A single crystal of a cuprous iodide cluster-based complex, its preparation method and application

Abstract

This invention belongs to the field of optoelectronic functional materials technology, and discloses a single crystal of a cuprous iodide cluster-based complex, its preparation method, and its application. The chemical formula of this cuprous iodide cluster-based complex is Cu9I. 13 (Et-ted)4;Cu9I 13 (Et-ted)4 is a non-centrosymmetric C2 space group, monoclinic crystal system, exhibiting a zero-dimensional structure, and containing a Cu4I4[(Et-ted)4] molecule. 4+ The cubane cluster nucleus cation and a [Cu5I9] group. 4− The cluster-based anion, [Cu5I9] in its spatial structure. 4− The nuclear cluster is composed of four Cu4I4[(Et-ted)4] 4+ The single crystal of the cuprous iodide cluster-based complex, surrounded by [the present invention], can be obtained by sequentially reacting cuprous iodide and Et-ted in a mixed solution, followed by volatilization and recrystallization, and exhibits nonlinear optical effects. Furthermore, using the single crystal of the cuprous iodide cluster-based complex disclosed in this invention as a scintillator, a scintillator thin film can be obtained through coating and microelectronic printing techniques. Under X-ray irradiation, the scintillator thin film can perform high-resolution X-ray imaging of the internal structure of a physical object and can also be used for three-dimensional imaging.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials technology, specifically a single crystal of a cuprous iodide cluster-based complex, its preparation method, and its application. Background Technology

[0002] X-ray imaging technology, with its strong penetrating power, is widely used in various fields such as medical diagnosis, industrial non-destructive testing, public safety, and nuclear radiation monitoring. Currently, X-ray detectors are mainly divided into direct detectors and indirect detectors. Direct detectors acquire high-energy photons and then generate a large number of free charges through Compton scattering and other photoelectric effects. These charges are collected by pixel electrodes, converted into voltage signals by charge amplifiers, and finally processed by readout integrated circuits. The core of this technology is the direct conversion of X-rays into electrical signals. Indirect detectors, on the other hand, use scintillators or phosphors to absorb high-energy X-rays and convert them into low-energy ultraviolet (UV) / visible (UVS) light. These low-energy photons can be received by array photodetectors or CMOS sensors and then converted into images. Therefore, developing novel high-performance scintillators is an important research goal with significant scientific and practical value.

[0003] Traditional inorganic scintillators are a widely used class of commercially available materials, with typical examples including thallium-doped cesium iodide (CsI:Tl), cerium-doped yttrium aluminum garnet (YAG:Ce), cerium-doped lutetium aluminum garnet (LuAG:Ce), and bismuth germanate (BGO). They possess advantages such as high atomic numbers, strong X-ray absorption, high light yield, and good chemical stability, meeting the needs of most conventional X-ray imaging scenarios. However, the fabrication of inorganic scintillators typically requires harsh conditions such as high temperatures (>1000 °C) and high vacuum, resulting in long production cycles, high energy consumption, and high costs. Furthermore, their high brittleness and poor flexibility prevent the fabrication of large-area flexible thin films, severely limiting their applications.

[0004] In recent years, lead halide perovskite scintillators such as CsPbBr3, MAPbBr3, and FAPbBr3 have become a research hotspot in the field of scintillators due to their high atomic number, high X-ray absorption coefficient, high photoluminescence quantum yield, and tunable emission wavelength. However, their commercial applications are limited by problems such as poor environmental stability, severe self-absorption, and lead toxicity. Organic scintillators, on the other hand, have the greatest advantage of good solution processability, tunable spectra, and good mechanical flexibility, allowing them to be manufactured at room temperature using simple processes. However, their low atomic number results in weak absorption of high-energy X-rays; simultaneously, due to low exciton binding energy and numerous non-radiative relaxation channels, their light yield is generally low, making it difficult to achieve high spatial resolution X-ray imaging, which severely limits their practical applications.

[0005] Cuprous halide complexes combine the tunable structure of cuprous halide clusters with the modifiability of organic ligand molecules, showing great potential in the development of novel high-performance scintillators. Based on their structure and bonding mechanisms, they can be classified into three main categories: ionic, neutral, and AIO (All-In-One). They are environmentally friendly, inexpensive to prepare, and possess rich structural tunability and high X-ray absorption efficiency, integrating the advantages of the aforementioned scintillator materials. Furthermore, the luminescence of cuprous halide complexes mainly originates from: metal-to-ligand charge transfer (MLCT), halogen-to-ligand charge transfer (XLCT), and cluster-centered charge transfer (CC) between metals, exhibiting advantages such as high quantum yield and tunable luminescence lifetime.

[0006] Common neutral cuprous halide complexes can form various charge-neutral inorganic clusters Cu through coordination bonds between Cu(I) and organic ligands. m X m These can be zero-dimensional (0D) molecular clusters, one-dimensional (1D) chains, or two-dimensional (2D) layers. Their luminescence quantum efficiency is significantly higher than that of ionic complexes, and their coordination bonds exhibit strong tunability. However, they suffer from poor thermal stability (e.g., decomposition temperature ≤200℃), insufficient consistency in luminescence efficiency, weak air and chemical stability, and high processing difficulty and ligand cost, limiting their large-scale application. Ionic cuprous halide cluster-based complexes consist of anionic inorganic modules (Cu... m X m+n ) n− Compared to neutral cuprous halide complexes, cuprous halide complexes exhibit higher stability when bonded to cationic organic ligands via ionic bonds. They also possess high scintillation yield, low detection limit, and good solution and melt processability, while being low in toxicity, low in cost, and low in self-absorption, making them suitable for low-dose imaging and flexible device requirements. However, they suffer from weak optical emission and low quantum efficiency (PLQY). AIO-type cuprous halide complexes are a novel type of hybrid cuprous halide structure containing both ionic and coordinate bonds, combining the advantages of both to achieve a balance between high luminescence efficiency, high stability, and good processability. However, current research on AIO-type cuprous iodide complexes is largely limited to synthesis and structural characterization, with a lack of systematic research on optical properties such as scintillation. Therefore, developing novel high-performance scintillators of this type and realizing high-resolution X-ray imaging applications has significant scientific and practical value. Summary of the Invention

[0007] This invention provides a single crystal of a cuprous iodide cluster-based complex and its preparation method, as well as its application in the fabrication of photoluminescent materials, scintillator materials, and nonlinear optical materials. The single crystal of the cuprous iodide cluster-based complex provided by this invention is a novel structure based on the 1-ethyl-1,4-diazacyclooctane Et-ted ligand. This invention uses the single crystal of the cuprous iodide cluster-based complex as a scintillator, and obtains a scintillator film by coating the prepared scintillator ink, achieving efficient green luminescence under X-ray irradiation, and enabling clear imaging of the internal structure of various physical objects.

[0008] The technical solution adopted in this invention is as follows:

[0009] In a first aspect, the present invention provides a single crystal of a cuprous iodide cluster-based complex, specifically an AIO cuprous iodide cluster-based complex scintillator material. The chemical formula of the single crystal of the cuprous iodide cluster-based complex is: Cu9I 13 (Et-ted)4, where Et-ted is 1-ethyl-1,4-diazacyclooctane, such as Figure 1a The crystal structure of this complex shows that it contains cuboethane-configured cationic structural units Cu4I4[(Et-ted)4]. 4+ This is a complex cation with a cubane core cluster structure, which also contains an anionic inorganic component [Cu5I9]. 4− That is, cluster anions; such as Figure 1b As shown, in its three-dimensional spatial arrangement, the cluster anion is surrounded by four complex cations of the above-mentioned cubane cluster structure; the single crystal of the cuprous iodide cluster-based complex is a non-centrosymmetric C2 space group, monoclinic crystal system, exhibiting a zero-dimensional structure; the Cu-I bond length ranges from 2.422(4) to 3.008(8) Å, and the spacing between Cu and Cu ranges from 2.63 to 2.76 Å. The cell parameters are: a = 25.608(3) Å, b = 9.0274(9) Å, c = 19.309(2) Å, α = 90°, β = 134.193(3)°, γ = 90°, V = 3200.5(6) Å. 3 .

[0010] Secondly, the present invention provides a method for preparing the above-mentioned cuprous iodide cluster-based complex single crystal. The cuprous iodide cluster-based complex single crystal is obtained by reacting cuprous iodide CuI and Et-ted sequentially through a mixed solution, filtering and washing to obtain a powder product, and then dissolving it in acetonitrile solvent and recrystallizing it by volatilization. The Et-ted product is obtained by the following preparation steps: at room temperature, triethylenediamine ted is dissolved in acetone to obtain a colorless and transparent solution with a concentration of 22.4 mg / mL; then 1-bromoethane with an equimolar amount of ted is added with stirring, and a precipitate is formed by reaction. The precipitate is then obtained by centrifugation, and the powder is washed with ethyl acetate and dried to obtain the product Et-ted.

[0011] As a preferred embodiment of the preparation method described in the second aspect of the present invention, the preparation method specifically includes the following steps: at room temperature, cuprous iodide is dissolved in acetonitrile to prepare a cuprous iodide acetonitrile solution, wherein the concentration of cuprous iodide CuI in the cuprous iodide acetonitrile solution is 0.02~0.1 mmol / mL; Et-ted ligand is dissolved in methanol, and then the ligand solution is slowly added to the cuprous iodide acetonitrile solution for mixing, wherein the molar ratio of CuI to Et-ted raw materials is (0.16~1.25):1, and a white powder is generated during the mixing process, and then the powder is filtered and washed; finally, the product is recrystallized using acetonitrile as a solvent, sealed with aluminum foil, and small holes are punched in the aluminum foil with a needle, and then the crystal is slowly grown by evaporation. The crystal obtained is a single crystal of cuprous iodide cluster-based complex.

[0012] The aforementioned cuprous iodide cluster-based complex single crystal exhibits an emission peak at 532 nm under ultraviolet light, displaying yellow-green light emission with a luminescence quantum efficiency of 84.8%. Thirdly, this invention also provides the application of the aforementioned cuprous iodide cluster-based complex single crystal in the fabrication of photoluminescent materials. These photoluminescent materials include ultraviolet-excited fluorescent materials or visible-light-responsive luminescent materials. For example, grinding the cuprous iodide cluster-based complex single crystal into powder, uniformly mixing it with epoxy resin, and then curing it can serve as a wavelength conversion layer for ultraviolet LED devices. This allows for the generation of high-brightness yellow-green fluorescence under 365-450 nm ultraviolet light excitation, enhancing the color gamut and visual effect of the light-emitting device. The aforementioned cuprous iodide cluster-based complex single crystal also exhibits high light yield under X-rays, reaching LuAG:Ce. 3+ 1.42 times,

[0013] Fourthly, the present invention also provides the application of the above-mentioned cuprous iodide cluster-based complex single crystal in the fabrication of scintillator materials.

[0014] The above-mentioned cuprous iodide cluster-based complex single crystal Cu9I 13When (Et-ted)4 is irradiated with a high-intensity laser, it generates a nonlinear optical signal, which is consistent with the space group characteristics of the non-centrosymmetric crystal, indicating that it has a good nonlinear optical response. Therefore, in a fifth aspect, the present invention also provides the application of the above-mentioned cuprous iodide cluster-based complex single crystal in the fabrication of nonlinear optical materials.

[0015] Sixthly, the present invention provides a scintillator ink, which is prepared by grinding the above-mentioned cuprous iodide cluster-based complex single crystal, first mixing it with water to form a suspension, and then thoroughly mixing it with a polymer solution, wherein the concentration of the suspension is 50-200 mg / mL; preferably, the step of thoroughly mixing with the polymer solution includes: adding the suspension to the polymer solution and thoroughly ultrasonically stirring to obtain a uniform scintillator ink. The polymer solution is a solution formed by dissolving any one of polyvinyl alcohol, polystyrene, polydimethylsiloxane, or polymethyl methacrylate in an organic solvent or water, and the concentration of the polymer solution is 50-200 mg / mL.

[0016] In a seventh aspect, the present invention also provides a scintillator film, which is obtained by coating the aforementioned scintillator ink; the coating method includes, but is not limited to, blade coating or drop coating; as a preferred preparation method of the scintillator film of the present invention, the preparation method includes the steps of: coating the scintillator ink onto a glass substrate by blade coating, allowing the scintillator film to evaporate at room temperature for 12 hours to form a flexible film, and then gently peeling it off from the glass substrate with tweezers. As a more preferred embodiment, the scintillator coating can be prepared by blade coating onto the glass substrate using microelectronic printing; when using microelectronic printing for blade coating, the specific steps are as follows: injecting the scintillator ink into the ink sac of a microelectronic printer, printing the ink onto the glass substrate by the pressure of a pump to obtain the scintillator coating, and then naturally drying it at room temperature (25°C) before scraping it off to obtain the scintillator film; further preferably, when using microelectronic printing for blade coating, the tube pressure is set to 0.1~0.2 MPa, the blade coating speed is 10~30 mm / s, and the blade height is 100~300 μm.

[0017] Eighthly, the present invention provides the application of the above-mentioned scintillator film in X-ray imaging. The X-ray imaging application uses an X-ray imaging platform to construct an X-ray imaging platform, with the above-mentioned scintillator film as a substrate, and the sample to be tested placed on the film. After the X-rays pass through the sample, they carry its structural information and irradiate the surface of the scintillator film, generating a visible light signal. The light signal is reflected by a prism and then collected and recorded by a camera, thereby realizing a complete X-ray imaging process.

[0018] Beneficial effects: The novel cuprous iodide cluster-based scintillator with an AIO (all-in-one) structure provided by this invention has a novel structure consisting of negatively charged units [Cu5I9]. 4− And the positively charged unit Cu4I4[(et-ted)4] 4+ The composition consists of a copper atom bonded to a cationic organic ligand within a positively charged unit, while the positive and negatively charged units are bonded by ionic bonds, belonging to a monoclinic crystal system. This invention synthesizes the Et ted ligand by quaternizing triethylenediamine according to the method reported by Ni Jianling in her master's thesis "Preparation and Performance Study of Luminescent Materials Based on Triethylenediamine Ligands" ([D], Jiangsu University of Science and Technology, 2022). This ligand is then coordinated with cuprous iodide to obtain a novel AIO-type cuprous iodide cluster-based complex Cu9I, which possesses both ionic and coordinate bonds. 13 (Et-ted)4, this compound contains two separate cluster nuclei, each being a Cu4I4[(Et-ted)4] 4+ The cubane cluster nucleus cation and a [Cu5I9] cation. 4− The cluster-based anion, [Cu5I9] in its spatial structure. 4− The nuclear cluster is composed of four Cu4I4[(Et-ted)4] 4+ Surrounded by [the surrounding element]. In most existing AIO-type cuprous iodide complexes, the negatively charged portion is an inorganic cluster core, and the positively charged portion is an organic cationic ligand with free P, N, or S binding sites. However, in the cuprous iodide cluster-based complex of this invention, in addition to the inorganic cluster core, the positively charged portion also has a cationic organic ligand that forms a coordination bond with Cu(I), which is different from the reported AIO (all-in-one) type cuprous halide complexes.

[0019] This invention also provides a method for preparing single crystals of cuprous iodide cluster-based complex scintillators, which is simple to prepare and exhibits excellent luminescence properties. This method is beneficial for the design of novel cuprous halide cluster-based complex scintillator structures and for achieving higher scintillator performance.

[0020] The cuprous iodide cluster-based complex single crystal provided by this invention exhibits almost unchanged emission intensity under X-rays as a scintillator, indicating high radiation resistance. Furthermore, the light yield of the prepared scintillator is LuAG:Ce. 3+ It is 1.42 times larger than that used for planar and 3D imaging, reaching 22.4 lp mm. −1 High spatial resolution. Attached Figure Description

[0021] Figure 1a Cu9I 13 The basic structural unit in (Et-ted)4;

[0022] Figure 1b Cu9I 13 The crystal stacking structure of (Et-ted)4;

[0023] Figure 2 Cu9I in Example 1 13 Nonlinear optical signal diagram of (Et-ted)4 crystal;

[0024] Figure 3 Cu9I in Example 1 13 Powder XRD patterns and simulated XRD patterns of (Et-ted)4 crystals;

[0025] Figure 4 Cu9I in Example 1 13 Excitation and emission spectra of (Et-ted)4 crystal;

[0026] Figure 5 Cu9I in Example 1 13 The lifetime decay curve of (Et-ted)4 crystal;

[0027] Figure 6 Cu9I in Example 1 13 Photoluminescence quantum efficiency of (Et-ted)4 crystal;

[0028] Figure 7 Cu9I in Example 1 13 The photochemical properties of (Et-ted)4 crystals;

[0029] Figure 8 Cu9I in Example 1 13 Radiation stability spectrum of (Et-ted)4 crystal;

[0030] Figure 9 Cu9I prepared in Example 3 13 (Et-ted)4 X-ray imaging images and X-ray resolution test results of powder scintillator thin films; the image shows the internal structure of the chip.

[0031] Figure 10a Cu9I prepared in Example 3 13 Color three-dimensional image of a freeze-dried shrimp head for X-ray imaging using (Et-ted)4 scintillator film;

[0032] Figure 10b Cu9I prepared in Example 3 13 (Et-ted)4 scintillator film for X-ray imaging: multi-angle 3D imaging of freeze-dried shrimp head for X-ray imaging;

[0033] Figure 10cCu9I prepared in Example 3 13 Cross-sectional view of a freeze-dried shrimp head used for X-ray imaging with (Et-ted)4 scintillator film;

[0034] Figure 10d Cu9I prepared in Example 3 13 Gray value analysis of freeze-dried shrimp heads for X-ray imaging using (Et-ted)4 scintillator films. Detailed Implementation

[0035] The technical solution of the present invention will be described in detail below, but the scope of protection of the present invention is not limited to the embodiments described. In the following embodiments, the raw materials and reagents were directly purchased as commercial chemical reagents without further purification.

[0036] Acetonitrile: Sinopharm, AR≥99%; KI: Sinopharm, AR powder; Water: Wahaha; Methanol: Sinopharm, AR≥99.5%; 1-Bromoethane; Acetone; Ethyl acetate; Triethylenediamine; CuI: Adamas reagent, 99%;

[0037] Equipment model and manufacturer:

[0038] X-ray tube system: Mini-X2, Amptek; Mini-X2 is an X-ray tube system that includes an X-ray tube, a Nikon digital camera, a lead box, a power supply, control electronics, and USB communication with a computer. Amptek is the company name.

[0039] Example 1

[0040] Example 1 provides a process for preparing a single crystal of a cuprous iodide cluster-based complex, namely Cu9I. 13 The specific synthesis process of (Et-ted)4 crystals is as follows: First, the synthesis of the 1-ethyl-1,4-diazacyclooctane (Et-ted) ligand is performed. 1.12 g (10 mmol) of ted was weighed, and then 50 ml of acetone was poured into a 100 ml round-bottom flask. 1-Bromoethane (1.09 g, 10 mmol) was added under magnetic stirring. After approximately 1 hour, a white precipitate formed. The precipitate was then centrifuged at 8000 r / min for 5 min. The products were separated by filtration, washed with ethyl acetate, and dried under vacuum.

[0041] Next, CuI (0.038 g, 0.2 mmol) was completely dissolved in 6 mL of acetonitrile in a 20 mL glass bottle to prepare a CuI acetonitrile solution. Then, Et-ted ligand (0.028 g, 0.2 mmol) was completely dissolved in 2 mL of methanol in a 10 mL glass bottle to prepare a ligand methanol solution. This prepared ligand methanol solution was slowly added dropwise to the CuI acetonitrile solution, and powder was rapidly obtained under magnetic stirring. The powder was filtered out, and residual CuI was washed away with saturated KI solution, and excess ligand was washed away with methanol. Recrystallization was then performed by dissolving the product in 20 mL of acetonitrile and slowly evaporating it for 72 h to grow bulk crystals. The process involved sealing the solution with aluminum foil and making small holes in the foil with a needle. The resulting crystals were the single crystals of the cuprous iodide cluster-based complex prepared in Example 1.

[0042] The product Cu9I prepared in Example 1 13 (Et-ted)4 crystals were characterized and tested, and the results are as follows:

[0043] Figure 2 The product Cu9I prepared in Example 1 13 Nonlinear optical signal diagram of (Et-ted)4 crystal; single-crystal directional second harmonic generation (SHG) test method was adopted. The sample under test was a complete single crystal, which was placed in the center of a quartz glass slide with the flat crystal face facing upwards. A KDP single crystal with similar size was used as a reference. A Q-switched Nd:YAG laser was used as the excitation source with a fundamental frequency of 1064 nm, a pulse width of 10 ns, a repetition frequency of 10 Hz, and a single pulse energy of 10 mJ. After the laser was focused, it was perpendicularly incident on the sample. The 532 nm second harmonic signal was collected in the range of 0° to 360° by rotating the sample stage and the maximum value was recorded. The results show that Cu9I 13 The SHG signal intensity of the (Et-ted)4 single crystal under optimal orientation is about 0.5 times that of the KDP single crystal under the same conditions, which is consistent with the characteristics of the non-centrosymmetric C2 space group of the crystal, confirming that it has good nonlinear optical response.

[0044] Figure 4 The product Cu9I prepared in Example 1 13 Excitation and emission spectra of (Et-ted)4 crystal. During testing, the single crystal obtained in Example 1 was selected as the sample to be tested directly. Its steady-state spectrum was directly tested at room temperature using an Edinburgh FLS980 transient spectrometer. The test parameters are as follows: measurement range: 300~800 nm, slit: 1.0. Figure 4 This indicates that under optimal excitation by a 348 nm xenon lamp source, Cu9I in Example 1... 13The emission spectrum of (Et-ted)4 crystals ranges from 400 nm to 800 nm, with the optimal emission peak at 532 nm, exhibiting yellow-green light emission.

[0045] Figure 5 The product Cu9I prepared in Example 1 13 (Et-ted)4 Crystal lifetime decay curve; During testing, the single crystal obtained in Example 1 was selected as the sample to be tested directly. The 375 nm pulsed laser of the Edinburgh FLS980 transient spectrometer was used for excitation, and the time-resolved decay signal at the 532 nm emission peak was monitored. The lifetime value was obtained by exponential fitting of the decay curve using the instrument's built-in software. The results show that Cu9I in Example 1... 13 The time required for the fluorescence intensity of the (Et-ted)4 crystal to drop to 1 / e of the maximum fluorescence intensity at excitation is 7.2 μs.

[0046] Figure 6 The product Cu9I prepared in Example 1 13 The photoluminescence quantum efficiency (PLQY) of the (Et-ted)4 crystal was tested. The single crystal obtained in Example 1 was used as the sample for direct testing. The instrument used was an Edinburgh FLS980 transient spectrometer with an integrating sphere. The photoluminescence quantum efficiency was obtained by comparing the result with a standard white plate and integrating the results using the instrument's built-in integration method. This yielded the Cu9I product prepared in Example 1. 13 The photoluminescence quantum efficiency of (Et-ted)4 crystal is 84.8%, indicating that it has excellent photoluminescence ability.

[0047] Figure 7 The product Cu9I prepared in Example 1 13 The X-ray yield (LY) of the (Et-ted)4 crystal was calculated by integrating the spectra obtained from a transient spectrometer and an X-ray tube. Before testing, the crystal obtained in Example 1 was ground into powder as the sample to be tested. A miniature X-ray source was used as the excitation source with Au as the target material, Pmax = 4 W, Vmax = 50 kV, and Imax = 80 μA. The detector of the F980 transient spectrometer was used as the signal receiver. Cu9I crystals were collected under the same X-ray tube excitation conditions. 13 (Et-ted)4 samples and LuAG:Ce 3+ The X-ray emission spectrum of the sample was obtained, and then the emission spectrum was integrated and normalized to the reference sample to obtain the relative light yield. Light yield data acquisition method: Under the same test conditions, using X-rays as the excitation source, the same volume of the standard reference material LuAG:Ce was tested. 3+ And Cu9I prepared in Example 1 13X-ray emission spectra of (Et-ted)4 crystals were obtained, and then the light production was calculated by integration and formulas. This was compared with commercial standard scintillator samples LuAG:Ce. 3+ In comparison, the photon yield under X-rays was calculated to be 1.42 times that of Cu9I, indicating that the product Cu9I prepared in Example 1 of this application... 13 The photon yield of the (Et-ted)4 crystal is significantly higher than that of commercial standard scintillator samples, indicating that it has excellent scintillator performance.

[0048] Figure 8 The product Cu9I prepared in Example 1 13 The radiation stability spectrum of the (Et-ted)4 crystal was obtained. The radiation stability of the X-ray was also measured using a combination of miniature X-ray and transient spectrometer. Before testing, the crystal obtained in Example 1 was ground into powder as the sample to be tested. During the test, a miniature X-ray tube was used as the excitation source, and a transient spectrometer was used to collect the emission intensity changes of the sample during the X-ray switch-on cycle irradiation. By irradiating the above scintillator material with X-ray excitation light at a total dose of 2.025 Gyair, and adjusting the X-ray power supply switch every 30 seconds for a total of 15 minutes, the X-ray radiation switch stability results of the sample were obtained. It was found that its emission intensity under X-rays remained almost unchanged, indicating high radiation resistance.

[0049] In summary, the results show that the cuprous iodide cluster-based complex Cu9I prepared in Example 1 is effective. 13 (Et-ted)4 crystal exhibits a green emission spectrum under ultraviolet and X-ray conditions, ranging from 400 nm to 800 nm, with an optimal emission peak at 532 nm. Its lifetime under room temperature ultraviolet light is 7.2 μs, and its luminescence quantum efficiency is 84.8%. Under X-ray conditions, its light yield is [missing value - likely a value related to LuAG:Ce]. 3+ 1.42 times.

[0050] Example 2

[0051] Example 2 provides a method for preparing a cuprous iodide cluster-based complex scintillator powder according to the present invention, namely a Cu9I 13 The specific synthesis process of the (Et-ted)4 scintillator powder includes: taking the single crystal from Example 1 and grinding it using an agate mortar and pestle. After initially breaking the crystal into small fragments, a small amount is placed in the mortar and ground with the pestle in a vertical, circular motion, gradually applying pressure to refine it. Intermittent operation is performed during the process to prevent overheating, and adhering powder is continuously scraped off to ensure uniformity. Finally, the powder is sieved through a 200-mesh sieve to obtain the desired particle size, carefully collected, labeled, and stored.

[0052] Figure 3 The product Cu9I prepared in Example 113 (Et-ted)4 crystal powder's actual detected XRD pattern and simulated XRD pattern; Before the test, the crystal powder ground in Example 2 was sieved to obtain the powder sample to be tested; The powder sample was tested using a powder X-ray diffractometer (Bruker D8 Advanced A25); The test parameters were tube voltage 40 kV, tube current 40 mA; Scanning range 2θ = 5° - 50°, step size 0.02°. To ensure the purity of this powder, the XRD test results of the ground powder were compared with the single crystal simulated structure data. The simulated PXRD pattern was exported from the CIF file obtained by single crystal structure analysis through Mercury software. Through comparison, it was found that the XRD test results of the ground powder were in agreement with the single crystal simulated structure data, the peak positions at each angle were the same, and there were no extra impurity peaks, indicating that the synthesized Cu9I 13 (Et-ted)4 crystal structure was consistent with the test results, and it had a high purity without other impurities.

[0053] Example 3

[0054] This Example 3 provided a specific process for preparing a scintillator ink and a scintillator thin film from a copper(I) iodide cluster-based complex powder. The specific preparation process included: adding 1.2 g of polyvinyl alcohol PVA to 10 ml of water, and using a sand bath to fully stir and dissolve it completely at 90 °C to prepare a 120 mg / mL PVA aqueous solution, and the solution was colorless and transparent. Taking 0.065 g of the copper(I) iodide cluster-based complex powder described in Example 2, adding 1 ml of water, after ultrasonic dispersion, adding 1 ml of the above-prepared polyvinyl alcohol PVA aqueous solution, and fully stirring for 6 h to make it fully dispersed to prepare a scintillator ink with a certain viscosity. The above scintillator ink was coated on a glass substrate using the scraping function of a microelectronic printer. First, the scintillator ink was injected into a syringe matching the instrument, the syringe and the scraper were installed, the tube pressure was set to 0.15 MPa, the scraping speed was 20 mm / s, the scraper height was 200 μm, and the scraping area was 50 mm × 50 mm. After scraping, a uniform large-area scintillator coating layer was obtained on the glass substrate. And after volatilizing at room temperature for 12 h, a Cu9I 13 (Et-ted)4 powder scintillator thin film was obtained, and finally the film was separated from the glass substrate using tweezers.

[0055] Example 3 used a copper(I) iodide cluster-based complex powder to prepare a scintillator thin film. The powder of the required particle size was obtained by sieving through a 200-mesh sieve, and the powder size was uniform, and finally a particle-free, uniformly translucent scintillator thin film was formed.

[0056] Test Example 1

[0057] X-ray static imaging: An X-ray imaging platform was constructed, utilizing a Mini-X2 as the X-ray tube system. The system consisted of a Mini-X2 X-ray tube (Amptek Inc.) as the excitation source, a charge-coupled device (CCD), a camera (Nikon D850), a multi-fiber spectrometer, and a camera. The target material for the Mini-X2 X-ray tube was Au, P. max = 4W, V max = 50 kV, I max = 80 μA, X-ray source distance 3 cm from scintillator film. Specifically, during the test, the X-ray source emission current was 70 μA, the voltage was 50 kV, and the X-ray source distance was 3 cm from the scintillator film.

[0058] The Cu9I prepared in Example 3 13 Using a (Et-ted)4 scintillator film as a substrate, an object is placed on top of the film. X-rays irradiate the surface of the film. The X-rays that pass through the chip are absorbed by the microcrystalline scintillator film and emitted as green visible light. After being reflected by a prism, the light is captured by a camera to obtain an image of the chip's internal structure. Figure 9 This is an image of the chip's internal structure.

[0059] During resolution testing, the chip is laid on a thin film surface, and the resolution is obtained through an X-ray imaging system. The resolution chip image is shown below. Figure 9 Show. Depend on Figure 9 It can be seen that its imaging resolution is as high as 22.4 lp mm. -1 .

[0060] The results of Test Example 1 confirm that the scintillator film prepared by the method of the present invention can be used for biological and industrial X-ray imaging, and can realize imaging of the internal structural information of chip objects.

[0061] Test Example 2

[0062] X-ray 3D Imaging: An X-ray imaging platform was constructed, utilizing a Mini-X2 as the X-ray tube system. The system consisted of a Mini-X2 X-ray tube (Amptek Inc.) as the excitation source, a charge-coupled device (CCD) camera (purchased from Nikon D850), a multi-fiber spectrometer, and the camera itself. The target material for the Mini-X2 X-ray tube was Au, P... max = 4 W, V max = 50 kV, I max = 80 μA, X-ray source distance 3 cm from scintillator film. Specifically, during the test, the X-ray source emission current was 70 μA, the voltage was 50 kV, and the X-ray source distance was 3 cm from the scintillator film.

[0063] The Cu9I prepared in Example 4 13 Using an (Et-ted)4 scintillator film as a substrate, an object is placed on top of the film. X-rays irradiating the film surface and penetrating the object's interior are absorbed by the powder scintillator film and emitted as green visible light. This light is then reflected by a prism and captured by a camera to obtain an image of the internal structure. To verify the feasibility of 3D image reconstruction, freeze-dried shrimp heads were selected as the test object and placed on a rotating stage perpendicular to the X-ray beam direction for multi-angle 2D projection imaging. Figure 10b The image shown consists of three photographs. 37 photographs were taken at 5° intervals from 0° to 180°, followed by dark field and background photographs, for a total of 39 photographs. Using AVIZO software to process the projection data, a 3D reconstruction model consisting of a series of Z-axis slices was successfully constructed. Figure 10a As shown, the surface contours and fine internal structure of the freeze-dried shrimp head are accurately reproduced. Thanks to the high spatial resolution of the thin film, the reconstructed model can achieve depth resolution based on differences in material density. For example... Figure 10c As shown, by performing feature segmentation on the tomographic slices, the extracted grayscale distribution curve clearly identifies the density gradient characteristics of the shrimp head. Figure 10d The figure shows the grayscale distribution curve of freeze-dried shrimp heads.

[0064] The results of Test Example 2 confirm that the scintillator film prepared by the method of the present invention can be used for three-dimensional X-ray imaging in biology and industry. This multi-dimensional characterization method realizes the simultaneous visualization of the internal structure and surface morphology of the device, opening up a new solution for the development of low-dose X-ray imaging technology.

[0065] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention.

Claims

1. A single crystal of a cuprous iodide cluster-based complex, characterized in that, The chemical formula of the single crystal of the cuprous iodide cluster-based complex is Cu9I. 13 (Et-ted)4 belongs to a class of AIO-type cuprous iodide cluster-based complexes. The single crystals of the cuprous iodide cluster-based complexes are non-centrosymmetric C2 space group, monoclinic crystal system, and exhibit a zero-dimensional structure, wherein Cu9I 13 (Et-ted)4 contains a Cu4I4[(Et-ted)4] 4+ The cubane cluster nucleus cation, and a [Cu5I9] group. 4− In the three-dimensional spatial arrangement of the cuprous iodide cluster-based complex single crystal, the cluster anion is surrounded by four complex cations with the above-mentioned cubane cluster structure.

2. The single crystal of the cuprous iodide cluster-based complex as described in claim 1, characterized in that, The Cu-I bond length ranges from 2.422(4) to 3.008(8) Å, and the spacing between Cu atoms ranges from 2.63 to 2.76 Å. The cell parameters are: a = 25.608(3) Å, b = 9.0274(9) Å, c = 19.309(2) Å, α = 90°, β = 134.193(3)°, γ = 90°, and V = 3200.5(6) Å. 3 .

3. The method for preparing single crystals of the cuprous iodide cluster-based complex according to claim 1, characterized in that, The single crystal of the cuprous iodide cluster complex was obtained by reacting cuprous iodide and 1-ethyl-1,4-diazacyclooctane (Et-ted) in a mixed solution and then recrystallizing by volatilization. The Et-ted was obtained by the following preparation steps: at room temperature, triethylenediamine (ted) was dissolved in acetone to obtain a colorless and transparent solution with a concentration of 22.4 mg / mL; then, 1-bromoethane with an equimolar amount of ted was added with stirring, and a precipitate was formed. The precipitate was then obtained by centrifugation, and the powder was washed with ethyl acetate and dried to obtain the product Et-ted.

4. The preparation method according to claim 3, characterized in that, The preparation method includes the following steps: at room temperature, cuprous iodide is dissolved in acetonitrile to prepare a cuprous iodide acetonitrile solution, wherein the concentration of cuprous iodide CuI in the cuprous iodide acetonitrile solution is 0.02~0.1 mmol / mL; Et-ted ligand is dissolved in methanol, and then the ligand solution is slowly added to the cuprous iodide acetonitrile solution for mixing, wherein the molar ratio of CuI to Et-ted raw materials is (0.16~1.25):1, and a white powder is generated during the mixing process, which is then filtered and washed; finally, the product is recrystallized using acetonitrile as a solvent to obtain the single crystal of the cuprous iodide cluster complex.

5. The application of the cuprous iodide cluster-based complex single crystal according to claim 1 in the fabrication of photoluminescent materials.

6. The application of the cuprous iodide cluster-based complex single crystal according to claim 1 in the fabrication of scintillator materials.

7. The application of the cuprous iodide cluster-based complex single crystal according to claim 1 in the fabrication of nonlinear optical materials.

8. A scintillator ink, wherein the scintillator ink is prepared by grinding the single crystal of the cuprous iodide cluster complex of claim 1, first mixing it with water to form a suspension, and then fully mixing it with a polymer solution, wherein the concentration of the suspension is 50~200 mg / mL.

9. A scintillator film, said scintillator film being obtained by coating the scintillator ink of claim 8.

10. The application of the scintillator thin film of claim 9 in X-ray imaging.

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