CN112521940B

CN112521940B - X-ray yellow fluorescent scintillator material and preparation method thereof

Info

Publication number: CN112521940B
Application number: CN202011413306.1A
Authority: CN
Inventors: 解仁国; 郭雪源; 张资序; 汪大洋; 杨文胜
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-09-21
Anticipated expiration: 2040-12-03
Also published as: CN112521940A

Abstract

The invention discloses an X-ray yellow fluorescent scintillator material and a preparation method thereof, belonging to the technical field of semiconductor material preparation. The X-ray yellow fluorescent scintillator material is metal halide Rb₂AgCl₃The preparation method comprises the following steps: firstly, uniformly mixing rubidium chloride and silver chloride, transferring the mixture to a hydrothermal reaction kettle, adding concentrated hydrochloric acid, heating the mixture to 130-210 ℃ in a tubular furnace for 3 hours, maintaining the temperature for 5 hours, and then slowly cooling the mixture to room temperature at the speed of 6 ℃/h to obtain acicular Rb₂AgCl₃Finally, the crystal is filtered, washed and dried to obtain the Rb which can be used as an X-ray yellow fluorescent scintillator₂AgCl₃Metal halide crystals. The crystal emits yellow fluorescence under the irradiation of an ultraviolet lamp with 254nm, and shows the luminescent property of a yellow scintillator under the irradiation of X rays, so that the crystal is a nontoxic, safe and green scintillator material, and the synthesis condition is simpler than that of the traditional scintillator and has low energy consumption.

Description

X-ray yellow fluorescent scintillator material and preparation method thereof

Technical Field

The invention belongs to the technical field of semiconductor material preparation, and particularly relates to metal halide Rb with X-ray fluorescence₂AgCl₃The preparation method of (1).

Background

Scintillator-based X-ray detectors are widely used in the commercial market because they are cheaper and more stable than direct-type detectors, which convert X-ray photons directly into electrical signals by applying a bias voltage in a photoconductor. At present, conventional scintillators, such as thallium-doped cesium iodide (CsI: Tl) and cerium-doped lutetium yttrium orthosilicate (LYSO: Ce), are generally prepared by crystallization under high temperature and vacuum conditions, and are complex and expensive.

In addition, the current radiation detectors in the market, such as CsI, Tl, CdZnTe, TlBr and the like, also face the high toxicity problem of thallium and cadmium. Meanwhile, the traditional scintillator is generally synthesized at a high temperature of more than 1700 ℃ by a pulling method, and the production condition is severe, so that the production cost is increased.

In recent years, all-inorganic lead-perovskite halide nanocrystals, as a new generation of scintillating materials, exhibit many exciting radiation detection characteristics, such as high blocking power, strong and tunable luminescence intensity, fast scintillation response, ultra-sensitive X-ray sensing, high-resolution imaging, and the like. Although these lead-perovskite-halide NCs exhibit high photoluminescence quantum yields (PLQY) of up to 90%, CsPbBr₃The RL light yield of NCs is only 21000 photos/MeV. This value is lower than that of conventional scintillators CsI: Tl (54000photons/MeV) and LYSO: Ce (33200 photons/MeV). The light yield of the lead perovskite NCs is relatively low due to their inherently small Stokes shifts and strong self-absorption effects, which will greatly reduce their out-coupling efficiency. Therefore, large Stokes shift, small self-absorption and high PLQY are the requirements for high RL light yield. In addition, the high toxicity and biological accumulation of lead in halogenated lead perovskite are potential problems which restrict the wide application of the halogenated lead perovskite. Therefore, the development of high PLQY, large Stokes shift, lead-free or environmentally friendly scintillators is of great significance.

Therefore, it is important to find a non-toxic metal halide with large Stokes shift and high light yield which can be synthesized at a lower temperature as an X-ray scintillator.

Disclosure of Invention

The invention aims to solve the technical problem of providing a novel metal halide which can be selected as an X-ray scintillator so as to solve the problems of toxicity of the traditional scintillator and high temperature condition required for synthesis.

The technical problem of the invention is solved by the following technical scheme:

an X-ray yellow fluorescent scintillator material is metal halide Rb₂AgCl₃。

A preparation method of an X-ray yellow fluorescent scintillator material comprises the following steps: firstly, mixing rubidium chloride and silver chloride according to a molar ratio of 4: 1-16, grinding in a mortar, uniformly mixing, transferring to a hydrothermal reaction kettle, adding concentrated hydrochloric acid according to the using amount of 1-6 mL per mmol of silver chloride, sealing the reaction kettle, putting into a tubular furnace, setting a program, heating to 130-210 ℃ from room temperature for 3h, maintaining for 5h at the temperature, and then slowly cooling to room temperature at 6 ℃/h to obtain needle-shaped Rb₂AgCl₃Transferring the obtained crystals to a Buchner funnel paved with filter paper for suction filtration, washing the crystals with isopropanol while suction filtration, transferring the washed crystals to a vacuum oven for drying at 60 ℃ overnight to obtain Rb₂AgCl₃Metal halide crystals. The crystal emits yellow fluorescence under the irradiation of an ultraviolet lamp with 254nm, and shows yellow scintillator luminescence property under the irradiation of X rays.

In the preparation method of the X-ray yellow fluorescent scintillator material, Rb is ensured₂AgCl₃The optimum ratio of the crystal production is 2: 1.

In the method for preparing the X-ray yellow fluorescent scintillator material, in order to improve the yield of crystals, the dosage of concentrated hydrochloric acid is preferably 2mL per 1mmol of silver chloride.

In the method for preparing the X-ray yellow fluorescent scintillator material, the temperature rise in the tube furnace is preferably 180 ℃ in order to improve the crystal yield.

Has the advantages that:

the invention synthesizes Rb with X-ray fluorescence property by a hydrothermal method₂AgCl₃The crystal has the light yield close to that of the lead perovskite halide reported at present, is a nontoxic, safe and green scintillator material, has simpler synthesis conditions than the traditional scintillator and has less energy consumption.

Drawings

FIG. 1 is Rb prepared in example 1₂AgCl₃Solid absorption spectrum of scintillator crystal material.

FIG. 2 is Rb prepared in example 1₂AgCl₃An X-ray fluorescence spectrum of the scintillator crystal material.

FIG. 3 is Rb prepared in example 1₂AgCl₃Solid XRD spectrum of scintillator crystal material.

FIG. 4 is Rb prepared in example 1₂AgCl₃A photograph of the scintillator crystal material after grinding into powder under X-ray irradiation.

FIG. 5 is Rb prepared in example 1₂AgCl₃A crystal photograph of (a).

Detailed Description

Example 1: firstly, mixing 2mmol of rubidium chloride and 1mmol of silver chloride, grinding the mixture in a mortar, uniformly mixing the mixture, transferring the two precursors into a 25mL hydrothermal reaction kettle, adding 2mL of concentrated hydrochloric acid, sealing the reaction kettle, putting the reaction kettle into a tube furnace, setting a program, heating the mixture to 180 ℃ from room temperature for 3 hours, maintaining the temperature for 5 hours, and then slowly cooling the mixture to room temperature at the speed of 8 ℃/h to obtain needle-shaped Rb₂AgCl₃And (3) transferring the obtained crystals to a Buchner funnel paved with filter paper for suction filtration, washing the crystals with isopropanol while suction filtration, and transferring the washed crystals to a vacuum oven for drying at 60 ℃ overnight. The yield of crystals obtained in this example was 60.8%, the crystals emitted yellow fluorescence under irradiation with an ultraviolet lamp at 254nm, and the crystals exhibited yellow scintillator emission under irradiation with X-rays.

The product was subjected to solid absorption analysis and fluorescence test, the absorption spectrum is shown in FIG. 1, the X-ray fluorescence spectrum is shown in FIG. 2, the light yield is 18300photons/MeV, the XRD spectrum of the product is shown in FIG. 3, and the emission photograph of the product under X-ray irradiation is shown in FIG. 4. This embodiment is the most preferred embodiment.

Example 2:

changing the feeding ratio of rubidium chloride and silver chloride in example 1 from 2mmol:1mmol to 4mmol:1mmol, 1mmol:1mmol and 1mmol:4mol respectively, and keeping other conditions and steps unchanged, Rb₂AgCl₃The yields of crystals were 30.4%, 35.7%, 20, respectively.6 percent, therefore, the optimal feeding ratio of the raw materials of rubidium chloride and silver chloride is 2mmol:1 mmol.

Example 3:

changing the dosage of concentrated hydrochloric acid in example 1 from 2mL to 1mL, 4mL and 6mL respectively, and changing other conditions and steps to Rb₂AgCl₃The yields of crystals were 27.1%, 18.4%, 15.5%, respectively.

Example 4:

rb changing the temperature of the tube furnace from 180 ℃ to 130 ℃, 150 ℃ and 210 ℃ in example 1, and keeping the other conditions and steps unchanged₂AgCl₃The yields of crystals were 5.1%, 14.2%, 15.6%, 37.3%, respectively.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A preparation method of an X-ray yellow fluorescent scintillator material comprises the following steps: firstly, mixing rubidium chloride and silver chloride according to a molar ratio of 4: 1-16, grinding in a mortar, uniformly mixing, transferring to a hydrothermal reaction kettle, adding concentrated hydrochloric acid according to the using amount of 1-6 mL per mmol of silver chloride, sealing the reaction kettle, putting into a tubular furnace, setting a program, heating from room temperature for 3h to 130-210 ℃, maintaining at the temperature for 5h, and then slowly cooling to room temperature at 6 ℃/h to obtain needle-shaped Rb₂AgCl₃Transferring the obtained crystal to a Buchner funnel paved with filter paper for suction filtration, washing the crystal with isopropanol while suction filtration, transferring the washed crystal to a vacuum oven for drying at 60 ℃ overnight to obtain Rb which can be used as an X-ray yellow fluorescent scintillator₂AgCl₃A metal halide crystalline material.

2. The method for preparing an X-ray yellow fluorescent scintillator material as claimed in claim 1, wherein the feeding ratio of rubidium chloride to silver chloride is 2: 1.

3. The method of claim 1, wherein the concentrated hydrochloric acid is used in an amount of 2mL per 1mmol of silver chloride.

4. The method of claim 1, wherein the temperature in the tube furnace is 180 ℃.