CN-115472753-B - X-ray detection composite material structure and preparation method thereof

Abstract

The invention discloses an X-ray detection composite material structure and a preparation method thereof. The composite material structure consists of a conductive substrate (ITO glass), a nickel oxide (NiOx) nanostructure, lead bromide formamidine (MAPbBr 3 ) monocrystal and an upper electrode. The preparation method comprises the steps of batching, liquid phase reaction method and solution method single crystal growth. The composite material structure prepared by the invention can realize self-driven X-ray detection, namely, under the condition of no external bias voltage, the incident X-rays are converted into current signals. The invention has the advantages of low detection limit, wide detection energy range, high resolution, quick response, good linearity, low manufacturing cost and the like, and can be applied to various fields such as X-ray detection, X-ray imaging, optical sensors and the like.

Inventors

• LI HUASHAN
• TAO KEWEN
• LIN SHAOPENG
• MA DECAI
• WANG BIAO

Assignees

• 中山大学

Dates

Publication Date

20260508

Application Date

20220727

Claims (1)

1. 1. An X-ray detection composite material structure is characterized in that a composite structure of ITO/NiO x /FAPbBr 3 /Ag is adopted, wherein NiO x is a nickel oxide nano structure, the value range of X is 0.9-1.1, and FAPbBr 3 is lead bromide formamidine perovskite structure single crystal; The thickness range of the FAPbBr 3 which is the lead bromide formamidine perovskite structure single crystal is 100 nanometers to 5 millimeters; the preparation method comprises the following steps: (1) Preparing NiO x nickel oxide nano particles by a liquid phase reaction method, dispersing the nano particles into alcohol by ultrasonic oscillation to form suspension, spin-coating the suspension on ITO glass, and annealing to form a nickel oxide nano structure film; (2) Dissolving lead acetate trihydrate and formamidine acetate into hydrobromic acid at 90 ℃ to form saturated solution, slowly cooling to 60 ℃, collecting lead bromide formamidine monocrystal particles separated out from the solution, washing with methanol, and dissolving in dimethylformamide to form precursor solution; (3) Placing the ITO substrate with the nickel oxide nano-structure thin layer obtained in the step (1) into the precursor liquid prepared in the step (2), maintaining the constant temperature for a period of time at 60 ℃ to form an ITO/NiO x /FAPbBr 3 composite structure, and annealing at 75-100 ℃; (4) And (3) evaporating the silver electrode on the composite structure obtained in the step (3) to form a final X-ray detection composite material structure.

Description

X-ray detection composite material structure and preparation method thereof Technical Field The invention belongs to the field of X-ray detection materials, and particularly relates to an X-ray detection composite material structure and a preparation method thereof. Background X-rays are light waves with the wavelength of 0.01 nm-10 nm, have penetrability and are widely used in the fields of medical imaging, nondestructive inspection, security and the like. The X-ray detecting material is capable of converting X-rays into electrical or optical signals and is therefore a core component for X-ray applications. The commonly used X-ray detection materials can be divided into two mechanisms of light-light conversion and light-electricity conversion, one is to convert X-ray photons into visible light, then collect and convert the visible light into electric signals by a photomultiplier tube for processing, typical materials such as thallium doped sodium iodide/cesium iodide, lead tungstate and other crystals have the advantages of high yield, high signal-to-noise ratio and the like, the main disadvantages are that the detector is large in size and low in resolution, and the other is to directly convert the X-ray photons into electric signals, such as a high-purity germanium and silicon drift detector, and particularly various novel perovskite materials which are rapidly developed in recent years and the like. Organic-inorganic hybrid perovskite materials based on lead-cesium bromide systems are a popular topic of X-ray detection materials in recent years. Compared with the light-light conversion mechanism, the novel material system has the advantages of small volume, high resolution, high sensitivity, low detection limit, simple detection circuit, low manufacturing cost and the like. However, the problems of low conversion rate, high noise, poor stability and the like still exist, and the higher signal-to-noise ratio and lower detection limit are realized through the optimal design of a material system and a detector structure, so that the method is an important subject for research in the field at present. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide an X-ray detection composite material structure capable of realizing self-driven detection and a preparation method thereof. The technical scheme adopted by the invention is as follows: The X-ray detection composite material structure of the invention consists of a conductive substrate (ITO glass), a nickel oxide (NiOx) nanostructure, lead bromide formamidine (MAPbBr 3) monocrystal and an upper electrode. Specifically, an X-ray detection composite material structure adopts a composite structure of ITO/NiO x/FAPbBr3/Ag, wherein NiO x is a nickel oxide nano structure, the value range of X is 0.9-1.1, and FAPbBr 3 is a lead bromide formamidine perovskite structure single crystal. The components of the nickel oxide nano particles are precisely controlled by chemical components, and the film thickness is precisely controlled by a spin coating process. Preferably, in the above-mentioned X-ray detection composite structure, the NiO x nickel oxide nanostructure is a nano film or a nano wire. Preferably, in the above-mentioned X-ray detection composite structure, the thickness of the FAPbBr 3 as a single crystal of lead bromide formamidine perovskite structure ranges from 100 nm to 5 mm. The thickness of the FAPbBr 3 single crystal can be controlled by the growth time. The preparation method of the X-ray detection composite material structure comprises the following steps: (1) Preparing NiO x nickel oxide nano particles by a liquid phase reaction method, dispersing the nano particles into alcohol by ultrasonic oscillation to form suspension, spin-coating the suspension on ITO glass, and annealing to form a nickel oxide nano structure film; (2) Dissolving lead acetate trihydrate and formamidine acetate into hydrobromic acid at 90 ℃ to form saturated solution, slowly cooling to 60 ℃, collecting lead bromide formamidine monocrystal particles separated out from the solution, washing with methanol, and dissolving in dimethylformamide to form precursor solution; (3) Placing the ITO substrate with the nickel oxide nano-structure thin layer obtained in the step (1) into the precursor liquid prepared in the step (2), maintaining the constant temperature for a period of time at 60 ℃ to form an ITO/NiO x/FAPbBr3 composite structure, annealing at 75-100 ℃ for 2-48 hours, wherein the annealing temperature and time have a remarkable influence on the X-ray detection limit sensitivity. (4) And (3) evaporating the silver electrode on the composite structure obtained in the step (3) to form a final X-ray detection composite material structure. Compared with the prior art, the invention has the following beneficial effects: (1) The X-ray detection composite material structure has the capability of self-driven detection of X-rays, nam