A novel nd:sc2s2o7 near-infrared fluorescent powder and a preparation method and application thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2026-02-10
- Publication Date
- 2026-06-09
Smart Images
Figure CN122166788A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of luminescent and laser materials technology, specifically relating to a Nd:Sc2Si2O7 near-infrared phosphor whose emission spectrum can effectively cover the 1.1 µm band and its preparation method. Background Technology
[0002] Rare-earth-doped luminescent materials play a vital role in industrial processing, medical diagnostics, spectral analysis, and high-precision detection. However, the 1.1 µm band in the near-infrared spectral range remains a relatively untapped but highly valuable spectral window. Lasers in this band are in urgent need of applications in biomedical imaging (such as optical coherence tomography), nonlinear frequency conversion (such as frequency doubling to generate yellow-green light), and as pump sources for mid-infrared lasers. For example, in biological tissues, photons in this band exhibit lower absorption and scattering losses, enabling deeper tissue penetration and higher signal-to-noise ratio imaging; frequency doubling techniques can be used to generate specific wavelengths of laser light for environmental monitoring or astronomical exploration.
[0003] Currently, rare earth-doped luminescent materials, including those doped with Yb 3+ 、Nd 3+ Ion-based glasses and crystals can achieve high-efficiency, high-intensity luminescence in the 1.0 µm band, but their effective emission is mainly concentrated in the 980 nm to 1060 nm range (DOI: 10.1016 / S0925-8388(03)00379-7, DOI: 10.1002 / pssa.200309016, DOI: 10.1016 / S0925-8388(02)00067-1), failing to effectively cover the target 1.1 µm band. Existing luminescence methods for this band mainly focus on transition metal-doped and main group Bi-doped luminescent materials. For example, CN116656362A discloses a Cr... 3+ Ion-doped halide perovskite materials can produce broadband emission covering 800-1400 nm under 310 nm ultraviolet light excitation. Zhejiang University reported that Bi-doped Y4GeO8 crystals can produce ultra-wideband near-infrared emission with a center at 1155 nm and a full width at half maximum (FWHM) exceeding 300 nm under 808 nm laser excitation (DOI:10.1149 / 1.3607428). However, the luminescence intensity of these materials is usually 1-2 orders of magnitude lower than that of rare-earth ions, and they have inherent defects such as energy dispersion, short excited-state lifetime, high laser threshold, and low slope efficiency. They are more suitable for fluorescent conversion broadband light sources (such as NIR pc-LEDs) where monochromaticity requirements are not high, and it is difficult to achieve efficient and stable high-brightness laser output. In addition, Cr 3+The optimal excitation source for ions is located in the ultraviolet band, which is incompatible with the pump source of commercial high-power near-infrared laser diodes (LDs). Furthermore, the poor chemical stability and low damage threshold of halide materials themselves severely limit their application in the laser field. Meanwhile, the luminescence center of bismuth ions in the near-infrared band is a low-valence state bismuth ion (such as Bi). 0 Bi + (etc.), requiring a harsh reducing atmosphere or high-energy radiation to induce the formation of high-valence Bi. 3+ Reduced to a low-valence state Bi with near-infrared activity + Or Bi 0 Stable and uniform formation of high concentrations of target valence state Bi ions in the matrix is a major process challenge, and the matching between the optimal excitation band and commonly used near-infrared LD pump sources still needs to be optimized. High-efficiency output in the 1.1 µm band still faces fundamental challenges from the gain medium itself.
[0004] Therefore, developing a rare-earth-doped gain medium with an emission spectrum center located in the 1.1 µm band is of urgent need and great significance for expanding the output range of near-infrared lasers and promoting the development of related application technologies. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a 1.1 µm band Nd:Sc2Si2O7 near-infrared phosphor and its preparation method. This method aims to overcome the technical problem that existing rare-earth ion-doped materials cannot achieve efficient luminescence in the 1.1 µm band, and provides a simple, reproducible preparation technique suitable for large-scale production.
[0006] The Nd:Sc2Si2O7 near-infrared phosphor provided by this invention has a Sc2Si2O7 matrix crystal structure that can modulate Nd 3+ The energy level structure of ions causes 4 F 3 / 2 → 4 I 11 / 2 The transition emission redshifts, thus effectively covering the 1.1 µm near-infrared band.
[0007] To achieve the above objectives, the technical solution of the present invention is as follows:
[0008] A 1.1 µm band Nd:Sc2Si2O7 near-infrared phosphor, with the general chemical formula: Sc 2-x Si2O7:xNd 3+ , where x is Nd 3+ The mole fraction of doped ions, where 0.01 ≤ x ≤ 0.07.
[0009] The preparation method of the above-mentioned 1.1 µm band Nd:Sc2Si2O7 near-infrared phosphor is characterized by comprising the following steps: (1) According to the general chemical formula Nd x Sc 2-x The stoichiometric ratio of Si2O7 is as follows: neodymium-containing compound, scandium-containing compound and silicon-containing compound are weighed as main raw materials, and flux is added. The mixture is ground and mixed evenly, and then sieved. (2) The sieve material obtained in step (1) is placed in an air atmosphere and subjected to high-temperature sintering treatment. After cooling to room temperature, it is taken out, ground to make it fine, and sieved to obtain the Nd. x Sc 2-x Si2O7 phosphor.
[0010] Preferably, in step (1), the flux can be selected from at least one or more of lithium fluoride, sodium fluoride, barium fluoride, boric acid, and sodium chloride, and its total addition amount is 0.5 wt.%-10 wt.% of the total mass of the main raw materials.
[0011] Preferably, in step (1), the neodymium-containing compound is selected from at least one of neodymium oxide, neodymium nitrate, neodymium carbonate, or neodymium oxalate; the scandium-containing compound is selected from at least one of scandium oxide, scandium nitrate, scandium carbonate, or scandium oxalate; and the silicon-containing compound is selected from at least one of silicon dioxide, silicate esters, silica sol, and soluble silicates.
[0012] More preferably, the neodymium-containing compound in step (1) is selected from neodymium oxide or neodymium carbonate; the scandium-containing compound is selected from scandium oxide or scandium carbonate; and the silicon-containing compound is selected from silicon dioxide.
[0013] Preferably, the grinding time in step (1) is 10-60 minutes.
[0014] Preferably, the heating rate of the sintering treatment in step (2) is 5-20℃ / min, the sintering temperature is 1300-1600℃, and the holding time is 2-8 hours.
[0015] The application of a Nd:Sc2Si2O7 near-infrared phosphor prepared by the above method in 1.1 µm near-infrared light sources and laser gain media is particularly suitable for specific application scenarios that require 1.1 µm laser output (such as biomedical imaging and treatment with water absorption windows, special material processing, etc.).
[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The emission spectrum of the Nd:Sc2Si2O7 phosphor prepared by this invention can effectively cover the 1.1 µm band, filling the gap of existing materials in this band.
[0017] 2. The Nd:Sc2Si2O7 phosphor prepared by this invention has a strong excitation peak near 808 nm, which is perfectly matched with the commercial, high-power and technically mature 808 nm semiconductor laser diode (LD) pump source.
[0018] 3. The excellent luminescence properties of the Nd:Sc2Si2O7 phosphor prepared by this invention in the 1.1 µm band give it a unique advantage in specific application scenarios that require 1.1 µm band laser output (such as biomedical imaging and treatment with water absorption windows, special material processing, etc.).
[0019] 4. The process technology provided by the present invention has the advantages of being simple and easy to implement, requiring no atmosphere protection, and producing high purity of the product phase. The preparation method adopted by the present invention does not require high production equipment, the process operation is simple and has good repeatability, which is conducive to industrial mass production. Attached Figure Description
[0020] Figure 1 The Sc prepared in Example 1 1.99 Si2O7:0.01Nd 3+ A comparison of the X-ray powder diffraction pattern of the phosphor with the Sc2Si2O7 standard card (ICDD 96-152-8086).
[0021] Figure 2 The Sc prepared in Example 2 1.97 Si2O7:0.03Nd 3+ Refined X-ray powder diffraction structure of phosphor.
[0022] Figure 3 The Sc prepared in Example 3 1.94 Si2O7:0.06Nd 3+ The phosphor was monitored at an excitation wavelength of 1089 nm.
[0023] Figure 4 The Sc prepared in Examples 1 to 4 2-x Si2O7:xNd 3+ Photoluminescence spectrum of phosphor under 808 nm laser excitation.
[0024] Figure 5 The Sc prepared in Example 4 1.93 Si2O7:0.07Nd 3+ The fluorescence decay curve of the phosphor at 1089 nm emission was monitored under 808 nm laser excitation. Detailed Implementation
[0025] To better understand the present invention, the following embodiments are provided for further explanation. However, the described embodiments are merely some, not all, of the embodiments of the present invention, and the scope of protection claimed by the present invention is not limited thereto. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0026] Example 1 The phosphor composition (S1) in this embodiment is: chemical composition Nd 0.01 Sc 1.99 Si₂O₇. The raw materials selected were neodymium carbonate, scandium oxide, and silicon dioxide with a purity of 99.99%. The main raw materials were weighed according to stoichiometric ratio. 10 wt.% of a composite flux (composed of sodium chloride and boric acid in a 1:1 mass ratio) was added to the main raw materials. The mixture was then ground in a mortar for 30 minutes, passed through a 250-mesh sieve, and subsequently transferred to a dense corundum crucible. The temperature was increased to 1300℃ at a heating rate of 20℃ / min and sintered for 8 hours. The furnace was then cooled to room temperature. The sample was removed, ground, and passed through a 325-mesh sieve to obtain Sc. 1.99 Si2O7:0.01Nd 3+ Fluorescent powder.
[0027] The XRD patterns of the phosphors were measured using an Aeris powder X-ray diffractometer (PANalytical Corporation, Netherlands), and the powder diffraction data were refined using GSAS-II software. The photoluminescence spectra of the phosphors were measured using a Zolix Omin3007 spectrometer (Beijing, China), with an 808 nm laser as the excitation source. The excitation spectrum and fluorescence decay lifetime of the phosphors were measured using an Edinburgh FLS920 spectrometer.
[0028] Sc prepared in Example 1 1.99 Si2O7:0.01Nd 3+ A comparison of the X-ray powder diffraction pattern of the phosphor and the standard card (ICDD 96-152-8086) is shown below. Figure 1 As shown, XRD pattern analysis indicates that the obtained sample phase is Sc2Si2O7, belonging to the monoclinic crystal system, and Nd 3+ Ion doping does not introduce other phases or impurities. For example... Figure 4 As shown, the phosphor prepared in Example 1 4 F 3 / 2 → 4 I 11 / 2 The main emission peak corresponding to the transition is centered at 1089 nm, with a full width at half maximum (FWHM) of 30 nm, a fluorescence lifetime of 249 µs, and a fluorescence branching ratio as high as 74.7%.
[0029] Example 2 The phosphor composition (S2) in this embodiment is: chemical composition Nd 0.03 Sc 1.97 Si₂O₇. The raw materials selected were neodymium oxide, scandium carbonate, and silicon dioxide with a purity of 99.99%. The main raw materials were weighed according to stoichiometric ratio. 5 wt.% of a composite flux (composed of lithium fluoride and sodium fluoride in a 1:1 mass ratio) was added to the main raw materials. The mixture was then ground in a mortar for 10 minutes, passed through a 250-mesh sieve, and subsequently transferred to a dense corundum crucible. The temperature was increased to 1400℃ at a heating rate of 15℃ / min and sintered for 6 hours. The furnace was then cooled to room temperature. The sample was removed, ground, and passed through a 325-mesh sieve to obtain Sc. 1.97 Si2O7:0.03Nd 3+ Fluorescent powder.
[0030] The XRD patterns of the phosphors were measured using an Aeris powder X-ray diffractometer (PANalytical Corporation, Netherlands), and the powder diffraction data were refined using GSAS-II software. The photoluminescence spectra of the phosphors were measured using a Zolix Omin3007 spectrometer (Beijing, China), with an 808 nm laser as the excitation source. The excitation spectrum and fluorescence decay lifetime of the phosphors were measured using an Edinburgh FLS920 spectrometer.
[0031] The Sc prepared in Example 2 1.97 Si2O7:0.03Nd 3+ The structure of the phosphor was refined using X-ray powder diffraction patterns, such as... Figure 2 As shown, the weighted residual factor R wp =9.853%, chi-square χ 2 =1.72, indicating that the refinement result is of very high quality, and the model and experimental data are in excellent agreement, fully demonstrating that the synthesized phosphor is the target phase with good crystallinity and high phase purity. Figure 4 As shown, the phosphor prepared in Example 2 4 F 3 / 2 → 4 I 11 / 2 The main emission peak corresponding to the transition is centered at 1089 nm, with a full width at half maximum (FWHM) of 30 nm, a fluorescence lifetime of 228 µs, and a fluorescence branching ratio of 71.6%.
[0032] Example 3 The phosphor composition (S3) in this embodiment is: chemical composition Nd 0.06 Sc 1.94Si₂O₇. The raw materials selected were neodymium oxide, scandium carbonate, and silicon dioxide with a purity of 99.99%. The main raw materials were weighed according to stoichiometric ratios. 0.5 wt.% of barium fluoride flux was added to the main raw materials, and the mixture was ground in a mortar for 20 minutes, passed through a 250-mesh sieve, and then transferred to a dense corundum crucible. The temperature was increased to 1500℃ at a heating rate of 10℃ / min and sintered for 4 hours. The mixture was then cooled to room temperature in the furnace, and the sample was removed, ground, and passed through a 325-mesh sieve to obtain Sc. 1.94 Si2O7:0.06Nd 3+ Fluorescent powder.
[0033] The XRD patterns of the phosphors were measured using an Aeris powder X-ray diffractometer (PANalytical Corporation, Netherlands), and the powder diffraction data were refined using GSAS-II software. The photoluminescence spectra of the phosphors were measured using a Zolix Omin3007 spectrometer (Beijing, China), with an 808 nm laser as the excitation source. The excitation spectrum and fluorescence decay lifetime of the phosphors were measured using an Edinburgh FLS920 spectrometer.
[0034] Sc prepared in Example 3 1.94 Si2O7:0.06Nd 3+ The excitation spectrum of the phosphor at a monitoring wavelength of 1089 nm is as follows: Figure 3 As shown, the excitation peak is strong at 808 nm, therefore a commercially available 808 nm laser can be used to effectively excite the sample. Figure 4 As shown, the Sc prepared in Example 3 1.94 Si2O7:0.06Nd 3+ fluorescent powder 4 F 3 / 2 → 4 I 11 / 2 The main emission peak corresponding to the transition is centered at 1089 nm, with a full width at half maximum (FWHM) of 30 nm, a fluorescence lifetime of 196 µs, and a fluorescence branching ratio as high as 73.4%, indicating that the Sc2Si2O7 crystal matrix is Nd. 3+ The ions provide a unique lattice environment, enabling the emission spectrum to be effectively redshifted and stably cover the 1.1 µm band. The high fluorescence branching ratio of 73.4% indicates that the luminescent material has an extremely high radiative transition probability in the 1.1 µm band, showing outstanding potential for achieving low threshold and high efficiency laser output. It is an ideal candidate gain medium for developing high-performance compact lasers in this band.
[0035] Example 4 The phosphor composition (S4) in this embodiment is: chemical composition Nd 0.07 Sc 1.93Si₂O₇. The raw materials selected were neodymium oxide, scandium oxide, and silicon dioxide with a purity of 99.99%. The raw materials were weighed according to stoichiometric ratio and ground in a mortar for 60 minutes. The mixture was then passed through a 250-mesh sieve and transferred to a dense corundum crucible. The temperature was increased to 1600℃ at a rate of 5℃ / min and sintered for 2 hours. The mixture was then cooled to room temperature in the furnace. The sample was removed, ground, and passed through a 325-mesh sieve to obtain Sc. 1.93 Si2O7:0.07Nd 3+ Fluorescent powder.
[0036] The XRD patterns of the phosphors were measured using an Aeris powder X-ray diffractometer (PANalytical Corporation, Netherlands), and the powder diffraction data were refined using GSAS-II software. The photoluminescence spectra of the phosphors were measured using a Zolix Omin3007 spectrometer (Beijing, China), with an 808 nm laser as the excitation source. The excitation spectrum and fluorescence decay lifetime of the phosphors were measured using an Edinburgh FLS920 spectrometer.
[0037] like Figure 4 As shown, the phosphor prepared in Example 4 4 F 3 / 2 → 4 I 11 / 2 The main emission peak corresponding to the transition is centered at 1089 nm, with a full width at half maximum (FWHM) of 30 nm and a fluorescence branching ratio of 76.4%. Example 4 shows the prepared Sc... 1.93 Si2O7:0.07Nd 3+ The fluorescence decay curve of the phosphor is as follows Figure 5 As shown, the phosphor obtained in this embodiment is excited at 808 nm, emits at a wavelength of 1089 nm, and has a fluorescence lifetime of 192 µs. The long excited-state lifetime and the high fluorescence branching ratio of 73.4% indicate that the luminescent material has both high energy radiation output capability and good energy storage capability, which are key advantages for evaluating laser gain media. This suggests that the luminescent material has great potential in achieving low threshold, high efficiency laser operation, especially high-energy pulsed laser output.
[0038] The above embodiments demonstrate that the Nd:Sc2Si2O7 phosphor provided by this invention can effectively cover the 1.1 µm near-infrared band, effectively filling the material gap near the 1.1 µm band, and has significant value in advancing the development of 1.1 µm band laser technology. The preparation method described in this invention is simple and has good repeatability, providing a feasible path for the development and large-scale production of novel gain materials.
[0039] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A 1.1 µm band Nd:Sc2Si2O7 near-infrared phosphor, characterized in that: The general chemical formula of the phosphor is Nd. x Sc 2-x Si2O7, where x is Nd 3+ The mole fraction of doped ions, where 0.01 ≤ x ≤ 0.
07.
2. The method for preparing 1.1 µm band Nd:Sc2Si2O7 near-infrared phosphor according to claim 1, characterized in that: Includes the following steps: (1) According to the general chemical formula Nd x Sc 2-x The stoichiometric ratio of raw materials containing neodymium, scandium and silicon compounds was used to prepare Si2O7. A flux was added, the mixture was ground and mixed evenly, and then the mixture was sieved. (2) The sieve material obtained in step (1) is placed in an air atmosphere and subjected to high-temperature sintering treatment. After cooling to room temperature, it is taken out, ground, and sieved to obtain the Nd. x Sc 2-x Si2O7 phosphor.
3. The preparation method according to claim 2, characterized in that: The neodymium-containing compound is selected from at least one of neodymium oxide, neodymium nitrate, neodymium carbonate, or neodymium oxalate; the scandium-containing compound is selected from at least one of scandium oxide, scandium nitrate, scandium carbonate, or scandium oxalate; and the silicon-containing compound is selected from at least one of silicon dioxide, silicates, silica sols, and soluble silicates.
4. The preparation method according to claim 3, characterized in that: The neodymium-containing compound is selected from neodymium oxide or neodymium carbonate; the scandium-containing compound is selected from scandium oxide or scandium carbonate; and the silicon-containing compound is selected from silicon dioxide.
5. The preparation method according to claim 2, characterized in that: In step (1), the flux is selected from at least one or more of lithium fluoride, sodium fluoride, barium fluoride, boric acid, and sodium chloride.
6. The preparation method according to claim 2, characterized in that: In step (1), the total amount of flux added is 0.5 wt.% to 10 wt.% of the total mass of the main raw materials.
7. The preparation method according to claim 2, characterized in that: In step (1), the grinding and mixing time is 10-60 minutes.
8. The preparation method according to claim 2, characterized in that: In step (2), the heating rate of the sintering treatment is 5-20℃ / min, the sintering temperature is 1300-1600℃, and the holding time is 2-8 hours.
9. A Nd:Sc2Si2O7 near-infrared phosphor prepared by the preparation method according to any one of claims 1-8.
10. The application of the Nd:Sc2Si2O7 near-infrared phosphor according to claim 9 in the preparation of 1.1 µm near-infrared light sources and laser gain media.