Rare earth doped gallium oxide microspheres and preparation method thereof
Rare earth-doped gallium oxide microspheres were prepared in room temperature air by gas-phase ablation, which solved the problems of high experimental conditions and major safety hazards in the prior art, and obtained a hollow core-shell structure microsphere with smooth surface, which had laser characteristics.
Patent Information
- Application Number
- CN202510760114.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-09
- Publication Date
- 2025-08-15
AI Technical Summary
The prior art has problems such as high experimental demand, high safety risks and difficult to control when preparing rare earth-doped gallium oxide microspheres, especially the risk of flammable and explosive gases in liquid ablation.
The gas-phase ablation method is used to ablate the rare-earth doped gallium oxide target using a focus pulse laser in room temperature air. By dropping solution on the substrate and adjusting the laser output power, a light-earth doped gallium oxide microspheres with a smooth surface are prepared.
A microsphere preparation is achieved with simple control in room temperature air, avoiding direct contact between high-energy laser and liquid, and obtaining hollow core-shell structure microspheres with micron diameters, with obvious laser characteristics.
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Figure CN120483236A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to microspheres and a preparation method thereof, in particular to rare earth doped gallium oxide microspheres and a preparation method thereof. Background Art
[0002] Rare earth ion materials, with their unique electronic energy level structure and unique optical properties, have attracted the attention of numerous researchers, who are dedicated to studying their sensing and tunable luminescence properties. By varying the type and concentration of the rare earth doping element and the carrier material, excellent luminescence properties have been demonstrated. Gallium oxide, a fourth-generation semiconductor, has an ultra-wide bandgap exceeding 4.6 eV at room temperature and exhibits excellent thermal and chemical stability, maintaining its original chemical properties under harsh environmental conditions such as high temperature and high pressure. Although gallium oxide is an indirect bandgap semiconductor material, making intrinsic luminescence difficult to achieve, it can serve as an excellent carrier material for rare earth ion doping.
[0003] Microsphere cavities are ideal optical microcavity structures, boasting exceptionally high light field confinement capabilities. They minimize optical losses during total internal reflection of light off the inner walls, resulting in the highest cavity quality factor. In particular, gallium oxide (GaO) possesses high dielectric constants and refractive indexes, further enhancing the localized amplification of light fields within micro- and nanostructures. Therefore, GaO microspheres are promising candidates for nanolasers.
[0004] Among existing preparation methods, chemical vapor deposition and hydrothermal methods have been successfully used to synthesize one-dimensional gallium oxide materials, successfully producing gallium oxide microrods, microribbons, and nanorod arrays. New methods for preparing nanomaterials using laser ablation of solid targets immersed in liquids have attracted widespread attention. However, liquid-phase ablation methods require high experimental requirements and pose certain safety risks. For example, the liquid-phase ablation process may generate flammable and explosive gases or vapors. Summary of the Invention
[0005] Purpose of the invention: In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing rare earth-doped gallium oxide microspheres that is easy to control. Another purpose of the present invention is to provide rare earth-doped gallium oxide microspheres with laser properties.
[0006] Technical solution: The method for preparing rare earth-doped gallium oxide microspheres of the present invention comprises the following steps:
[0007] Step 1: focusing the laser beam of a pulsed laser and adjusting its focus to the surface of a rare earth-doped gallium oxide target;
[0008] Step 2: Add the solution dropwise onto the substrate whose position has been pre-adjusted, so that the solution evenly covers the surface of the substrate;
[0009] Step 3: Adjust the laser output power to 1.7-2.0 mW and ablate the rare earth-doped gallium oxide target in air at room temperature;
[0010] Step 4: Dry the substrate in a clean environment to obtain rare earth-doped gallium oxide microspheres on the substrate.
[0011] Furthermore, in step 1, the laser beam of the pulsed laser passes through a lens and is focused on the surface of the rare earth-doped gallium oxide target.
[0012] Furthermore, in step 2, the solution is deionized water or anhydrous ethanol. The diameter of the rare earth-doped gallium oxide microspheres finally obtained varies depending on the solution added dropwise. The rare earth-doped gallium oxide microspheres obtained in deionized water are larger in size. Deionized water is preferably the solution.
[0013] Furthermore, in step 2, the substrate is a silicon wafer or a sapphire wafer. The substrate is positioned 4 to 8 mm laterally from the rare earth-doped gallium oxide target and 0.8 to 1.2 cm vertically from the focal point of the laser beam. The substrate is placed on a storage platform.
[0014] Furthermore, in step 3, the ablation time is 5 to 20 minutes. Rare earth-doped gallium oxide microspheres with laser properties cannot be produced if the laser output power is too low or too high.
[0015] Furthermore, in step 4, the drying temperature is 55-65°C.
[0016] The rare earth-doped gallium oxide microspheres of the present invention have a smooth surface and a hollow core-shell structure.
[0017] Furthermore, the diameter is 2 to 3 μm.
[0018] Preparation principle: The preparation method is gas phase ablation. In the air, the plasma generated by the thermal effect falls into the liquid on the substrate to produce agglomeration, and due to the effect of surface tension, spherical micron particles can be formed.
[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant features:
[0020] 1. The preparation method is a template-free preparation method. Compared with the existing commonly used template method, it omits the template preparation process and the method is simple and easy to operate;
[0021] 2. The preparation method of rare earth-doped gallium oxide microspheres is vapor phase ablation. Compared with liquid phase ablation, laser ablation in air has lower requirements for experimental conditions. Rare earth-doped gallium oxide microspheres can be obtained only in room temperature air environment, avoiding the direct interaction between high energy laser and liquid, and are easy to control.
[0022] 3. Rare earth-doped gallium oxide microspheres with a diameter of micrometers can be obtained. The rare earth-doped gallium oxide microspheres have a hollow core-shell structure, a smooth spherical morphology, and a nanometer-sized shell wall;
[0023] 4. Rare earth-doped gallium oxide microspheres with obvious laser properties can be produced. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic structural diagram of the equipment used for preparing rare earth-doped gallium oxide microspheres of the present invention;
[0025] Figure 2 is a scanning electron microscope photograph of the micrometer-scale core-shell structured Er-doped gallium oxide microspheres prepared in Example 1;
[0026] Figure 3 is an excitation spectrum of Er-doped gallium oxide microspheres prepared in Example 1;
[0027] Figure 4 is a scanning electron microscope photograph of the micrometer-scale core-shell structure Ho-doped gallium oxide microspheres prepared in Example 2;
[0028] Figure 5 This is a scanning electron microscope photograph of the micrometer-scale core-shell structured Cr-doped gallium oxide microspheres prepared in Example 3;
[0029] Figure 6 The present invention discloses an XRD pattern of rare earth-doped gallium oxide microspheres. DETAILED DESCRIPTION
[0030] In the following examples, the materials and reagents used are commercially available unless otherwise specified. Experimental methods without specific conditions in the examples are generally performed under conventional conditions or those recommended by the manufacturer.
[0031] like Figure 1 The preparation apparatus includes a pulsed laser 1, a lens 2, a rare-earth-doped gallium oxide target 3, a stage 4, and a substrate 5. The laser beam from the pulsed laser 1 is focused by the lens 2 onto the surface of the rare-earth-doped gallium oxide target 2, which is placed on the stage 4. Laser light is used to directly ablate the rare-earth-doped gallium oxide target 3 in an air environment. The high-energy laser ablation generates metallic plasma, which then aggregates and oxidizes in the liquid environment on the substrate 5, ultimately forming rare-earth-doped gallium oxide microspheres on the substrate 5.
[0032] Example 1
[0033] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0034] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (Er) doped gallium oxide target 3.
[0035] (2) Then place the silicon wafer substrate 5 at a position 5 mm away from the target material in the horizontal direction and 1 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0036] (3) The laser output power was adjusted to 1.75 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 5 minutes.
[0037] (4) Drying the substrate in a clean environment at 60° C. to obtain rare earth-doped gallium oxide microspheres on the surface of the substrate 5 .
[0038] like Figure 2 It can be seen that the rare earth-doped gallium oxide microspheres are hollow core-shell composite microspheres with a smooth spherical morphology and a diameter of about 3 μm.
[0039] like Figure 3 Er-doped gallium oxide microspheres have obvious laser properties. With their unique microsphere cavity structure, they are an ideal candidate material for nanolasers.
[0040] Example 2
[0041] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0042] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (Ho) doped gallium oxide target 3.
[0043] (2) Then place the silicon wafer substrate 5 at a position 5 mm away from the target material in the horizontal direction and 1 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0044] (3) The laser output power was adjusted to 1.75 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 5 minutes.
[0045] (4) Drying the substrate in a clean environment at 60° C. to obtain rare earth-doped gallium oxide microspheres on the surface of the substrate 5 .
[0046] The rare earth doped gallium oxide microspheres obtained in this example are hollow core-shell composite microspheres with a smooth spherical morphology and a diameter of about 2 μm. Figure 4 As shown, it also has obvious laser characteristics.
[0047] Example 3
[0048] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0049] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (Cr) doped gallium oxide target 3.
[0050] (2) Then place the silicon wafer substrate 5 at a position 5 mm away from the target material in the horizontal direction and 1 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0051] (3) The laser output power was adjusted to 1.75 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 5 minutes.
[0052] (4) Drying the substrate in a clean environment at 60° C. to obtain rare earth-doped gallium oxide microspheres on the surface of the substrate 5 .
[0053] The rare earth doped gallium oxide microspheres obtained in this example are hollow core-shell composite microspheres with a smooth spherical morphology and a diameter of about 2 μm. Figure 5 As shown, it also has obvious laser characteristics.
[0054] like Figure 6 , three kinds of gallium oxide microspheres doped with different rare earth elements were analyzed by XRD, and similar spectral results were obtained, which were consistent with the standard card peak position of β-gallium oxide, confirming that the microspheres obtained by this research method are gallium oxide microspheres.
[0055] Example 4
[0056] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0057] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (Ce) doped gallium oxide target 3.
[0058] (2) Then place the silicon wafer substrate 5 at a position 4 mm away from the target material in the horizontal direction and 0.5 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0059] (3) The laser output power was adjusted to 1.7 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 20 minutes.
[0060] (4) Drying the substrate in a clean environment at 65° C. to obtain rare earth-doped gallium oxide microspheres on the surface of the substrate 5 .
[0061] The rare earth-doped gallium oxide microspheres are hollow core-shell composite microspheres with a smooth spherical morphology and a diameter of about 2.5 μm.
[0062] Example 5
[0063] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0064] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (La) doped gallium oxide target 3.
[0065] (2) Then place the silicon wafer substrate 5 at a position 8 mm away from the target material in the horizontal direction and 1.5 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0066] (3) The laser output power was adjusted to 2.0 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 10 minutes.
[0067] (4) Drying the substrate in a clean environment at 55° C. to obtain rare earth-doped gallium oxide microspheres on the surface of the substrate 5 .
[0068] The rare earth-doped gallium oxide microspheres are hollow core-shell composite microspheres with a smooth spherical morphology and a diameter of about 3 μm.
[0069] Comparative Example 1
[0070] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0071] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (Ho) doped gallium oxide target 3.
[0072] (2) Then place the silicon wafer substrate 5 at a position 5 mm away from the target material in the horizontal direction and 1 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0073] (3) The laser output power was adjusted to 1.86 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 10 minutes.
[0074] (4) Drying the substrate in a clean environment at 60° C. to obtain rare earth-doped gallium oxide microspheres formed by agglomeration of different bulk substances on the surface of the substrate 5 .
[0075] Comparative Example 2
[0076] A method for preparing rare earth-doped gallium oxide microspheres comprises the following steps:
[0077] (1) Turn on the pulse laser 1, adjust the position of the lens 2, and focus the laser beam so that the focus is located on the surface of the rare earth (Ho) doped gallium oxide target 3.
[0078] (2) Then place the sapphire substrate 5 at a position 5 mm away from the target material in the horizontal direction and 1 cm away from the laser focus point in the vertical direction, and add several drops of deionized water on the substrate 5 until the substrate 5 is evenly covered.
[0079] (3) The laser output power was adjusted to 1.75 mW, and the rare earth-doped gallium oxide target 3 was ablated in air at room temperature for 5 minutes.
[0080] (4) Drying the substrate in a clean environment at 60° C. to obtain rare earth-doped gallium oxide microspheres on the surface of the substrate 5 .
[0081] The number of microspheres obtained in the same time is small, the diameter is about 1 μm, and the morphology is similar to that of Example 2. The laser characteristics are slightly worse than those of Example 2.
[0082] Comparative Example 3
[0083] The remaining steps of this comparative example are the same as those of Example 1, with the only difference being that in step (3), the laser output power is replaced with 1.08 mW.
[0084] The results showed that rare earth-doped gallium oxide microspheres were grown on the silicon wafer. However, due to the low laser output power, the morphology of the rare earth-doped gallium oxide microspheres was irregular and no smooth and regular composite particles were formed.
[0085] Analysis of Comparative Examples 1-3 and Examples 1-5 shows that micrometer-sized rare earth-doped gallium oxide microspheres can be produced by dripping deionized water onto substrate 5. Furthermore, smooth gallium oxide microspheres can be obtained by varying the rare earth doping elements in the gallium oxide, such as Er, Ho, and Cr.
Claims
1. A method for preparing rare earth-doped gallium oxide microspheres, characterized in that: The following steps are involved: Step 1: focusing the laser beam of the pulsed laser (1) and adjusting its focus to the surface of the rare earth-doped gallium oxide target (3); Step 2: adding the solution dropwise onto the substrate (5) whose position has been pre-adjusted, so that the solution evenly covers the surface of the substrate (5); Step 3: adjusting the laser output power to 1.7-2.0 mW, and ablating the rare earth-doped gallium oxide target (3) in air at room temperature; Step 4: Dry the substrate (5) in a clean environment to obtain rare earth-doped gallium oxide microspheres on the substrate (5).
2. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the step 1, the laser beam of the pulse laser (1) passes through the lens (2) and is focused on the surface of the rare earth-doped gallium oxide target (3).
3. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the step 2, the solution is deionized water or anhydrous ethanol.
4. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the step 2, the substrate (5) is a silicon wafer or a sapphire wafer.
5. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the second step, the substrate (5) is 4 to 8 mm away from the rare earth-doped gallium oxide target (3) in the horizontal direction, and 0.8 to 1.2 cm away from the focus of the laser beam in the vertical direction.
6. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the second step, the substrate (5) is placed on the storage platform (4).
7. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the step 3, the ablation time is 5 to 20 minutes.
8. The method for preparing rare earth-doped gallium oxide microspheres according to claim 1, wherein: In the step 4, the drying temperature is 55-65°C.
9. The rare earth-doped gallium oxide microspheres obtained by the method for preparing rare earth-doped gallium oxide microspheres according to any one of claims 1 to 8, characterized in that: It has a smooth surface and a hollow core-shell structure.
10. The rare earth-doped gallium oxide microspheres according to claim 9, characterized in that: The diameter is 2 to 3 μm.