Aluminum-based phosphate near-infrared luminescent material and preparation method and application thereof

Abstract

The present invention belongs to the technical field of luminescent materials, and discloses an aluminum-based phosphate near-infrared luminescent material, a preparation method thereof and an application thereof. The chemical formula of the luminescent material is K2Al 1‑x Cr x MP3O 12 ; M is selected from one or more of Ti, Sn, Zr or Hf, and 0.001 ≤ x ≤ 0.2. By adjusting the proportion of the Hf, Ti, Zr or Sn component, the present material realizes fine regulation of the emission peak position and emission intensity. The prepared luminescent material can be effectively excited by blue light and red light in the range of 400-750 nm. The main excitation peak in the blue light region is located at 445-465 nm, which can effectively match a high-efficiency commercial blue LED chip; under blue light excitation, its emission spectrum covers 700-1200 nm, the emission main peak is located at 800-840 nm and can vary continuously, and the relative emission intensity is relatively high, which can effectively meet the requirements of a broadband near-infrared LED device.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials, and more specifically, relates to an aluminum-based phosphate near-infrared luminescent material and a preparation method and application thereof. Background Art

[0002] Near-infrared spectroscopy technology has the characteristics of being fast, safe, and non-destructive. It is widely used in many fields such as medical diagnosis, security monitoring, biological imaging, and food quality analysis. However, traditional near-infrared light sources (halogen lamps, incandescent lamps, etc.) generally have disadvantages such as low efficiency, large size, and high power consumption. Although infrared LEDs are small in size and low in power consumption, their emission spectrum is narrow and cannot cover a larger spectral range, limiting their application in many fields. In recent years, near-infrared fluorescence conversion light-emitting diodes (NIR pc-LEDs) have made up for the inherent shortcomings of traditional near-infrared light sources with their advantages of low power consumption, small size, high efficiency, and adjustable emission spectrum, and are considered to be a new generation of near-infrared light sources. Usually, the transition metal ion Cr 3+ and rare earth ion Eu 2 + It is used as an activator ion for wide-spectrum near-infrared luminescent materials. 2+ The activated near-infrared luminescent materials are generally of low efficiency and the emission wavelength is difficult to exceed 750nm, while Cr 3+ Activated near-infrared luminescent materials are generally highly efficient, and tunable broadband emission from deep red to near infrared can be achieved by adjusting the intensity of the crystal field. 3+ The peak wavelengths of activated materials are mostly concentrated within 800nm. The materials with peak wavelengths greater than 800nm ​​are rare and have low efficiency. This problem limits the Cr 3+ In addition, most of the near-infrared materials currently developed use expensive elements such as Sc, In, Ga, and Ge as raw materials, which is not conducive to the large-scale commercial application of such materials. Therefore, it is necessary to explore and develop cheap Cr 3+ High-efficiency near-infrared broadband materials with an activated peak wavelength greater than 800nm ​​are an urgent intrinsic need for the development of near-infrared fluorescence conversion LED devices and are of great significance. Summary of the invention

[0003] In order to solve the deficiencies and shortcomings of the above-mentioned prior art, the primary purpose of the present invention is to provide an aluminum-based phosphate near-infrared luminescent material, which can be effectively excited by blue light and red light in the range of 400 to 750 nm, and the main excitation peak in the blue light region is located at 445 to 465 nm, which can effectively match high-efficiency commercial blue light LED chips; under blue light excitation, its emission spectrum covers 700 to 1200 nm, the main emission peak is located at 800 to 840 nm and can change continuously, and the relative luminous intensity is high, which can effectively meet the needs of wide-spectrum near-infrared LED devices.

[0004] Another object of the present invention is to provide a method for preparing the above-mentioned aluminum-based phosphate near-infrared luminescent material.

[0005] Another object of the present invention is to provide an application of the above aluminum-based phosphate near-infrared luminescent material.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] An aluminum-based phosphate near-infrared luminescent material, wherein the chemical formula of the near-infrared luminescent material is K2Al 1- x Cr x MP3O 12 ; M is selected from one or more of Ti, Sn, Zr or Hf, 0.001≤x≤0.2.

[0008] Preferably, M is Ti or / and Hf, and 0.002≤x≤0.04.

[0009] The method for preparing the aluminum-based phosphate near-infrared luminescent material comprises the following specific steps:

[0010] S1. The M compound, the Al compound, the K compound, the P compound and the Cr compound are ground and mixed uniformly to obtain a mixture;

[0011] S2. Sinter the mixture at 900-1100° C. in air, and crush and grind the product to obtain an aluminum-based phosphate near-infrared luminescent material.

[0012] Preferably, in step S1, the M compound is one or more of titanium dioxide, tin dioxide, zirconium oxide or hafnium oxide; the Al compound is aluminum oxide, aluminum hydroxide or aluminum nitrate; the K compound is potassium carbonate, potassium oxide or potassium hydroxide; the P compound is ammonium hydrogen phosphate, ammonium dihydrogen phosphate or phosphorus pentoxide; and the Cr compound is chromium oxide or chromium nitrate.

[0013] Preferably, the sintering time in step S2 is 4 to 48 hours, and the sintering temperature is 920 to 1080°C.

[0014] Application of the aluminum-based phosphate near-infrared luminescent material in photoconversion devices.

[0015] Preferably, the light conversion device is a near-infrared LED device.

[0016] The present invention uses the optically active element Cr 3+ Dissolved in K2AlMP3O with cubic structure 12 By doping a compound (M = one or more of Hf, Ti, Zr or Sn) in the crystalline phase alone, a luminescent material with a new structure and new composition is obtained, whose excitation peak wavelength covers the 445-465nm band and the emission peak wavelength is located at 800-840nm, which is a new wide-spectrum near-infrared luminescent material system.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The aluminum-based phosphate near-infrared luminescent material provided by the present invention can be effectively excited by blue light and red light in the range of 400 to 750 nm. The main excitation peak in the blue light region is located at 445 to 465 nm, which can be well matched with the blue light LED and is very practical.

[0019] 2. The aluminum-based phosphate near-infrared luminescent material provided by the present invention can emit near-infrared light with a peak wavelength of about 800-840nm under the excitation of 455nm blue light, and is a near-infrared material that is currently in short supply.

[0020] 3. The aluminum-based phosphate near-infrared luminescent material provided by the present invention achieves fine control of the luminescence peak position and luminescence efficiency by adjusting the ratio of Hf, Ti, Zr or Sn components.

[0021] 4. The raw materials of the aluminum-based phosphate near-infrared luminescent material provided by the present invention are cheap and easy to obtain. Moreover, the synthesis temperature is relatively low, the preparation process is simple, no special reaction equipment is required, and industrial production is very convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 K2Al in the embodiment 0.96 Cr 0.04 TiP3O 12 X-ray powder diffraction pattern of

[0023] Figure 2 is K2Al in Example 1 0.96 Cr 0.04 TiP3O 12 The excitation spectrum of

[0024] Figure 3 is K2Al in Example 1 0.96 Cr 0.04 TiP3O12 The emission spectrum of

[0025] Figure 4 is K2Al in Example 2 0.98 Cr 0.02 HkDJ 12 The excitation spectrum of

[0026] Figure 5 is K2Al in Example 2 0.98 Cr 0.02 HkDJ 12 The emission spectrum of

[0027] Figure 6 is K2Al in Example 3 0.997 Cr 0.003 ZrPO 12 The excitation spectrum of

[0028] Figure 7 is K2Al in Example 3 0.997 Cr 0.003 ZrPO 12 The emission spectrum of

[0029] Figure 8 is K2Al in Example 4 0.998 Cr 0.002 SnP3O 12 The excitation spectrum of

[0030] Fig. 9 is K2Al in Example 4 0.998 Cr 0.002 SnP3O 12 The emission spectrum of . DETAILED DESCRIPTION

[0031] The content of the present invention is further described below in conjunction with specific examples, but it should not be construed as limiting the present invention. If not specifically indicated, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0032] Example 1

[0033] According to the chemical formula K2Al 0.96 Cr 0.04 TiP3O 12Weigh 0.1 mol K2CO3, 0.048 mol Al2O3, 0.002 mol Cr2O3, 0.05 mol TiO2, and 0.3 mol NH4H2PO4. All the above raw materials are analytically pure. Weigh and mix them, grind them thoroughly for 30 minutes, mix them evenly, put them into an alumina crucible, roast them at 920℃ for 6 hours, and after cooling to room temperature, crush, grind, wash and other post-processing to obtain a product with a chemical composition of K2Al 0.96 Cr 0.04 TiP3O 12 of luminous material.

[0034] Figure 1 K2Al in the embodiment 0.96 Cr 0.04 TiP3O 12 X-ray powder diffraction pattern of Figure 1 It can be seen that the X-ray powder diffraction pattern (Cu target, λ = 0.15406nm) is similar to that of K2Al 0.96 Cr 0.04 TiP3O 12 Compared with the standard card, it shows that K2Al 0.96 Cr 0.04 TiP3O 12 . Figure 2 is K2Al in Example 1 0.96 Cr 0.04 TiP3O 12 The excitation spectrum of Figure 2 It can be seen that when the luminescent material is monitored at 840nm, the excitation spectrum covers the range of 400 to 750nm, and the main excitation peak in the blue light region is located at 460nm. Figure 3 In this embodiment, K2Al 0.96 Cr 0.04 TiP3O 12 The emission spectrum of Figure 3 It can be seen that the emission spectrum covers 700-1200nm, and its main emission peak is located at 840nm. Under the excitation of 455nm blue light, the relative luminous intensity reaches 88%, as shown in Table 1.

[0035] Example 2

[0036] According to the chemical formula K2Al 0.98 Cr 0.02 HkDJ 12Weigh 2 mol KOH, 0.99 mol Al(OH)3, 0.01 mol Cr(NO3)3, 1 mol HfO2, and 3 mol NH4H2PO4. All the above raw materials are analytically pure. Weigh and mix them, grind them thoroughly for 30 minutes, and mix them evenly. Then put them into an alumina crucible and roast them at 950℃ for 10 hours. After cooling to room temperature, crush, grind, wash, and other post-processing are performed to obtain a product with a chemical composition of K2Al 0.98 Cr 0.02 HkDJ 12 of luminous material.

[0037] Figure 4 is K2Al in Example 2 0.98 Cr 0.02 HkDJ 12 Excitation spectrum under 800nm ​​monitoring. Figure 4 It can be seen that the luminescent material can be effectively excited by blue light and red light in the range of 400 to 750 nm, and the main excitation peak in the blue light region is located at 455 nm. Figure 5 In this embodiment, K2Al 0.98 Cr 0.02 HkDJ 12 The emission spectrum of Figure 5 It can be seen that the emission spectrum covers 700-1000nm, and its main emission peak is located at 800nm. Under the excitation of 455nm blue light, the relative luminous intensity reaches 100% (see Table 1).

[0038] Example 3

[0039] According to the chemical formula K2Al 0.997 Cr 0.003 ZrPO 12 Weigh 0.01mol K2O, 0.00997molAl(NO3)3, 0.000015mol Cr2O3, 0.01mol ZrO2, and 0.015mol P2O5. All the above raw materials are analytically pure. Weigh and mix them, grind them thoroughly for 30 minutes, mix them evenly, put them into an alumina crucible, roast them at 980℃ for 14 hours, and after cooling to room temperature, crush, grind, wash and other post-processing to obtain a product with a chemical composition of K2Al 0.997 Cr 0.003 ZrPO 12 of luminous material.

[0040] Figure 6 is K2Al in Example 3 0.997 Cr 0.003 ZrPO 12 Excitation spectrum under 810nm monitoring. Figure 6It can be seen that the luminescent material can be effectively excited by blue light and red light in the range of 400 to 750 nm, and the main excitation peak in the blue light region is located at 465 nm. Figure 7 In this embodiment, K2Al 0.997 Cr 0.003 ZrPO 12 The emission spectrum of Figure 7 It can be seen that the emission spectrum covers 700-1050nm, and its main emission peak is located at 810nm. Under the excitation of 455nm blue light, the relative luminous intensity reaches 74% (see Table 1).

[0041] Example 4

[0042] According to the chemical formula K2Al 0.998 Cr 0.002 SnP3O 12 Weigh 2 mol KOH, 0.998 mol Al(OH)3, 0.001 mol Cr2O3, 1 mol SnO2, 3 mol NH4HPO4. All the above raw materials are analytically pure. Weigh and mix them, grind them thoroughly for 30 minutes, mix them evenly, put them into an alumina crucible, roast them at 1000℃ for 18 hours, and after cooling to room temperature, crush, grind, wash and other post-processing to obtain a product with a chemical composition of K2Al 0.998 Cr 0.002 SnP3O 12 of luminous material.

[0043] Figure 8 is K2Al in Example 4 0.998 Cr 0.002 SnP3O 12 Excitation spectrum under 810nm monitoring. Figure 8 It can be seen that the luminescent material can be effectively excited by blue light and red light in the range of 400 to 750 nm, and the main excitation peak in the blue light region is located at 465 nm. Fig. 9 is K2Al in Example 4 0.998 Cr 0.002 SnP3O 12 The emission spectrum of Fig. 9 It can be seen that the emission spectrum of the luminescent material covers 700-1200 nm, and its emission main peak is located at 820 nm. Under the excitation of 455 nm blue light, the relative luminescence intensity reaches 63% (see Table 1).

[0044] Example 5

[0045] According to the chemical formula K2Al 0.998 Cr 0.002 Hf 0.8 Ti 0.2 P3O 12Weigh 0.1mol K2CO3, 0.0499molAl2O3, 0.0001mol Cr2O3, 0.08mol HfO2, 0.02mol TiO2, and 0.15mol P2O5. All the above raw materials are analytically pure. Weigh and mix them and grind them thoroughly for 30 minutes. After mixing them evenly, put them into an alumina crucible and roast them at 1020℃ for 24 hours. After cooling to room temperature, crush, grind, wash and other post-processing are carried out to obtain a product with a chemical composition of K2Al 0.998 Cr 0.002 Hf 0.8 Ti 0.2 P3O 12 of luminous material.

[0046] The luminescent material can be effectively excited by blue light and red light in the range of 400-750nm, and the main excitation peak in the blue light region is located at 445nm. The emission spectrum covers 700-1200nm, and its main emission peak is located at 830nm. Under the excitation of 455nm blue light, the relative luminous intensity reaches 96% (see Table 1).

[0047] Example 6

[0048] According to the chemical formula K2Al 0.98 Cr 0.02 Hf 0.2 Ti 0.8 P3O 12 Weigh 0.01mol K2CO3, 0.0049molAl2O3, 0.0001mol Cr2O3, 0.002mol HfO2, 0.008mol TiO2, and 0.03mol NH4H2PO4. All the above raw materials are analytically pure. Weigh and mix them, grind them thoroughly for 30 minutes, mix them evenly, put them into an alumina crucible, and roast them at 1050℃ for 28 hours. After cooling to room temperature, crush, grind, wash, and other post-processing to obtain a product with a chemical composition of K2Al 0.98 Cr 0.02 Hf 0.2 Ti 0.8 P3O 12 of luminous material.

[0049] The luminescent material can be effectively excited by blue light and red light in the range of 400-700nm, and the main excitation peak in the blue light region is located at 460nm. The emission spectrum covers 700-1050nm, and its main emission peak is located at 832nm. Under the excitation of 455nm blue light, the relative luminous intensity reaches 90% (see Table 1).

[0050] Example 7

[0051] According to the chemical formula K2Al 0.96 Cr0.04 Hf 0.5 Ti 0.5 P3O 12 Weigh 1 mol K2CO3, 0.48 mol Al2O3, 0.02 mol Cr2O3, 0.5 mol HfO2, 0.5 mol TiO2, and 3 mol NH4HPO4. All the above raw materials are analytically pure. Weigh and mix them and grind them thoroughly for 30 minutes. After mixing them evenly, put them into an alumina crucible and roast them at 1080℃ for 32 hours. After cooling to room temperature, crush, grind, wash and other post-processing are carried out to obtain a product with a chemical composition of K2Al 0.98 Cr 0.02 Hf 0.2 Ti 0.8 P3O 12 The luminescent material can be effectively excited by blue light and red light in the range of 400-750nm, and the main excitation peak in the blue light region is located at 450nm. The emission spectrum covers 700-1100nm, and its main emission peak is located at 830nm. Under the excitation of 455nm blue light, the relative luminescence intensity reaches 94% (see Table 1).

[0052] Example 8

[0053] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.998 Cr 0.002 Zr 0.8 Hf 0.2 P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0054] Example 9

[0055] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.95 Cr 0.05 Zr 0.2 Hf 0.8 P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0056] Example 10

[0057] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.9 Cr 0.1 Zr 0.7 Ti 0.3 P3O 12 The emission peak wavelength and relative luminous intensity of the luminescent material are shown in Table 1.

[0058] Embodiment 11

[0059] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.97 Cr 0.03 Zr 0.1 Ti 0.9 P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0060] Example 12

[0061] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.996 Cr 0.004 Zr 0.4 Sn 0.6 P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0062] Embodiment 13

[0063] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.997 Cr 0.003 Zr 0.4 Sn 0.4 Hf 0.2 P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0064] Embodiment 14

[0065] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.98 Cr 0.02 Zr 0.4 Sn 0.3 Ti 0.3 P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0066] Embodiment 15

[0067] The chemical formula of the luminescent material prepared according to the method of Example 7 is K2Al 0.995 Cr 0.005 Zr 0.3 Sn 0.3 Ti 0.2 Hf 0. 2P3O 12 The emission peak wavelength and relative luminescence intensity of the luminescent material are shown in Table 1.

[0068] Table 1 shows the emission peak positions and relative luminescence intensities of the luminescent materials of Examples 1-15 under 455 nm excitation.

[0069]

[0070]

[0071] Table 1 shows the emission peak positions and relative luminescence intensities of the luminescent materials of Examples 1-15 under 455 nm excitation. As can be seen from Table 1, the chemical formula of the near-infrared luminescent material is K2Al 1-x Cr x MP3O 12 ; M is one or more of Ti, Sn, Zr or Hf, 0.001≤x≤0.2, and the relative luminescence intensity under 455nm excitation is 66-100%. In particular, when M is Ti or / and Hf, 0.002.x≤0.04, the relative luminescence intensity under 455nm excitation is 88-100%, indicating that Cr 3+ Doping concentration within this range can effectively avoid concentration quenching and achieve higher luminescence intensity.

[0072] The aluminum-based phosphate near-infrared luminescent material of the present invention can be effectively excited by blue light and red light in the range of 400 to 750 nm, and the main excitation peak in the blue light region is located at 445 to 465 nm, which can effectively match high-efficiency commercial blue light LED chips; under blue light excitation, its emission spectrum covers 700 to 1200 nm, and the main emission peak is located at 800 to 840 nm, which can meet the application requirements in the fields of near-infrared spectral analysis, night vision, biological imaging, etc.

[0073] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An aluminum-based phosphate near-infrared luminescent material, characterized in that: The chemical formula of the near-infrared luminescent material is K2Al 1-x Cr x MP3O 12 ; M is selected from one or more of Ti, Sn, Zr or Hf, 0.001≤x≤0.

2.

2. The aluminum-based phosphate near-infrared luminescent material according to claim 1, characterized in that: The M is Ti and / or Hf, 0.002≤x≤0.

04.

3. The method for preparing the aluminum-based phosphate near-infrared luminescent material according to claim 1 or 2, characterized in that: The specific steps include: S1. The M compound, the Al compound, the K compound, the P compound and the Cr compound are ground and mixed uniformly to obtain a mixture; S2. Sinter the mixture at 900-1100° C. in air, and crush and grind the product to obtain an aluminum-based phosphate near-infrared luminescent material.

4. The method for preparing the aluminum-based phosphate near-infrared luminescent material according to claim 3, characterized in that: In step S1, the M compound is one or more of titanium dioxide, tin dioxide, zirconium oxide or hafnium oxide; the Al compound is aluminum oxide, aluminum hydroxide or aluminum nitrate; the K compound is potassium carbonate, potassium oxide or potassium hydroxide; the P compound is ammonium hydrogen phosphate, ammonium dihydrogen phosphate or phosphorus pentoxide; and the Cr compound is chromium oxide or chromium nitrate.

5. The method for preparing the aluminum-based phosphate near-infrared luminescent material according to claim 3, characterized in that: The sintering time in step S2 is 4 to 48 hours; the sintering temperature is 920 to 1080°C.

6. Use of the aluminum-based phosphate near-infrared luminescent material according to claim 1 or 2 in a photoconversion device.

7. The use according to claim 6, characterized in that: The light conversion device is a near-infrared LED device.

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