X-ray detection composite material structure and method of manufacturing the same

Abstract

The application discloses an X-ray detection composite material structure and a preparation method thereof. The composite material structure is composed of a conductive substrate (ITO glass), a nickel oxide (NiOx) nanostructure, a lead bromide formamidine (MAPbBr3) single crystal and an upper electrode. The preparation method comprises batching, a liquid phase reaction method and a solution method single crystal growth. The composite material structure prepared by the application can realize self-driven X-ray detection, that is, converts incident X-rays into current signals without an external bias voltage. The application has the advantages of low detection limit, wide detection energy range, high resolution, rapid response, good linearity and low manufacturing cost, and can be applied to X-ray detection, X-ray imaging, light sensors and many other fields.

Description

Technical Field

[0001] This invention belongs to the field of X-ray detection materials, specifically, it relates to an X-ray detection composite material structure and its preparation method. Background Technology

[0002] X-rays are light waves with wavelengths between 0.01 nm and 10 nm. They are penetrating and widely used in medical imaging, non-destructive testing, and security, among other fields. X-ray detection materials can convert X-rays into electrical or optical signals, making them core components in X-ray applications. Commonly used X-ray detection materials can be categorized into two mechanisms: photo-to-photon conversion and photo-to-electrical conversion. One mechanism converts X-ray photons into visible light, which is then collected by a photomultiplier tube and converted into an electrical signal for processing. Typical materials include thallium-doped sodium iodide / cesium iodide and lead tungstate crystals, which offer advantages such as high yield and high signal-to-noise ratio. However, their main disadvantages are large detector size and low resolution. The other mechanism directly converts X-ray photons into electrical signals, such as high-purity germanium and silicon drift detectors, especially various novel perovskite materials that have seen rapid development in recent years. These materials offer advantages such as small size, high resolution, simple circuitry, and low detection limits, representing the main development direction for future X-ray detectors.

[0003] Organic-inorganic hybrid perovskite materials based on the bromine-lead-cesium system have become a hot topic in X-ray detection materials in recent years. Compared with light-to-light conversion mechanisms, this novel material system has many advantages, including small size, high resolution, high sensitivity, low detection limit, simple detection circuit, and low manufacturing cost. However, it still suffers from problems such as low conversion rate, high noise, and poor stability. Achieving a higher signal-to-noise ratio and a lower detection limit through optimized design of the material system and detector structure is an important research topic in this field. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the purpose of this invention is to provide an X-ray detection composite material structure and its preparation method that can achieve self-driven detection. This invention has the advantages of simple preparation method, low cost, easy integration, high sensitivity and low detection dose limit.

[0005] The technical solution adopted in this invention is as follows:

[0006] The X-ray detection composite material structure of the present invention consists of a conductive substrate (ITO glass), a nickel oxide (NiOx) nanostructure, a lead bromide formamidine (MAPbBr3) single crystal, and an upper electrode.

[0007] Specifically: an X-ray detection composite material structure, using ITO / NiO x The composite structure of / FAPbBr3 / Ag, in which NiO x It is a nickel oxide nanostructure.x The value ranges from 0.9 to 1.1, and FAPbBr3 is a single crystal with a lead bromide formamidinium perovskite structure. The composition of the nickel oxide nanoparticles is precisely controlled by the chemical composition, and the film thickness is precisely controlled by the spin-coating process.

[0008] Preferably, in the above-mentioned X-ray detection composite material structure, the NiO x Nickel oxide nanostructures can be nanofilms or nanowires.

[0009] Preferably, in the above-mentioned X-ray detection composite material structure, the thickness of the FAPbBr3 single crystal with a lead bromide formamidinium perovskite structure ranges from 100 nanometers to 5 millimeters. The thickness of the FAPbBr3 single crystal can be controlled by the growth time.

[0010] The preparation method of the above-mentioned X-ray detection composite material structure includes the following steps:

[0011] (1) Preparation of nickel oxide nanostructures: NiO was prepared by liquid-phase reaction method. x Nickel oxide nanoparticles are dispersed in alcohol to form a suspension by ultrasonic vibration. The suspension is then spin-coated onto ITO glass and annealed to form a nickel oxide nanostructure film.

[0012] (2) Preparation of lead bromide formamidine precursor solution: At 90°C, lead acetate trihydrate and formamidine acetate are dissolved in hydrobromic acid to form a saturated solution. The solution is slowly cooled to 60°C. The lead bromide formamidine single crystal particles precipitated in the solution are collected and washed with methanol. The solution is then dissolved in dimethylformamide to form a precursor solution.

[0013] (3) The ITO substrate with a thin layer of nickel oxide nanostructure obtained in step (1) is placed in the precursor solution prepared in step (2) and kept at a constant temperature of 60°C for a period of time to form ITO / NiO. x The FAPbBr3 composite structure was annealed at 75~100℃ for 2~48 hours; the annealing temperature and time had a significant impact on the sensitivity of the X-ray detection limit.

[0014] (4) The composite structure obtained in step (3) is vapor-deposited with silver electrodes to form the final X-ray detection composite material structure.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The X-ray detection composite material structure of the present invention has the ability to self-drive X-ray detection, that is, it can convert incident X-rays into current and voltage signals without external bias voltage. The detectable X-ray energy range is 1 keV to 100 keV; the lowest detectable X-ray dose rate is less than 173 nGy. air s−1 .

[0017] (2) The X-ray detection composite material structure of the present invention has an extremely low dose rate detection limit and high detection sensitivity.

[0018] (3) The X-ray detection composite material structure of the present invention has an extremely high response speed and a decay time of less than 200 nanoseconds.

[0019] (4) The X-ray detection composite material structure of the present invention has the potential for high-density integration and can be made into a high-resolution X-ray detection array.

[0020] (5) The preparation process of the X-ray detection composite material structure of the present invention is suitable for large-scale industrial production, with low cost, and has high application potential in many fields such as X-ray detection, X-ray imaging, and optical sensors. Attached Figure Description

[0021] Figure 1 Schematic diagram of composite material structure for X-ray detection;

[0022] Figure 2 X-ray detection of dose response in composite material structures;

[0023] Figure 3 X-ray detection of the lower limit of the detection dose rate for composite material structures. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0025] Example 1:

[0026] (1) Dissolve 0.01 mol of high-purity NiCl2·6H2O in 20 mL of deionized water, stir thoroughly with a magnetic stirrer, and gradually add 10 mol / L NaOH solution until the pH value is greater than 10. Wash the white product several times with deionized water and centrifugation, and then place the product in an 80℃ oven for 12 hours to generate black nickel oxide nanoparticles NiO. 1.02 .

[0027] (2) Dissolve 10 mmol of lead acetate trihydrate and 10 mmol of formamidine acetate in hydrobromic acid, keep magnetically stirred and heat to 90°C for 1-2 hours. Slowly cooling will allow red lead bromide formamidine single crystals to precipitate from the solution.

[0028] (3) Separate the red lead bromide formamidin single crystal particles from the solution in step (2), wash them repeatedly with methanol, and dissolve them in 0.5 g / mL dimethylformamide to form a crystal precursor solution.

[0029] (4) Dissolve the nickel oxide nanoparticles produced in step (1) in alcohol, and form a uniform nanoparticle suspension by ultrasonic vibration. Spin-coat the suspension onto a clean ITO glass at a speed of 3000 rpm for 40 seconds. Place the spin-coated ITO glass in an 80℃ oven for 1 hour to form ITO / NiO. 1.02 structure.

[0030] (5) The ITO / NiO produced in step (4) 1.02 The structure was placed in the precursor solution produced in step (3) and kept at a constant temperature of 60°C for 6 hours to form ITO / NiO. 1.02 / FAPbBr3 composite structure, at 80 o Anneal at C for 2 hours.

[0031] (6) The ITO / NiO produced in step (5) 1.02 The FAPbBr3 composite structure is deposited with silver electrodes to form the final X-ray detection composite material structure.

[0032] A schematic diagram of the structure of the X-ray detection composite material prepared in this embodiment is shown below. Figure 1 As shown.

[0033] The X-ray detection composite material prepared in this embodiment generates current under irradiation with different doses of X-rays, such as... Figure 2 As shown, this composite material can convert incident X-rays into current and voltage signals without the need for external bias voltage.

[0034] Example 2:

[0035] (1) Dissolve 0.01 mol of high-purity NiCl2·6H2O in 20 mL of deionized water, stir thoroughly with a magnetic stirrer, and gradually add 10 mol / L NaOH solution until the pH value is equal to 9. Place the cleaned ITO glass and the prepared solution together in a hydrothermal reactor and maintain at 200℃ for 10 hours. Black nickel oxide (NiO) will form on the surface of the ITO glass. 0.98 The nanowire thin layer was repeatedly washed with deionized water and placed in an 80℃ oven for 12 hours.

[0036] (2) Dissolve 10 mmol of lead acetate trihydrate and 10 mmol of formamidine acetate in hydrobromic acid, keep magnetically stirred and heat to 90°C for 1-2 hours. Slowly cooling will allow red lead bromide formamidine single crystals to precipitate from the solution.

[0037] (3) Separate the red lead bromide formamidin single crystal particles from the solution in step (2), wash them repeatedly with methanol, and dissolve them in 0.5 g / mL dimethylformamide to form a crystal precursor solution.

[0038] (5) The ITO / NiO produced in step (1) 0.98 The structure was placed in the precursor solution produced in step (3) and kept at a constant temperature of 60°C for 6 hours to form ITO / NiO. 0.98 / FAPbBr3 composite structure, at 80 o Anneal at C for 2 hours.

[0039] (6) The ITO / NiO produced in step (5) 0.98 The FAPbBr3 composite structure is deposited with silver electrodes to form the final X-ray detection composite material structure.

[0040] A schematic diagram of the structure of the X-ray detection composite material prepared in this embodiment is shown below. Figure 1 As shown, the difference from Example 1 is that NiO 0.98 NiO is present at the junction of the thin film surface and FAPbBr3. 0.98 Nanowires, with lengths ranging from 500 nanometers to 10 micrometers and diameters ranging from 50 nanometers to 200 nanometers.

[0041] Experimental results of the X-ray detection composite material prepared in this embodiment show that the composite material can convert incident X-rays into current and voltage signals without external bias voltage, and the lower limit of the detection dose rate of this structure was measured to be 173 nGy. air s −1 like Figure 3 As shown, the conversion efficiency is higher than that of the sample in Example 1.

Claims

1. A composite material structure for X-ray detection, characterized in that, ITO / NiO x The composite structure of / FAPbBr3 / Ag, in which NiO x It is a nickel oxide nanostructure. x The value ranges from 0.9 to 1.1, and FAPbBr3 is a single crystal with a lead bromide formamidinium perovskite structure. The FAPbBr3 is a single crystal of lead bromide formamidinium perovskite structure with a thickness ranging from 100 nanometers to 5 millimeters. The preparation method includes the following steps: (1) Preparation of nickel oxide nanostructures: NiO was prepared by liquid-phase reaction method. x Nickel oxide nanoparticles are dispersed in alcohol to form a suspension by ultrasonic vibration. The suspension is then spin-coated onto ITO glass and annealed to form a nickel oxide nanostructure film. (2) Preparation of lead bromide formamidine precursor solution: At 90°C, lead acetate trihydrate and formamidine acetate are dissolved in hydrobromic acid to form a saturated solution. The solution is slowly cooled to 60°C. The lead bromide formamidine single crystal particles precipitated in the solution are collected and washed with methanol. The solution is then dissolved in dimethylformamide to form a precursor solution. (3) The ITO substrate with a thin layer of nickel oxide nanostructure obtained in step (1) is placed in the precursor solution prepared in step (2) and kept at a constant temperature of 60°C for a period of time to form ITO / NiO. x / FAPbBr3 composite structure, annealed at 75~100℃; (4) The composite structure obtained in step (3) is vapor-deposited with silver electrodes to form the final X-ray detection composite material structure.

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