A manganese-based pixelated scintillator array and methods of making and using the same

Abstract

The application belongs to the field of scintillator material preparation, and particularly relates to a manganese-based pixelated scintillator array and a preparation method and application thereof. The (BuTPP)2MnBr4 scintillator material in a molten state is filled into a quartz glass cavity by capillary action, and a glass scintillator matrix is formed by cooling and quenching; then, in-situ crystallization is realized in the glass scintillator by using femtosecond laser direct writing processing, and a pixelated array is precisely constructed. The in-situ crystallization induced by the femtosecond laser significantly improves the photoluminescence intensity and the radiation luminescence intensity of the material, effectively solves the problems of low luminescence efficiency, high pixelation processing difficulty and poor crystallization controllability of the traditional glass scintillator, and the prepared pixelated scintillator array has stable optical performance and clear pixel boundary, is suitable for X-ray imaging, radiation detection and the like, and has simple preparation process and strong controllability of parameters, thereby providing a new implementation method for the preparation of arrayed X-ray scintillators.

Description

Technical Field

[0001] This invention belongs to the field of scintillator material preparation, specifically relating to a manganese-based pixelated scintillator array, its preparation method, and its application. Background Technology

[0002] Scintillators are functional materials that convert high-energy radiation (such as X-rays and gamma rays) into visible light. They are the core of indirect X-ray detectors and are widely used in medical imaging, security inspection, and high-energy physics detection. Compared with direct X-ray detectors, indirect X-ray detectors have advantages such as higher detection efficiency and better stability.

[0003] Currently, commercially available scintillators mainly include inorganic crystal scintillators (such as Tl-doped cesium iodide CsI:Tl) and ceramic scintillators (such as Tb-doped gadolinium oxysulfide GOS:Tb). These types of scintillators generally suffer from inherent drawbacks such as high preparation costs, complex synthesis processes, and long production cycles. In contrast, glass scintillators based on organic-inorganic hybrid metal halides, prepared via a melt-quenching method, offer significant advantages such as simple preparation processes, ease of large-area molding, and excellent luminescence performance, making them a promising new scintillator material system. However, compared to their single-crystal counterparts, these glass scintillators suffer from reduced luminescence intensity and decreased scintillation performance, while single-crystal preparation is time-consuming, costly, and limited in size, making control difficult.

[0004] To further improve material properties, pixelation in scintillators helps to confine photon transmission, reduce optical crosstalk, and improve imaging quality. Conventional pixelation processes often employ cutting and template filling techniques, which are not only complex and prone to causing irreversible damage to the material, but also make it difficult to achieve precise in-situ crystallization control at the microscale.

[0005] Therefore, developing a simple, in-situ controllable crystallization method for preparing pixelated scintillators that significantly improves luminescence performance has important engineering application value. Summary of the Invention

[0006] The technical problem this invention aims to solve is to address the shortcomings of existing technologies by providing a method for enhancing the performance of manganese-based pixelated scintillators through pixelation processing and in-situ crystallization. Because organic components have low melting points, organic-inorganic hybrid metal halides can melt at low temperatures, and organic-inorganic hybrid metal halide glasses can be obtained through a quenching process, offering the advantage of high transparency compared to traditional scintillators. This invention uses (BuTPP)2MnBr4 as the manganese-based bromide and employs laser direct writing processing to fabricate the (BuTPP)2MnBr4 glass scintillator, achieving in-situ growth and crystallization of the pixelated array. This solves the problem of decreased luminous efficiency in glass scintillators, enhances the luminous intensity of the scintillator, improves X-ray imaging quality, and facilitates the development of practical applications for scintillators.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides a manganese-based pixelated scintillator array, wherein the manganese-based pixelated scintillator array is a (BuTPP)2MnBr4 pixelated scintillator array; the (BuTPP)2MnBr4 pixelated scintillator array includes two quartz glass plates disposed opposite each other and a (BuTPP)2MnBr4 pixelated scintillator disposed between the quartz glass plates; wherein the (BuTPP)2MnBr4 pixelated scintillator is formed by femtosecond laser direct writing induction of a (BuTPP)2MnBr4 bromide glass scintillator.

[0009] Specifically, the (BuTPP)₂MnBr₄ glass scintillator is an isotropic organic-inorganic hybrid metal halide glass, composed of organic cations and metal halide anions, BuTPP + It is butyltriphenylphosphine bromide, C 22 H 24 BrP;Mn 2+ It is derived from manganese bromide tetrahydrate.

[0010] Specifically, (BuTPP)2MnBr4 is an organic-inorganic hybrid metal halide that is used in X-ray detection and has advantages such as simple preparation process and excellent luminescence performance.

[0011] Specifically, the (BuTPP)2MnBr4 pixelated scintillator is used to generate radiative emission. The (BuTPP)2MnBr4 pixelated scintillator is an isotropic organic-inorganic hybrid metal halide glass, which is prepared by in-situ crystal growth on the glass through laser direct writing. Under X-ray irradiation, the (BuTPP)2MnBr4 pixelated scintillator emits bright green fluorescence.

[0012] A second aspect of this invention provides a method for preparing a manganese-based pixelated scintillator array, comprising the following steps:

[0013] Step 1: Mix manganese bromide tetrahydrate (MnBr2·4H2O) with butyltriphenylphosphine bromide (BuTPP-Br, molecular formula C... 22 H 24 (BuTPP)2MnBr4 powder was obtained by adding BrP to ethanol, stirring and reacting, filtering and drying.

[0014] Step 2: Place (BuTPP)2MnBr4 powder at the inlet of the quartz glass interlayer, heat it to completely melt the powder to form a melt, and use capillary action to fill the interior of the quartz glass interlayer; then quench it, and after the melt has completely solidified, you will get (BuTPP)2MnBr4 glass scintillator.

[0015] Step 3: The (BuTPP)2MnBr4 glass scintillator is directly written using a femtosecond laser to achieve in-situ crystallization of the (BuTPP)2MnBr4 bromide glass scintillator in the laser irradiation area, forming a pixelated scintillator array according to a preset dot matrix pattern; after annealing, the manganese-based pixelated scintillator array is obtained.

[0016] In step one, the molar ratio of manganese bromide tetrahydrate to butyltriphenylphosphine bromide is 1:2; and the concentration of manganese bromide tetrahydrate in ethanol is 0.67 mol / L.

[0017] In some embodiments of the present invention, in step one, the stirring reaction takes 5 minutes; the drying process takes place at 80°C for 30 minutes.

[0018] In step two, the thickness of the quartz glass interlayer is 0.1~1.0 mm.

[0019] In some embodiments of the present invention, in step two, the quartz glass interlayer consists of two quartz glass pieces arranged opposite each other and a stainless steel ball disposed between the two quartz glass pieces.

[0020] In some embodiments of the present invention, in step two, the quartz glass has a length of 75 mm, a width of 25 mm, and a thickness of 1 mm; the stainless steel ball has a diameter of 0.1~1.0 mm.

[0021] In some embodiments of the present invention, in step two, the preparation steps of the quartz glass interlayer are as follows: take two pieces of quartz glass, coat the four vertices of one of the quartz glass pieces with UV-curable adhesive; place a stainless steel ball at the vertices as a support fulcrum, then cover and adhere the other piece of quartz glass, place it under a UV lamp for 1 minute, and after curing, form an interlayer mold with uniform thickness.

[0022] In step two, the heating temperature is 185 °C; the quenching temperature is 20 °C.

[0023] In step three, the femtosecond laser has the following process parameters: a center wavelength of 1030 nm, a repetition frequency of 100 kHz, a pulse width of 300 fs, a laser objective lens magnification of 50×, a laser power of 150 W, a power attenuation of 5%, a scanning speed of 1 mm / s, and a dot matrix pattern with a dot matrix spacing of 50 μm.

[0024] Specifically, the (BuTPP)2MnBr4 pixelated scintillator array is formed by in-situ crystallization through femtosecond laser direct writing. The array size, pixel spacing, and arrangement can be controlled by adjusting the laser parameters and programming. Moreover, the femtosecond laser direct writing process does not require a mask or etching, and achieves non-destructive pixelation crystallization directly inside the glass scintillator.

[0025] In step three, the annealing is carried out at a temperature of 50 °C for 10 min.

[0026] A third aspect of the present invention provides an application of a manganese-based pixelated scintillator array in X-ray imaging.

[0027] In some embodiments of the present invention, a pixelated scintillator array of (BuTPP)₂MnBr₄ was successfully prepared using the above-described preparation method. Testing the photoluminescence and radiative emission intensities of the (BuTPP)₂MnBr₄ pixelated scintillator array showed that its luminescence intensity was significantly improved compared to that of the (BuTPP)₂MnBr₄ glass scintillator, indicating an improvement in luminous efficiency. This demonstrates the promising application prospects of the above-described (BuTPP)₂MnBr₄ pixelated scintillator array in X-ray imaging.

[0028] Beneficial effects:

[0029] (1) This invention achieves fixed-point, controllable, and efficient crystallization within a glass scintillator through femtosecond laser direct writing and in-situ crystallization, significantly improving the intensity of photoluminescence and radiative emission, and enhancing the luminous efficiency of the scintillator. Laser direct writing eliminates the need for masks, etching, and mechanical processing damage, and allows for flexible control of pixel size, spacing, shape, and arrangement, achieving high-precision pixelation.

[0030] (2) The glass scintillator prepared by using quartz glass sandwich encapsulation combined with capillary infusion and quenching processes has good uniformity, no bubbles, and high stability. The raw materials are non-toxic, the process is simple, the conditions are mild, the cost is low, and it is easy to mass-produce. It is suitable for applications such as X-ray detectors, medical imaging, and security detection, and has strong practicality, providing a new solution for the design of pixelated scintillator arrays. Attached Figure Description

[0031] The present invention will be further described in detail below with reference to the accompanying drawings, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0032] Figure 1 This is a schematic diagram of the structure of the (BuTPP)2MnBr4 pixelated scintillator array provided in an embodiment of the present invention, wherein 1 is a (BuTPP)2MnBr4 pixelated scintillator, 2 is quartz glass, 3 is quartz glass, and 4 is a stainless steel ball.

[0033] Figure 2 This is a schematic diagram of the laser direct writing processing system provided in an embodiment of the present invention, wherein 1 is a (BuTPP)2MnBr4 bromide glass scintillator, 2 is a femtosecond laser, 3 is an objective lens, and 4 is a displacement platform.

[0034] Figure 3 This is a differential scanning calorimetry (DSC) spectrum of the (BuTPP)2MnBr4 bromide glass scintillator in an embodiment of the present invention.

[0035] Figure 4 This is a microscope image of the (BuTPP)2MnBr4 pixelated scintillator array prepared in the embodiments of the present invention under 365 nm excitation.

[0036] Figure 5 The images show the X-ray diffraction (XRD) patterns of the (BuTPP)2MnBr4 pixelated scintillator array, the glass before processing, and the (BuTPP)2MnBr4 calculated based on the single crystal structure in this embodiment of the invention.

[0037] Figure 6 This is a comparison chart of the photoluminescence quantum yield (PLQY) of (BuTPP)2MnBr4 crystal and (BuTPP)2MnBr4 glass scintillator in the embodiments of the present invention.

[0038] Figure 7 The images show a comparison of photoluminescence intensity and radiative emission intensity between the (BuTPP)2MnBr4 pixelated scintillator array and the (BuTPP)2MnBr4 glass scintillator in this embodiment of the invention.

[0039] Figure 8 This is a comparison of X-ray imaging of (BuTPP)2MnBr4 pixelated scintillator array and (BuTPP)2MnBr4 glass scintillator in an embodiment of the present invention. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0041] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0042] Example 1:

[0043] This embodiment provides a manganese-based pixelated scintillator array. During experiments, the inventors discovered that while X-ray imaging using manganese-based bromide glass scintillators achieves high resolution, the luminous efficiency of these scintillators is attenuated compared to single-crystal scintillators. This is due to nonradiative recombination caused by long-range disorder in the glass structure; furthermore, severe light scattering and crosstalk still exist within the scintillator. To address this, the inventors proposed an in-situ crystal growth process within the glass scintillator to improve its luminous efficiency. The manganese-based pixelated scintillator array includes a quartz glass interlayer filled with scintillators. Figure 1 This is a schematic diagram of a manganese-based pixelated scintillator array, where 1 is a (BuTPP)2MnBr4 pixelated scintillator, 2 is quartz glass, 3 is quartz glass, and 4 is a stainless steel ball.

[0044] The specific fabrication method of the (BuTPP)2MnBr4 pixelated scintillator array is as follows:

[0045] Step 1: Weigh 2.86 g of manganese bromide tetrahydrate (MnBr2·4H2O) and 7.98 g of butyltriphenylphosphine bromide (BuTPPBr), add 15 mL of ethanol, stir for 5 min to precipitate the green powder, filter through filter paper and dry at 80 ℃ for 30 min to obtain (BuTPP)2MnBr4 powder.

[0046] Step 2: Take two pieces of quartz glass, each 75 mm long, 25 mm wide, and 1 mm thick. Apply UV-curable adhesive to the four vertices of one piece of quartz glass. Place stainless steel balls with a diameter of 0.1~1.0 mm at the vertices as support points, then cover and adhere the other piece of quartz glass. Irradiate under a UV lamp for 1 minute to cure, forming a sandwich mold with uniform thickness. Place (BuTPP)2MnBr4 powder at the inlet of the glass sandwich and heat it at 185 ℃ to melt it, forming a clear melt without bubbles. Then, use capillary action to fill the interior of the glass sandwich. After filling, place the quartz glass sandwich on a metal table at 20 ℃ for quenching. After the melt has completely solidified, the (BuTPP)2MnBr4 glass scintillator is obtained.

[0047] Step 3: Place the (BuTPP)2MnBr4 glass scintillator obtained in Step 2 on the three-dimensional displacement platform of the femtosecond laser processing system. Use a computer to move the platform, control the position and scanning speed of the scintillator, adjust the laser power through the attenuator, and perform laser irradiation processing under preset conditions to promote in-situ crystal growth.

[0048] Figure 2 This is a schematic diagram of a laser direct writing processing system, where 1 is a (BuTPP)2MnBr4 glass scintillator, 2 is a femtosecond laser, 3 is an objective lens, and 4 is a displacement platform.

[0049] Specifically, the laser parameters in femtosecond laser direct writing processing include: laser center wavelength of 1030 nm, repetition frequency of 100 kHz, pulse width of 300 fs, laser objective magnification of 50× (NA= 0.65), laser power of 150W, power attenuation to 5%, scanning speed of 1 mm / s, processing pattern of dot matrix, and dot matrix spacing of 50 μm.

[0050] Step 4: Anneal the scintillator processed in Step 3 at 50 °C for 10 min to obtain a (BuTPP)2MnBr4 pixelated scintillator array.

[0051] Differential scanning calorimetry (DSC) was used to analyze the (BuTPP)₂MnBr₄ glass scintillator prepared in step two, and the glass transition temperature (T) of the scintillator was measured. g ), crystallization temperature (T) c ), melting temperature (T) m ), Figure 3 The image shows the differential scanning calorimetry (DSC) spectrum of the (BuTPP)₂MnBr₄ glass scintillator. Figure 3 It is evident that the (BuTPP)₂MnBr₄ scintillator undergoes a glass transition at 44 °C, crystallizes at 92 °C, and melts at 145 °C. According to the Turnbull criterion, when T... g / T m (T) g and T m When the temperature (in Kelvin) is > 0.67, the material exhibits good glass transition ability, and (BuTPP)₂MnBr₄ has a value of 0.75, demonstrating excellent glass transition ability. Furthermore, because high-temperature processing can damage the substrate and degrade material properties, this low-temperature processing capability is advantageous for manufacturing photonic or imaging devices.

[0052] A pixelated scintillator array of (BuTPP)2MnBr4 was fabricated in situ on the (BuTPP)2MnBr4 glass scintillator prepared in step two using a 1030 nm femtosecond laser processing system. Figure 4 The image shows a microscopic image of the prepared (BuTPP)₂MnBr₄ pixelated scintillator array under 365 nm excitation. The luminescence intensity at the laser-processed crystal array is significantly higher than that at the background glass, and the dots are uniformly arranged and regularly sized. This characteristic is beneficial for applying the (BuTPP)₂MnBr₄ pixelated scintillator array to X-ray imaging.

[0053] The powder X-ray diffraction pattern of the (BuTPP)2MnBr4 pixelated scintillator array prepared in step four was measured using an X-ray diffractometer (Bruker D8 Advance A25). Figure 5 The XRD pattern of the (BuTPP)2MnBr4 pixelated scintillator array is obtained from... Figure 5 It can be seen that, by comparing with the X-ray diffraction pattern of simulated (BuTPP)2MnBr4, the pixelated scintillator array has obvious crystal peaks corresponding to the single crystal, and the peak shape is similar to that of the (BuTPP)2MnBr4 glass scintillator, which verifies that a crystal phase was generated by laser processing.

[0054] The photoluminescent quantum yield (PLQY) of the (BuTPP)₂MnBr₄ glass scintillator and the (BuTPP)₂MnBr₄ pixelated scintillator array prepared in steps two and four was measured using a fluorescence spectrometer (FLS980 Edinburgh spectrometer). Figure 6 The image shows a comparison of the photoluminescence quantum yield (PLQY) of a (BuTPP)2MnBr4 pixelated scintillator array crystal and a (BuTPP)2MnBr4 pixelated scintillator array crystal. Figure 6 In this context, 'a' represents the PLQY of a (BuTPP)2MnBr4 pixelated scintillator array crystal. Figure 6 In the figure, b represents the PLQY of the (BuTPP)2MnBr4 glass scintillator. The PLQY of the (BuTPP)2MnBr4 pixelated scintillator array crystal is significantly higher than that of the (BuTPP)2MnBr4 glass scintillator, which indicates that the (BuTPP)2MnBr4 pixelated scintillator array has higher luminous efficiency.

[0055] The photoluminescence spectra of the (BuTPP)₂MnBr₄ glass scintillator and the (BuTPP)₂MnBr₄ pixelated scintillator array prepared in steps two and four were measured using a Hitachi F-4700 fluorescence spectroscopy instrument. Figure 7 Figure 'a' in the figure shows a comparison of the photoluminescence intensity of the (BuTPP)₂MnBr₄ pixelated scintillator array and the (BuTPP)₂MnBr₄ glass scintillator. The (BuTPP)₂MnBr₄ pixelated scintillator array exhibits a stronger photoluminescence intensity, which demonstrates that the (BuTPP)₂MnBr₄ pixelated scintillator array has higher luminous efficiency. The radioluminescence spectra of the (BuTPP)₂MnBr₄ glass scintillator and the (BuTPP)₂MnBr₄ pixelated scintillator array prepared in steps two and four were measured using an X-ray tube system (miniX2 X-ray tube (Amptek Inc.)) and a spectrometer (Ocean Optics Spectrograph). Figure 7 Figure b in the figure shows a comparison of the measured radiative emission intensity of the (BuTPP)2MnBr4 pixelated scintillator array and the (BuTPP)2MnBr4 glass scintillator. The (BuTPP)2MnBr4 pixelated scintillator array exhibits a stronger radiative emission intensity, and therefore has a higher light yield than the (BuTPP)2MnBr4 glass scintillator. This characteristic gives it excellent X-ray detection performance.

[0056] X-ray imaging was performed on the (BuTPP)2MnBr4 glass scintillator and (BuTPP)2MnBr4 pixelated scintillator array prepared in steps two and four using an X-ray imaging system. The X-ray imaging system consisted of an X-ray source (miniX2 X-ray tube (Amptek Inc.)), a flat scintillator, a reflecting prism, and a CMOS camera. Figure 8 In the image, 'a' represents the X-ray image of the (BuTPP)2MnBr4 glass scintillator against the standard line card. Figure 8 In the image, b represents the X-ray image of a (BuTPP)2MnBr4 pixelated scintillator array relative to a standard line pair card. Compared to a (BuTPP)2MnBr4 glass scintillator, the (BuTPP)2MnBr4 pixelated scintillator array can clearly resolve 10 lp mm. −1 The line pairs indicate that the (BuTPP)2MnBr4 pixelated scintillator array has better X-ray imaging performance than the (BuTPP)2MnBr4 glass scintillator.

[0057] This invention provides a manganese-based pixelated scintillator array, its fabrication method, and its application. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A manganese-based pixelated scintillator array, characterized in that, The manganese-based pixelated scintillator array includes two quartz glass plates arranged opposite each other and a manganese-based pixelated scintillator disposed between the quartz glass plates; wherein the manganese-based pixelated scintillator is formed by femtosecond laser direct writing induction of a manganese-based bromide glass scintillator.

2. The manganese-based pixelated scintillator array according to claim 1, characterized in that, The manganese-based bromide is (BuTPP)2MnBr4.

3. The method for preparing the manganese-based pixelated scintillator array according to claim 1 or 2, characterized in that, Includes the following steps: Step 1: Add manganese bromide tetrahydrate and butyltriphenylphosphine bromide to ethanol, stir to react, filter and dry to obtain (BuTPP)2MnBr4 powder; Step 2: Place (BuTPP)2MnBr4 powder at the inlet of the quartz glass interlayer, heat it to completely melt the powder to form a melt, and use capillary action to fill the interior of the quartz glass interlayer; then quench it, and after the melt has completely solidified, you will get (BuTPP)2MnBr4 glass scintillator. Step 3: The (BuTPP)2MnBr4 glass scintillator is directly written using a femtosecond laser to achieve in-situ crystallization of the (BuTPP)2MnBr4 glass scintillator in the laser irradiation area, forming a pixelated scintillator array according to a preset dot matrix pattern; after annealing, the manganese-based pixelated scintillator array is obtained.

4. The preparation method according to claim 3, characterized in that, In step one, the molar ratio of manganese bromide tetrahydrate to butyltriphenylphosphine bromide is 1:2; the concentration of manganese bromide tetrahydrate in ethanol is 0.67 mol / L.

5. The preparation method according to claim 3, characterized in that, In step two, the thickness of the quartz glass interlayer is 0.1~1.0 mm.

6. The preparation method according to claim 5, characterized in that, In step two, the quartz glass interlayer consists of two quartz glass pieces arranged opposite each other and a stainless steel ball placed between the two quartz glass pieces.

7. The preparation method according to claim 3, characterized in that, In step two, the heating temperature is 185 °C; the quenching temperature is 20 °C.

8. The preparation method according to claim 3, characterized in that, In step three, the process parameters of the femtosecond laser are as follows: the center wavelength of the femtosecond laser is 1030 nm, the repetition frequency is 100 kHz, the pulse width is 300 fs, the magnification of the laser objective lens is 50×, the laser power is 150 W, the power attenuation is 5%, the scanning speed is 1 mm / s, the processing pattern is a dot matrix, and the dot matrix spacing is 50 μm.

9. The preparation method according to claim 3, characterized in that, In step three, the annealing is performed at a temperature of 50 °C for 10 min.

10. The application of the manganese-based pixelated scintillator array according to claim 1 or 2 in X-ray imaging.

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