Preparation method of near-infrared light-emitting halide single crystal scintillator

Abstract

The invention discloses a preparation method of a near-infrared light-emitting halide single crystal scintillator, and belongs to the technical field of scintillators. The basic unit of the near-infrared light-emitting copper-based metal halide (4-ATHP) CuI is composed of a protonated ATHP (4-aminotetrahydropyrane) cation and a [CuI] anion cluster. The material is a yellow transparent block under sunlight, and the volume is about 1 cubic centimeter. Under ultraviolet excitation, the crystal shows polychromatic photoluminescence, and is successfully used for anti-counterfeiting and information encryption based on unique excitation dependent multicolor emission. The near-infrared luminescent copper-based metal halide (4-ATHP) CuI has a high light yield of 55, 923 eV / MeV and a low detection limit of 81.99 nGyair in the aspect of X-ray detection, wherein the light yield of the near-infrared luminescent copper-based metal halide (4-ATHP) CuI is 55,923 eV / MeV, and the low detection limit of 81.99 nGyair is 81.99 nGyair. According to the prepared large-area (15 * 20 cm) flexible scintillator film based on (4-ATHP) CuI, the high spatial resolution of 20 lp / mm is achieved. By integrating this film into a CMOS imager, these materials have a huge potential in high performance X-ray imaging applications.

Description

Technical Field

[0001] This invention relates to the field of scintillator technology, and more particularly to a method for preparing a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal. Background Technology

[0002] X-ray detection technology is widely used in medical diagnostic imaging, oil exploration, safety screening, and aerospace exploration. Low cost, high sensitivity, and excellent stability have made indirect detection systems the dominant technology in X-ray imaging. As a core component of indirect detection, high-performance scintillators play a crucial role in achieving efficient X-ray detection and imaging. Over the past few decades, traditional commercial pure inorganic scintillators, such as CsI:Tl and LaBr3:Ce, have been widely used. However, these scintillators also have several limitations, including complex and expensive manufacturing processes, insufficient flexibility, and relatively low photoluminescence yield, hindering their further development. Copper-based halide scintillators have attracted much attention in radiation detection and X-ray imaging due to their non-toxicity, high photoluminescence quantum yield (PLQY), and high photoluminescence yield. Initially developed inorganic crystals possess structural rigidity and stability, but their low solubility and solution processability hinder wider application. To overcome these challenges, organic-inorganic hybrid copper halide scintillators have been engineered. The incorporation of organic components combines the structural stability of inorganic clusters with the tunability of organic cations. For example, (TMAA)2Cu4Br6 and [BAPMA]Cu2Br5, this strategy significantly improves the optoelectronic properties, processability, and environmental stability of the materials.

[0003] However, the structure-property relationship induced by organic components and copper-iodide clusters remains insufficient in current research. Comprehensive reports on how specific bonding modes between organic components and clusters affect the performance of copper-based halide scintillators are still lacking. Reports on copper-based halides achieving high-resolution X-ray imaging are scarce, and few studies demonstrate their practical integration as scintillator screens in commercial devices. Therefore, investigating the feasibility of applying copper-based halides in commercial imaging devices is crucial and a key step towards practical application. Summary of the Invention

[0004] This invention provides a method for preparing near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystals and related products, exhibiting unique excitation-dependent multicolor emission, suitable for X-ray imaging, anti-counterfeiting, and information encryption. The specific scheme is as follows:

[0005] This invention provides a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal with the following chemical formula:

[0006] (4-ATHP)2CuI3;

[0007] In one possible implementation, in the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided in this embodiment of the invention, the 4-ATHP is 4-aminotetrahydropyran, and each copper atom is coordinated by four iodine atoms, forming a tetrahedral geometric structure. The 4-ATHP ligand remains in a deprotonated state and is directly connected to the metal center. The copper-iodine tetrahedra are interconnected through edge sharing and further extended into a one-dimensional (1D) chain structure through vertex sharing.

[0008] In one possible implementation, the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided in the embodiments of the present invention has the following cell parameters: a = 11.8986 Å, b = 12.3535 Å, c = 12.6596 Å, α = 90.264°, β = 90.243°, γ = 92.897°.

[0009] In one possible implementation, the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided in this embodiment of the invention exhibits a strong PLE peak at 340 nm in its high-energy emission band, with the emission peak at 535 nm when excited at this wavelength. The low-energy emission band shows strong PLE peaks at both 380 nm and 450 nm. When excited at 380 nm, the dominant emission peak is at 690 nm, accompanied by a weak high-energy emission shoulder at 535 nm. When excited at 450 nm, a red emission peak is generated at 690 nm.

[0010] In one possible implementation, the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided in this embodiment of the invention achieves >95% absorption of 13 keV photons at a thickness of 121 micrometers, resulting in a light yield of 55,923 photons / MeV and a detection limit of 81.99 nGy. e / s.

[0011] Accordingly, embodiments of the present invention also provide a method for preparing a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal as described in any one of the above embodiments of the present invention, comprising:

[0012] The precursor CuI was synthesized by dissolving a predetermined mass of copper oxide (I) in hydroiodic acid and stirring.

[0013] A first preset volume of 4-aminotetrahydropyran is injected into the completely dissolved precursor solution while stirring continuously to obtain a mixed solution.

[0014] Add the mixed solution to a second predetermined volume of hypophosphoric acid to obtain a colorless solution;

[0015] The colorless growth solution was filtered through a PTFE filter membrane with a pore size of 0.22 micrometers to obtain a purified solution.

[0016] The purified solution was placed in a ventilation hood and grown at room temperature for a preset time to obtain a near-infrared luminescent copper-based metal halide single crystal.

[0017] In one possible implementation, in the preparation method provided in the embodiments of the present invention, the preset mass is 1.43 grams, the first preset volume is 4.0 ml, the second preset volume is 1.0 ml, and the preset time is 1-3 days.

[0018] Accordingly, embodiments of the present invention also provide a method for preparing a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ flexible thin film, comprising:

[0019] (4-ATHP)2CuI3 powder is uniformly mixed with N,N-dimethylformamide (DMF) and thermoplastic polyurethane (TPU) in a predetermined ratio;

[0020] The mixture is spin-coated onto a flexible polyethylene terephthalate (PET) substrate;

[0021] A flexible (4-ATHP)2CuI3@TPU scintillation film was obtained by curing at room temperature.

[0022] In one possible implementation, in the preparation method provided in the embodiments of the present invention, the preset ratio is 8g (4-ATHP)2CuI3 powder, 6ml DMF, and 3g TPU.

[0023] In one possible implementation, in the preparation method provided in the embodiments of the present invention, the flexible film is transparent under sunlight and emits bright light under 254 nm ultraviolet irradiation.

[0024] In one possible implementation, in the preparation method provided in the embodiments of the present invention, the spatial resolution of the flexible thin film is typically 20 lp / mm.

[0025] The beneficial effects of the embodiments of the present invention are as follows:

[0026] This invention provides a method for preparing a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal and related products. The basic unit of the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ is centered on Cu, with each copper atom coordinated by four iodine atoms, forming a tetrahedral inorganic framework. It consists of protonated ATHP⁺ (4-aminotetrahydropyran) cations and [CuI₃]²⁻ anion clusters. The 4-ATHP ligands remain in an unprotonated state and are directly connected to the metal center. The copper-iodine tetrahedra are interconnected through edge sharing and further extended into a one-dimensional (1D) chain structure through vertex sharing. The near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided by this invention appears as a yellow transparent bulk with a volume of approximately 1 cubic centimeter under sunlight. Under ultraviolet excitation, the crystal exhibits multicolor photoluminescence: its emission color can be tunably changed from green to yellow, and further changes to red emission when excited by blue-violet light. Exhibiting excellent X-ray absorption properties, it has been successfully used for anti-counterfeiting and information encryption. Furthermore, the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided by this invention exhibits a high light yield of 55,923 eV / MeV and a low detection limit of 81.99 nGyair in X-ray detection. Therefore, this invention, through precise synthetic control, successfully synthesized a near-infrared luminescent copper-based halide (4-ATHP)₂CuI₃ with an ionic bond and cluster structure, possessing excellent characteristics of multicolor emission and luminescence, combining high light yield and low detection limit. Attached Figure Description

[0027] Figure 1 The crystal structure of (4-ATHP)2CuI3 was determined by single-crystal X-ray diffraction (XRD).

[0028] Figure 2 A photograph of a (4-ATHP)2CuI3 single crystal under sunlight;

[0029] Figure 3 Image of (4-ATHP)2CuI3 single crystal under ultraviolet excitation at wavelengths of 310 to 450 nm;

[0030] Figure 4 X-ray diffraction pattern of single-crystal powder and simulated single-crystal diffraction pattern of (4-ATHP)2CuI3;

[0031] Figure 5 The images show the photoluminescence (PL) and photoluminescence excitation (PLE) spectra of a (4-ATHP)₂CuI₃ single crystal at room temperature.

[0032] Figure 6A schematic diagram of the photoluminescent recombination mechanism in (4-ATHP)2CuI3 crystal;

[0033] Figure 7 The time-resolved photoluminescence spectrum of (4-ATHP)₂CuI₃ single crystal;

[0034] Figure 8 The radioluminescence (RL) spectra of (4-ATHP)2CuI3 and BGO scintillators are shown (tube voltage: 50 kV; tube current: 200 μA).

[0035] Figure 9 A schematic diagram of a method for preparing a near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 single crystal according to an embodiment of the present invention;

[0036] Figure 10 A schematic diagram of the preparation method of a near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 flexible thin film provided in an embodiment of the present invention;

[0037] Figure 11 The images provided in this invention are scintillation film photographs taken under white light and 254 nm ultraviolet light irradiation on a polyethylene terephthalate (PET) substrate, representing a near-infrared luminescent copper-based metal halide (4-ATHP) 2CuI3 flexible film, as well as X-ray images of a standard resolution test pattern.

[0038] Figure 12 The present invention provides an embodiment of a near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 flexible film for X-ray imaging and corresponding optical photographs of Bluetooth headsets, chargers, computer mice and encapsulation spring structures.

[0039] Figure 13 A Morse code template for message encryption and transmission was designed based on a near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 single crystal powder provided in an embodiment of the present invention.

[0040] Figure 14 Digital anti-counterfeiting photos designed for a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal powder provided in this embodiment of the invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict. Based on the described 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.

[0042] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "comprising" or "including," and similar terms used in this invention, mean that the element or object preceding the term encompasses the element or object listed following the term and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "inner," "outer," "upper," and "lower" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] As used in this invention, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0044] As used in this invention, "parallel," "perpendicular," and "equal" include the described situation and situations that are similar to the described situation, within an acceptable deviation range, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism can be, for example, within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can also be, for example, within 5°. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality can be, for example, the difference between the two equals being less than or equal to 10% of either one.

[0045] In this invention, circles, triangles, rectangles, trapezoids, pentagons, or hexagons are not strictly defined, but can be approximate circles, triangles, rectangles, trapezoids, pentagons, or hexagons. Small deformations due to tolerances are possible, and chamfers, curved edges, and other deformations are possible.

[0046] This invention provides a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal with the following chemical formula:

[0047] (4-ATHP)2CuI3;

[0048] The near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ provided in this invention has a basic unit centered on Cu, with each copper atom coordinated by four iodine atoms, forming a tetrahedral inorganic framework. It consists of protonated ATHP⁺ (4-aminotetrahydropyran) cations and [CuI₃]²⁻ anion clusters, with the 4-ATHP ligands remaining in an unprotonated state and directly connected to the metal center. The copper-iodine tetrahedra are interconnected through edge sharing and further extended into a one-dimensional (1D) chain structure through vertex sharing. The near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal provided by this invention appears as a yellow transparent bulk with a volume of approximately 1 cubic centimeter under sunlight. Under ultraviolet excitation, the crystal exhibits multicolor photoluminescence: its emission color can be tunably changed from green to yellow, and further changes to red emission when excited by blue-violet light. Based on its unique excitation-dependent multicolor emission, it has been successfully used for anti-counterfeiting and information encryption. Furthermore, the invention provides a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ exhibiting a high light yield of 55,923 eV / MeV and a low detection limit of 81.99 nGyair in X-ray detection. A large-area (15 × 20 cm²) flexible scintillator film based on (4-ATHP)₂CuI₃ was prepared, achieving a high spatial resolution of 20 lp / mm. Therefore, through precise synthetic control, this invention successfully synthesized a near-infrared luminescent copper-based halide (4-ATHP)₂CuI₃ with an ionic bond and cluster structure, possessing excellent properties of multicolor emission and luminescence, combining high light yield and a low detection limit.

[0049] Specifically, such as Figure 1 As shown, in (4-ATHP)₂CuI₃, the copper-iodine tetrahedra are interconnected through edge sharing and further extended into a one-dimensional (1D) chain structure through vertex sharing. Each copper atom is coordinated by four iodine atoms, forming a tetrahedral geometry. The 4-ATHP ligand remains in a deprotonated state and is directly connected to the metal center. (4-ATHP)₂CuI₃ crystallizes in the triclinic system with space group [space group missing]. The unit cell parameters are a = 11.8986 Å, b = 12.3535 Å, c = 12.6596 Å, α = 90.264°, β = 90.243°, and γ = 92.897°.

[0050] like Figure 2 As shown, the (4-ATHP)2CuI3 single crystal appears as a yellow transparent block under sunlight, with a volume of approximately 1 cubic centimeter.

[0051] like Figure 3 As shown, under ultraviolet excitation, the crystal exhibits multicolor photoluminescence: its emission color can be tunably changed from green to yellow, and further changes to red emission when excited by blue-violet light.

[0052] like Figure 4 The powder X-ray diffraction (PXRD) pattern of the (4-ATHP)2CuI3 material shown is in high agreement with the simulated pattern of the single crystal structure, confirming the high phase purity of these compounds.

[0053] Specifically, such as Figure 5 As shown in the embodiments of the present invention, the aforementioned near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ exhibits dual-band emission at room temperature. The high-energy emission band displays the strongest PLE peak at 340 nm, followed by a broad yellow-green emission peak at 535 nm upon excitation at this wavelength. This high-energy emission has a large Stokes shift of 195 nm and a full width at half maximum (FWHM) of 127 nm. The low-energy emission band exhibits strong PLE peaks at both 380 nm and 450 nm. Upon excitation at 380 nm, a dominant red low-energy emission peak appears at 690 nm, accompanied by a weak high-energy emission shoulder at 535 nm. In contrast, upon excitation at 450 nm, a red emission peak is produced only at 690 nm, without a high-energy shoulder. This low-energy emission has a large Stokes shift of 240 nm and an FWHM of 134 nm.

[0054] Specifically, the photoluminescence mechanism of (4-ATHP)2CuI3 was further investigated, such as... Figure 6 Under short-wavelength excitation (340 nm) at room temperature, electrons are excited to a high-excited state. This is followed by a transition to a charge-transfer (X / MLCT) state, resulting in a high-energy green emission peak. At 80 K, the number of initial excited states increases, and the photon energy at 340 nm is insufficient to effectively fill this high-energy state, leading to a decrease in high-energy emission. Conversely, under long-wavelength excitation (450 nm) at room temperature, electrons are directly excited to a lower excited state. This is followed by a transition from the X / MLCT state to the triple cluster center (³CC) state, producing the observed red emission.

[0055] Furthermore, to gain a deeper understanding of the electronic properties of the (4-ATHP)₂CuI₃ single crystal, the inventors of this case conducted further research, performing density functional theory (DFT) calculations using PBE mixed functional theory. Its electronic band structure, density of states (DOS), and partial charge density isosurfaces were calculated. (4-ATHP)₂CuI₃ has a direct band gap, with a calculated value of 2.61 eV. The predicted density of states (PDOS) analysis of (4-ATHP)₂CuI₃ shows that the valence band maximum (VBM) is mainly composed of Cu-*d* and I-*p* orbitals, with the main contribution coming from the Cu-*d* orbitals. Conversely, the conduction band minimum (CBM) is dominated by Cu-*s* and I-*p* orbitals, with the I-*p* orbitals contributing the most.

[0056] like Figure 7 The yellow-green emission of (4-ATHP)₂CuI₃ exhibits single exponential decay with a lifetime of 8.67 μs, while its red emission exhibits double exponential decay: the lifetimes are τ₁ = 3.13 μs and τ₂ = 12.01 μs under 380 nm excitation, and slightly decrease to τ₁ = 2.74 μs and τ₂ = 11.61 μs under 450 nm excitation.

[0057] The potential applications of (4-ATHP)₂CuI₃ in X-ray scintillation imaging were investigated. Its scintillation characteristics were initially evaluated using fiber optic spectroscopy with a calibrated integrating sphere. The attenuation coefficient was calculated based on a photon absorption cross-section database and compared with commercial scintillators. The attenuation coefficient of (4-ATHP)₂CuI₃ falls between that of BGO and silicon (Si) in the studied photon energy range, exhibiting good X-ray absorption. (4-ATHP)₂CuI₃ achieved >95% absorption for 13 keV photons at a thickness of 121 μm. Using a similar wafer (18 mm diameter, 0.5 mm thickness) and with BGO as a reference, radioluminescence (RL) spectra were obtained under the same dose conditions. The absolute light yield was calibrated using the pulse height spectroscopy method, and the light yield of (4-ATHP)₂CuI₃ reached 55,923 photons / MeV. Figure 8 As shown, it exhibits excellent flicker performance.

[0058] This invention provides a method for preparing the near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal described above. Figure 9 As shown, the preparation method may include:

[0059] 1.43 g of copper oxide (I) was dissolved in hydroiodic acid and stirred to synthesize the precursor CuI. After complete dissolution, 4.0 mL of 4-aminotetrahydropyran was injected into the completely dissolved precursor solution while stirring continuously to obtain a mixed solution. 1 mL of hypophosphoric acid was added to the mixed solution to obtain a colorless solution to prevent Cu⁺ oxidation. The colorless growth solution was filtered through a PTFE filter membrane with a pore size of 0.22 μm. The purified solution was placed in a ventilation hood and grown at room temperature. After 1-3 days, a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ single crystal was obtained.

[0060] This invention also provides a method for preparing the above-mentioned near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ flexible thin film, as described in this invention embodiment. Figure 10 As shown, the preparation method may include:

[0061] 8 g of (4-ATHP)2CuI3 powder was mixed with 6 mL of N,N-dimethylformamide (DMF) and 3 g of thermoplastic polyurethane (TPU) to form a homogeneous mixture. The mixture was spin-coated onto a flexible polyethylene terephthalate (PET) substrate and cured at room temperature to obtain a flexible (4-ATHP)2CuI3@TPU scintillation film.

[0062] like Figure 11 , Figure 12 As shown, Figure 11 Images of the (4-ATHP)₂CuI₃ flexible film prepared above, taken on a polyethylene terephthalate (PET) substrate under white light and 254 nm ultraviolet light irradiation, are shown. X-ray images of the standard resolution test pattern are also included. The formed scintillation film is transparent in sunlight and emits bright light under 254 nm ultraviolet light irradiation. The spatial resolution of the (4-ATHP)₂CuI₃@TPU film was evaluated against a test chart using standard lines. The scintillation screen resolution reaches 20 lp / mm, significantly exceeding that of commercial CsI:Tl scintillator detectors. Figure 12 As shown, this high resolution makes the internal structures clearly visible, including the integrated circuit (IC) components inside the USB drive, the complex structure of the Bluetooth headset, and a high-resolution image of the copper bookmark, highlighting the great potential of flexible films in high-resolution X-ray imaging applications.

[0063] Due to the monophase multicolor luminescence properties of (4-ATHP)₂CuI₃, this invention explores its potential in information storage and anti-counterfeiting. A Morse code template for message encryption and transmission was designed. For example... Figure 13As shown, when (4-ATHP)₂CuI₃ powder is placed in a template, the Morse code is decoded as "BPFJHXQ" under 254 nm UV excitation. Utilizing the property that its luminescence is quenched by methanol but restored upon heating, methanol is dripped onto a specific area. Under 400 nm UV light, the red fluorescent area displays the decoded information "WMTOIKG". After heating to restore the original state, the Morse code is restored to "BPFJHXQ" under 365 nm UV light. This method effectively promotes the encryption and transmission of sensitive information, highlighting the versatility of materials in secure communication. Figure 14 The anti-counterfeiting labels containing (4-ATHP)₂CuI₃ powder shown display patterns of "8888", "2025", and "2026" under daylight. These patterns exhibit a bright green emission under 254 nm ultraviolet light, a bright orange-yellow emission under 365 nm ultraviolet light, and a bright red emission under 400 nm ultraviolet light. This multi-wavelength response demonstrates that (4-ATHP)₂CuI₃ anti-counterfeiting labels can achieve double or multiple encryption using different ultraviolet wavelengths, confirming their significant application potential in advanced anti-counterfeiting technology.

[0064] Although preferred embodiments of this disclosure 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 disclosure. Clearly, those skilled in the art can make various alterations and variations to the embodiments of this disclosure without departing from the spirit and scope of the embodiments of this disclosure. Thus, if such modifications and variations to the embodiments of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure also intends to include such modifications and variations.

Claims

1. A near-infrared luminescent halide single-crystal scintillator, characterized in that, The chemical formula of the near-infrared luminescent halide single-crystal scintillator is: (4-ATHP)2CuI3; 4-ATHP is 4-aminotetrahydropyran, with each copper atom coordinated by four iodine atoms, forming a tetrahedral geometry. The 4-ATHP ligand remains in a deprotonated state and is directly connected to the metal center. The copper-iodine tetrahedra are interconnected through edge sharing and extend into a one-dimensional 1D chain structure through vertex sharing.

2. The near-infrared luminescent halide single-crystal scintillator according to claim 1, characterized in that, The unit cell parameters of the crystal structure are a=11.8986Å, b=12.3535Å, c=12.6596Å, α=90.264°, β=90.243°, and γ=92.897°.

3. The near-infrared luminescent halide single-crystal scintillator according to claim 1, characterized in that, The near-infrared luminescent metal halide (4-ATHP)₂CuI₃ exhibits a strong PLE peak at 340 nm in its high-energy emission band, with the emission peak at 535 nm when excited at this wavelength. The low-energy emission band also shows strong PLE peaks at both 380 nm and 450 nm. When excited at 380 nm, the dominant emission peak is at 715 nm, accompanied by a high-energy emission shoulder at 535 nm. When excited at 450 nm, a red emission peak is generated at 715 nm.

4. The near-infrared luminescent halide single-crystal scintillator according to claim 1, characterized in that, The aforementioned near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃, at a thickness of 121 micrometers, achieves >95% absorption of 13 keV photons, with a light yield of 55,923 photons / MeV and a detection limit of 81.99 nGy. e / s.

5. A method for preparing a near-infrared luminescent halide single-crystal scintillator as described in any one of claims 1-4, characterized in that, include: The precursor CuI was synthesized by dissolving a predetermined mass of copper oxide in hydroiodic acid and stirring. A first preset volume of 4-aminotetrahydropyran is injected into the completely dissolved precursor solution while stirring continuously to obtain a mixed solution. Add the mixed solution to a second predetermined volume of hypophosphoric acid to obtain a colorless solution; The colorless growth solution was filtered through a PTFE filter membrane with a pore size of 0.22 micrometers to obtain a purified solution. The purified solution was placed in a ventilation hood and grown at room temperature for a preset time to obtain a near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 single crystal.

6. The preparation method according to claim 5, characterized in that, The preset weight is 1.43 grams, the first preset volume is 4.0 ml, the second preset volume is 1.0 ml, and the preset time is 1-3 days.

7. A method for preparing a near-infrared luminescent copper-based metal halide (4-ATHP)₂CuI₃ flexible thin film, characterized in that, include: (4-ATHP)2CuI3 powder is uniformly mixed with N,N-dimethylformamide and thermoplastic polyurethane in a predetermined ratio; The mixture was spin-coated onto a flexible polyethylene terephthalate substrate; Curing at room temperature yields a flexible (4-ATHP)2CuI3@TPU scintillation film, namely a near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 flexible film.

8. The preparation method according to claim 7, characterized in that, The preset ratio is 8 grams of (4-ATHP)2CuI3 powder, 6 ml of DMF, and 3 grams of TPU.

9. The preparation method according to claim 7 or 8, characterized in that, A near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 flexible film is transparent under sunlight and emits bright light under 254 nm ultraviolet irradiation.

10. The preparation method according to any one of claims 7-9, characterized in that, A near-infrared luminescent copper-based metal halide (4-ATHP)2CuI3 flexible thin film has a spatial resolution of 20 lp / mm.

Images