A type of Cr 3+ Doped oxide phosphors, their preparation methods and applications

Abstract

This invention relates to a Cr 3+ Doped oxide phosphors, their preparation methods and applications, wherein the Cr 3+ The structural formula of the doped oxide phosphor is AB 1‑x Cr x W₂O₈, wherein A comprises any one or a combination of at least two of Li, Na, K, Rb, or Cs; B comprises any one or a combination of at least two of Sc, Y, Ga, or Gd; 0.01 ≤ x ≤ 0.18. The Cr of this invention... 3+ Doped oxide phosphors, single-doped Cr 3+ When excited by green or red light, near-infrared emission is achieved, with an emission peak around 1060 nm, covering the deep red region to the near-infrared II region, making it an ultra-wideband near-infrared oxide phosphor; by exciting the phosphor with a matched LED, a near-infrared light emitting device can be obtained.

Description

Technical Field

[0001] This invention relates to the field of fluorescent materials technology, specifically to a Cr... 3+ Doped oxide phosphors, their preparation methods, and applications. Background Technology

[0002] In recent years, PC-LEDs, fabricated by combining green or red LED chips with near-infrared phosphors, have found wide application in various fields, offering advantages such as small size, wide emission bandwidth, high radiative flux, and long lifespan. In this approach, the phosphor has a significant impact on the performance of the PC-LED; however, currently, there are relatively few near-infrared phosphors suitable for matching LED chips, and those that exist have narrow full width at half maximum (FWHM).

[0003] CN116656360A discloses an ultra-wideband emission near-infrared phosphor, the chemical composition of which is expressed as: (Nd x La 1-x )2Ca(Cr y Zr 1-y O6, where x and y take values ​​in the range of 0.001≤x≤0.10 and 0.005≤y≤0.05. This phosphor has two emission peaks with peak wavelengths at 900nm and 1100nm respectively, but their full width at half maximum (FWHM) is only about 100nm.

[0004] Currently, most phosphors have limited emission bandwidth in the near-infrared region, which restricts their application in many fields. Therefore, developing a new ultra-wideband near-infrared phosphor to extend its emission range in the infrared band and broaden its application scope has become an urgent problem to be solved in this field. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a Cr 3+ Doped oxide phosphor with the structural formula AB 1- x Cr x W₂O₈, 0.01≤x≤0.18, belongs to the monoclinic crystal system with space group C² / m. Under green or red light excitation, its emission peak is around 1060 nm, covering the deep red region to the near-infrared II region, making it an ultra-wideband near-infrared oxide phosphor.

[0006] To achieve this objective, the present invention employs the following technical solution:

[0007] Firstly, the present invention provides a Cr 3+ Doped oxide phosphor, wherein the Cr 3+ The structural formula of the doped oxide phosphor is AB 1-x Cr x W2O8;

[0008] Wherein, A includes any one or at least two of Li, Na, K, Rb or Cs; B includes any one or at least two of Sc, Y, Ga or Gd; 0.01≤x≤0.18.

[0009] The Cr provided by this invention 3+ Doped oxide phosphors, specifically tungstate phosphors, are selected because they have a monoclinic crystal system and contain Cr. 3+ Entering positions with larger B ion radii, a weaker crystal field can be generated, while simultaneously reducing Cr... 3+ As a single-doped luminescent center, using Cr 3+ It occupies the lattice site of the B ion, enters the octahedron, and undergoes... 4 T2→ 4 The A2 transition, when the activating ion occupies the B ion site, results in a weak crystal field, achieving an emission peak at around 1060 nm, which can cover the ultra-wideband near-infrared emission from the deep red region to the near-infrared II region.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0011] Preferably, A includes any one or at least two combinations of Li, Na, K, Rb, or Cs. Typical but non-limiting examples of such combinations include combinations of Li and Na, Li and K, Li and Rb, Li and Cs, Na and K, Na and Rb, Na and Cs, Rb and K, Cs and K, and Rb and Cs.

[0012] Preferably, B includes any one or a combination of at least two of Sc, Y, Ga, or Gd, with typical but non-limiting examples of such combinations including combinations of Sc and Y, Sc and Ga, Sc and Gd, Y and Ga, Y and Gd, and Ga and Gd.

[0013] Preferably, 0.01≤x≤0.18, for example, x is 0.01, 0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16 or 0.18, etc., but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0014] Preferably, the Cr 3+ The doped oxide phosphor is monoclinic.

[0015] Preferably, the Cr 3+The space group of the doped oxide phosphor is C2 / m.

[0016] Preferably, the Cr 3+ The effective excitation wavelength for doped oxide phosphors is 250–900 nm, such as 250 nm, 280 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 720 nm, 750 nm, 850 nm, or 900 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0017] Secondly, the present invention provides a Cr according to the first aspect. 3+ A method for preparing doped oxide phosphors, the method comprising the following steps:

[0018] (1) Based on the structural formula AB 1-x Cr x W2O8, weigh out raw materials containing A, B, W and Cr according to stoichiometric ratio, mix them evenly to obtain a mixture;

[0019] Wherein, A includes any one or at least two of Li, Na, K, Rb or Cs; B includes any one or at least two of Sc, Y, Ga or Gd; 0.01≤x≤0.18;

[0020] (2) The mixture described in step (1) is sintered to obtain Cr. 3+ Doped oxide phosphors.

[0021] Preferably, the A-containing raw material in step (1) includes any one or a combination of at least two of A-containing carbonates, A-containing oxides, or A-containing hydroxides. Typical but non-limiting examples of such combinations include combinations of A-containing carbonates and A-containing oxides, combinations of A-containing carbonates and A-containing hydroxides, and combinations of A-containing oxides and A-containing hydroxides. Preferably, it contains A-containing oxides and / or A-containing carbonates.

[0022] Preferably, the B-containing raw material in step (1) includes any one or a combination of at least two of B-containing carbonates, B-containing oxides, or B-containing hydroxides. Typical but non-limiting examples of such combinations include combinations of B-containing carbonates and B-containing oxides, combinations of B-containing oxides and B-containing hydroxides, and combinations of B-containing carbonates and B-containing hydroxides.

[0023] Preferably, the W-containing raw material in step (1) includes any one of W-containing nitrates and W-containing oxides, and is preferably a W-containing oxide.

[0024] Preferably, the Cr-containing raw material in step (1) includes any one or a combination of at least two of Cr-containing oxides, Cr-containing nitrides, Cr-containing halides, Cr-containing nitrates, or Cr-containing carbonates. Typical but non-limiting examples of such combinations include combinations of Cr-containing oxides and Cr-containing nitrides, combinations of Cr-containing oxides and Cr-containing halides, combinations of Cr-containing oxides and Cr-containing nitrates, combinations of Cr-containing nitrides and Cr-containing halides, combinations of Cr-containing oxides and Cr-containing carbonates, combinations of Cr-containing nitrides and Cr-containing nitrates, combinations of Cr-containing nitrides and Cr-containing carbonates, combinations of Cr-containing halides and Cr-containing nitrates, combinations of Cr-containing halides and Cr-containing carbonates, and combinations of Cr-containing nitrates and Cr-containing carbonates.

[0025] Preferably, the mixing method in step (1) includes mechanical grinding or manual grinding, preferably manual grinding.

[0026] Preferably, the manual grinding is carried out in an agate mortar.

[0027] Preferably, the sintering in step (2) is carried out in an air atmosphere.

[0028] Preferably, the sintering temperature in step (2) is 800 to 1100°C, such as 800°C, 820°C, 840°C, 860°C, 880°C, 900°C, 920°C, 940°C, 960°C, 980°C, 1000°C, 1020°C, 1040°C, 1060°C, 1080°C, or 1100°C, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0029] The sintering temperature described in this invention is 800-1100℃. If the sintering temperature is higher than 1100℃, the resulting oxide phosphor will volatilize, which is not conducive to subsequent processing. If the sintering temperature is lower than 800℃, the resulting tungstate phosphor will be impure and have low luminous brightness. This is because the reaction cannot be fully carried out even with a long sintering time due to the low temperature.

[0030] Preferably, the sintering holding time in step (2) is 1 to 10 hours, such as 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0031] Preferably, the preparation method further includes processing the Cr obtained in step (2) 3+ The doped oxide phosphors were sequentially ground, washed, dried, and sieved.

[0032] As a preferred technical solution, the preparation method includes the following steps:

[0033] (1) Based on the structural formula AB 1-x Cr x W2O8, weigh out raw materials containing A, B, W and Cr according to stoichiometric ratio, mix them evenly to obtain a mixture;

[0034] Wherein, A includes any one or at least two of Li, Na, K, Rb, or Cs; B includes any one or at least two of Sc, Y, Ga, or Gd; 0.01≤x≤0.18; the A-containing raw material includes any one or at least two of A-containing carbonates, A-containing oxides, or A-containing hydroxides; the B-containing raw material includes any one or at least two of B-containing oxides, B-containing carbonates, or B-containing hydroxides; the W-containing raw material includes any one of W-containing nitrates or W-containing oxides; the Cr-containing raw material includes any one or at least two of Cr-containing oxides, Cr-containing nitrides, Cr-containing halides, Cr-containing nitrates, or Cr-containing carbonates.

[0035] (2) The mixture obtained in step (1) is sintered in air at 800–1100°C for 1–10 h, and then subjected to grinding, washing, drying and sieving to obtain the Cr. 3+ Doped oxide phosphors.

[0036] Thirdly, the present invention provides a Cr 3+ The application of doped oxide phosphors, specifically the Cr described in the first aspect... 3+ Doped oxide phosphors, or Cr prepared by the preparation method described in the second aspect. 3+ Doped oxide phosphors are used in near-infrared light-emitting devices.

[0037] Preferably, the near-infrared light-emitting device includes a near-infrared light-emitting diode excited by a green or red light chip.

[0038] It should be noted that the emission spectrum of this material is in the near-infrared II region.

[0039] Compared with the prior art, the present invention has at least the following beneficial effects:

[0040] (1) The Cr described in this invention 3+ Doped oxide phosphors, Cr 3+ When used as a single-doped luminescent center, its emission peak is around 1060 nm under green or red light excitation, covering the deep red region to the near-infrared II region, making it an ultra-wideband near-infrared oxide phosphor.

[0041] (2) The Cr of the present invention3+ The doped oxide phosphor is prepared by a high-temperature solid-state method. The reaction is carried out under normal pressure, the reaction conditions are mild, easy to operate, and the cost is low. Attached Figure Description

[0042] Figure 1 The Cr obtained in Example 1 of this invention 3+ XRD pattern of doped oxide phosphor;

[0043] Figure 2 The Cr obtained in Example 1 of this invention 3+ Excitation and emission spectra of doped oxide phosphors. Detailed Implementation

[0044] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0045] Example 1

[0046] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is LiSc 0.99 Cr 0.01 W2O8, the preparation method includes the following steps:

[0047] (1) Based on the structural formula LiSc 0.99 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0048] (2) The mixture obtained in step (1) is sintered in air at 900°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain LiSc. 0.99 Cr 0.01 W2O8 phosphor.

[0049] Example 2

[0050] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is Li 0.98 Na 0.02 Sc 0.99 Cr 0.01 W2O8, the preparation method includes the following steps:

[0051] (1) Based on the structural formula Li 0.98 Na 0.02 Sc 0.99 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Na2CO3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0052] (2) The mixture described in step (1) is sintered in air at 950°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain Li. 0.98 Na 0.02 Sc 0.99 Cr 0.01 W2O8 phosphor.

[0053] Example 3

[0054] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is Li 0.98 K 0.02 Sc 0.99 Cr 0.01 W2O8, the preparation method includes the following steps:

[0055] (1) Based on the structural formula Li 0.98 K 0.02 Sc 0.99 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, K2CO3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0056] (2) The mixture described in step (1) is sintered in air at 900°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain Li. 0.98 K 0.02 Sc 0.99 Cr 0.01 W2O8 phosphor.

[0057] Example 4

[0058] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is Li 0.98 Rb 0.02 Sc 0.99 Cr 0.01The preparation method of W2O8 by stoichiometry includes the following steps:

[0059] (1) Based on the structural formula Li 0.98 Rb 0.02 Sc 0.99 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Rb2CO3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0060] (2) The mixture described in step (1) is sintered in air at 900°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain Li. 0.98 Rb 0.02 Sc 0.99 Cr 0.01 W2O8 phosphor.

[0061] Example 5

[0062] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is Li 0.98 Cs 0.02 Sc 0.99 Cr 0.01 W2O8, the preparation method includes the following steps:

[0063] (1) Based on the structural formula Li 0.98 Cs 0.02 Sc 0.99 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Cs2CO3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0064] (2) The mixture described in step (1) is sintered in air at 900°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain Li. 0.98 Cs 0.02 Sc 0.99 Cr 0.01 W2O8 phosphor.

[0065] Example 6

[0066] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is LiSc 0.97 Ga 0.02 Cr0.01 W2O8, the preparation method includes the following steps:

[0067] (1) Based on the structural formula LiSc 0.97 Ga 0.02 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Ga2O3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0068] (2) The mixture obtained in step (1) is sintered in air at 900°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain LiSc. 0.97 Ga 0.02 Cr 0.01 W2O8 phosphor.

[0069] Example 7

[0070] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is LiSc 0.97 Y 0.02 Cr 0.01 W2O8, the preparation method includes the following steps:

[0071] (1) Based on the structural formula LiSc 0.97 Y 0.02 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Y2O3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0072] (2) The mixture obtained in step (1) is sintered in air at 950°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain LiSc. 0.97 Y 0.02 Cr 0.01 W2O8 phosphor.

[0073] Example 8

[0074] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is LiSc 0.97 Gd 0.02 Cr 0.01 W2O8, the preparation method includes the following steps:

[0075] (1) Based on the structural formula LiSc0.97 Gd 0.02 Cr 0.01 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Gd2O3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0076] (2) The mixture obtained in step (1) is sintered in air at 950°C for 4 hours, and then subjected to grinding, washing, drying and sieving to obtain LiSc. 0.97 Gd 0.02 Cr 0.01 W2O8 phosphor.

[0077] Example 9

[0078] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is Li 0.98 Na 0.02 Sc 0.8 Gd 0.02 Cr 0.18 W2O8, the preparation method includes the following steps:

[0079] (1) Based on the structural formula Li 0.98 Na 0.02 Sc 0.8 Gd 0.02 Cr 0.18 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Na2CO3, Gd2O3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0080] (2) The mixture obtained in step (1) is sintered in air at 1100°C for 1 hour, and then subjected to grinding, washing, drying and sieving to obtain Li. 0.98 Na 0.02 Sc 0.8 Gd 0.02 Cr 0.18 W2O8 phosphor.

[0081] Example 10

[0082] This embodiment provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structural formula of the doped oxide phosphor is LiSc 0.88 Gd 0.03 Cr 0.09 W2O8, the preparation method includes the following steps:

[0083] (1) Based on the structural formula LiSc 0.88 Gd 0.03 Cr 0.09 To determine the stoichiometric ratio of W2O8, weigh out Li2CO3, Gd2O3, Sc2O3, Cr2O3, and WO3, place them in an agate mortar, and grind and mix them thoroughly to obtain a mixture.

[0084] (2) The mixture obtained in step (1) is sintered in air at 800°C for 10 hours, and then subjected to grinding, washing, drying and sieving to obtain LiSc. 0.88 Gd 0.03 Cr 0.09 W2O8 phosphor.

[0085] Comparative Example 1

[0086] This comparative example provides an Eu 3+ The difference between this comparative example and Example 1 is that Eu is used. 3+ As a single-doped luminescent center, the Eu 3+ The structural formula of the doped oxide phosphor is Na 0.8 Li 0.2 Y 0.91 Eu 0.09 (WO4)2, in step (1), according to the structural formula Na 0.8 Li 0.2 Y 0.91 Eu 0.09 The stoichiometric ratio of (WO4)2 was determined by weighing Na2CO3, Li2CO3, Y2O3, Eu2O3, and WO3, with the remaining preparation methods and parameters consistent with those in Example 1.

[0087] Comparative Example 2

[0088] This comparative example provides a Cr 3+ Doped oxide phosphors and their preparation methods: This comparative example differs from Example 6 in that Ga is replaced with La, and the Cr... 3+ The structural formula of the doped oxide phosphor is LiSc 0.97 La 0.02 Cr 0.01 W2O8, in step (1), according to the structural formula LiSc 0.97 La 0.02 Cr 0.01 The stoichiometric ratio of W2O8 was determined by weighing Li2CO3, La2O3, Sc2O3, Cr2O3, and WO3, with the remaining preparation methods and parameters consistent with those in Example 6.

[0089] Comparative Example 3

[0090] This comparative example provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structure of the doped oxide phosphor is the same as that in Example 1. The difference between this comparative example and Example 1 is that the sintering temperature in step (2) is 700℃, and the rest of the preparation methods and parameters are the same as those in Example 1.

[0091] Comparative Example 4

[0092] This comparative example provides a Cr 3+ Doped oxide phosphors and their preparation methods, wherein the Cr 3+ The structure of the doped oxide phosphor is the same as that in Example 1. The difference between this comparative example and Example 1 is that the sintering temperature in step (2) is 1200℃, and the rest of the preparation methods and parameters are the same as those in Example 1.

[0093] Cr obtained in Example 1 3+ XRD pattern of doped oxide phosphor as shown in Figure 1 As shown, by Figure 1 It can be seen that the LiSc obtained in this embodiment 0.99 Cr 0.01 The crystal phases of W2O8 and LiScW2O8 are consistent.

[0094] Cr obtained in Example 1 3+ The excitation and emission spectra of doped oxide phosphors are as follows: Figure 2 As shown, by Figure 2 It can be seen that LiSc 0.99 Cr 0.01 W2O8 can be effectively excited by light in the range of 250–800 nm. When excited by green or red light, its emission peak is located in the near-infrared region of 1060 nm.

[0095] Near-infrared light sources were prepared by using the oxide phosphors obtained in Examples 1-10 and Comparative Examples 1-4 according to the following process: using green or red LEDs as excitation light sources, the phosphors and silica gel were mixed evenly at a mass ratio of 1:1 and then coated onto green or red LED chips. The mixtures were then placed in a drying oven and dried at 100°C for 12 hours to obtain the near-infrared light source.

[0096] Test methods

[0097] The PLE and PL spectra were recorded using an FLS1000 spectrometer (Edinburgh) equipped with a 450W xenon lamp as the excitation source. The specific test results are shown in Table 1.

[0098] Table 1

[0099]

[0100]

[0101] Note: " / " indicates that the target oxide phosphor has not formed a phase and cannot be tested to obtain corresponding data.

[0102] The test results show that:

[0103] (1) As can be seen from Examples 1 to 10, the Cr of the present invention 3+ Doped oxide phosphors achieve broadband emission in the near-infrared region by utilizing the presence of Cr in the material. 3+ The octahedral environment characteristic of this material enabled the realization of single-doped Cr. 3+ A near-infrared ultrawideband oxide phosphor was obtained;

[0104] (2) Comparing Example 1 with Examples 2-10, it can be seen that changing the cations in the matrix will narrow the emission peak and cause a blue shift in the emission peak position, but the full width at half maximum (FWHM) is still at a relatively wide level.

[0105] (3) Comparing Examples 1-5 with Examples 1, 6-8, it can be seen that the full width at half maximum (FWHM) of the cation at position A in the matrix changes by 23 nm; the full width at half maximum (FWHM) of the cation at position B in the matrix changes by 47 nm. It is evident that the change in FWHM of the cation at position B in the matrix is ​​more significant.

[0106] (4) Comparing Example 1 with Comparative Example 1, it can be seen that if Eu is used... 3+ When used as a single-doped luminescent center, its emission peak is only 614 nm and its full width at half maximum (FWHM) is only 5.32 nm, which is significantly lower than that of Example 1 of this application. This indicates that Cr... 3+ When used as a single-doped luminescent center, its emission peak value and full width at half maximum (FWHM) are both superior.

[0107] (5) Comparing Example 6 with Comparative Example 2, it can be seen that if La is used to replace Ga, since the radius of La is much different from that of Cr, it is difficult for Cr to enter the lattice of La, resulting in a reduction in both the emission peak value and the full width at half maximum (FWHM).

[0108] (6) Comparing Example 1 with Comparative Examples 3-4, when the sintering temperature is too high or too low, Cr 3+ Doped oxide phosphors cannot form phases, thus making testing impossible.

[0109] In summary, this invention provides a Cr 3+ Doped oxide phosphor with the structural formula AB 1-x Cr xW₂O₈, 0.01≤x≤0.18, belongs to the monoclinic crystal system with space group C² / m. Under green or red light excitation, its emission peak is around 1060 nm, covering the deep red region to the near-infrared II region, making it an ultra-wideband near-infrared oxide phosphor.

[0110] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An ultrawideband near-infrared Cr 3+ Doped oxide phosphor, characterized in that, The Cr 3+ The structural formula of the doped oxide phosphor is AB 1-x Cr x W2O8; Wherein, A includes any one or at least two of Li, Na, K, Rb or Cs; B includes any one or at least two of Sc, Y, Ga or Gd; 0.01≤x≤0.18; The Cr 3+ The space group of the doped oxide phosphor is C2 / m; The Cr 3+ The effective excitation wavelength for doped oxide phosphors is 500~850nm.

2. The ultra-wideband near-infrared Cr as described in claim 1 3+ Doped oxide phosphor, characterized in that, The Cr 3+ The doped oxide phosphor is monoclinic.

3. An ultra-wideband near-infrared Cr according to claim 1 or 2 3+ A method for preparing doped oxide phosphors, characterized in that, The preparation method includes the following steps: (1) Based on the structural formula AB 1-x Cr x W2O8, weigh out raw materials containing A, B, W and Cr according to stoichiometric ratio, mix them evenly to obtain a mixture; Wherein, A includes any one or at least two of Li, Na, K, Rb or Cs; B includes any one or at least two of Sc, Y, Ga or Gd; 0.01≤x≤0.18; (2) The mixture described in step (1) is sintered at a temperature of 800~1100℃ to obtain ultra-wideband near-infrared Cr. 3+ Doped oxide phosphors.

4. The preparation method according to claim 3, characterized in that, The raw material containing A in step (1) includes any one or a combination of at least two of the following: A-containing carbonates, A-containing oxides, or A-containing hydroxides.

5. The preparation method according to claim 4, characterized in that, The raw material containing A in step (1) is an A-containing carbonate and / or an A-containing oxide.

6. The preparation method according to claim 3, characterized in that, The B-containing raw material in step (1) includes any one or a combination of at least two of B-containing carbonates, B-containing oxides, or B-containing hydroxides.

7. The preparation method according to claim 3, characterized in that, The W-containing raw material in step (1) includes W-containing oxides.

8. The preparation method according to claim 3, characterized in that, The Cr-containing raw materials in step (1) include any one or a combination of at least two of the following: Cr-containing oxides, Cr-containing nitrides, Cr-containing halides, Cr-containing nitrates, or Cr-containing carbonates.

9. The preparation method according to claim 3, characterized in that, The mixing method described in step (1) includes mechanical grinding or manual grinding.

10. The preparation method according to claim 9, characterized in that, The mixing method described in step (1) is manual grinding.

11. The preparation method according to claim 9, characterized in that, The manual grinding is carried out in an agate mortar.

12. The preparation method according to claim 3, characterized in that, The sintering in step (2) is carried out in an air atmosphere.

13. The preparation method according to claim 3, characterized in that, The holding time for sintering in step (2) is 1~10h.

14. The preparation method according to claim 3, characterized in that, The preparation method further includes processing the Cr obtained in step (2) 3+ The doped oxide phosphors were sequentially ground, washed, dried, and sieved.

15. The preparation method according to claim 3, characterized in that, The preparation method includes the following steps: (1) Based on the structural formula AB 1-x Cr x W2O8, weigh out raw materials containing A, B, W and Cr according to stoichiometric ratio, mix them evenly to obtain a mixture; Wherein, A includes any one or at least two of Li, Na, K, Rb, or Cs; B includes any one or at least two of Sc, Y, Ga, or Gd; 0.01≤x≤0.18; the A-containing raw material includes any one or at least two of A-containing carbonates, A-containing oxides, or A-containing hydroxides; the B-containing raw material includes any one or at least two of B-containing oxides, B-containing carbonates, or B-containing hydroxides; the W-containing raw material includes W-containing oxides; the Cr-containing raw material includes any one or at least two of Cr-containing oxides, Cr-containing nitrides, Cr-containing halides, Cr-containing nitrates, or Cr-containing carbonates. (2) The mixture described in step (1) is sintered in air at 800~1100℃ for 1~10h, and then successively ground, washed, dried and sieved to obtain the Cr. 3+ Doped oxide phosphors.

16. A Cr 3+ The application of doped oxide phosphors is characterized by, The Cr as described in claim 1 or 2 3+ Doped oxide phosphor, or Cr prepared by the preparation method according to any one of claims 3-15. 3+ Doped oxide phosphors are used in near-infrared light-emitting devices.

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