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CN-121975244-A - Preparation method of high-brightness high-resolution scintillator composite film

CN121975244ACN 121975244 ACN121975244 ACN 121975244ACN-121975244-A

Abstract

A preparation method of a scintillator composite film with high brightness and high resolution belongs to the technical field of high-energy ray detection. Adding scintillator powder and a surfactant into a polymer solution, mixing and stirring to obtain scintillator composite film slurry, coating the scintillator composite film slurry on a substrate, and curing to obtain the scintillator composite film, wherein the mass percent of the scintillator powder in the scintillator composite film slurry is 50-100wt% and the mass concentration of the surfactant is 10-100 mg/mL. According to the invention, the rheological property and solid-liquid interface behavior of the slurry are optimized by utilizing the amphiphilic molecular structure of the surfactant, the hydrophilic head group acts on the crystals, and the hydrophobic long chain extends to the solvent to form an effective steric hindrance layer, so that disordered aggregation among particles is inhibited, uniform distribution of the particles in the film forming process is promoted, and the overall appearance is more uniform and compact.

Inventors

  • Bai sai
  • ZHANG DI
  • LI XIN

Assignees

  • 电子科技大学

Dates

Publication Date
20260505
Application Date
20260310

Claims (10)

  1. 1. A preparation method of a high-brightness and high-resolution scintillator composite film is characterized by adding scintillator powder and a surfactant into a polymer solution, mixing and stirring to obtain scintillator composite film slurry, coating the scintillator composite film slurry on a substrate, and curing to obtain the scintillator composite film, wherein the mass percent of the scintillator powder in the scintillator composite film slurry is 50-100wt%, and the mass concentration of the surfactant is 10-100 mg/mL.
  2. 2. The method for producing a high-luminance, high-resolution scintillator composite film according to claim 1, wherein the scintillator powder is CsCu 2 I 3 powder, cs 3 Cu 2 I 5 powder, cs 3 Cu 2 I 5 (0.1 to 5 mol%) K powder, csPbBr 3 powder or CsMnCl 3 powder.
  3. 3. The method for producing a high-brightness, high-resolution scintillator composite film according to claim 1, wherein the polymer solution is a PMMA solution, PS solution, PMDS solution or PDVF solution.
  4. 4. The method for producing a high-brightness high-resolution scintillator composite film according to claim 1, wherein the surfactant has a general formula of Wherein, R group is long chain alkyl, Is quaternary ammonium cation head group, X-is replaceable halogen ion.
  5. 5. The method for preparing a high-brightness high-resolution scintillator composite film according to claim 1, wherein the surfactant is butyl trimethyl ammonium bromide, octyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide or octadecyl trimethyl ammonium bromide.
  6. 6. The preparation method of the high-brightness and high-resolution scintillator composite film is characterized by comprising the following steps of: step 1, preparation of scintillator powder: 1.1, weighing halogen salt A, halogen salt B and halogen salt C according to the mol ratio of (1-3) 1 (0.1-0.5), mixing in a solvent A to obtain a mixed solution B, adding an additive C into the mixed solution B, uniformly mixing, and stirring at 50-60 ℃ for reacting for 1-2h to obtain a precursor solution, wherein the concentration of the additive C in the precursor solution is 8-10 mol/L; Step 1.2, dropwise adding the precursor solution in the step 1.1 into the solvent B, and stirring for 1-5min to obtain a crude solution; Step 1.3, separating the crude solution in the step 1.2, adding a detergent into the obtained precipitate, and then performing secondary centrifugation to collect the precipitate; Step 1.4, drying the precipitate collected in the step 1.3 to obtain scintillator powder; step 2, preparation of scintillator slurry: Mixing polymer powder with the solvent C, dissolving to obtain a polymer solution, mixing the surfactant with the scintillator powder obtained in the step 1.4, dissolving into the solvent C, uniformly stirring, mixing with the polymer solution, heating and stirring for 1-2h at 50-60 ℃ to obtain scintillator slurry; step3, preparing a scintillator composite film: And (3) uniformly coating the scintillator slurry obtained in the step (2) on a substrate, and curing to obtain the scintillator composite film.
  7. 7. The method for preparing a high-brightness high-resolution scintillator composite film according to claim 6, wherein in the step 1.1, the halogen salt A is formamidine hydroiodide, cesium iodide, formamidine hydrobromide or cesium bromide, the halogen salt B is lead iodide, lead bromide, cuprous iodide or cuprous bromide, the halogen salt C is potassium iodide, zinc iodide, the solvent A is ethanol, isopropanol or N, N-dimethylformamide, and the additive C is oleic acid, oleylamine or hypophosphorous acid.
  8. 8. The method for producing a high-luminance, high-resolution scintillator composite film according to claim 6, wherein in step 1.2, the solvent B is ethyl acetate, methyl acetate, chlorobenzene, methanol, ethanol, toluene, chloroform or acetonitrile, and the stirring rate is 1,000 to 2,000 rpm.
  9. 9. The method of producing a high-brightness high-resolution scintillator composite film according to claim 6, wherein in step 1.3, the separation is a centrifugal separation at a rotational speed of 5,000-10,000 rpm for a period of 1-10min, and the washing agent is cyclohexane, chlorobenzene, methanol, ethanol, toluene or chloroform.
  10. 10. The method for producing a high-brightness high-resolution scintillator composite film according to claim 6, wherein in the step 2, the solvent C is chlorobenzene, toluene or chloroform, the polymer is PMMA, PS, PMDS or PDVF, the scintillator powder is CsCu 2 I 3 powder, cs 3 Cu 2 I 5 powder, cs 3 Cu 2 I 5 (0.1-5 mol%) K powder, csPbBr 3 powder or CsMnCl 3 powder, and the surfactant has the general formula Wherein, the R group is long-chain alkyl, Is quaternary ammonium cation head group, X-is replaceable halogen ion.

Description

Preparation method of high-brightness high-resolution scintillator composite film Technical Field The invention belongs to the technical field of high-energy ray detection, and particularly relates to a method for regulating and controlling an inorganic metal halide scintillator film by using different surfactants so as to reduce noise level, improve signal-to-noise ratio and enhance spatial resolution of the film. Background The high-energy ray detection technology is used as a core support technology in the fields of high-energy physics, nuclear physics, celestial physics, nuclear medicine and the like, and the development level of the high-energy ray detection technology is very important in the aspects of medical diagnosis, safety inspection, space exploration and the like. With the rapid development of materials science and the field of photovoltaic devices, inorganic metal halide scintillator films are exhibiting revolutionary advantages. Compared with the technical bottlenecks faced by traditional scintillators (such as NaI: tl, BGO and the like) in realizing high spatial resolution and sensitivity, inorganic metal halide scintillators (typically representing perovskite CsPbBr 3, cs 3Cu2I5 and the like) rapidly develop in the field of ray detection by virtue of unique crystal structure diversity, excellent photoelectric conversion characteristics and tunable optical performance. The film has the core advantages of excellent material and photoelectric properties, namely high absorption coefficient and high irradiation hardness, high-efficiency blocking and converting capability on high-energy rays (such as X rays), and high photoluminescence quantum efficiency and quick decay life through component engineering (such as halogen mixing), so that high brightness and quick response are ensured. More importantly, the method can be prepared by adopting a low-temperature solution method such as spin coating, knife coating or printing, so that the process cost is greatly reduced, the integration of micron-sized pixelation and large-area flexible devices is easier to realize, and a subversion technical path is provided for developing a next-generation high-resolution dynamic real-time imaging flat panel detector. The scintillator film is used as a core sensing element for high-energy particle and ray detection, and the performance of the scintillator film directly determines the sensitivity and the precision of an imaging system. The ideal high performance scintillator film needs to have both high luminous efficiency (i.e., high light output) and high spatial resolution, however, these two key performance parameters often have an inherent competition relationship at the material preparation level. The traditional preparation method of the scintillation film is often limited in microstructure regulation and control, and the cooperative optimization of the traditional preparation method and the scintillation film is difficult to realize. The core contradiction is that in the process of preparing the high-performance scintillator film, the inherent constraint relationship exists between the addition concentration (namely the loading) of the scintillator powder and the comprehensive performance of the film. To achieve high luminous efficiency, the loading of the powder must be significantly increased. However, at high loadings, serious particle agglomeration effects are inevitably induced, which not only destroy the morphological uniformity of the macrostructure of the film, but also degrade the modulation transfer function performance due to significant light scattering phenomena, thereby causing degradation of imaging contrast and degradation of spatial resolution. On the contrary, if the powder loading is reduced for high spatial resolution, the surface flatness can be effectively improved and the scattering can be reduced, but the insufficient blocking capability to high-energy photons and the reduction of the effective luminous center density can be directly caused, so that the light yield and the detection efficiency of the film are greatly reduced. Therefore, achieving synergistic optimization of luminous efficiency and spatial resolution is a challenging systematic balancing process. Research shows that most of the current scintillator film preparation processes are based on lower perovskite loading parameters. Under specific experimental conditions, the low-load system can obtain satisfactory imaging results by means of a high-sensitivity optical camera and a complex optical amplifying system. However, this type of architecture presents significant functional limitations in practical device integration, particularly at the system level with Thin Film Transistor (TFT) backplanes. The method is based on the fact that the density of effective luminescence centers in a unit area is insufficient, so that the overall luminescence intensity output by the film is obviously lower than the minimum signal threshold