A rare earth element doped tellurite scintillating glass thin film, a preparation method and application thereof

Abstract

This invention discloses a rare-earth element-doped tellurate scintillation glass thin film, its preparation method, and its applications. It belongs to the field of materials science and technology, using tellurate glass as a substrate and uniformly co-doping with Eu. 3+ Ions and Yb 3+ Ions; the tellurate scintillation glass film has a thickness of approximately 80 nm to 200 nm. The tellurate scintillation glass film obtained by this invention has a uniform thickness and is defect-free, exhibiting high efficiency in Eu scintillation. 3+ →Yb 3+ Its energy down-conversion properties enable it to be used as a near-infrared luminescent or down-conversion material, and it has superior performance potential in areas such as serving as a spectral conversion layer to improve the light response of silicon-based solar cells or as a near-infrared micro scintillator.

Description

Technical Field

[0001] This invention belongs to the field of materials science and technology, and particularly relates to a rare earth element-doped tellurate scintillation glass film, its preparation method and application. Background Technology

[0002] Tellurate glass matrices are used because of their lower phonon energies (typically 700-800 cm⁻¹). -1 Within a certain range, it can effectively suppress non-radiative transitions of rare earth ions, thereby increasing the radiative transition probability and fluorescence efficiency of rare earth luminescent centers, which is crucial for achieving high-efficiency luminescence. Simultaneously, tellurate glass possesses a wide transmittance range (extending from ultraviolet to mid-infrared), a high refractive index, and good chemical stability, providing a favorable dissolution and luminescence environment for rare earth ions.

[0003] The hydrolysis sol-gel method for preparing luminescent film materials allows for atomic-level uniform doping in the solution stage, which is crucial for ensuring the uniform distribution of rare earth ions in the glass matrix and avoiding concentration quenching. The synthesis temperature required by this process is significantly lower than that of traditional high-temperature melting methods, helping to avoid problems such as component volatilization, crystallization, and excessive energy consumption caused by high temperatures. Furthermore, this method facilitates the preparation of compositionally controllable, uniform, and dense films on complex-shaped or large-area substrates by adjusting parameters such as sol viscosity, pulling or spin-coating speed. However, applying the hydrolysis sol-gel method to prepare tellurate glass films, especially functionalized rare earth-doped films, presents some inherent technical challenges. The primary difficulty lies in the extreme sensitivity of tellurate precursors to water, which readily undergoes rapid hydrolysis leading to precipitation and compromising sol stability. Additionally, tellurate glass films crack during drying and heat treatment due to capillary forces and organic matter decomposition. Overcoming this challenge requires precise control of the sol composition and aging time, as well as the design of optimized drying procedures and slow heat treatment temperature rise curves; however, this process is difficult to operate and precisely control.

[0004] Therefore, how to provide a tellurate glass luminescent thin film material with a simple preparation method and stable performance is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a rare earth element-doped tellurate scintillation glass thin film, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A rare-earth element-doped tellurite scintillation glass thin film, using tellurite glass as a substrate, uniformly co-doped with Eu. 3+ Ions and Yb 3+ ion; The thickness of the tellurate scintillation glass film is approximately 80-200 nm.

[0007] Preferably, relative to the Te element, the Eu 3+ The doping concentration of the ions is 2-8 mol%, and the Yb 3+ The doping concentration of the ions is 2-8 mol.

[0008] Beneficial effects: This invention improves upon the selection and co-doping of rare earth ions, using Eu... 3+ As the main luminescent center, upon excitation, energy level transitions can produce a red region (approximately 610-620 nm, corresponding to...). 5 D0→ 7 Characteristic emission is dominated by F2 transition. Yb 3+ The introduction of this technology serves two purposes: firstly, it enables emission in the near-infrared region (-980 nm); secondly, and more importantly, it allows it to interact with Eu. 3+ Energy transfer occurs between them. Specifically, under appropriate excitation, energy can be transferred from Eu... 3+ Passed to Yb 3+ This Eu 3+ →Yb 3+ The energy downconversion process, theoretically, can convert a high-energy photon (such as ultraviolet or blue light) into two low-energy near-infrared photons. This not only potentially improves the quantum efficiency of luminescent materials, but more importantly, the converted near-infrared light matches the absorption spectrum of silicon-based solar cells quite well. Therefore, Eu... 3+ Yb 3+ Co-doped systems have unique advantages in improving the utilization efficiency of solar spectrum in solar cells and show significant application potential as down-conversion materials in optoelectronic devices.

[0009] A method for preparing rare earth element-doped tellurate scintillation glass thin films, using the sol-gel method, specifically includes the following steps: (1) Add acetylacetone to TeCl4 solution to obtain tellurate mother liquor; add Eu to the tellurate mother liquor 3+ Ions and Yb 3+ The rare earth-doped solution of ions is mixed evenly and then aged to obtain an aged sol. (2) The aged sol is spin-coated onto a substrate, gelled, dried, and then subjected to programmed temperature rise heat treatment to obtain the tellurate scintillation glass film.

[0010] Preferably, the TeCl4 solution in step (1) is a TeCl4 solution with a concentration of 0.2-0.5 M; The solvent for the TeCl4 solution is ethylene glycol methyl ether or anhydrous ethanol.

[0011] Preferably, the molar ratio of TeCl4 to acetylacetone in step (1) is 1:(2-4).

[0012] Preferably, the TeCl4 and Eu in step (1) 3+ Ions, Yb 3+ The molar ratio of ions is 1:(0.02-0.08):(0.02-0.08).

[0013] Preferably, in step (1), the rare earth doping solution contains Eu(NO3)3·6H2O or EuCl3·6H2O, the Yb source is Yb(NO3)3·6H2O or YbCl3·6H2O, and the solvent is ethylene glycol methyl ether or anhydrous ethanol.

[0014] More preferably, the rare earth doped solution also includes acetylacetone.

[0015] Preferably, the aging time in step (1) is 12-24 hours and the temperature is room temperature.

[0016] More preferably, the aging process further includes a filtration step, specifically: using a needle filter with a pore size of 0.22 micrometers to filter the aged sol to remove any possible particulate matter.

[0017] Preferably, the gelation treatment in step (2) involves placing the sol-coated substrate after spin coating and aging in a closed, humid, alkaline atmosphere for 1 hour to gel. More preferably, the gelation treatment temperature is 25℃-80℃. After spin coating, the wet film is left to stand at room temperature for a few minutes to tens of minutes. Then, in order to completely remove residual solvent and strengthen the gel network, the film is placed in an oven at 40-80℃ for a period of time (e.g., 30-50 minutes).

[0018] More preferably, the sealed, humid, alkaline atmosphere is created by placing deionized water and ammonia solution with a mass concentration of 28% into the sealed device. There are no absolute limits on the humidity and ammonia concentration in the sealed environment; the goal is a high-humidity environment with a noticeable ammonia odor.

[0019] More preferably, the drying temperature in step (2) is 80~120℃ and the time is 10~30min.

[0020] Beneficial effects: The above drying process can remove most of the solvent and reaction byproducts (such as Hacac and HNO3), forming a dry gel film.

[0021] Preferably, the programmed heating heat treatment in step (2) includes the following steps: Increase the temperature to 250-350℃ at a rate of 1-2℃ / min and hold for 30-60min. Then increase the temperature to 350-450℃ at a rate of 2-5℃ / min and hold for 15-30min.

[0022] Beneficial effects: The process of heating to 250-350℃ and holding it at that temperature can completely remove all organic matter; the process of heating to 350-450℃ and holding it at that temperature can fully densify the inorganic network and form an amorphous glass film.

[0023] Application of a rare earth element-doped tellurate scintillation glass film in optoelectronic devices.

[0024] Compared with the prior art, the present invention has the following advantages and technical effects: This invention fully utilizes the low phonon energy characteristics of tellurate glass matrix and the advantages of low-temperature synthesis and controllable composition of the sol-gel method, by introducing Eu... 3+ Yb 3+ Ion pairs are linked and energy transfer is facilitated between them to obtain high-performance tellurate scintillation glass films. The tellurate scintillation glass films obtained in this invention have uniform thickness and are defect-free. This is achieved through the analysis of Eu... 3+ / Yb 3+ Precise optimization of doping concentration enables the prepared thin film material to exhibit high Eu efficiency. 3+ →Yb 3+ Energy downconversion characteristics, Yb 3+ The characteristic near-infrared emission (~980 nm) is significantly enhanced. This material can be used as a near-infrared emitting or downconversion material. It has superior performance potential as a spectral conversion layer to improve the light response of silicon-based solar cells or as a near-infrared micro scintillator. It provides a broad research space and application prospect for the development of new functional thin films for optoelectronic devices such as solar cell spectral conversion and planar waveguide amplifiers. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram illustrating the principle of preparing tellurate scintillation glass films using the sol-gel method in this invention.

[0026] Figure 2 These are irradiation images of the tellurate scintillation glass films obtained in Examples 5-10 under a three-in-one ultraviolet analyzer; Figure 3 This is a schematic diagram of the luminescence of the tellurate scintillation glass film obtained in Example 1 under 200nm ultraviolet light irradiation, where the arrows represent the direction of light propagation; Figure 4 Comparison of fluorescence spectra of tellurate scintillation glass films obtained in Examples 1, 4-7, and 9; Figure 5 The fluorescence lifetime decay curves of the tellurate scintillation glass films obtained in Examples 4, 6, and 9 are shown. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels; Unless otherwise specified, room temperature or normal temperature in the embodiments of the present invention refers to 25±3℃.

[0030] Example 1 A method for preparing rare earth element-doped tellurate scintillation glass thin films, such as... Figure 1 As shown, it includes the following steps: (1) Under ice-water bath conditions, 1 mmol of TeCl6 was dissolved in 20 mL of ethylene glycol methyl ether, and then 3 mmol of acetylacetone was added. The mixture was stirred at room temperature for 40 minutes to obtain a pale yellow transparent solution, which is the tellurate mother liquor.

[0031] (2) Weigh 0.02 mmol of Eu(NO3)3·6H2O (corresponding to Eu 3+ Doping concentration of 2 mol% and 0.08 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The doping concentration was 8 mol%, denoted as Eu2, which was dissolved in 5 mL of anhydrous ethylene glycol methyl ether and 0.3 mmol of acetylacetone was added. The mixture was stirred until completely dissolved to obtain a rare earth doped solution.

[0032] (3) Under vigorous stirring, the rare earth doping solution was slowly added dropwise to the tellurate mother liquor. After mixing, the mixture was aged at room temperature for 24 hours and then filtered using a needle filter with a pore size of 0.22 micrometers to obtain a uniform and transparent coating sol. Then, a film was formed on a clean high-purity SiO2 glass substrate by spin coating (low speed 800 rpm / 10s, high speed 3000 rpm / 30s): spin coating at a low speed of 800 rpm for 10s to allow the sol to spread fully on the substrate surface; the second step was to immediately switch to high speed spin coating at 3000 rpm for 30s to remove excess sol and obtain a uniform wet film.

[0033] (4) Place the substrate with wet film in a sealed desiccator containing 1 mL of deionized water and 0.5 mL of concentrated ammonia (28%). After gelling for 1 hour, remove it and dry it in an oven at 100°C for 20 minutes. Finally, place it in a muffle furnace for programmed temperature rise heat treatment. Raise the temperature to 300°C at 1°C / min and hold for 30 minutes. Then raise the temperature to 400°C at 3°C / min and hold for 30 minutes. Cool it with the furnace to obtain the final product.

[0034] The film obtained in this embodiment has a thickness of 120 nm, is uniform in thickness, transparent, and crack-free. Under irradiation with an approximately 200 nm ultraviolet lamp, significant Eu content can be observed. 3+ Red glowing, like Figure 4 Mid-fluorescence spectroscopy showed moderate intensity of Eu at ~616 nm. 3+ The emission peak is observed, along with a strong Yb emission at ~980 nm. 3+ The emission peak indicates the presence of Eu 3+ To Yb 3+ Energy transfer.

[0035] Figure 3 This is a schematic diagram of the light emission of the tellurate scintillation glass thin film obtained in Example 1 under 200nm ultraviolet light irradiation. The arrows represent the direction of light propagation. It can be seen that the effective light conversion capability, good optical propagation characteristics, and structural advantages of low optical loss and high uniformity of the thin film-substrate system under 200nm ultraviolet excitation of the film are direct visual evidence of its potential for spectral conversion applications.

[0036] Example 2 The only difference from Example 1 is that in step (2), 0.04 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ Doping concentration of 4 mol% and 0.06 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The doping concentration was 6 mol%. Other process steps and parameters were the same as in Example 1.

[0037] The film obtained in this embodiment has a thickness of 118 nm and is of good quality. Under UV excitation, the red emission intensity is significantly enhanced compared to Example 1. Fluorescence spectroscopy shows that the emission peak intensity at ~616 nm is comparable to that at ~980 nm, indicating that Eu... 3+ Intrinsic luminescence and Yb 3+ The energy transfer processes are all very efficient.

[0038] Example 3 The only difference from Example 1 is that in step (2), 0.06 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ Doping concentration of 6 mol% and 0.04 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The doping concentration was 4 mol%. Other process steps and parameters were the same as in Example 1.

[0039] The film obtained in this embodiment has a thickness of 116 nm, is uniform in thickness, and is transparent. Under ultraviolet light irradiation, it emits a very bright red light. Fluorescence spectroscopy shows that Eu at ~616 nm... 3+ The emission peak intensity reaches its highest point, while the Yb at ~980 nm... 3+ The relative decrease in emission peak intensity indicates that with the increase in Yb 3+ As concentration decreases, energy transfer efficiency declines, and more energy is transferred as Eu. 3+ It is released in the form of visible light.

[0040] Example 4 The only difference from Example 1 is that in step (2), 0.08 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ Doping concentration of 8 mol% and 0.02 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The doping concentration was 2 mol%, denoted as Eu8. All other process steps and parameters were the same as in Example 1.

[0041] The film thickness obtained in this embodiment is 114 nm, indicating good quality. The red emission is extremely strong, the brightest among all embodiments. In the near-infrared spectrum, Yb reaches ~980 nm. 3+ The emission peak became very weak, indicating the presence of an energy transfer process, but the process was not significant.

[0042] Example 5 The only difference from Example 1 is that in step (2), 0.003 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+The doping concentration was 0.3 mol% and 0.097 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The resulting tellurate scintillation glass film, with a doping concentration of 9.7 mol%, is denoted as Eu0.3. All other process steps and parameters are the same as in Example 1.

[0043] The film obtained in this embodiment is uniform and transparent, with a thickness of approximately 130 nm. Only a weak red emission was observed under UV excitation. Fluorescence spectroscopy indicates that Eu at ~616 nm... 3+ The characteristic emission peak intensity of Yb is very weak, while at ~980 nm... 3+ The characteristic emission peak intensity is the strongest in the series. This confirms that in ultra-low Eu... 3+ At a concentration of 0.3%, energy changes from Eu. 3+ To Yb 3+ The transfer is extremely complete, and the material mainly exhibits highly efficient near-infrared luminescence characteristics.

[0044] Example 6 The only difference from Example 1 is that in step (2), 0.005 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ The doping concentration was 0.5 mol% and 0.095 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The resulting tellurate scintillation glass film, with a doping concentration of 9.5 mol%, is denoted as Eu0.5. All other process steps and parameters are the same as in Example 1.

[0045] The film obtained in this embodiment is of good quality, with a thickness of approximately 126 nm. The red emission intensity is significantly improved compared to Eu0.3. Fluorescence spectroscopy shows that the emission peak intensity at ~616 nm is approximately 40% of that in Example 1 (Eu2), while the emission peak intensity at ~980 nm remains very high. This indicates that under low Eu conditions... 3+ At a concentration of 0.5%, the material exhibits both considerable red visible light and efficient near-infrared light emission capabilities, with energy transfer being the dominant process.

[0046] Example 7 The only difference from Example 1 is that in step (2), 0.01 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ Doping concentration of 1 mol% and 0.09 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The resulting tellurate scintillation glass film (with a doping concentration of 9 mol%) is denoted as Eu1. Other process steps and parameters are the same as in Example 1.

[0047] The film obtained in this embodiment has a thickness of approximately 122 nm and exhibits excellent luminescent properties. The red light emission intensity at ~616 nm reaches 75% of that in Example 1 (Eu2), while the Yb emission intensity at ~980 nm is also high. 3+ The emission peak intensity is significant. This component achieves a good balance between red and near-infrared light emission, and is one of the optimized ratios that takes into account both emission modes.

[0048] Example 8 The only difference from Example 1 is that in step (2), 0.012 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ The doping concentration was 1.2 mol% and 0.088 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The resulting tellurate scintillation glass film, with a doping concentration of 8.8 mol%, is designated Eu1.2. All other process steps and parameters are the same as in Example 1.

[0049] The film thickness obtained in this embodiment is approximately 121 nm. Its red emission intensity continues to increase, reaching approximately 90% of that in Example 1 (Eu2), while the near-infrared emission decreases accordingly.

[0050] Example 9 The only difference from Example 1 is that in step (2), 0.015 mmol of Eu(NO3)3·6H2O (corresponding to Eu) is weighed. 3+ Doping concentration of 1.5 mol% and 0.085 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The doping concentration was 8.5 mol%, and the resulting tellurate scintillation glass film was denoted as Eu1.5. Other process steps and parameters were the same as in Example 1.

[0051] The film obtained in this embodiment has a thickness of approximately 118 nm and good uniformity. The red emission intensity reaches a peak at ~616 nm, approximately 98% of that in Example 1 (Eu2), indicating that the emission intensity is close to saturation. The emission peak at ~980 nm further weakens. Fluorescence lifetime characterization tests were performed on the film obtained in this embodiment using a pulsed laser with a wavelength of 394 nm for excitation, and the Eu emission intensity was monitored. 3+ At 616 nm ( 5 D0→ 7 The fluorescence decay process of the F2 transition was observed. Test results showed a fluorescence lifetime of 1.8 ms, the highest among all examples in this series. This data directly proves that at this doping concentration, Eu... 3+ The radiative transition efficiency of ions reaches its optimum, and non-radiative energy loss is effectively suppressed, indicating that the thin film of this composition has a highly efficient downconversion luminescence capability.

[0052] Example 10 The difference from Example 1 is only that in step (2), 0.05 mmol of Eu(NO3)3·6H2O (corresponding to Eu doping concentration of 5 mol%) and 0.05 mmol of Yb(NO3)3·6H2O (corresponding to Yb doping concentration of 5 mol%) are weighed. Other process steps and parameters are the same as those in Example 1.

[0053] The thickness of the thin film obtained in this example is about 116 nm, with uniform thickness, transparency and no cracks. Under the irradiation of a ~200 nm ultraviolet lamp, medium-intensity Eu red luminescence can be observed. The fluorescence spectrum shows that the emission peak intensities at ~616 nm and ~980 nm are similar, indicating that the energy transfer between Eu and Yb reaches a good balance, and both visible and near-infrared luminescence properties are achieved.

[0054] Figure 2 The irradiation diagrams of the tellurite scintillation glass thin films obtained in Examples 5 - 10 under a three-purpose ultraviolet analyzer are shown. It can be seen that all thin films can produce characteristic red luminescence under ultraviolet excitation. The overall luminescence of the thin films is uniform, without local dark areas or light spots, visually verifying that the tellurite scintillation glass thin films obtained in Examples 5 - 10 have uniform thickness, and rare earth ions are atomically uniformly doped in the tellurite glass matrix, without the problem of local luminescence failure caused by concentration quenching, and the structural integrity and optical uniformity of the thin films are good. The red luminescence intensity of the thin film shows an increasing trend of Eu0.3 < Eu0.5 < Eu1 < Eu1.2 < Eu1.5. Eu0.3 only shows weak red luminescence. As the Eu doping concentration gradually increases, the red luminescence brightness continuously increases. When it reaches Eu1.5, the red luminescence intensity reaches the visual peak, which is completely consistent with the fluorescence spectrum test conclusion that "the 616 nm red light emission intensity of Eu1.5 is close to saturation" in Example 9. The red luminescence intensity of Eu2 is slightly lower than that of Eu1.5, and the visual brightness is slightly weaker than that of Eu1.5, indicating that when the Eu doping concentration reaches 2 mol%, a slight concentration quenching effect begins to appear, resulting in the non-continuous increase of its red luminescence intensity, which also verifies the technical key point of precise regulation of rare earth ion doping concentration. The visual difference in luminescence is directly related to the energy transfer law. At low Eu concentrations of Eu0.3 and Eu0.5, due to the energy transfer from Eu to Yb​​​​​​​​​​​​​​​​​​​​​​​​​The energy transfer is extremely complete, with most of the energy released in the form of near-infrared light; therefore, the red emission in the visible light region is visually very weak. 3+ Concentration increase, Yb 3+ The concentration decreases accordingly, Eu 3+ →Yb 3+ Energy transfer efficiency decreases, with more energy being converted into Eu. 3+ The emission of red light gradually increases the visual brightness of the red glow, directly demonstrating Eu's... 3+ / Yb 3+ The effect of doping ratio on the energy transfer and luminescence mode of both.

[0058] Figure 4 These are comparative fluorescence spectra of the tellurate scintillation glass films obtained in Examples 1, 4-7, and 9; it can be seen that as Eu... 3+ With increasing doping concentration, Eu 3+ The emission peak intensity at 616 nm first increases and then tends to saturate, while Yb 3+ The intensity of the emission peak at 980 nm gradually decreases.

[0059] Figure 5 The fluorescence lifetime decay curves of the tellurate scintillation glass films obtained in Examples 4, 6, and 9 show that as Eu decreases... 3+ With increasing doping concentration, the fluorescence lifetime initially increases and then decreases. Example 9 (Eu1.5) exhibits the longest fluorescence lifetime (1.8 ms), indicating that at this doping ratio, nonradiative transitions are effectively suppressed, resulting in the highest luminous efficiency.

[0060] Example 11 A method for preparing a rare earth element-doped tellurite scintillation glass thin film includes the following steps: (1) Under ice-water bath conditions, 1 mmol of TeCl6 was dissolved in 30 mL of ethylene glycol methyl ether, and then 2 mmol of acetylacetone was added. The mixture was stirred at room temperature for 40 minutes to obtain a pale yellow transparent solution, which is the tellurate mother liquor.

[0061] (2) Weigh 0.02 mmol of Eu(NO3)3·6H2O (corresponding to Eu 3+ Doping concentration of 2 mol% and 0.08 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The rare earth doped solution was obtained by dissolving a doping concentration of 8 mol% in 5 mL of anhydrous ethylene glycol methyl ether and adding 0.2 mmol of acetylacetone, stirring until completely dissolved.

[0062] (3) Under vigorous stirring, the rare earth doping solution was slowly added dropwise to the tellurate mother liquor. After mixing, the mixture was aged at room temperature for 48 hours and then filtered using a needle filter with a pore size of 0.22 micrometers to obtain a uniform and transparent coating sol. Then, a film was formed on a clean high-purity SiO2 glass substrate by spin coating: spin coating at a low speed of 500 rpm for 10s to allow the sol to spread fully on the substrate surface; the second step was to immediately switch to high speed spin coating at 3000 rpm for 30s to remove excess sol and obtain a uniform wet film.

[0063] (4) Place the substrate with wet film in a sealed desiccator containing 1 mL of deionized water and 0.5 mL of concentrated ammonia (28%). After gelation for 1 hour, remove it and dry it in an 80°C oven for 40 minutes. Finally, place it in a muffle furnace for programmed temperature rise heat treatment, raise the temperature to 250°C at 1°C / min and hold for 60 minutes, then raise the temperature to 380°C at 2°C / min and hold for 60 minutes. Cool it with the furnace to obtain the final product.

[0064] This embodiment achieved a high-quality thin film with a thickness of approximately 176 nm, extremely uniform texture, and very low internal stress by reducing the precursor concentration, extending the aging time, and employing a gentler drying and heat treatment process. Although its luminescence intensity was slightly lower than that of Example 1 (due to the reduction in luminescence centers per unit volume caused by increased film thickness), its fluorescence lifetime was longer, indicating fewer film defects and that the luminescence centers were located in a more favorable crystal field environment.

[0065] Example 12 A method for preparing a rare earth element-doped tellurite scintillation glass thin film includes the following steps: (1) Under ice-water bath conditions, 1 mmol of TeCl6 was dissolved in 15 mL of ethylene glycol methyl ether, and then 4 mmol of acetylacetone was added. The mixture was stirred at room temperature for 40 minutes to obtain a pale yellow transparent solution, which is the tellurate mother liquor.

[0066] (2) Weigh 0.02 mmol of Eu(NO3)3·6H2O (corresponding to Eu 3+ Doping concentration of 2 mol% and 0.08 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The rare earth doped solution was obtained by dissolving a doping concentration of 8 mol% in 5 mL of anhydrous ethylene glycol methyl ether and adding 0.5 mmol of acetylacetone, stirring until completely dissolved.

[0067] (3) Under vigorous stirring, the rare earth doping solution was slowly added dropwise to the tellurate mother liquor. After mixing, the mixture was aged at room temperature for 12 hours and then filtered using a needle filter with a pore size of 0.22 micrometers to obtain a uniform and transparent coating sol. Then, a film was formed on a clean high-purity SiO2 glass substrate by spin coating: spin coating at a low speed of 500 rpm for 10 seconds to allow the sol to spread fully on the substrate surface; the second step was to immediately switch to high-speed spin coating at 3000 rpm for 30 seconds to remove excess sol and obtain a uniform wet film.

[0068] (4) Place the substrate with wet film in a sealed desiccator containing 1 mL of deionized water and 0.5 mL of concentrated ammonia (28%). After gelation for 1 hour, remove it and dry it in an oven at 120°C for 12 minutes. Finally, place it in a muffle furnace for programmed temperature rise heat treatment. Raise the temperature to 280°C at 5°C / min and hold for 20 minutes. Then raise the temperature to 420°C at 5°C / min and hold for 20 minutes. Cool it with the furnace to obtain the final product.

[0069] This embodiment successfully prepared a thin film with a thickness of approximately 80 nm using a process with a high precursor concentration and short aging and heat treatment times. The film exhibited strong adhesion, stable luminescence performance, and an emission peak intensity at ~616 nm that was approximately 85% of that in Example 1. This embodiment demonstrates the feasibility of significantly shortening the preparation cycle by optimizing process parameters while maintaining performance, and shows good potential for industrial application.

[0070] Comparative Example 1 The only difference from Example 1 is that step (2) does not include Eu(NO3)3·6H2O, but only weighs 0.1 mmol of Yb(NO3)3·6H2O (corresponding to Yb 3+ The doping concentration was 10 mol%. Other process steps and parameters were the same as in Example 1.

[0071] Characterization of the obtained film: The film is uniform, transparent, and crack-free. Under irradiation with a UV lamp of approximately 200 nm, the film does not show Eu. 3+ It emits red light, but strong Yb at ~980 nm can be detected by near-infrared spectroscopy. 3+ Feature emission.

[0072] Comparative Example 2 The only difference from Example 1 is that step (2) does not include Yb(NO3)3·6H2O, but only weighs 0.1 mmol of Eu(NO3)3·6H2O (corresponding to Eu 3+ The doping concentration was 10 mol%. Other process steps and parameters were the same as in Example 1.

[0073] Characterization of the obtained film: The film is uniform, transparent, and crack-free. Under illumination with a UV lamp of approximately 200 nm, it emits an extremely strong, pure red light. Only Eu can be detected in the fluorescence spectrum. 3+ The characteristic emission peaks (~590 nm, ~616 nm, etc.) were completely undetectable, indicating the absence of Yb in the thin film. 3+ No energy transfer occurred.

[0074] A comparison of Examples 1-4 with Comparative Examples 1-2 shows that the method of the present invention successfully prepared a series of tellurate scintillation glass films with different rare earth doping concentrations, and with the increase of Eu... 3+ Concentration gradually increased and Yb 3+ As the concentration gradually decreases, the luminescent properties of the thin film exhibit a regular change: Eu 3+ The intensity of the red emission of Yb first increases and then tends to stabilize (possibly due to concentration quenching), while Yb 3+ The near-infrared luminescence intensity of the material continuously decreases, providing sufficient experimental basis and material foundation for the selection of the material in different application scenarios.

[0075] Comparative Example 3 The only difference from Example 1 is that acetylacetone is not added in step (1), while the other process steps and parameters are the same as in Example 1.

[0076] In this comparative example, a white flocculent precipitate was observed during the mixing step, making it impossible to obtain a uniform and transparent sol, and subsequent spin coating failed to form a continuous film. This demonstrates that acetylacetone, as a chelating agent, is essential for stabilizing the TeCl4 precursor and preventing its premature hydrolysis and precipitation.

[0077] Comparative Example 4 The only difference from Example 1 is that in step (1), TeCl6 is replaced with an equimolar mass of Na6TeO6, and the remaining process steps and parameters are the same as in Example 1.

[0078] In this comparative example, the precursor was difficult to dissolve in ethylene glycol methyl ether, or the resulting solution was not homogeneous with the alcohol solution of rare earth nitrates, leading to phase separation during aging. The resulting film was severely cracked, opaque, and lacked effective luminescence. This demonstrates that the non-hydrolyzable sol-gel route using TeCl4 as the tellurium source is key to achieving molecular-level uniform doping and high-quality film formation.

[0079] Comparative Example 5 The only difference from Example 1 is that in steps (1) and (2), ethylene glycol methyl ether is replaced with an equal volume of water, while the other process steps and parameters are the same as in Example 1.

[0080] In this comparative example, TeCl4 underwent violent hydrolysis upon contact with water, immediately producing a large amount of white TeO2 precipitate, making the reaction impossible. This demonstrates that using anhydrous organic solvents is a necessary condition for this preparation method.

[0081] Comparative Example 6 The only difference from Example 1 is that the spin coating method in step (3) is changed, specifically including the following steps: Steps (1)-(2) are the same as in Example 1; (3) Under vigorous stirring, the rare earth doping solution was slowly added dropwise to the tellurate mother liquor. After mixing, the mixture was aged at room temperature for 24 hours, and then filtered using a needle filter with a pore size of 0.22 micrometers to obtain a uniform and transparent coating sol. Then, a film was formed on a clean, high-purity SiO2 glass substrate using spin coating: spin coating was performed at a single speed of 3000 rpm for 40 seconds. A uniform wet film was obtained.

[0082] Step (4) is the same as in Example 1.

[0083] The film obtained in this comparative example had uneven thickness, being thicker at the edges and thinner in the center. Cracks appeared in the edge region of the film after heat treatment. This demonstrates that the two-step spin coating method is crucial for obtaining films with uniform thickness and large-area flatness.

[0084] A comparison of the above comparative examples and embodiments shows that each key step and raw material selection in the method of the present invention is interconnected and indispensable. Together they constitute a complete and efficient technical solution. The absence or replacement of any key element will lead to preparation failure or product performance degradation.

[0085] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A rare earth element-doped tellurate scintillation glass film, characterized in that, Using tellurate glass as a substrate, uniformly co-doped with Eu 3+ Ions and Yb 3+ ion; The thickness of the tellurate scintillation glass film is 80nm-200nm.

2. The rare earth element-doped tellurate scintillation glass film according to claim 1, characterized in that, Relative to the Te element, the Eu 3+ The doping concentration of the ions is 2-8 mol%, and the Yb 3+ The doping concentration of the ions is 2-8 mol.

3. A method for preparing a rare earth element-doped tellurite scintillation glass thin film as described in claim 1 or 2, characterized in that, It is prepared by the sol-gel method, specifically including the following steps: (1) Add acetylacetone to TeCl4 solution to obtain tellurate mother liquor; add Eu to the tellurate mother liquor 3+ Ions and Yb 3+ The rare earth-doped solution of ions is mixed evenly and then aged to obtain an aged sol. (2) The aged sol is spin-coated onto a substrate, gelled, dried, and then subjected to programmed temperature rise heat treatment to obtain the tellurate scintillation glass film.

4. The preparation method according to claim 3, characterized in that, The TeCl4 solution mentioned in step (1) is a TeCl4 solution with a concentration of 0.2-0.5 mol / L; The solvent for the TeCl4 solution is ethylene glycol methyl ether or anhydrous ethanol.

5. The preparation method according to claim 3, characterized in that, The molar ratio of TeCl4 to acetylacetone in step (1) is 1:(2-4). The Te element in TeCl4 and Eu 3+ Ions, Yb 3+ The molar ratio of ions is 1:(0.02-0.08):(0.02-0.08).

6. The preparation method according to claim 3, characterized in that, In step (1), the Eu source in the rare earth doping solution is Eu(NO3)3·6H2O or EuCl3·6H2O, the Yb source is Yb(NO3)3·6H2O or YbCl3·6H2O, and the solvent is ethylene glycol methyl ether or anhydrous ethanol.

7. The preparation method according to claim 3, characterized in that, The aging time mentioned in step (1) is 12-24 hours.

8. The preparation method according to claim 3, characterized in that, The gelation process described in step (2) involves placing the spin-coated and aged sol substrate in a sealed, humid, alkaline atmosphere for 1 hour to gel. The sealed, humid, alkaline atmosphere is created by placing deionized water and ammonia water with a mass concentration of 28% into the sealed device.

9. The preparation method according to claim 3, characterized in that, The programmed temperature rise heat treatment described in step (2) includes the following steps: Increase the temperature to 250-350℃ at a rate of 1-2℃ / min and hold for 30-60min. Then increase the temperature to 350-450℃ at a rate of 2-5℃ / min and hold for 15-30min.

10. The application of a rare earth element-doped tellurite scintillation glass thin film as described in claim 1 or 2 in optoelectronic devices.

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