A Cr 3+ Doped near-infrared phosphor with narrow-band emission and preparation method thereof

Abstract

The invention discloses a Cr 3+ Doped near-infrared phosphor with narrow-band emission and preparation method thereof, the chemical formula of the near-infrared phosphor is Sc m Al 2‑m‑x (RO4)3: x Cr 3+ ; The preparation method comprises the following steps: S1: according to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of the compound containing each element as the preparation raw material; S2: add the preparation raw material weighed in S1 to anhydrous ethanol, grind it to make it uniformly mixed, and obtain the grinding raw material; S3: sinter the grinding raw material obtained in S2 at a temperature of 1000-1300°C for 4-48 hours, and then cool the sample to room temperature to obtain the first sample; S4: grind the first sample obtained in S3 uniformly, sinter it at a temperature of 1000-1300°C for 4-48 hours, and then cool the sample to room temperature to obtain the second sample; S5: grind the second sample obtained in S4 uniformly to obtain the near-infrared phosphor. Advantages: Achieve narrow-band near-infrared emission of 650-950 nm.

Description

Technical Field

[0001] The present invention relates to the technical field of near-infrared phosphors, and in particular to a Cr 3+ Doped near-infrared phosphor with narrow-band emission and preparation method thereof. Background Art

[0002] During plant growth, the most sensitive area to the solar spectrum is in the red light region, while it is insensitive to green light. Although far-red light (680-800nm) does not participate in photosynthesis, it plays a role in regulating the absorption state of photosensitive pigments (i.e., P R and P FR The phytochrome has the greatest impact on plant photosynthesis and can be divided into red light absorbing (P R ) and far-red light absorption (P FR ), the available red light of the two is around 660 nm and 730 nm respectively. After absorbing the corresponding light, P R and P FR They can be converted into each other, and the relative proportion of the two controls the flowering, fruiting and light cycle of the plant, thus affecting the growth process of the plant.

[0003] There are currently two main technologies for obtaining LED light sources for plant growth: (1) combining blue and red LED lights and (2) covering blue LED chips with red phosphors. The first technology is difficult to apply because it has some major disadvantages, including complex control circuits, high costs, low thermal stability, and low luminous efficiency. Compared with the first technology, the second technology avoids the disadvantages of absorption and difficulty in adjusting the ratio between multiple phosphors, reduces production costs, and improves luminous efficiency. At the same time, the technology is simple to operate and low in cost, and is widely used in practical applications.

[0004] In addition, the transition element Mn 4+ and Cr 3+ Activated oxygen-containing salts can achieve spectral emission in the red light band, especially the far-red light band, and show high excitation efficiency in the blue light region, and have become the focus of the industry.

[0005] The Chinese patent application with application number 202410661787.X discloses a Cr 3+ Doped ultra-broadband oxide phosphor and preparation method thereof, the chemical formula of which is AB 1-x Cr x W2O8, the oxide phosphor is monoclinic, and the space group is C2 / m; a representative example is LiSc 0.99 Cr 0.01W2O8, but the emission peak of this near-infrared oxide phosphor is around 1060nm, and the half-width is about 224nm, which does not match the absorption spectrum of plant pigments and cannot be used in the field of plant growth lighting.

[0006] Japanese patent application number CN201410612834.8 discloses a fluorescent powder for LED for plant cultivation and its preparation method, the chemical formula of which is CaAlSiN3:Eu 2+ Nitride red phosphor is a new type of widely used red phosphor. It is made of calcium nitride, silicon nitride, aluminum nitride and europium nitride as raw materials. However, this type of nitride red phosphor has poor thermal stability and high production cost.

[0007] Chinese patent application with application number CN201210096455.9 discloses several nitride red phosphors and preparation methods thereof, whose general chemical formula is Ca2Si5N8, Sr2Si5N8 or Ba5Si5N8. The synthesis of ion-doped nitrides requires a high temperature and high pressure environment. The harsh synthesis conditions and ion doping make their preparation cost too high.

[0008] The Chinese patent application with application number CN201910131359.5 discloses a deep red fluorescent material and its preparation method, whose chemical formula is Ca3La2W2O 12 :Mn 4+ The quantum efficiency of this phosphor is low, making it difficult to be widely used in the field of plant lighting.

[0009] The Chinese patent application with application number CN202110973378.X discloses a high-stability near-infrared phosphor for LED plant lamps and its preparation method, the chemical formula of which is Zn3Ga 2-2x Al 2x GeO8:yCr 3+ The emission peak of the phosphor is 700nm, and the emission band is narrow, while the plant far-red light absorbing photosensitive pigment P FR The absorption band is wide, and the spectrum of this phosphor is similar to that of plant far-red light absorbing photosensitive pigment P FR The absorption band range has low overlap and a small coverage area, which has certain defects for plant growth. Summary of the invention

[0010] The first object of the present invention is to provide a Cr 3+ Doped near-infrared phosphor with narrow-band emission.

[0011] The second object of the present invention is to provide a Cr 3+ A method for preparing doped near-infrared phosphor with narrow-band emission.

[0012] The first object of the present invention is implemented by the following technical solution: A near-infrared phosphor doped with Cr and having narrow-band emission, and the chemical formula of the near-infrared phosphor is Sc 3+ Al m Al 2-m-x (RO4)3: x Cr 3+ , where R is any one or a combination of two of W or Mo; x and m are mole fractions, and 0 < x ≤ 0.3, 0 < m < 2; the near-infrared phosphor can achieve narrow-band near-infrared emission at 650 - 950 nm under the excitation of light with a wavelength of 350 - 600 nm, and its emission peak is 695 nm.

[0013] The second object of the present invention is implemented by the following technical solution: A preparation method of a near-infrared phosphor doped with Cr and having narrow-band emission, which includes the following steps: 3+ S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, respectively weigh the corresponding masses of compounds containing each element as preparation raw materials;

[0014] S2: Add the preparation raw materials weighed in S1 to anhydrous ethanol, grind and mix them evenly to obtain a ground raw material;

[0015] S3: Sinter the ground raw material obtained in S2 at a temperature of 1000 - 1300 °C for 4 - 48 hours, and then cool it to room temperature to obtain a first sample;

[0016] S4: After grinding the first sample obtained in S3 evenly, sinter it at a temperature of 1000 - 1300 °C for 4 - 48 hours, and then cool it to room temperature to obtain a second sample;

[0017] S5: Grind the second sample obtained in S4 evenly to prepare the near-infrared phosphor.

[0018] Further, in S1, the compounds containing Sc and Al are their respective oxides or nitrates, the compound containing Cr is its oxide, the compound containing Mo is molybdate, and the compound containing W is its tungstate.

[0019]

[0020] Advantages of the present invention: The near-infrared phosphor provided by the present invention has a simple synthesis method, low cost, good thermal stability, narrow excitation and emission wavelength ranges, can achieve narrow-band near-infrared emission at 650 - 950 nm under the excitation of light with a wavelength of 350 - 600 nm, and the peak of the normalized emission spectrum is at 695 nm, which matches the absorption spectrum of plant pigments and can be applied in the field of plant growth lighting. Description of the Drawings

[0021] Figure 1 The normalized emission spectra of the phosphors of Examples 1 to 3 of the present invention and the plant phytochrome P FR Absorption spectrum comparison chart.

[0022] Figure 2 Spectra of the phosphors of Examples 1 and 3 of the present invention.

[0023] Figure 3 The normalized emission spectra of the phosphors of Examples 1 to 3 and Comparative Example 1 of the present invention.

[0024] Figure 4 1 is the XRD spectrum of the phosphors of Examples 1 to 3 of the present invention. DETAILED DESCRIPTION

[0025] Example 1: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 0.2 Al 1.76 W3O 12 : 0.04Cr 3+ , where R is W; x and m are mole fractions, where x is 0.04 and m is 0.2m.

[0026] The preparation method thereof comprises the following steps:

[0027] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.0276g of Sc2O3, 0.1794g of Al2O3, 1.3910g of WO3 and 0.0060g of Cr2O3;

[0028] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0029] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 6 hours, and then cooling to room temperature to obtain a first sample;

[0030] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1200° C. for 6 hours, and then cooling it to room temperature to obtain a second sample;

[0031] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0032] Example 2: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.6 Al0.36 W3O 12 :0.04Cr 3+ , where R is W; x and m are mole fractions, where x is 0.04 and m is 1.6.

[0033] The preparation method thereof comprises the following steps:

[0034] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.2207g of Sc2O3, 0.0367g of Al2O3, 1.3910g of WO3 and 0.0060g of Cr2O3;

[0035] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0036] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 6 hours, and then cooling to room temperature to obtain a first sample;

[0037] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1200° C. for 6 hours, and then cooling it to room temperature to obtain a second sample;

[0038] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0039] Example 3: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc1Al 0.96 Mo3O 12 :0.04Cr 3+ , where R is Mo; x and m are mole fractions, where x is 0.04 and m is 1.

[0040] The preparation method thereof comprises the following steps:

[0041] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.1379g of Sc2O3, 0.0979g of Al2O3, 0.8636g of MoO3 and 0.0060g of Cr2O3;

[0042] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0043] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 6 hours, and then cooling to room temperature to obtain a first sample;

[0044] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1200° C. for 6 hours, and then cooling it to room temperature to obtain a second sample;

[0045] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0046] Example 4: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc1Al 0.96 W 1.5 Mo 1.5 O 12 :0.04Cr 3+ , where R is Mo; x and m are mole fractions, where x is 0.04 and m is 1.

[0047] The preparation method thereof comprises the following steps:

[0048] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.1379g of Sc2O3, 0.0979g of Al2O3, 0.6955g of WO3, 0.8636g of MoO3 and 0.0060g of Cr2O3;

[0049] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0050] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 6 hours, and then cooling to room temperature to obtain a first sample;

[0051] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1200° C. for 6 hours, and then cooling it to room temperature to obtain a second sample;

[0052] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0053] Example 5: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 0.1 Al 1.6 W3O 12 :0.3Cr 3+ , where R is W; x and m are mole fractions, where x is 0.3 and m is 0.1.

[0054] The preparation method thereof comprises the following steps:

[0055] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.0138g of Sc2O3, 0.1631g of Al2O3, 1.4782g of (NH4)6H2W 12 O 40 xH2O and 0.2401 g of Cr2O3;

[0056] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0057] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 4 hours, and then cooling to room temperature to obtain a first sample;

[0058] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1100° C. for 4 hours, and then cooling it to room temperature to obtain a second sample;

[0059] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0060] Example 6: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 0.8 Al 1.1 W3O 12 :0.1Cr 3+ , where R is W; x and m are mole fractions, where x is 0.1 and m is 0.8.

[0061] The preparation method thereof comprises the following steps:

[0062] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.1103g of Sc2O3, 0.1122g of Al2O3, 1.4782g of (NH4)6H2W 12 O 40 xH2O and 0.0152g of Cr2O3;

[0063] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0064] S3: sintering the ground raw material obtained in S2 at a temperature of 1100° C. for 10 hours, and then cooling to room temperature to obtain a first sample;

[0065] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1100° C. for 20 hours, and then cooling it to room temperature to obtain a second sample;

[0066] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0067] Example 7: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 0.5 Al 1.3 Mo3O 12 :0.2Cr 3+ , where R is Mo; x and m are mole fractions, where x is 0.2 and m is 0.5.

[0068] The preparation method thereof comprises the following steps:

[0069] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.0690g of Sc2O3, 0.1325g of Al2O3, 1.4518g of Na2MoO4·2H2O and 0.0304g of Cr2O3;

[0070] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0071] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 8 hours, and then cooling to room temperature to obtain a first sample;

[0072] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1100° C. for 10 hours, and then cooling it to room temperature to obtain a second sample;

[0073] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0074] Example 8: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.5 Al 0.48 W3O 12 :0.02Cr 3+ , where R is W; x and m are mole fractions, where x is 0.02 and m is 1.5.

[0075] The preparation method thereof comprises the following steps:

[0076] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.6930g of Sc(NO3)3·xH2O, 0.3601g of Al(NO3)3·9H2O, 1.3910g of WO3 and 0.0160g of Cr(NO3)3·9H2O;

[0077] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0078] S3: sintering the ground raw material obtained in S2 at a temperature of 1300° C. for 24 hours, and then cooling to room temperature to obtain a first sample;

[0079] S4: grinding the first sample obtained in S3 uniformly, sintering at 1300° C. for 48 hours, and then cooling to room temperature to obtain a second sample;

[0080] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0081] Example 9: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.5 Al 0.44 WM0 12 :0.06Cr 3+ , where R is the combination of W and Mo; x and m are mole fractions, where x is 0.06 and m is 1.5.

[0082] The preparation method thereof comprises the following steps:

[0083] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.2069 g of Sc2O 3， 0.0449 g Al2O3, 0.9854 g (NH4)6H2W 12 O 40 ·xH2O, 0.4839 g of Na2MoO4·2H2O and 0.0091 g of Cr2O3;

[0084] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0085] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 12 hours, and then cooling to room temperature to obtain a first sample;

[0086] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1200° C. for 15 hours, and then cooling it to room temperature to obtain a second sample;

[0087] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0088] Example 10: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.4 Al 0.52 W1Mo2O 12 :0.08Cr 3+ , where R is the combination of W and Mo; x and m are mole fractions, where x is 0.08 and m is 1.4.

[0089] The preparation method thereof comprises the following steps:

[0090] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.6467 g of Sc(NO3)3·xH2O ， 0.3901 g of Al(NO3)3·9H2O, 0.4927 g of (NH4)6H2W 12 O 40 ·xH2O, 0.9678 g of Na2MoO4·2H2O and 0.0640 g of Cr(NO3)3·9H2O;

[0091] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0092] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 10 hours, and then cooling to room temperature to obtain a first sample;

[0093] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1100° C. for 12 hours, and then cooling it to room temperature to obtain a second sample;

[0094] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0095] Example 11: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.3 Al 0.58 Mo3O 12 :0.12Cr 3+, where R is Mo; x and m are mole fractions, where x is 0.12 and m is 1.3.

[0096] The preparation method thereof comprises the following steps:

[0097] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.6005g of Sc(NO3)3·xH2O, 0.4352g of Al(NO3)3·9H2O, 1.4518g of Na2MoO4·2H2O and 0.9604g of Cr(NO3)3·9H2O;

[0098] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0099] S3: sintering the ground raw material obtained in S2 at a temperature of 1100° C. for 6 hours, and then cooling to room temperature to obtain a first sample;

[0100] S4: grinding the first sample obtained in S3 uniformly, sintering at 1200° C. for 24 hours, and then cooling to room temperature to obtain a second sample;

[0101] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0102] Example 12: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.1 Al 0.87 W 2.5 Mo 0.5 O 12 :0.03Cr 3+ , where R is the combination of W and Mo; x and m are mole fractions, where x is 0.03 and m is 1.1.

[0103] The preparation method thereof comprises the following steps:

[0104] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.1517g of Sc2O3, 0.0887g of Al2O3, 1.2318g of (NH4)6H2W 12 O 40 ·xH2O, 0.02420 g of Na2MoO4·2H2O and 0.0046 g of Cr2O3;

[0105] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0106] S3: sintering the ground raw material obtained in S2 at a temperature of 1200° C. for 48 hours, and then cooling to room temperature to obtain a first sample;

[0107] S4: grinding the first sample obtained in S3 uniformly, sintering at 1250° C. for 48 hours, and then cooling to room temperature to obtain a second sample;

[0108] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0109] Example 13: A Cr 3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 1.9 Al 0.09 W 0.5 Mo 2.5 O 12 :0.01Cr 3+ , where R is the combination of W and Mo; x and m are mole fractions, where x is 0.01 and m is 1.9.

[0110] The preparation method thereof comprises the following steps:

[0111] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.2620g of Sc2O3, 0.0092g of Al2O3, and 0.2464g of (NH4)6H2W 12 O 40 ·xH2O, 1.2098 g of Na2MoO4·2H2O and 0.0080 g of Cr(NO3)3·9H2O;

[0112] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0113] S3: sintering the ground raw material obtained in S2 at a temperature of 1050° C. for 20 hours, and then cooling to room temperature to obtain a first sample;

[0114] S4: grinding the first sample obtained in S3 uniformly, sintering at 1150° C. for 36 hours, and then cooling to room temperature to obtain a second sample;

[0115] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0116] Comparative Example 1: A Cr3+ Doped near-infrared phosphor with narrow-band emission, the chemical formula of the near-infrared phosphor is Sc 0.2 Al 1.4 W3O 12 : 0.4Cr 3+ , wherein R is any one of W or Mo or a combination of two; x and m are mole fractions, wherein x is 0.4 and m is 0.2; the near-infrared phosphor can achieve broadband near-infrared emission of 600 to 1000 nm under light excitation of a wavelength of 400 to 550 nm, and its emission peak is 815 nm.

[0117] The preparation method thereof comprises the following steps:

[0118] S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh the corresponding mass of compounds containing each element as preparation raw materials; specifically, weigh 0.0276g of Sc2O3, 0.1427g of Al2O3, 1.3910g of WO3 and 0.0608g of Cr2O3;

[0119] S2: placing the prepared raw material weighed in S1 in an agate mortar, adding anhydrous ethanol, and grinding to make the mixture uniform, thereby obtaining a ground raw material;

[0120] S3: sintering the ground raw material obtained in S2 at a temperature of 1000° C. for 6 hours, and then cooling to room temperature to obtain a first sample;

[0121] S4: grinding the first sample obtained in S3 uniformly, sintering it at 1200° C. for 6 hours, and then cooling it to room temperature to obtain a second sample;

[0122] S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

[0123] The normalized emission spectra of the near-infrared phosphors obtained in Examples 1 to 3 and the absorption spectra of the plant phytochromes are shown in Table 1. FR Contrast, such as Figure 1 As shown, from Figure 1 It can be seen that the phosphor is a narrow-band near-infrared phosphor with a normalized emission spectrum peak at 695 nm. The normalized emission spectra of the near-infrared phosphors in the other embodiments are similar to that in Example 1. The emission spectrum of the phosphor is similar to the absorption spectrum of the plant photosensitive pigment. FR It is well matched and has important application value in plant growth.

[0124] The near-infrared phosphor excitation spectra obtained in Example 1 and Example 3 are shown in FIG. Figure 2 As shown, from Figure 2It can be seen that the phosphor contains two effective excitation bands, which are 350 nm~470 nm and 470 nm~650 nm respectively. The excitation spectra of the near-infrared phosphors of the other embodiments are similar to that of Example 1, indicating that the near-infrared phosphor can be effectively excited by blue light and emit narrow-band red light.

[0125] The normalized emission spectra of the near-infrared phosphors obtained in Examples 1 to 3 and Comparative Example 1 are shown in FIG. Figure 3 As shown, from Figure 3 It can be seen that Examples 1 to 3 are narrow-band near-infrared phosphors, and their emission peaks are all 695nm, while Comparative Example 1 is a broadband near-infrared phosphor with a peak of 815nm. The comparative phosphor is a broadband near-infrared phosphor with an absorption spectrum P of a plant photosensitive pigment. FR The normalized emission spectrum of the phosphor in Example 1 is not well matched to the absorption spectrum of the plant photosensitive pigment P FR Good match.

[0126] The near-infrared phosphors obtained in Examples 1 to 3 were subjected to XRD testing. The XRD diffraction patterns are as follows: Figure 4 As shown, from Figure 4 It can be seen that the phosphors synthesized in Examples 1 to 3 are single phase, and the crystal structures of the near-infrared phosphors in the other examples are similar to that in Example 1, and a single phase can be obtained.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Cr 3+ A doped near-infrared phosphor having narrow-band emission, characterized in that: The chemical formula of the near-infrared phosphor is Sc m Al 2-m-x (RO4)3: x Cr 3+ , where R is any one or a combination of two of W or Mo; x and m are mole fractions, and 0 < x ≤ 0.3, 0 < m < 2; the near-infrared phosphor can achieve narrow-band near-infrared emission at 650 - 950 nm under the excitation of light with a wavelength of 350 - 600 nm, and its emission peak is 695 nm.

2. A Cr according to claim 1 3+ A method for preparing a doped near-infrared phosphor having narrow-band emission, characterized in that: It includes the following steps: S1: According to the stoichiometric ratio in the chemical formula of the near-infrared phosphor, weigh corresponding masses of compounds containing various elements as preparation raw materials; S2: adding anhydrous ethanol to the prepared raw material weighed in S1, grinding to make it uniformly mixed, and obtaining a grinding raw material; S3: sintering the ground raw material obtained in S2 at a temperature of 1000-1300° C. for 4-48 hours, and then cooling to room temperature to obtain a first sample; S4: grinding the first sample obtained in S3 uniformly, sintering at a temperature of 1000-1300° C. for 4-48 hours, and then cooling to room temperature to obtain a second sample; S5: Grind the second sample obtained in S4 evenly to obtain near-infrared phosphor.

3. A Cr according to claim 2 3+ A method for preparing a doped near-infrared phosphor having narrow-band emission, characterized in that: In the above-mentioned S1, the compounds containing Sc and Al are their respective oxides or nitrates, the compound containing Cr is its oxide, the compound containing Mo is molybdate, and the compound containing W is its tungstate.

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