Copper-based halide scintillator and preparation method thereof
The preparation of copper-based halide scintillators by rotary evaporation solves the problems of high energy consumption, uncontrollable crystallization, and environmental pollution in existing technologies, and realizes the preparation of low-cost and sustainable copper-based halide scintillators and their large-area thin film applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANGZHOU TIGUANG TECH CO LTD
- Filing Date
- 2025-12-31
- Publication Date
- 2026-05-12
AI Technical Summary
Existing methods for preparing copper-based halide scintillator materials suffer from problems such as high energy consumption, uncontrollable crystallization process, uneven product morphology, poor reproducibility, and environmental pollution. In particular, the use of high-temperature solid-state methods and anti-solvent methods leads to increased costs and the inability to recycle solvents.
Copper-based halide scintillators were prepared using a rotary evaporation process. By rotary evaporating the precursor solution in a rotary evaporator and combining it with an organic carboxylic acid solvent, the crystallization process was made mild and controllable. The solvent was then recovered and recycled to form copper-based halide scintillator microcrystals.
It achieves a low-energy, controllable crystallization process, significantly improves the repeatability and luminescence performance of the product, reduces raw material costs, and realizes zero solvent emissions and sustainable production, making it suitable for large-area thin film preparation and commercial detector coupling.
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Figure CN122012085A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of scintillator materials technology, and particularly relates to a copper-based halide scintillator and its preparation method. Background Technology
[0002] In recent years, all-inorganic halide perovskites and their derivatives have become a research hotspot in scintillator materials due to their excellent photoelectric properties, solution processability, and cost advantages. Newly discovered copper-based halide scintillators, such as Cs3Cu2X5 (X=Cl,Br,I) and CsCu2I3, as low-toxicity and environmentally friendly scintillator materials, exhibit excellent properties such as high light yield, fast decay time, and low self-absorption, showing great application potential in X-ray imaging. However, current preparation methods for copper-based halide scintillator materials mainly employ high-temperature solid-state methods and anti-solvent crystallization methods. High-temperature solid-state methods require high-temperature, long-term sintering under an inert atmosphere, resulting in high energy consumption. Anti-solvent methods induce crystallization by rapidly adding antisolvents to the precursor solution, but suffer from problems such as uncontrollable crystallization processes, uneven product morphology, and poor reproducibility. More seriously, the large amount of organic solvent used cannot be effectively recycled, causing environmental pollution and increased costs. Therefore, developing a novel preparation method that is continuous, solvent-recoverable, product-controllable, and suitable for large-area film formation is of great significance for promoting the practical application of copper-based halide scintillator materials. Summary of the Invention
[0003] In a first aspect, the present invention discloses a method for preparing a copper-based halide scintillator, comprising the following steps: S1. Preparation of precursor solution: Cesium source, copper source, and optional one or more dopant element sources are dissolved in a mixed solvent to obtain a clear and transparent precursor solution; the mixed solvent is composed of a polar aprotic solvent and an organic carboxylic acid in a volume ratio of (95:5) to (85:15); S2. Rotary evaporation crystallization: The precursor solution is placed in the rotary evaporator flask, the water bath temperature is set to 80-120 °C, the rotation speed is 2-10 rpm, and rotary evaporation is carried out for 30-180 min to obtain the solid scintillator product in the flask; S3. Product collection and post-processing: The solid scintillator product is taken out from the rotary evaporation flask, washed and dried with an organic solvent to obtain the copper-based halide scintillator.
[0004] In one embodiment, the cesium source is one or more of cesium iodide, cesium bromide, and cesium chloride; the copper source is one or more of cuprous iodide, cuprous bromide, and cuprous chloride.
[0005] In one embodiment, the dopant element M is selected from one or more of Na, Zn, Pb, Mn, Ag, In, Sb, Tl, Tb, Pr, Ce, Yb, Gd, Nd, or Lu.
[0006] In one embodiment, the polar aprotic solvent is N,N-dimethylformamide (DMF), dimethyl sulfoxide, or N-methylpyrrolidone, and the organic carboxylic acid is formic acid or acetic acid.
[0007] In one embodiment, during the rotary evaporation process in step S2, the evaporated solvent vapor is recovered after condensation, and the recovered mixed solvent can be directly used to prepare the precursor solution again, with a recycling number of ≥5 times.
[0008] In one embodiment, in step S2, the water bath temperature is 100±2 °C and the rotation speed is 5 rpm.
[0009] On the other hand, the present invention provides a copper-based halide scintillator prepared by any of the above methods, which has an A3Cu2X5 crystal structure, wherein A is Cs. + X is Cl - ,Br - I - One or more of them.
[0010] On the other hand, the present invention provides a copper-based halide scintillator film, which is made by mixing the above-mentioned copper-based halide scintillator as a light-emitting material with a highly transparent polymer resin and then coating it onto a substrate.
[0011] On the other hand, the present invention provides a method for preparing a copper-based halide scintillator thin film, comprising the following steps: T1. A copper-based halide scintillator was prepared using the above method; T2. Mix the scintillator with an organic solvent and a highly transparent polymer resin to form a slurry; T3. The slurry is coated onto an optically transparent substrate and dried or annealed to form the scintillator film.
[0012] On the other hand, the present invention provides a radiation detector comprising the aforementioned copper-based halide scintillator thin film.
[0013] Compared with the prior art, this application has at least the following beneficial effects: Compared with existing high-temperature solid-phase or anti-solvent processes, this invention replaces high-temperature sintering and instantaneous crystallization with rotary evaporation. The crystallization conditions are mild, the process is fully visible, and the batch-to-batch deviation of microcrystal morphology and luminescence performance is extremely low, with significantly better repeatability than traditional methods. The evaporation solvent condensation recovery rate is nearly 100%, and it can be directly recycled without purification. It maintains high luminescence efficiency even after five cycles, achieving zero organic solvent emissions and significantly reducing raw material costs. It has completed tenfold scale-up and 24-hour continuous production verification, with simultaneous improvement in yield and luminescence intensity. It can directly prepare large-area scintillator thin films and couple them to commercial detectors, possessing the engineering capability to seamlessly transfer from the laboratory to large-scale production lines. Attached Figure Description
[0014] Figure 1 The Cs3Cu2I5 scintillator microcrystals prepared in Example 1 of this invention; Figure 2 The XRD pattern of Cs3Cu2I5 scintillator microcrystals prepared in Example 1 of this invention; Figure 3 The X-ray emission spectrum of the Cs3Cu2I5 scintillator microcrystals prepared in Example 1 of this invention; Figure 4 This is a photograph of the scintillator thin film prepared in Example 1 of the present invention; Figure 5 The scintillator film prepared in Example 1 of the present invention is attached to the detector for X-ray imaging test, wherein (a) is a real pig's foot and (b) is an X-ray transmission image of the pig's foot. Detailed Implementation
[0015] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.
[0016] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.
[0017] Furthermore, the shapes and dimensions of the components in the figures do not reflect actual size and proportion, but are merely illustrative of embodiments of this disclosure. Additionally, any reference numerals placed between parentheses in the claims should not be construed as limiting the scope of the claims.
[0018] In order to achieve near-complete recovery and direct recycling of the reaction solvent, and significantly reduce costs and environmental pollution, this invention uses a rotary evaporation process to make the crystallization process mild, controllable and highly repeatable. The following description is in conjunction with the accompanying drawings and specific embodiments.
[0019] Example 1: Preparation of Cs3Cu2I5 scintillator microcrystals 1. Preparation of precursor solution Weigh 9 mmol (2.34 g) of cesium iodide (CsI, 99.99%) and 6 mmol (1.14 g) of cuprous iodide (CuI, 99.99%) and place them in a clean 50 mL rotary evaporator flask. Add 9 mL of DMF and 1 mL of formic acid. Seal the flask with a rubber stopper and sonicate for 15 min until the solution is colorless, transparent, and free of undissolved particles.
[0020] 2. Rotary evaporation crystallization Install the rotary evaporator flask onto the rotary evaporator and connect the splash-proof recovery bottle. Set the parameters: Water bath temperature: 100±2 ℃, rotation speed: 5 rpm, condenser temperature: -15 °C; Start rotary evaporation for 90 minutes until a large amount of white microcrystals precipitate at the bottom of the flask, and the solvent is basically evaporated.
[0021] 3. Product collection and drying Close the vacuum and purge with nitrogen to atmospheric pressure. Remove the rotary evaporator flask, add 5 mL of n-butanol to wet the product, and easily scrape off the microcrystals from the flask wall and bottom with a spatula. Transfer to a centrifuge tube, centrifuge at 6000 rpm for 3 min, and remove the supernatant. Wash twice with n-butanol, and finally dry in a vacuum drying oven at 60 ℃ for 12 hours to obtain 3.13 g of Cs3Cu2I5 scintillator microcrystals. The X-ray emission spectrum results are as follows. Figure 1 As shown, the emission peak is located at 446 nm, and the yield is 89.9%.
[0022] 4. Solvent recovery A total of 9.8 mL of mixed solvent was collected during the evaporation process, with a recovery rate of 98%. Gas chromatography analysis showed that the solvent purity was >99.5%, and no decomposition products were detected.
[0023] 5. Preparation of scintillator thin films Take 15 g of the microcrystals prepared in the above steps, mix with 15 mL of acetonitrile and 0.3 g of high-transparency polymethyl methacrylate (PMMA), and ball mill for 30 min to form a slurry. On a 16 × 13 cm² optical glass substrate, a slurry with a thickness of 300 μm is formed by slurry coating at a speed of 5 mm / s. Anneal at 80 ℃ for 60 min to obtain a uniform scintillator film with a thickness of approximately 270 mm. The scintillator film is then bonded to a commercial flat panel detector to test its luminescence performance.
[0024] Example 2: Mixed Halogen Cs3Cu2Cl 2.5 I 2.5 Synthesis Weigh out 4.5 mmol of CsCl (0.76 g), 4.5 mmol of CsI (1.17 g), 3 mmol of CuCl (0.30 g), and 3 mmol of CuI (0.57 g). The solvent is 9 mL of DMF + 1 mL of formic acid. Other steps are the same as in Example 1. Under X-ray excitation, the emission peak of the product is located at 430 nm.
[0025] Example 3: Mn²⁺ doped Cs₃Cu₂I₅: Mn (5%) Based on Example 1, 0.3 mmol of manganese chloride (MnCl2) was added, and the other steps were the same as in Example 1. After rotary evaporation, Mn was obtained. 2+ The doped sample exhibits dual emission peaks at 446 nm and 561 nm under X-ray excitation.
[0026] Example 4: Tl⁺ doped Cs3Cu2I5: Tl (0.1%) Based on Example 1, 0.01 mmol of thallium iodide (TlI) was added, and other steps were the same as in Example 1. After rotary evaporation, TlI was obtained. + Doped sample. Under X-ray excitation, the main emission peak is located at 504 nm.
[0027] Example 5 The only adjustment was to set the water bath temperature to 80 °C during the rotary evaporation crystallization step; the other steps were the same as in Example 1.
[0028] Example 6 The only adjustment was to set the water bath temperature to 120 °C during the rotary evaporation crystallization step; the other steps were the same as in Example 1.
[0029] Example 7 The rotation speed in the rotary evaporation crystallization step was adjusted to 2 rpm / min, while the other steps were the same as in Example 1.
[0030] Example 8 The rotation speed in the rotary evaporation crystallization step was adjusted to 10 rpm / min, while the other steps were the same as in Example 1.
[0031] Example 9: Scale-up Experiment (10x) The raw materials were scaled up 10 times (90 mmol CsI, 60 mmol CuI) and the solvents were 90 mL DMF + 10 mL formic acid, using a 500 mL large-capacity rotary evaporator flask. The parameters were maintained at 100 °C and 5 rpm / min, and the evaporation time was extended to 150 min. Other steps were the same as in Example 1. The product was collected to test the yield and luminescence properties.
[0032] Example 10: Continuous Production Simulation A continuous operation device was designed: the precursor solution was continuously pumped into the rotary evaporator at a rate of 5 mL / min using a peristaltic pump, with parameters maintained at 100 °C, 5 rpm / min, and an evaporation time of 150 min. The product was continuously collected via a bottom screw conveyor, and the solvent was condensed from the vapor and returned to the storage tank, with raw materials added in real time. Preliminary tests showed that the device could operate continuously for 24 hours. The yield and luminescence results of three batches of product samples are recorded in Table 1.
[0033] Example 11: Solvent recycled 5 times Using the 9.8 mL mixed solvent recovered in Example 1, fresh CsI (9 mmol) and CuI (6 mmol) were added, and after complete dissolution, the preparation steps of Example 1 were repeated. This cycle was repeated 5 times, and the product results for each cycle are shown in Table 2.
[0034] Comparative Example 1: No formic acid added Pure DMF was used as the solvent, without the addition of formic acid. Other steps were the same as in Example 1. The product was collected to test the yield and luminescence properties.
[0035] Comparative Example 2: Antisolvent Method Weigh 9 mmol (2.34 g) of cesium iodide (CsI, 99.99%) and 6 mmol (1.14 g) of cuprous iodide (CuI, 99.99%) and place them in a 50 mL beaker. Add 9 mL of DMF and 1 mL of formic acid. Seal the beaker with aluminum foil and sonicate for 15 min until the solution is colorless, transparent, and free of undissolved particles.
[0036] The precursor solution was then rapidly injected into 24 mL of toluene, and the mixture was stirred continuously until a large amount of white precipitate formed. The precipitate was transferred to a centrifuge tube and centrifuged at 5000 rpm for 3 min to remove the supernatant solvent. The precipitate was washed twice with n-butanol and then dried in a vacuum drying oven at 60 °C for 12 hours. The Cs3Cu2I5 scintillator microcrystals were collected to test the yield. The subsequent thin film preparation steps were the same as in Example 1.
[0037] Table 1 shows the yield and luminescence performance of each embodiment. .
[0038] Table 2 shows the product performance results after 5 cycles in Example 11. .
[0039] This invention successfully prepared copper-based halide scintillator microcrystals using a rotary evaporation process. Figure 1 As shown, through Figure 2 XRD characterization results show that the prepared Cs3Cu2I5 microcrystals have excellent crystallinity and good matching with the standard card. Using Example 1 as a baseline, a high yield of 89.9% was obtained, exhibiting excellent luminescence performance. Examples 2-4 demonstrate the universality of this method, allowing for flexible control of halogen components (such as Cl / I mixing) and the achievement of various ion doping (Mn). 2+ 、Tl + ), significantly altering or even enhancing luminescent properties, such as Tl + Doping increased the luminescence intensity to 181.65% of the baseline. Examples 5-8 verified the process windows for temperature and rotation speed. Excessively high or low temperatures led to poor crystallization consistency, resulting in reduced luminescence performance, while the effect of rotation speed was relatively low. Examples 9-10 successfully simulated 10x scale-up and continuous production. The three batches of products produced in the continuous simulation showed highly consistent and excellent performance (yield > 92.5%, luminescence intensity > 102%). The improved yield and luminescence intensity were attributed to reducing errors caused by residues in the washing and purification steps during scale-up production. In Example 11, the recovered solvent could be reused without complex purification steps such as distillation and chromatography, simply by adding precursor salt. The solvent could be recycled more than 5 times, and the product performance remained above 95%, demonstrating significant economic and environmental value. In Comparative Example 1, the absence of organic carboxylic acids reduced luminescence performance by approximately 34%, mainly because some cuprous ions in the reactants were oxidized, leading to weakened luminescence. This indicates that carboxylic acids can effectively prevent the oxidation of cuprous ions in the reactants. Although the scintillator prepared in Comparative Example 2 has comparable luminescent performance, it generates a large amount of solvent that cannot be quickly recycled, further highlighting the absolute advantages of this invention in terms of controllability and sustainability.
[0040] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a copper-based halide scintillator, characterized in that, Includes the following steps: S1. Preparation of precursor solution: Cesium source, copper source, and optional one or more dopant element sources are dissolved in a mixed solvent to obtain a clear and transparent precursor solution; the mixed solvent is composed of a polar aprotic solvent and an organic carboxylic acid in a volume ratio of (95:5) to (85:15); S2. Rotary evaporation crystallization: The precursor solution is placed in the rotary evaporator flask, the water bath temperature is set to 80-120 °C, the rotation speed is 2-10 rpm, and rotary evaporation is carried out for 30-180 min to obtain the solid scintillator product in the flask; S3. Product collection and post-processing: The solid scintillator product is taken out from the rotary evaporation flask, washed and dried with an organic solvent to obtain the copper-based halide scintillator.
2. The method for preparing a copper-based halide scintillator according to claim 1, characterized in that, The cesium source is one or more of cesium iodide, cesium bromide, and cesium chloride; the copper source is one or more of cuprous iodide, cuprous bromide, and cuprous chloride.
3. The method for preparing a copper-based halide scintillator according to claim 1, characterized in that, The doping element M is selected from one or more of Na, Zn, Pb, Mn, Ag, In, Sb, Tl, Tb, Pr, Ce, Yb, Gd, Nd, or Lu.
4. The method for preparing a copper-based halide scintillator according to claim 1, characterized in that, The polar aprotic solvent is N,N-dimethylformamide, dimethyl sulfoxide, or N-methylpyrrolidone, and the organic carboxylic acid is formic acid or acetic acid.
5. The method for preparing a copper-based halide scintillator according to claim 1, characterized in that, During the rotary evaporation process in step S2, the evaporated solvent vapor is recovered after condensation, and the recovered mixed solvent can be directly used to prepare the precursor solution again, with a recycling rate of ≥5 times.
6. The method for preparing a copper-based halide scintillator according to claim 1, characterized in that, In step S2, the water bath temperature is 100±2 °C and the rotation speed is 5 rpm.
7. The copper-based halide scintillator prepared by the method according to any one of claims 1-6, characterized in that, It has an A3Cu2X5 crystal structure, where A is Cs. + X is Cl - ,Br - I - One or more of them.
8. A copper-based halide scintillator thin film, characterized in that, It is made by mixing the copper-based halide scintillator as described in claim 7 with a highly transparent polymer resin and then coating it onto a substrate.
9. A method for preparing a copper-based halide scintillator thin film, characterized in that, Includes the following steps: T1. A copper-based halide scintillator is prepared by the method according to any one of claims 1-6; T2. Mix the scintillator with an organic solvent and a highly transparent polymer resin to form a slurry; T3. The slurry is coated onto an optically transparent substrate and dried or annealed to form the scintillator film.
10. A radiation detector, characterized in that, It includes the copper-based halide scintillator thin film as described in claim 8.