A type of Mn 4+ Ion-doped fluoride ceramic sheets and their preparation methods
By preparing Mn4+ ion-doped Rb2GeF6 fluoride ceramic sheets, the problem of poor thermal conductivity of phosphors was solved, enabling their application in high-power LED chips and improving luminous efficiency and thermal stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YUNNAN MINZU UNIV
- Filing Date
- 2024-05-16
- Publication Date
- 2026-06-30
Smart Images
Figure CN118479882B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of luminescent material synthesis technology, specifically to a Mn 4+ Ion-doped fluoride ceramic sheets and their preparation methods. Background Technology
[0002] With the increasing maturity of chip manufacturing processes, white light sources based on high-power blue LEDs have great application prospects in high-power-density lighting fields such as aviation, high-speed rail, and deep sea.
[0003] The phosphor-based LED packaging solution is only suitable for low-power LED devices because the phosphor has low thermal conductivity, which reduces the heat dissipation performance of the LED device. As the current increases, the white LED produced exhibits drawbacks such as reduced luminous efficiency and color shift (References: YCLin, M. Karlsson, M. Bettinelli, Top. Curr. Chem., 2016, 374:1; Zheng Zhehan, Zhang Xiang, Xu Xiaoke, Liu Qian, Shi Yun, Li Ru, Wang Huan, Wang Fei, Liu Guanghui, Journal of Luminescence, 2020, 41:1411), thus limiting the application of phosphors in high-power LED lighting.
[0004] Mn 4+ As a type of transition metal ion luminescent center with excellent luminescent properties, it has attracted widespread attention in recent years. It exhibits strong broadband absorption in the blue light region and strong narrowband emission in the red light region. 2 E g → 4 A 2g For example, Rb2GeF6:Mn 4+ Fluoride red phosphors exhibit efficient red light emission under blue light excitation (Reference: W. Wu, M. Fang, W. Zhou, T. Lesniewski, S. Mahlik, M. Grinberg, MGBrik, H. Sheu, B. Cheng, J. Wang, Ru-Shi Liu, Chem. Mater. 2017, 29, 3, 935). However, these phosphors still suffer from poor thermal conductivity, thus limiting their application in high-power LED chips. Therefore, the preparation of Mn-containing phosphors... 4+ Achieving high levels of thermal conductivity is of great significance for other forms of fluorescent materials. Summary of the Invention
[0005] To address the above problems, the present invention provides a Mn 4+ Ion-doped fluoride ceramic sheets, the ceramic sheets being Mn 4+ Doping with Rb2GeF6, Rb2GeF6 and Mn4+ The molar ratio is 1:0.09.
[0006] On the other hand, the present invention provides a Mn 4+ The method for preparing ion-doped fluoride ceramic sheets includes the following steps:
[0007] Step 1: Add Rb2GeF6:0.09Mn 4+ The powder is placed in a mold, heated, and pressed to form the desired shape.
[0008] Step 2: After cooling to room temperature, Rb2GeF6:0.09Mn is obtained. 4+ Fluoride ceramic sheet.
[0009] Furthermore, in step 1, the Rb2GeF6:0.09Mn 4+ The powder preparation method includes the following steps:
[0010] Step 01: Dissolve 5 mmol of GeO2 in 5 mL of HF;
[0011] Step 02: Add 0.25 mmol of K2MnF6 and 11 mmol of CsF, stir, and precipitate.
[0012] Step 03: The obtained precipitate is washed five times with methanol and dried to obtain Rb2GeF6:0.09Mn. 4+ powder.
[0013] Furthermore, in step 01, the mixture is stirred for 2 hours.
[0014] Furthermore, in step 03, the drying temperature is 80°C.
[0015] Furthermore, in step 1, the heating temperature is 50℃-300℃.
[0016] Furthermore, in step 1, the pressure applied is 10MPa-30MPa.
[0017] Furthermore, in step 1, the pressing time is 0.5 hours to 3 hours.
[0018] The beneficial effects of this invention are:
[0019] (1) The present invention provides Rb2GeF6:0.09Mn 4+ Ceramic sheets have high thermal conductivity and are suitable for high-power LED devices.
[0020] (2) The preparation method of Rb2GeF6:0.09Mn provided by the present invention 4+The ceramic sheet method only requires heating and pressurization, making it simple and low-cost.
[0021] Based on the above beneficial effects, this invention has good application prospects in the field of luminescent material synthesis technology. Attached Figure Description
[0022] Figure 1 It is Rb2GeF6:0.09Mn 4+ Scanning electron microscope image of the powder;
[0023] Figure 2 It is Rb2GeF6:xMn 4+ Emission spectra of (x = 0.03, 0.05, 0.07, 0.09, 0.11);
[0024] Figure 3 It is Rb2GeF6:0.09Mn in Example 1. 4+ Scanning electron microscope images of ceramic sheets; the inset shows the transparency of the ceramic sheets.
[0025] Figure 4 It is Rb2GeF6:0.09Mn in Example 1. 4+ Emission spectra of ceramic sheets at different temperatures;
[0026] Figure 5 In Example 1, Rb2GeF6:0.09Mn was used. 4+ Ceramic tiles, YAG:Ce 3+ The spectrum of a white LED packaged with ceramic sheet and GaN chip under 300mA current driving and different working times;
[0027] Figure 6 Rb2GeF6:0.09Mn at different sintering temperatures 4+ XRD diffraction pattern of ceramic sheet;
[0028] Figure 7 Rb2GeF6:0.09Mn at different sintering temperatures 4+ Temperature-dependent emission spectrum of ceramic sheet;
[0029] Figure 8 Rb2GeF6:0.09Mn under different pressures 4+ XRD diffraction pattern of ceramic sheet;
[0030] Figure 9 Rb2GeF6:0.09Mn under different pressures 4+ Emission spectrum of the ceramic sheet;
[0031] Figure 10 The Rb2GeF6:0.09Mn values were obtained under different pressing times.4+ XRD diffraction pattern of ceramic sheet;
[0032] Figure 11 The Rb2GeF6:0.09Mn values were obtained under different pressing times. 4+ Emission spectrum of the ceramic sheet. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments.
[0034] Example 1
[0035] This invention provides a Mn 4+ The specific steps for preparing ion-doped fluoride ceramic sheets are as follows:
[0036] First, weigh out 0.45 grams of Rb2GeF6:0.09Mn. 4+ The powder was placed in a cylindrical mold, and then pressed for 2 hours at 300℃ and 30MPa to form the phosphor. After cooling to room temperature, a uniform, translucent fluorescent sheet was removed, which was the prepared Rb2GeF6:0.09Mn. 4+ Ceramic sheet fluorescent material.
[0037] Among them, Rb2GeF6:0.09Mn 4+ The powder preparation steps included: dissolving 5 mmol of GeO2 in 5 mL of HF, adding 0.25 mmol of K2MnF6 and 11 mmol of CsF, and stirring for 2 hours. The resulting precipitate was washed five times with methanol and dried at 80 °C for 12 hours to obtain Rb2GeF6:0.09Mn. 4+ Powder, scanning electron microscope images as follows Figure 1 As shown. Sample Rb2GeF6:xMn 4+ The samples (x = 0.03, 0.05, 0.07, 0.11) were synthesized using a similar method, with the amount of K₂MnF₆ changed according to the stoichiometric ratio. The emission spectra of all samples are attached. Figure 2 As shown, in these samples, Rb2GeF6:0.09Mn 4+ The powder exhibits the strongest luminescence; therefore, Rb2GeF6:0.09Mn was selected for this invention. 4+ Powder is pressed into ceramic materials.
[0038] Figure 3 Rb2GeF6:0.09Mn 4+ Scanning electron microscope images of ceramic slides, and Figure 1 In comparison, Rb2GeF6:0.09Mn 4+Micron-sized powder particles are pressed into ceramic sheets, which have a smooth surface without obvious gaps or cracks. Figure 3 The inset is Rb2GeF6:0.09Mn. 4+ Ceramic shard photos have a certain degree of light transmittance (such as...) Figure 3 (As shown in the illustration).
[0039] Rb2GeF6:0.09Mn 4+ Under natural light, the ceramic sample appears yellow, indicating that it exhibits strong absorption of blue light; Rb2GeF6:0.09Mn 4+ The ceramic sheet exhibits bright red light emission when illuminated by blue light.
[0040] Figure 4 Rb2GeF6:0.09Mn 4+ The emission spectra of the ceramic sheet at different temperatures were obtained with an excitation wavelength of 470 nm. As can be seen from the figure, the luminescence of the sample did not weaken significantly with increasing temperature. At 150℃, the emission intensity of the sample was essentially the same as that at room temperature, indicating that the obtained ceramic sheet has excellent thermal stability.
[0041] Figure 5 To utilize Rb2GeF6:0.09Mn 4+ Ceramic tiles, YAG:Ce 3+ The spectrum of a white LED packaged with a ceramic wafer and a GaN chip at different operating times under a 300mA current drive is shown in the figure. The blue emission peak near 460nm originates from the GaN chip, while the emission peak in the 500nm to 600nm range originates from YAG:Ce. 3+ Yellow light emission from the ceramic sheet. Rb2GeF6:0.09Mn 4+ The ceramic sheet emits light in the red light region, with the strongest emission occurring at 630 nm. The resulting white LED device shows no significant change in luminous efficiency over different operating times, indicating that this invention possesses excellent heat dissipation and thermal stability.
[0042] Example 2
[0043] Based on Example 1, the heating temperature was 50℃-300℃, the pressure was 10MPa, and the remaining parameters and steps were the same as in Example 1. Finally, a translucent Rb2GeF6:0.09Mn was obtained. 4+ Ceramic shards.
[0044] Appendix Figure 6 The figure shows Rb2GeF6:0.09Mn at different sintering temperatures. 4+The XRD diffraction pattern of the ceramic sheet shows that the powder diffraction peaks of the obtained sample are a series of independent narrow peaks. The bottom curve in the figure is the XRD standard card of Rb2GeF6 (card number 74-0229). All the diffraction peaks of the sample are consistent with the XRD standard card of Rb2GeF6, indicating that the obtained ceramic sheet has a single pure phase.
[0045] Appendix Figure 7 The figure shows Rb2GeF6:0.09Mn at different sintering temperatures. 4+ The temperature-dependent emission spectrum of the ceramic sheet shows that the sample exhibits a series of peak emission under blue light excitation. The luminescence is strongest at a temperature of 100°C. Therefore, the preferred heating temperature for preparing the ceramic sheet of this invention is 100°C.
[0046] Example 3
[0047] Based on Example 1, the heating temperature was 100℃, the pressure was 10MPa-30MPa, and the remaining parameters and steps were the same as in Example 1. Finally, a translucent Rb2GeF6:0.09Mn was obtained. 4+ Ceramic shards.
[0048] Figure 8 To determine Rb2GeF6:0.09Mn under different pressures 4+ The XRD diffraction pattern of the ceramic sheet shows that the powder diffraction peaks of the obtained sample are a series of independent narrow peaks, and it also has a single crystal phase.
[0049] Figure 9 To determine Rb2GeF6:0.09Mn under different pressures 4+ The emission spectrum of the ceramic sheet shows a series of sharp emission peaks under blue light excitation. The graph shows that the luminescence gradually decreases with increasing pressure; at a pressure of 25 MPa, the luminescence intensity is 85% of that at 15 MPa. Considering the density of the ceramic material, a pressure of 25 MPa is preferred.
[0050] Example 4
[0051] Based on Example 1, the pressing time was 0.5 hours to 3 hours, and the remaining parameters and steps were the same as in Example 1. Finally, a semi-transparent Rb2GeF6:0.09Mn was obtained. 4+ Ceramic shards.
[0052] Figure 10 For Rb2GeF6:0.09Mn under different pressing times in Example 4 4+ The XRD diffraction pattern of the ceramic sheet shows a series of independent narrow peaks in the powder diffraction pattern. When the pressing time exceeds 1 hour, the Rb2GeF6:0.09Mn... 4+A phase transition occurs, changing the space group from P63mc of Rb2GeF6 to P-3m1 of Rb2GeF6. The ceramic sheet exhibits two phases, so the preferred pressing time is 1 hour.
[0053] Figure 11 For Rb2GeF6:0.09Mn under different pressing times in Example 4 4+ The emission spectrum of the ceramic sheet, when the pressing time exceeds 1 hour, shows Rb2GeF6:0.09Mn. 4+ A phase transition occurs, Mn 4+ The zero-phonon line gradually disappears, and the luminescence intensity gradually weakens. Therefore, the preferred pressing time is 1 hour.
[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A type of Mn 4+ A method for preparing ion-doped fluoride ceramic sheets, characterized in that: The ceramic sheet is Mn 4+ Doping with Rb2GeF6, Rb2GeF6 and Mn 4+ The molar ratio is 1:0.09, and the process includes the following steps: Step 1: Add Rb2GeF6:0.09Mn 4+ The powder is placed in a mold, heated and pressed into shape. The heating temperature is 50℃-300℃, the pressure is 10MPa-30MPa, and the pressing time is 1 hour. Step 2: After cooling to room temperature, Rb2GeF6:0.09Mn is obtained. 4+ Fluoride ceramic sheet, wherein Rb2GeF6:0.09Mn 4+ The space group of the fluoride ceramic sheet is P63mc; In step 1, the Rb2GeF6:0.09Mn 4+ The powder preparation method includes the following steps: Step 01: Dissolve 5 mmol of GeO2 in 5 mL of HF; Step 02: Add 0.25 mmol of K2MnF6 and 11 mmol of RbF, stir, and precipitate. Step 03: The obtained precipitate is washed five times with methanol and dried to obtain Rb2GeF6:0.09Mn. 4+ powder.
2. The Mn as described in claim 1 4+ A method for preparing ion-doped fluoride ceramic sheets, characterized in that: In step 01, stir for 2 hours.
3. The Mn as described in claim 2 4+ A method for preparing ion-doped fluoride ceramic sheets, characterized in that: In step 03, the drying temperature is 80°C.