosphors prepared in Examples 1-7 were subjected to fluorescence spectroscopy testing using an Edinburgh FS5 fluorescence spectrometer equipped with an SC-30 integrating sphere module. The excitation and emission spectra of the ultranarrowband violet phosphor prepared in Example 1 are shown below. Figure 2 The emission spectra of the ultranarrowband violet phosphors prepared in Examples 1-7 are shown below. Figure 3 .

[0063] Examples 1-7 illustrate the ultranarrowband ultraviolet phosphor K2Sr(PO3)4:zEu of the present invention. 2+ The influence of the z-value range on the luminescence properties and full width at half maximum (FWHM) of the powder emission spectrum. Figures 1-3 It can be seen that the emission peak position of the phosphors in Examples 1 to 7 is 418 nm, the half width at half maximum (WHM) of the emission spectrum of the phosphors obtained in Examples 1 to 6 is 21 nm, and the color purity is 99.4%; the half width at half maximum (WHM) of the emission spectrum of the phosphor obtained in Example 7 is 22 nm, and the color purity is 99.3%.

[0064] Example 8

[0065] An ultra-narrowband violet phosphor with the chemical composition K2(Sr) 1-y Ca y (PO3)4:0.025Eu 2+ y = 0.1, its preparation method includes the following steps:

[0066] (1) Accurately weigh the high-purity raw material powders of Ca(OH)2, Sr(NO3)2, K2CO3, NH4H2PO4 and Eu2O3 according to the stoichiometric ratio, and use planetary ball milling to fully mix the raw materials.

[0067] (2) Transfer the raw material mixture to a corundum crucible, place it in a muffle furnace, and perform slow pre-calcination in an air atmosphere. Slowly raise the temperature to 70℃, 100℃, 130℃, 170℃ and 200℃, and hold for 30 minutes at each temperature. Then, hold at the final pre-calcination temperature of 300℃ for 4 hours. The heating rate is 0.5℃ / min. After cooling, take out the sample and grind it again until uniform.

[0068] (3) The ground powder was transferred to a high-temperature atmosphere reactor and calcined at 600°C for 6 hours under a mixture of hydrogen and nitrogen. After natural cooling, it was taken out and ground to obtain ultra-narrow band purple phosphor.

[0069] Example 9

[0070] The remaining steps in this embodiment are the same as in embodiment 8, except that y = 0.2.

[0071] Example 10

[0072] The remaining steps in this embodiment are the same as in embodiment 8, except that y = 0.3.

[0073] Example 11

[0074] The remaining steps in this embodiment are the same as in embodiment 8, except that y = 0.4.

[0075] Example 12

[0076] The remaining steps in this embodiment are the same as in embodiment 8, except that y = 0.6.

[0077] Example 13

[0078] The remaining steps in this embodiment are the same as in embodiment 8, except that y = 0.8.

[0079] Examples 8-13 are provided to better illustrate the preparation and performance of ultranarrow-band violet phosphors with different Sr and Ca solid solution ratios in this invention. The powder diffraction patterns of the ultranarrow-band violet phosphors obtained in Examples 8-13 are shown below. Figure 4 Its emission spectrum is shown in Figure 5 .

[0080] Depend on Figures 4-5It can be seen that the phosphors obtained in Examples 8 to 13, when excited by excitation light at 336 nm, have emission peaks at 417, 417, 417, 418, 418 and 418 nm, respectively. The half-width at half maximum (WHM) of the emission spectra of the phosphors obtained in Examples 8 to 13 is 23 nm, and the color purity is 99%. The half-width at half maximum (WHM) of the emission spectrum of the phosphor obtained in Example 7 is 22.5 nm, and the color purity is 99.1%.

[0081] Example 14

[0082] An ultra-narrowband violet phosphor with the chemical composition K2(Sr) 1-y Ba y (PO3)4:0.04Eu 2+ y = 0.2, its preparation method includes the following steps:

[0083] (1) Accurately weigh high-purity raw material powders of Ba(NO3)2, SrCO3, KOH, (NH4)2HPO4 and Eu(NO3)3 according to the stoichiometric ratio, and use planetary ball milling to fully mix the raw materials.

[0084] (2) Transfer the raw material mixture to a corundum crucible, place it in a muffle furnace, and perform slow pre-calcination in an air atmosphere. Slowly raise the temperature to 70℃, 100℃, 150℃ and 200℃ and hold for 60 minutes each time. Then, hold at the final pre-calcination temperature of 250℃ for 10 hours. The heating rate is 0.2℃ / min. After cooling, take out the sample and grind it again until uniform.

[0085] (3) The ground powder was transferred to a high-temperature atmosphere reactor and calcined at 550°C for 10 hours under a mixture of argon and ammonia. After natural cooling, it was taken out and ground thoroughly to obtain ultra-narrow band purple phosphor.

[0086] Example 15

[0087] The remaining steps in this embodiment are the same as in embodiment 14, except that y = 0.4.

[0088] Example 16

[0089] The remaining steps in this embodiment are the same as in embodiment 14, except that y = 0.6.

[0090] Example 17

[0091] The remaining steps in this embodiment are the same as in embodiment 14, except that y = 0.8.

[0092] Example 18

[0093] The remaining steps in this embodiment are the same as in embodiment 14, except that y = 1.0.

[0094] The emission spectra of the violet phosphors prepared in Examples 14-18 are shown below. Figure 6 .Depend on Figure 6 It can be seen that under ultraviolet light excitation at 336 nm, the emission peak position of the phosphors obtained in Examples 14 to 18 is 418 nm, the half width at half maximum (WHM) of the emission spectrum of the phosphors obtained in Examples 14 to 16 is 22 nm, and the color purity is 99.2%. The WHM of the emission spectrum of the phosphors obtained in Examples 17 to 18 is 22.5 nm, and the color purity is 99.1%.

[0095] Example 19

[0096] An ultra-narrowband violet phosphor with the chemical composition (K 1-x Na x )2Sr(PO3)4:0.015Eu 2+ The preparation method for x = 0.1 includes the following steps:

[0097] (1) Accurately weigh high-purity raw materials of NaCO3, K2CO3, SrCO3, NH4H2PO4 and Eu2O3 according to the stoichiometric ratio, and use planetary ball milling to fully mix the raw materials.

[0098] (2) Transfer the raw material mixture to a corundum crucible, place it in a muffle furnace, and perform slow pre-calcination in an air atmosphere. Slowly raise the temperature to 90℃ and 150℃ and hold for 30 minutes each, and hold at the final pre-calcination temperature of 350℃ for 2 hours. The heating rate is 0.8℃ / min. After cooling, take out the sample and grind it again until uniform.

[0099] (3) The ground powder was transferred to a high-temperature atmosphere reactor and calcined at 600°C for 6 hours under a mixture of hydrogen and nitrogen. After natural cooling, it was taken out and ground thoroughly to obtain ultra-narrow band purple phosphor.

[0100] Example 20

[0101] The remaining steps in this embodiment are the same as in embodiment 19, except that x = 0.2.

[0102] Example 21

[0103] The remaining steps in this embodiment are the same as in embodiment 19, except that x = 0.3.

[0104] Example 22

[0105] The remaining steps in this embodiment are the same as in embodiment 19, except that x = 0.4.

[0106] Example 23

[0107] The remaining steps in this embodiment are the same as in embodiment 19, except that x = 0.5.

[0108] Examples 19-23 are provided to better illustrate the preparation and performance of ultranarrowband violet phosphors with different K and Na solid solution doping concentrations in this invention.

[0109] The emission spectra of the ultranarrowband violet phosphors obtained in Examples 19-23 are shown below. Figure 7 The relevant performance data obtained are shown in Table 1. From Table 1 and... Figure 7 It can be seen that under ultraviolet light excitation at 336 nm, the emission peak positions of the phosphors obtained in Examples 19 to 23 are all 418 to 419 nm. The half-width at half maximum (WHM) of the emission spectrum of the phosphors obtained in Examples 19 and 21 to 23 is 22 to 24 nm, and the color purity is 98.8% to 99.2%. The half-width at half maximum (WHM) of the emission spectrum of the phosphor obtained in Example 20 is 20.5 nm, and the color purity is 99.5%. Its color purity is the highest among the examples listed in this invention.

[0110] Table 1. Emission peak positions and full width at half maximum (FWHM) of the violet phosphors obtained in Examples 19-23.

[0111] Example 19 0.1 22.6 418 99.2％ Example 20 0.2 20.5 419 99.5％ Example 21 0.3 23 418 99.0％ Example 22 0.4 23.4 418 98.9％ Example 23 0.5 24 418 98.8％

[0112] Of the above embodiments, Embodiment 20 is the best embodiment, with the highest color purity, high luminous efficiency, and good chemical stability.

[0113] Example 24

[0114] An ultra-narrowband violet phosphor, the chemical composition of which is Na2Sr(PO3)4:zEu 2+ The z-value is 0.001, and its preparation method includes the following steps:

[0115] (1) Accurately weigh high-purity raw material powders of NaCO3, Sr(NO3)2, NH4H2PO4 and Eu(NO3)3 according to the stoichiometric ratio, and use planetary ball milling to fully mix the raw materials.

[0116] (2) Transfer the raw material mixture to a corundum crucible, place it in a muffle furnace, and slowly pre-calcine it in an air atmosphere. Slowly raise the temperature to 90, 130 and 160°C and hold for 10 minutes each time. Then, hold it at the final pre-calcine temperature of 200°C for 24 hours. The heating rate is 0.1°C / minute. After cooling, take out the sample and grind it evenly again.

[0117] (3) The ground powder was transferred to a high-temperature atmosphere reactor and fired at 550°C for 24 hours under a mixture of hydrogen and argon. After natural cooling, it was taken out and ground to obtain ultra-narrow band purple phosphor.

[0118] Example 25

[0119] An ultranarrow-band ultraviolet phosphor with the chemical composition K₂Ca(PO₃)₄: 0.025Eu 2+ The preparation method for y=1 includes the following steps:

[0120] (1) Accurately weigh the high-purity raw material powders of Ca(OH)2, Sr(NO3)2, K2CO3, NH4H2PO4 and Eu2O3 according to the stoichiometric ratio, and use planetary ball milling to fully mix the raw materials.

[0121] (2) Transfer the raw material mixture to a corundum crucible, place it in a muffle furnace, and perform slow pre-calcination in an air atmosphere. Slowly raise the temperature to 70℃, 100℃, 130℃, 170℃ and 200℃, and hold for 60 minutes at each temperature. Then, hold at the final pre-calcination temperature of 350℃ for 1 hour. The heating rate is 1℃ / minute. After cooling, take out the sample and grind it again until uniform.

[0122] (3) The ground powder was transferred to a high-temperature atmosphere reactor and calcined at 700°C for 2 hours under a mixture of hydrogen and nitrogen. After natural cooling, it was taken out and ground to obtain ultra-narrow band purple phosphor.

[0123] Application Example 1

[0124] The phosphor obtained in Example 20 was applied to a display device. The specific steps were as follows: the phosphor (0.166, 0.011) obtained in Example 3 of the present invention and commercially available β-Sialon:Eu were mixed. 2+ Green phosphor (0.290, 0.680), K2SiF6:Mn 4+ Red phosphors (0.680, 0.320) are mixed uniformly at a mass ratio of 60:10:1, and then encapsulated with a near-ultraviolet LED chip with an emission wavelength of 365nm to produce a white LED device with CIE chromaticity coordinates of (0.3262, 0.3341).

[0125] Using this LED device as the backlight for the LCD, a color gamut of 96.6% NTSC is achieved. (See...) Figure 8 .

[0126] Application Comparative Example 1

[0127] Using CaBe2(PO4)2:Eu 2+ Violet phosphor (emission peak at 425 nm, full width at half maximum (FWHM) at 27 nm, chromaticity coordinates (0.155, 0.090)) and β-Sialon:Eu 2+ Green phosphor, K2SiF6:Mn 4+Red phosphors are mixed uniformly at a mass ratio of 60:10:1, and then encapsulated with a near-ultraviolet LED chip with an emission wavelength of 365nm to create a white LED device with CIE chromaticity coordinates of (0.3362, 0.3341).

[0128] Using this LED device as the backlight for the LCD, the color gamut reaches 88.1% NTSC. (See...) Figure 8 .

[0129] Depend on Figure 8 It can be seen that compared with the white LED device used in Comparative Example 1 as the backlight of the liquid crystal display, the color gamut of Application Example 1 is significantly improved.

[0130] Application Example 2

[0131] The phosphor obtained in Example 20 was applied to a display device. The specific steps were as follows: the phosphor (0.165, 0.010) obtained in Example 11 of the present invention and commercially available β-Sialon:Eu were mixed. 2+ Green phosphor (0.290, 0.680), K2SiF6:Mn 4+ Red phosphors (0.680, 0.320) are mixed uniformly at a mass ratio of 70:12:1, and then encapsulated with a near-ultraviolet LED chip with an emission wavelength of 370nm to produce a white LED device with CIE chromaticity coordinates of (0.3190, 0.3218).

[0132] Using this LED device as the backlight for the LCD, the color gamut reaches 96.9% NTSC.

[0133] Application Example 3

[0134] The phosphor obtained in Example 20 was applied to a display device. The specific steps were as follows: the phosphor (0.165, 0.010) obtained in Example 11 of this invention and commercially available Sr3Si were mixed. 13 Al3O2N 21 Eu 2+ Green phosphor (0.221, 0.617), CaAlSiN3:Eu 2+ Red phosphors (0.656, 0.341) are mixed uniformly at a mass ratio of 60:15:1, and then encapsulated with a near-ultraviolet LED chip with an emission wavelength of 370nm to produce a white LED device with CIE chromaticity coordinates of (0.3219, 0.3431).

[0135] Using this LED device as the backlight for the LCD, the color gamut reaches 88.4% NTSC. (See...) Figure 9 .

[0136] Application Comparative Example 2

[0137] Using CaBe2(PO4)2:Eu 2+ Violet phosphor (0.155, 0.090) and β-Sialon:Eu 2+ Green phosphor, K2SiF6:Mn 4+ Red phosphors are mixed uniformly at a mass ratio of 60:15:1, and then encapsulated with a near-ultraviolet LED chip with an emission wavelength of 365nm to produce a white LED device with CIE chromaticity coordinates of (0.3362, 0.3341).

[0138] Using this LED device as the backlight for the LCD, a color gamut of 78.2% NTSC is achieved. (See...) Figure 9 .

[0139] Depend on Figure 8 It can be seen that, compared with the white LED device used in Comparative Example 2 as the backlight of the liquid crystal display, the color gamut of Application Example 3 is significantly improved.

[0140] Application Example 4

[0141] The phosphor obtained in Example 20 was applied to temperature sensing, and the specific steps were as follows:

[0142] The phosphor obtained in Example 20 of this invention was combined with a zero-thermal quenching phosphor Na3Sc2(PO4)3:Eu with an emission peak at 455 nm. 2+ Mix them together.

[0143] The resulting composite powder exhibits excellent fluorescence temperature sensing performance. Emission spectra of the phosphor were collected at different temperatures, and the luminescence intensity values ​​(I) at the two peaks of 455 nm and 418 nm were directly read. 455 and I 418 The fluorescence intensity ratio (FIR = I) at various temperatures was obtained. 455 / I 418 This allows us to obtain a curve showing the fitting relationship between fluorescence intensity ratio (FIR) and temperature (T). Figure 10 This is the fitted temperature measurement curve of the fluorescent temperature sensing material described in this application example. As can be seen from the figure, its temperature measurement equation is FIR=17839.18*exp(-3286.38 / T)+0.090, with a goodness of fit higher than 0.996 and a temperature measurement accuracy exceeding 0.01℃, demonstrating high temperature measurement accuracy. Figure 11 The absolute and relative sensitivity of the fluorescent temperature sensing material prepared in Application Example 4 are shown. Relative sensitivity is a key parameter for fluorescent temperature sensing materials; therefore, the material described in this application example exhibits high sensitivity, with a maximum relative sensitivity of 2.84% K. -1 .

[0144] The fluorescent temperature sensing material described in this invention is unaffected by the ratio and amount of the two phosphors used, nor by the ambient electromagnetic field, the model of the testing instrument, or the intensity of the light source. Temperature measurement method: Spectral data is collected under the conditions of the environment to be tested to obtain the FIR value. Temperature measurement and sensing can then be performed based on the relationship curve. Not only is the testing method simple, but it also requires no reference calibration and has the characteristic of self-calibrating temperature measurement.

[0145] The temperature sensing applications of the phosphor described in this invention are not limited to Application Example 4. Based on the temperature response characteristics of the phosphor described in this invention, when combined with another phosphor exhibiting excellent fluorescence thermal stability, high-precision, self-calibrating, and high-sensitivity temperature measurement can be achieved.

Claims

1. An ultranarrow-band ultraviolet phosphor for temperature sensing, characterized in that: Its general chemical formula is (K 1-x Na x )2(Sr 1- y Ca y (PO3)4:zEu 2+ or (K) 1-x Na x )2(Sr 1-y Ba y (PO3)4:zEu 2+ Where 0 < x < 1, 0 ≤ y ≤ 1, and the value range of z is 0.001 ≤ z ≤ 0.12; the ultra-narrow band refers to the half-width at half maximum (FWHM) of the phosphor emission spectrum being less than 25 nm.

2. The method for preparing an ultranarrowband violet phosphor for temperature sensing according to claim 1, characterized in that, Includes the following steps: Step 1: Weigh the raw materials according to the stoichiometric ratio of the above general chemical formula. The raw materials include potassium-containing compounds, sodium-containing compounds, calcium-containing compounds, strontium-containing compounds, barium-containing compounds, phosphorus-containing compounds, and europium-containing compounds. Ball mill them to mix them thoroughly and evenly. Step 2: Transfer the contents obtained in Step 1 into a crucible and slowly pre-calcine it in an air atmosphere. Hold it at multiple temperature ranges of 70-200°C, and finally raise it to the pre-calcine temperature of 200-350°C and hold it thereafter. After cooling down, grind it to make it evenly mixed. Step 3: The product obtained in Step 2 is synthesized in a reducing atmosphere at 550~700℃, kept at this temperature, and taken out after natural cooling. It is then ground to obtain ultra-narrow band violet phosphor.

3. The method for preparing an ultranarrowband violet phosphor for temperature sensing according to claim 2, characterized in that: In step one, the potassium-containing compound is one or more of potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium dihydrogen phosphate, or potassium nitrate; the sodium-containing compound is one or more of sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium dihydrogen phosphate, or sodium nitrate; the strontium-containing compound is one or more of strontium hydroxide, strontium carbonate, strontium phosphate, strontium hydrogen phosphate, or strontium nitrate; the calcium-containing compound is one or more of calcium hydroxide, calcium oxide, calcium carbonate, calcium phosphate, calcium hydrogen phosphate, or calcium nitrate; the barium-containing compound is one or more of barium hydroxide, barium oxide, barium carbonate, barium phosphate, barium hydrogen phosphate, or barium nitrate; the phosphorus-containing compound is one or more of diammonium hydrogen phosphate or ammonium dihydrogen phosphate; and the europium-containing compound is europium oxide or europium nitrate.

4. The method for preparing an ultranarrowband violet phosphor for temperature sensing according to claim 2, characterized in that: In step two, the heating rate of the pre-calcination is 0.1~1℃ / min, and the temperature is maintained at each of the multiple heat preservation stages for 10~60 minutes.

5. The method for preparing an ultranarrowband violet phosphor for temperature sensing according to claim 2, characterized in that: In step two, the temperature is finally raised to a pre-calcination temperature of 200-350℃ and held for 1-24 hours.

6. The method for preparing an ultranarrowband violet phosphor for temperature sensing according to claim 2, characterized in that: In step three, the reducing atmosphere is one or more of hydrogen, ammonia, and carbon monoxide.

7. The method for preparing an ultranarrowband violet phosphor for temperature sensing according to claim 2, characterized in that: In step three, the heat preservation time is 2 to 24 hours.

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