A rare earth organic-inorganic hybrid complex scintillator and a preparation method and application thereof

Abstract

This invention relates to the field of scintillator materials and X-ray detection technology, specifically to a rare-earth organic-inorganic hybrid complex scintillator, its preparation method, and its applications. The general formula of the rare-earth organic-inorganic hybrid complex scintillator is [RE(L)4]. ‑ ·[A] + ; where RE is selected from Eu, Tb, Sm, or Dy; L is a β-diketone ligand; [A] + Selected from carbon atoms with C8~C 20 Furthermore, it does not contain long-chain hydrophobic quaternary ammonium salt cations or heterocyclic quaternary ammonium cations with active functional groups. The rare-earth organic-inorganic hybrid complex scintillator of this invention exhibits good solubility and molecular-level dispersion. The rare-earth organic-inorganic hybrid complex scintillator film prepared using it has the characteristics of high scintillator loading and high light transmittance compatibility, overcoming the problems of low scintillator loading, poor transparency and limited imaging resolution of traditional scintillator films, and has excellent practical value and promotion prospects.

Description

Technical Field

[0001] This invention relates to the field of scintillator materials and X-ray detection technology, specifically to a rare-earth organic-inorganic hybrid complex scintillator, its preparation method, and its application. Background Technology

[0002] With the rapid development of flexible electronic devices, wearable imaging equipment, and portable security inspection systems, multiple requirements have been placed on X-ray detection materials, including lightweight, flexibility, high resolution, and high stability. As a core response component, the scintillator thin film's photon conversion efficiency, light transmittance, and mechanical properties largely determine the sensitivity and spatial resolution of the imaging system.

[0003] Currently widely used inorganic bulk scintillation materials, such as CsI:Tl, LuAG:Ce, and Gd2O2S:Tb, although they have high X-ray absorption efficiency and luminescence performance, are often difficult to achieve thin film and flexible fabrication due to their rigid intrinsic structure. They also suffer from problems such as opacity, fragility, and complex preparation processes, making it difficult to meet the needs of emerging flexible imaging platforms.

[0004] To this end, researchers have attempted to incorporate inorganic scintillator particles into flexible polymers to prepare flexible composite scintillator films. Typical methods include incorporating Eu... 3+ 、Tb 3+ Rare-earth luminescent nanoparticles are dispersed in PDMS, PVA, or PMMA matrices. While these materials offer both luminescence and flexibility, they generally suffer from the following technical bottlenecks: First, low transmittance and weak luminescence intensity. Due to the tendency of particles to aggregate, severe scattering occurs within the film, resulting in significant turbidity and limiting the effective transmission of light through the output path. For example, the LaF3:Eu@PDMS composite film reported in J. Mater. Chem. C (2022) exhibits significant fogging when the scintillator loading exceeds 8 wt%; the NaGdF4:Tb@PVA film in ACS Appl. Mater. Interfaces (2020) also demonstrates poor film transparency, limiting its application to low-resolution applications.

[0005] Secondly, the scintillator loading capacity is limited. To balance film formation and transparency, existing materials generally control the inorganic scintillator component below 10 wt%, which directly leads to a decrease in X-ray absorption capacity, making it difficult to meet the requirements of high-sensitivity detection. Thirdly, imaging resolution is limited. Due to the discontinuous energy transfer channels and significant self-absorption, composite films typically struggle to achieve spatial resolutions higher than 10 lp / mm. Furthermore, most materials lack environmental adaptability, easily experiencing performance degradation or peeling in humid, high-temperature, or complex curved surface bonding scenarios, affecting reliability. More importantly, existing flexible rare-earth scintillator films generally suffer from wide emission bandwidth and low color purity. This broadband emission limits the effective collection of imaging photons and contrast enhancement, particularly hindering high-resolution fine structure imaging. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a rare-earth organic-inorganic hybrid complex scintillator, its preparation method, and its applications. The general formula of the rare-earth organic-inorganic hybrid complex scintillator of this invention is [RE(L)4]. - ·[A] + Where RE represents rare earth elements, L represents β-diketone ligands, and [A] + Selected from carbon atoms with C8~C 20 Furthermore, it does not contain long-chain hydrophobic quaternary ammonium salt cations or heterocyclic quaternary ammonium cations with active functional groups. The rare-earth organic-inorganic hybrid complex scintillator of this invention has good solubility and molecular-level dispersion ability. Even at high loading levels, the prepared rare-earth organic-inorganic hybrid complex scintillator film can simultaneously possess high transmittance, excellent flexibility, and high spatial resolution, and exhibit strong X-ray response, high color purity, and narrow-band emission optical advantages. The rare-earth organic-inorganic hybrid complex scintillator film prepared by this invention successfully overcomes the problems of low transmittance, limited loading, wide emission spectrum, insufficient resolution, and poor environmental adaptability that are common in existing flexible scintillator films, and can meet the multi-scenario application needs of next-generation flexible X-ray detection systems in the medical, industrial, and security fields.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first objective of this invention is to provide a rare-earth organic-inorganic hybrid complex scintillator with the general formula [RE(L)4]. - ·[A] + ; where RE is selected from Eu, Tb, Sm, or Dy; L is a β-diketone ligand; [A] + Selected from carbon atoms with C8~C 20 It does not contain long-chain hydrophobic quaternary ammonium salt cations or heterocyclic quaternary ammonium cations with active functional groups.

[0008] Preferably, the β-diketone ligand is selected from 2-thiophenecarboxyltrifluoroacetone, dibenzoylmethane, or benzoyltrifluoroacetone.

[0009] Preferably, the carbon number is C8~C 20 Furthermore, the long-chain hydrophobic quaternary ammonium salt cation, which does not contain active functional groups, is selected from tetrabutylammonium cation, hexadecyltrimethylammonium cation, octadecyltrimethylammonium cation, or tetrahexylammonium cation, and has a carbon number of C8~C9. 20 Furthermore, the heterocyclic quaternary ammonium cations that do not contain active functional groups are selected from 1-butyl-3-methylpyridinium cations, 1-butyl-3-methylimidazolium cations, or 1-hexyl-3-methylimidazolium cations.

[0010] Preferably, the rare earth organic-inorganic hybrid complex scintillator has a transmittance of not less than 88% in the 470nm~750nm wavelength range.

[0011] Preferably, the photoluminescence quantum efficiency of the rare earth organic-inorganic hybrid complex scintillator is not less than 70%.

[0012] Preferably, the photoluminescence emission peak of the rare earth organic-inorganic hybrid complex scintillator is located at 612±2nm, and the full width at half maximum (FWHM) of the emission peak is not greater than 10nm; more preferably, it is not greater than 5nm; wherein, when RE is Eu, the main emission peak is located at 612±2nm; when RE is Tb, the main emission peak is preferably located at 544±2nm; when RE is Dy, the main emission peak is preferably located at about 575nm (±5nm); when RE is Sm, the main emission peak is preferably located at 600nm~620nm.

[0013] A second objective of this invention is to provide a method for preparing the above-mentioned rare-earth organic-inorganic hybrid complex scintillator, comprising the following steps: Using rare earth element salts, β-diketone ligands, and organic cations as raw materials, in the presence of alcohol solvents, the β-diketone ligands are first deprotonated under the action of a base to generate the coordination anion L in the form of its ligand salt. - ·M + Subsequently, the coordinating anion L - ·M + RE in rare earth element salts 3+ Coordination-cation substitution occurs, generating [RE(L)4]. - Finally, [RE(L)4] - With [A] + Ion association and slow crystallization yield rare-earth organic-inorganic hybrid scintillators. The rare-earth element salts are selected from Eu, Tb, Sm, or Dy salts; the organic cations have a carbon number of C8~C9. 20It contains no long-chain hydrophobic quaternary ammonium salt cations or heterocyclic quaternary ammonium cations with active functional groups; the base is selected from KOH, NaOH or alkoxides, preferably KOH.

[0014] Preferably, the molar ratio of rare earth element salt, β-diketone ligand and organic cation is 1:3.8~4.2:0.9~1.1.

[0015] Preferably, the crystallization treatment conditions are: standing at room temperature for 5 to 7 days.

[0016] Preferably, the heat treatment conditions are: drying at 60℃~90℃ for 4h~12h.

[0017] Preferably, the generated rare earth organic-inorganic hybrid complex scintillator is further subjected to drying treatment under the following conditions: drying at 40°C to 60°C for 8 to 24 hours in a vacuum or inert atmosphere; more preferably, drying at 45°C to 55°C for 10 to 14 hours; and even more preferably, drying at 50°C for 12 hours.

[0018] A third objective of this invention is to provide a rare-earth organic-inorganic hybrid complex scintillator film, made from the aforementioned rare-earth organic-inorganic hybrid complex scintillator and a polymer matrix; wherein the polymer matrix is ​​selected from transparent thermoplastic polymers capable of forming films.

[0019] In rare earth organic-inorganic hybrid complex scintillator films, the mass fraction of rare earth organic-inorganic hybrid complex scintillator is 10wt%~60wt%. When it is below 10wt%, the X-ray induced emission (RL) signal is significantly weak, making it difficult to obtain a stable linear response and a resolution of ≥20lp / mm. When it exceeds 60wt%, microcrystal precipitation and phase separation are likely to occur, resulting in increased haze, a drop in transmittance below 88%, and embrittlement of the rare earth organic-inorganic hybrid complex scintillator film, with an increase in film formation defects (pinholes / cracks).

[0020] Preferably, the transparent and film-forming thermoplastic polymer is selected from polymethyl methacrylate, polycarbonate or polyurethane; more preferably polymethyl methacrylate.

[0021] Preferably, in the rare-earth organic-inorganic hybrid scintillator film, the mass fraction of the rare-earth organic-inorganic hybrid scintillator is 30wt%~50wt%. Within this range, it can balance high light transmittance (≥88%), good flexibility, and high light output, resulting in the best overall imaging quality.

[0022] Preferably, the thickness of the rare earth organic-inorganic hybrid complex scintillator film is 30 μm to 150 μm; this thickness range can cover the rare earth organic-inorganic hybrid complex scintillator film and the mechanical / optical window required for imaging; below 30 μm, pinholes and strong scattering are easily generated, while above 150 μm, the transmittance and flexibility decrease and the drying stress increases.

[0023] Preferably, under X-ray excitation, the light output intensity of the rare-earth organic-inorganic hybrid complex scintillator film exhibits a linear response and a spatial resolution higher than 20 lp / mm, making it suitable for high-precision imaging scenarios.

[0024] A fourth objective of this invention is to provide a method for preparing the above-mentioned rare-earth organic-inorganic hybrid complex scintillator thin film, comprising the following steps: S1. The rare earth organic-inorganic hybrid complex scintillator is mixed with the polymer matrix solution to obtain the precursor solution.

[0025] S2. The precursor solution is loaded onto the substrate, and after degassing and heat treatment, a scintillator film based on rare earth organic-inorganic hybrid complex is obtained.

[0026] Preferably, the solvent in the polymer matrix solution is an organic solvent, selected from γ-valerolactone, N-methylpyrrolidone, or dichloromethane.

[0027] Preferably, the loading operation is as follows: the precursor solution is loaded onto the substrate by pouring, scraping or spin coating.

[0028] Preferably, the substrate is selected from PET film, PI film, glass or quartz sheet.

[0029] The fifth objective of this invention is to provide an X-ray detection device, which is made using the above-mentioned rare-earth organic-inorganic hybrid complex scintillator thin film, and the X-ray detection device converts X-ray signals into visible light imaging signals.

[0030] Preferably, the X-ray detection device is used in medical imaging, flexible security inspection panels, portable X-ray detectors, or non-destructive testing systems for complex surfaces.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a rare-earth organic-inorganic hybrid complex scintillator with the general formula [RE(L)4]. - ·[A] + ; where RE is selected from Eu, Tb, Sm, or Dy; L is a β-diketone ligand; [A] + Selected from carbon atoms with C8~C 20Furthermore, it does not contain long-chain hydrophobic quaternary ammonium salt cations or heterocyclic quaternary ammonium cations with active functional groups. This invention significantly improves the solubility and dispersibility of rare-earth organic-inorganic hybrid complex scintillators in polymer matrices by using long-chain hydrophobic quaternary ammonium salts or heterocyclic quaternary ammonium cations without active functional groups as balancing ions, giving them excellent solubility and molecular-level dispersion capabilities. The rare-earth organic-inorganic hybrid complex scintillator-based thin films prepared using this method exhibit high scintillator loading and high transmittance compatibility. Even with a high loading of 60 wt% of rare-earth organic-inorganic hybrid complex scintillators, its transmittance in the visible light band (470 nm~750 nm) still exceeds 88%, far exceeding the 10 wt% limit of traditional scintillator films. This overcomes the problems of low scintillator loading, poor transparency, and limited imaging resolution of traditional scintillator films, demonstrating excellent practical value and promising application prospects.

[0032] 2. The rare-earth organic-inorganic hybrid complex scintillator film of the present invention emits 612nm orange-red light under ultraviolet or X-ray excitation, with an emission peak FWHM of about 3nm, a luminescence quantum efficiency of up to 73.14%, high spectral purity, and effectively improves imaging contrast.

[0033] 3. The rare-earth organic-inorganic hybrid complex scintillator thin film of the present invention exhibits good linear response and spatial resolution under X-ray excitation, with a spatial resolution of over 20 lp / mm, which can be used for detailed imaging and high-precision structural detection.

[0034] 4. The rare earth organic-inorganic hybrid complex scintillator film of the present invention can work stably with a bending radius of less than 1 cm, can be used in complex curved surface bonding scenarios, and maintains stable light-emitting performance in humid, high temperature or variable environments.

[0035] 5. This invention also provides a method for preparing rare earth organic-inorganic hybrid complex scintillators, using rare earth element salts, β-diketone ligands, and organic cations as raw materials. Under the presence of alkali and alcohol solvents, the β-diketone ligands are deprotonated to form a coordination anion, which then reacts with RE... 3+ Coordination-cation substitution occurs, resulting in the formation of [RE(L)4]. - Finally, [RE(L)4] - With [A] + Ion association and crystallization are performed to obtain rare-earth organic-inorganic hybrid complex scintillators. The preparation method of this invention is simple and can be mass-produced. This invention employs a low-temperature solution process, eliminating the need for high-vacuum or high-temperature sintering, making it suitable for roll-to-roll continuous coating processes and possessing the potential for low-cost, large-area industrial applications. Attached Figure Description

[0036] Figure 1The diagram shows the single-crystal structure of the Eu(TTA)4(TBA) complexes from Examples 1 to 5.

[0037] Figure 2 The images show the X-ray diffraction pattern and UV-Vis absorption spectrum of the Eu(TTA)4(TBA) complex in Example 4, where a is the X-ray diffraction pattern, b is the UV-Vis absorption spectrum and the optical band gap obtained by fitting the Tauc plot, and the inset in b is the optical band gap obtained by fitting the Tauc plot.

[0038] Figure 3 The image shows the optical properties of the Eu(TTA)4(TBA) complex in Example 4, where a is the appearance under visible light, b is the emission under ultraviolet light, c is the excitation and emission spectrum, and d is the photoluminescence lifetime decay curve.

[0039] Figure 4 The image shows the X-ray excitation luminescence performance of the Eu(TTA)4(TBA) complex single crystal in Example 4. In the image, a is a comparison of the absolute radiation emission spectrum with Ce:YAG at a dose rate of 821.19 μGy / s, b is the radiation emission spectrum at different X-ray dose rates, and the inset in b is a linear response curve of dose rate versus RL intensity.

[0040] Figure 5 The images shown are optical performance diagrams of the rare earth organic-inorganic hybrid complex scintillator thin film of Example 6, where a is the appearance under sunlight, b is the emission diagram under ultraviolet light, c is a high-transparency real shot over the "JGSU" mark, and d is the transmittance curve of the thin film in the visible light range.

[0041] Figure 6 Example 6 shows the X-ray imaging performance of a rare-earth organic-inorganic hybrid complex scintillator film; where a is a standard line pair card (lp / mm) imaging image, b is an X-ray imaging image of dried fish based on a flexible film, and c is a corresponding visible light image of dried fish. Detailed Implementation

[0042] The technical solution of the present invention will be clearly and completely described below with reference to the data in the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] It should be noted that the technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased commercially or prepared by existing methods. Among them, tetrabutylammonium is denoted as TBA; hexadecyltrimethylammonium is denoted as CTNA; octadecyltrimethylammonium is denoted as OTA; tetrahexylammonium is denoted as THA; 1-butyl-3-methylpyridinium is denoted as BMP; 1-butyl-3-methylimidazolium is denoted as BMIM; and 1-hexyl-3-methylimidazolium is denoted as HMIM.

[0044] In the existing technology, flexible composite scintillator films generally suffer from problems such as easy aggregation of inorganic scintillator particles, limited loading (usually less than 10 wt%), low transmittance, wide emission spectrum, low color purity, limited spatial resolution (usually less than 10 lp / mm), and poor environmental adaptability.

[0045] To address the problems existing in the prior art, this invention provides a rare-earth organic-inorganic hybrid complex scintillator with the general formula [RE(L)4]. - ·[A] + The rare-earth organic-inorganic hybrid scintillator was composited with a transparent polymer matrix capable of film formation. By employing long-chain hydrophobic quaternary ammonium salts or heterocyclic quaternary ammonium cations without active functional groups as balancing ions, the solubility and dispersibility of the rare-earth organic-inorganic hybrid scintillator in the polymer matrix were significantly improved. This resulted in the rare-earth organic-inorganic hybrid scintillator film maintaining over 88% light transmittance in the 470nm–750nm wavelength range at scintillator loadings of 10wt%–60wt%. Furthermore, leveraging the 4f–4f characteristic transitions of rare-earth elements, the rare-earth organic-inorganic hybrid scintillator film… - The inorganic hybrid complex scintillator film emits a narrow band (FWHM≤10nm) with high color purity, thereby improving imaging contrast. Thanks to the synergistic effect of the molecularly dispersed hybrid structure and the highly transparent matrix, a spatial resolution of ≥20lp / mm is achieved in X-ray imaging, significantly reducing resolution loss caused by scattering. At the same time, the matching of hydrophobic organic cations and stable polymer matrix improves the stability and mechanical flexibility of the rare earth organic-inorganic hybrid complex scintillator film under humid, high temperature and bending conditions, improves environmental adaptability and reduces the risk of aging and peeling.

[0046] To enable those skilled in the art to more clearly understand the technical solution of the present invention, the following will provide a detailed description in conjunction with specific embodiments: Example 1 A method for preparing a scintillator thin film based on a rare-earth organic-inorganic hybrid complex includes the following steps: Preparation of S1, Eu(TTA)4(TBA) complex scintillators: 2-Thiophenecarboxyltrifluoroacetone (TTA, C8H5F3O2S, 4 mmol) and potassium hydroxide (4 mmol) were placed in a mortar, and 20 mL of anhydrous ethanol was added. The mixture was ground thoroughly at room temperature until 2-thiophenecarboxyltrifluoroacetone was dehydrogenated and the corresponding potassium salt was formed. Then, tetrabutylammonium chloride (TBACl, 1 mmol) and europium chloride hexahydrate (EuCl3·6H2O, 1 mmol) were added and stirred for 30 min to form an emulsion.

[0047] Centrifuge the emulsion at 8000 rpm for 10 min, collect the supernatant and place it in an open beaker sealed with plastic wrap. Let it stand at room temperature for 7 days to crystallize, obtaining light yellow transparent crystals. Wash the crystals twice with ice-cold anhydrous ethanol to remove impurities, and then dry them in a vacuum drying oven at 50℃ for 12 h to obtain the Eu(TTA)4(TBA) complex, denoted as Eu(TTA)4(TBA), for later use.

[0048] S2. Rare-earth organic-inorganic hybrid complex scintillator thin films: 10g of polymethyl methacrylate (PMMA) with a molecular weight of approximately 50,000 was dissolved in 40g of γ-valerolactone. The solution was stirred in a water bath at 80°C until fully dissolved, resulting in a 20wt% polymer solution, denoted as PMMA / γ-valerolactone solution.

[0049] Eu(TTA)4(TBA) was added to the PMMA / γ-valerolactone solution at a mass ratio of 1:10, and the mixture was stirred with a magnetic stirrer to obtain a homogeneous and transparent precursor solution.

[0050] The precursor solution was poured onto the surface of a flexible PET substrate (fixed with an iron ring around the perimeter) and vacuumed at room temperature for 20 minutes to remove air bubbles. Then, it was heat-treated in an oven at 80°C for 4 hours to form a uniform, smooth, flexible, and transparent scintillator film based on a rare earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(TBA)@PMMA.

[0051] Optical transmittance: The transmittance is higher than 88% in the range of 470nm~750nm.

[0052] Photoluminescence properties: Under 365nm ultraviolet light excitation, the main emission peak is located at 612±2nm, and the FWHM is less than 5nm.

[0053] Scintillation performance: Under X-ray excitation, the scintillator film based on rare earth organic-inorganic hybrid complexes exhibits strong red luminescence, and the brightness increases linearly with the irradiation dose.

[0054] Spatial resolution: Using a high-precision resolution tester, the rare-earth organic-inorganic hybrid complex scintillator film can achieve an imaging resolution of over 21 lp / mm under gain-free conditions, with sharp images and clear edges.

[0055] Flexibility: Based on rare earth organic-inorganic hybrid complex scintillator films, the films can be bent multiple times within a radius of 5 mm without cracking, making them suitable for wearable or curved surface imaging applications.

[0056] Example 2 A method for preparing a scintillator film based on a rare earth organic-inorganic hybrid complex is the same as the preparation method in Example 1, except that the mass ratio of Eu(TTA)4(TBA) to PMMA / γ-valerol solution in S2 is replaced from 1:10 to 2:10 to obtain a scintillator film based on a rare earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(TBA)@PMMA.

[0057] Example 3 A method for preparing a scintillator film based on a rare earth organic-inorganic hybrid complex is the same as the preparation method in Example 1, except that the mass ratio of Eu(TTA)4(TBA) to PMMA / γ-valerol solution in S2 is replaced from 1:10 to 3:10, thus obtaining a scintillator film based on a rare earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(TBA)@PMMA.

[0058] Example 4 A method for preparing a scintillator film based on a rare earth organic-inorganic hybrid complex is the same as the preparation method in Example 1, except that the mass ratio of Eu(TTA)4(TBA) to PMMA / γ-valerol solution in S2 is replaced from 1:10 to 4:10, thus obtaining a scintillator film based on a rare earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(TBA)@PMMA.

[0059] Example 5 A method for preparing a scintillator film based on a rare earth organic-inorganic hybrid complex is the same as the preparation method in Example 1, except that the mass ratio of Eu(TTA)4(TBA) to PMMA / γ-valerol solution in S2 is replaced from 1:10 to 5:10, thus obtaining a scintillator film based on a rare earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(TBA)@PMMA.

[0060] Example 6 A method for preparing a scintillator film based on a rare earth organic-inorganic hybrid complex is the same as the preparation method in Example 1, except that the mass ratio of Eu(TTA)4(TBA) to PMMA / γ-valerol solution in S2 is replaced from 1:10 to 6:10, thus obtaining a scintillator film based on a rare earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(TBA)@PMMA.

[0061] Example 7 A method for preparing a scintillator thin film based on a rare-earth organic-inorganic hybrid complex includes the following steps: Preparation of S1, Eu(TTA)4(BMP) complex scintillators: 2-Thiophenecarboxyltrifluoroacetone (TTA, C8H5F3O2S, 4 mmol) and potassium hydroxide (4 mmol) were placed in a mortar, and 20 mL of anhydrous ethanol was added. The mixture was ground thoroughly at room temperature until 2-thiophenecarboxyltrifluoroacetone was dehydrogenated and the corresponding potassium salt was formed. Then, 1-butyl-3-methylpyridinium cation (BMP, 1 mmol) and europium chloride hexahydrate (EuCl3·6H2O, 1 mmol) were added and stirred for 30 min to form an emulsion.

[0062] Centrifuge the emulsion at 8000 rpm for 10 min, collect the supernatant and place it in an open beaker sealed with plastic wrap. Let it stand at room temperature for 7 days to crystallize, obtaining light yellow transparent crystals. Wash the crystals twice with ice-cold anhydrous ethanol to remove impurities, and then dry them in a vacuum drying oven at 50℃ for 12 h to obtain the Eu(TTA)4(BMP) complex, denoted as Eu(TTA)4(BMP), for later use.

[0063] S2. Rare-earth organic-inorganic hybrid complex scintillator thin films: 10g of polymethyl methacrylate (PMMA) with a molecular weight of approximately 50,000 was dissolved in 40g of γ-valerolactone. The solution was stirred in a water bath at 80°C until fully dissolved, resulting in a 20wt% polymer solution, denoted as PMMA / γ-valerolactone solution.

[0064] Eu(TTA)4(BMP) was added to the PMMA / γ-valerolactone solution at a mass ratio of 4:10, and the mixture was stirred with a magnetic stirrer to obtain a homogeneous and transparent precursor solution.

[0065] The precursor solution was poured onto the surface of a flexible PET substrate. After vacuuming at room temperature for 20 minutes to remove air bubbles, it was then heat-treated in an oven at 80°C for 4 hours to form a uniform, smooth, flexible, and transparent scintillator film based on a rare-earth organic-inorganic hybrid complex, denoted as Eu(TTA)4(BMP)@PMMA.

[0066] Rare-earth organic-inorganic hybrid complex scintillator films maintain a transmittance of over 90% in the 470nm~750nm wavelength range and exhibit typical Eu characteristics under X-ray excitation. 3+ The emission characteristics show that the main emission peak is located at 612nm, the FWHM is 4.8nm, and the spatial resolution reaches 21lp / mm, demonstrating good visible light output and imaging clarity.

[0067] Example 8 A method for preparing a scintillator thin film based on a rare-earth organic-inorganic hybrid complex includes the following steps: Preparation of S1, Eu(DBM)4(TBA) complex scintillators: Dibenzoylmethane (DBM, 4 mmol) and potassium hydroxide (4 mmol) were placed in a mortar, and 20 mL of anhydrous ethanol was added. The mixture was ground thoroughly at room temperature until 2-thiophenecarboxyltrifluoroacetone was dehydrogenated and formed a stable complex anion. Then, tetrabutylammonium chloride (TBACl, 1 mmol) and europium chloride hexahydrate (EuCl3·6H2O, 1 mmol) were added and stirred for 30 min to form an emulsion.

[0068] Centrifuge the emulsion at 8000 rpm for 10 min, collect the supernatant and place it in an open beaker sealed with plastic wrap. Let it stand at room temperature for 7 days to crystallize, and obtain light yellow transparent crystals. Wash the crystals twice with ice-cold anhydrous ethanol to remove impurities, and then dry them in a vacuum drying oven at 50℃ for 12 h to obtain the Eu(DBM)4(TBA) complex, denoted as Eu(DBM)4(TBA), for later use.

[0069] S2. Rare-earth organic-inorganic hybrid complex scintillator thin films: 10g of polymethyl methacrylate (PMMA) with a molecular weight of approximately 50,000 was dissolved in 40g of γ-valerolactone. The solution was stirred in a water bath at 80°C until fully dissolved, resulting in a 20wt% polymer solution, denoted as PMMA / γ-valerolactone solution.

[0070] Eu(DBM)4(TBA) was added to the PMMA / γ-valerol solution at a mass ratio of 4:10, and stirred with a magnetic stirrer to obtain a homogeneous and transparent precursor solution.

[0071] The precursor solution was loaded onto the PI film by a blade coating method. After vacuuming at room temperature for 20 minutes to remove air bubbles, it was transferred to an oven at 80°C for 4 hours to form a uniform, flat, and flexible scintillator film based on rare earth organic-inorganic hybrid complex, denoted as Eu(DBM)4(TBA)@PMMA.

[0072] Rare-earth organic-inorganic hybrid complex scintillator films exhibit strong red light emission under X-ray excitation, with a main peak at 614 nm, a bandwidth of 5.2 nm, a quantum efficiency exceeding 65%, and a spatial resolution close to 20 lp / mm, making them suitable for mid-to-high-end X-ray imaging applications.

[0073] Example 9 A method for preparing a scintillator thin film based on a rare-earth organic-inorganic hybrid complex includes the following steps: Preparation of S1, Eu(BTA)4(BMIM) complex scintillators: Benzoyltrifluoroacetone (BTA, 4 mmol) and potassium hydroxide (4 mmol) were placed in a mortar, and 20 mL of anhydrous ethanol was added. The mixture was ground thoroughly at room temperature until benzoyltrifluoroacetone was dehydrogenated and formed a stable ligand anion. Then, 1-butyl-3-methylimidazolium (BMIM, 5 mmol) and europium chloride hexahydrate (EuCl3·6H2O, 20 mmol) were added and stirred for 30 min to form an emulsion.

[0074] Centrifuge the emulsion at 8000 rpm for 10 min, collect the supernatant and place it in an open beaker sealed with plastic wrap. Let it stand at room temperature for 7 days to crystallize, and obtain light yellow transparent crystals. Wash the crystals twice with ice-cold anhydrous ethanol to remove impurities, and then dry them in a vacuum drying oven at 50℃ for 12 h to obtain the Eu(BTA)4(BMIM) complex, denoted as Eu(BTA)4(BMIM), for later use.

[0075] S2. Rare-earth organic-inorganic hybrid complex scintillator thin films: 10g of polymethyl methacrylate (PMMA) with a molecular weight of approximately 50,000 was dissolved in 40g of γ-valerolactone. The solution was stirred in a water bath at 80°C until fully dissolved, resulting in a 20wt% polymer solution, denoted as PMMA / γ-valerolactone solution.

[0076] Eu(BTA)4(BMIM) was added to the PMMA / γ-valerolactone solution at a mass ratio of 4:10, and stirred with a magnetic stirrer to obtain a homogeneous and transparent precursor solution.

[0077] The precursor solution was poured onto the surface of a flexible PET substrate. After vacuuming at room temperature for 20 minutes to remove air bubbles, it was then heat-treated in an oven at 80°C for 4 hours to form a uniform, smooth, flexible, and transparent scintillator film based on a rare-earth organic-inorganic hybrid complex, denoted as Eu(BTA)4(BMIM)@PMMA.

[0078] The film is uniformly formed and free of visible particles or bubbles. Based on rare earth organic-inorganic hybrid complex scintillator film, the transmittance in the visible region reaches more than 89%. Under X-ray excitation, it exhibits strong red light emission with the main peak at 613nm, an FWHM of 5.1nm, and a spatial resolution of 21lp / mm¹, which can be used in flexible medical imaging equipment.

[0079] Example 10 A method for preparing a scintillator thin film based on a rare-earth organic-inorganic hybrid complex includes the following steps: Preparation of S1, Tb(DBM)4(CTA) complex scintillators: Dibenzoylmethane (DBM, 80 mmol) and potassium hydroxide (80 mmol) were placed in a mortar, and 20 mL of anhydrous ethanol was added. The mixture was ground thoroughly at room temperature until the dibenzoylmethane was dehydrogenated and formed a stable complex anion. Subsequently, hexadecyltrimethylammonium (CTA, 5 mmol) and terbium chloride hexahydrate (TbCl3·6H2O, 20 mmol) were added and stirred for 30 min to form an emulsion.

[0080] Centrifuge the emulsion at 8000 rpm for 10 min, collect the supernatant and place it in an open beaker sealed with plastic wrap. Let it stand at room temperature for 7 days to crystallize, obtaining light yellow transparent crystals. Wash the crystals twice with ice-cold anhydrous ethanol to remove impurities, and then dry them in a vacuum drying oven at 50℃ for 12 h to obtain the Tb(DBM)4(CTA) complex, denoted as Tb(DBM)4(CTA), for later use.

[0081] S2. Rare-earth organic-inorganic hybrid complex scintillator thin films: 10g of polymethyl methacrylate (PMMA) with a molecular weight of approximately 50,000 was dissolved in 40g of γ-valerolactone. The solution was stirred in a water bath at 80°C until fully dissolved, resulting in a 20wt% polymer solution, denoted as PMMA / γ-valerolactone solution.

[0082] Tb(DBM)4(CTA) was added to the PMMA / γ-valerolactone solution at a mass ratio of 3:10, and the mixture was stirred with a magnetic stirrer to obtain a homogeneous and transparent precursor solution.

[0083] The precursor solution was loaded onto the PI film by a blade coating method. After vacuuming at room temperature for 20 minutes to remove air bubbles, it was transferred to an oven at 80°C for 4 hours to form a uniform, flat, and flexible scintillator film based on rare earth organic-inorganic hybrid complex, denoted as Tb(DBM)4(CTA)@PMMA.

[0084] Based on the rare earth organic-inorganic hybrid complex scintillator film, it exhibits strong fluorescence emission in the green band (main peak at 544nm), with an FWHM of about 6.2nm, and a transmittance of over 87% in the 480nm~700nm band, achieving a spatial resolution of 20lp / mm¹, making it suitable for X-ray green light imaging systems.

[0085] like Figure 1 As shown in the single crystal structure diagram of Eu(TTA)4(TBA), Eu 3+ by four TTAs - Ligand coordination, TBA + Cations balance charge.

[0086] Figure 2 The results show that the diffraction peaks of Eu(TTA)4(TBA) in this invention correspond one-to-one with the peak positions of the simulated spectrum, with no obvious impurity peaks, proving that the Eu(TTA)4(TBA) structure is correct and has high crystallinity; the UV-Vis absorption and Tauc fitting yielded a band gap of approximately 3.05 eV, which is consistent with Eu... 3+ The matching of excitation / emission energy levels provides an energy level basis for subsequent efficient photoluminescence and radiative emission.

[0087] Figure 3 The results showed that the single crystal appeared pale yellow under visible light and emitted bright orange-red light under ultraviolet irradiation; the PLE / PL ratio showed a main emission peak at 612 nm, an FWHM at 2 nm, and CIE color coordinates of (0.577, 0.3761), with a PLQY as high as 73.14%; the lifetime decay was approximately 892 μs, corresponding to Eu... 3+ of 5 D0→ 7 The F2 (4f-4f) transition confirms its narrow band, high color purity, and high-efficiency luminescence characteristics.

[0088] Figure 4 Comparing the absolute radiative emission spectra of the rare-earth organic-inorganic hybrid complex scintillator of this invention with Ce:YAG at a dose rate of 821.19 μGy / s, the intensity in the orange-red region is significantly better than that of Ce:YAG; the RL spectrum is stable at different dose rates, and the intensity shows a linear relationship with the dose (RL). 2 ≥0.98, with a maximum of 0.99), indicating that the dose response is calibrable and has good repeatability.

[0089] Figure 5The results showed that 60wt% high-load Eu(TTA)4(TBA)@PMMA still maintained high transparency and the edges were clear when covering the "JGSU" mark; the transmittance curve showed that the transmittance was ≥88% in the range of 470nm~750nm, indicating that the rare earth organic-inorganic hybrid complex scintillator was nearly uniformly dispersed in the polymer matrix, with extremely low scattering and excellent film quality.

[0090] Figure 6 The standard line shown in the image clearly shows a resolution of ≥20 lp / mm, proving that the rare earth organic-inorganic hybrid complex scintillator film of the present invention has high spatial resolution. In the X-ray imaging of heterogeneous dried fish samples, the boundaries between bone spurs and fine tissues are clear and the contrast is high, which fully verifies the high-definition imaging capability and practical reliability of the rare earth organic-inorganic hybrid complex scintillator film of the present invention in real complex scenes.

[0091] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

Claims

1. A scintillator thin film based on rare-earth organic-inorganic hybrid complexes, characterized in that, It is made of rare earth organic-inorganic hybrid complex scintillators and a polymer matrix, wherein the polymer matrix is ​​selected from polycarbonate or polyurethane; In rare earth organic-inorganic hybrid scintillator films, the mass fraction of the rare earth organic-inorganic hybrid scintillator is 10wt%~60wt%. The general formula of the rare earth organic-inorganic hybrid complex scintillator is [RE(L)4] - ·[A] + ; RE is selected from Eu or Tb; L is a β-diketone ligand; [A] + selected from a tetrabutylammonium cation or a l-butyl-3-methylpyridinium cation.

2. The scintillator thin film based on rare earth organic-inorganic hybrid complex according to claim 1, characterized in that, The β-diketone ligand is selected from 2-thiophenecarboxyltrifluoroacetone, dibenzoylmethane, or benzoyltrifluoroacetone.

3. The scintillator thin film based on rare earth organic-inorganic hybrid complex according to claim 1, characterized in that, Rare earth organic-inorganic hybrid complex scintillators have a transmittance of not less than 88% in the 470nm~750nm wavelength range and a photoluminescence quantum efficiency of not less than 70%.

4. The scintillator thin film based on rare earth organic-inorganic hybrid complex according to claim 1, characterized in that, The general formula of the rare earth organic-inorganic hybrid complex scintillator is [RE(L)4] - ·[A] + The preparation method of the rare earth organic-inorganic hybrid complex scintillator comprises the following steps: Using rare earth element salts, β-diketone ligands, and organic cations as raw materials, in the presence of alkaline and alcoholic solvents, the β-diketone ligands are deprotonated to form coordination anions, which then react with REs. 3+ Coordination-cation substitution occurs, generating [RE(L)4]. - Finally, [RE(L)4] - With [A] + Ion association was performed, and crystallization was carried out after standing at room temperature for 5 to 7 days to obtain rare earth organic-inorganic hybrid complex scintillators; The rare earth element salts are selected from Eu or Tb salts; the organic cations are tetrabutylammonium cations or 1-butyl-3-methylpyridinium cations.

5. The scintillator thin film based on rare earth organic-inorganic hybrid complex according to claim 4, characterized in that, The molar ratio of rare earth element salts, β-diketone ligands and organic cations is 1:3.8~4.2:0.9~1.

1.

6. A method for preparing a scintillator thin film based on a rare-earth organic-inorganic hybrid complex as described in claim 1, characterized in that, Includes the following steps: The rare earth organic-inorganic hybrid complex scintillator was mixed with the polymer matrix solution to obtain the precursor solution; The precursor solution was loaded onto the substrate, and after degassing and heat treatment, a scintillator film based on rare earth organic-inorganic hybrid complex was obtained.

7. An X-ray detection device, characterized in that, The X-ray detection device is prepared by using the rare earth organic-inorganic hybrid complex scintillator thin film according to any one of claims 1 to 5, and converts the X-ray signal into a visible light imaging signal.

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