Visible light-X-ray detector structure

Abstract

The utility model discloses a visible light-X ray detector structure, which comprises a top electrode, transparent ceramic and a bottom electrode, the transparent ceramic is arranged on the bottom electrode, and the top electrode is arranged on the transparent ceramic; the input end of the detector structure is also provided with a shading shutter which is not transparent to visible light. And the transparent ceramic is APbX3 transparent ceramic. When the visible light shading door is closed, the detector only obtains an X-ray detection signal; when the visible light shading shutter is opened, the detector obtains an X-ray and visible light detection signal. And the two signals are subtracted to obtain a visible light detection signal. The same detector provided by the utility model can respectively detect the visible light signal and the X-ray signal of the object, so that the object identification capability is improved.

Description

Technical Field

[0001] The utility model relates to the field of visible light detection and X-ray detection, and in particular to a visible light-X-ray detector structure. Background Art

[0002] In medical imaging, the combination of visible light and X-ray imaging can provide more comprehensive and accurate diagnostic information. Visible light images can show the surface of the skin, while X-ray images can look deep into the body to observe bone or tissue structures. By combining these two imaging technologies, doctors can obtain more dimensional information, which helps to diagnose diseases more accurately. In the industrial field, the combination of visible light detection and X-ray imaging can also improve the efficiency and accuracy of material detection. Visible light images can show defects or foreign objects on the external surface, while X-ray images can detect whether the internal structure is intact. By comprehensively analyzing these two types of imaging data, the quality and performance of materials can be more comprehensively evaluated. In general, the combination of visible light detection and X-ray imaging can bring us more comprehensive and accurate information in many fields, which helps to improve work efficiency and accuracy.

[0003] Perovskite has great application potential in the field of visible light and direct X-ray detection due to its advantages such as high photon absorption efficiency, large carrier mobility and long carrier lifetime. In order to fully absorb visible light and reduce the scattering of visible light, the perovskite active layer should have high transparency. In addition, in order to fully absorb high-energy X-rays, the thickness of the perovskite active layer should reach hundreds of microns. At present, the application of perovskite in X-ray is mainly based on single crystal and thin film, but the growth of perovskite single crystal is time-consuming and difficult to prepare on a large scale. Due to the limited solubility of the precursor, it is also difficult to prepare a perovskite thick film that meets the requirements by solution method. Compacting perovskite powder to form a polycrystalline perovskite wafer can construct a perovskite X-ray detection photosensitive layer with adjustable size and thickness, but the polycrystalline inorganic perovskite wafer prepared in this way usually contains many voids and grain boundaries. The prepared polycrystalline wafer has problems such as low transparency and insufficient density, which increases the scattering of visible light, affects the effective collection of charge carriers, and ultimately restricts the performance of the detector. In addition, it seriously affects the efficiency and working stability of the X-ray detector, and it is difficult to further integrate it with the substrate circuit.

[0004] In summary, in order to further promote the application of perovskite materials in the field of visible light and X-ray detectors, it is necessary to improve the quality of perovskite crystals and perovskite thick films to prepare high-performance visible light / X-ray detectors. Utility Model Content

[0005] In order to solve the above problems existing in the prior art, the utility model proposes a visible light-X-ray detector structure to obtain high-efficiency visible light detection and X-ray imaging application capabilities.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a visible light-X-ray detector structure, comprising a top electrode, a transparent ceramic and a bottom electrode, wherein the transparent ceramic is arranged on the top of the bottom electrode, and the top electrode is arranged on the transparent ceramic;

[0007] The input end of the detector structure is also provided with a light-shielding shutter which is opaque to visible light.

[0008] Preferably, the transparent ceramic has a thickness >100 μm.

[0009] Preferably, the transparent ceramic is APbX3 transparent ceramic.

[0010] Preferably, in order to further reduce the detection dark current and noise, a lamination pressing technology can be used to obtain a detector structure of top electrode / transparent ceramic one / transparent ceramic two / bottom electrode, that is, the transparent ceramic includes laminated pressed transparent ceramic one and transparent ceramic two.

[0011] Preferably, the transparent ceramic 1 and the transparent ceramic 2 have certain energy band barriers.

[0012] Preferably, the energy band barriers of the transparent ceramic 1 and the transparent ceramic 2 are greater than 0.2 eV.

[0013] The utility model obtains an X-ray detection signal when the detector shutter is closed, and obtains a visible light plus X-ray detection signal when the shutter is opened. The visible light detection signal can be obtained by subtracting the two signals.

[0014] The utility model discloses a method for preparing transparent ceramics for direct detection of visible light and X-rays, comprising the following steps:

[0015] Step 1: preparing ABX3 microcrystalline powder: dissolving BX2 and AX in an organic solvent to obtain an ABX3 perovskite precursor solution, precipitating by heating and stirring to obtain ABX3 microcrystalline, drying, and grinding to obtain ABX3 microcrystalline powder with uniform particles;

[0016] The ABX3, wherein A is a methylamine cation CH3NH3 + 、Formamidinium cation HC(NH2)2 + or Cesium ion Cs + One or more mixed cations in; B is a metal ion, a germanium ion Ge 2+ 、Sn 2+ or lead ion Pb 2+ One or more mixed metal ions; X halogen ion is iodine I - , Br - or chlorine -One or more mixed halogen elements;

[0017] The molar ratio of BX2 to AX is 1:1-2; the organic solvent is N,N-dimethylformamide DMF and dimethyl sulfoxide;

[0018] Step 2: Prepare the wafer: Place the ABX3 microcrystalline powder into the hot pressing mold; set the temperature, pressure and time parameters, and start the pressurization process after the heating temperature reaches the set value; after the hot pressing is completed, open the mold after the equipment cools down and take out the transparent ceramic prepared by hot pressing.

[0019] Beneficial effects: The utility model is simple to operate, novel and unique, and can obtain transparent ceramics with controllable thickness and area and high crystal quality without using a large amount of solvents and complex and expensive equipment, and has the potential for large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a visible light-X-ray detector of the utility model (the light-shielding shutter is closed and only X-ray signals are detected);

[0021] Figure 2 This is a schematic diagram of the structure of a visible light-X-ray detector of the utility model (the light-shielding shutter is opened, and X-ray signals and visible light signals are detected simultaneously);

[0022] Figure 3 This is a schematic diagram of a method for preparing transparent ceramics in a visible light-X-ray detector structure of the utility model;

[0023] In the figure: 1. Transparent ceramic; 2. Top electrode; 3. Bottom electrode; 4. Light-shielding shutter. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific implementations and accompanying drawings:

[0025] like Figure 1 and Figure 2 As shown, a visible light-X-ray detector structure includes a top electrode 2, a transparent ceramic 1 and a bottom electrode 3, wherein the transparent ceramic 1 is arranged on the bottom electrode 3, and the top electrode 2 is arranged on the transparent ceramic 1;

[0026] The input end of the detector structure is also provided with a light-shielding shutter 4 which is opaque to visible light.

[0027] The thickness of the transparent ceramic 1 is >100 μm. The transparent ceramic is APbX3 transparent ceramic. In order to further reduce the detection dark current and noise, a detector structure of top electrode / transparent ceramic 1 / transparent ceramic 2 / bottom electrode can be obtained by using a stacking pressing technology, that is, the transparent ceramic 1 includes a stacked pressed transparent ceramic 1 and a transparent ceramic 2. The energy band barrier of the transparent ceramic 1 and the transparent ceramic 2 is greater than 0.2 eV.

[0028] like Figure 1 As shown in Figure 1, when the light-shielding shutter is closed, only X-rays can pass through the shutter to reach the detector, and X-ray detection signals can be obtained at this time; when the light-shielding shutter is opened, as shown in Figure 1 Figure 2 As shown, the detector obtains X-ray and visible light detection signals at the same time. The visible light detection signal is obtained by subtracting the above two signals.

[0029] Experimental steps for preparing MAPbBr3 metal halide perovskite transparent ceramics (such as Figure 3 shown):

[0030] (1) Lead bromide and methylamine bromide are dissolved in N,N-dimethylformamide and stirred in a beaker until completely dissolved at a stirring rate of 800 rpm. The solution is filtered using a 22 μm organic filter to form a clear and transparent MAPbBr3 precursor solution, wherein the molar ratio of lead bromide to methylamine bromide is 1:1. 2+ The concentration is 1M;

[0031] (2) The solution prepared in step 2 was placed on a stirring heater, the temperature was set to 80°C, the stirring rate was 800 rpm and the heating and stirring were continued for 3 hours. As the solubility of the solution decreased, MAPbBr3 microcrystals gradually precipitated. The precipitated microcrystals were placed in a vacuum dryer at 60°C and dried for 12 hours and then taken out.

[0032] (3) Grind the dried MAPbBr3 microcrystals in an agate mortar and repeat the grinding for 3 to 5 times, with each grinding time being 30 to 60 minutes, until a MAPbBr3 perovskite microcrystal powder with a particle size of about 50 μm is obtained.

[0033] (4) Weigh an appropriate amount of perovskite powder and put it into a hot pressing mold. Select a mold with a size of 10 cm*10 cm and use a hydraulic press to press it at 150°C and 200 MPa for 60 minutes to press the chip. In this embodiment, the thickness of the transparent ceramic obtained by pressing is about 600 μm.

[0034] (5) After the hot pressing is completed, the mold is opened after the equipment is cooled to 50°C, and the wafer prepared by hot pressing is taken out. The preparation method of the utility model obtains perovskite ceramics with good optical transparency, and the XRD spectrum shows that the prepared MAPbBr3 transparent ceramics have good crystallinity.

[0035] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. For those skilled in the art, the utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A visible light-X-ray detector structure, characterized in that: It comprises a top electrode, a transparent ceramic and a bottom electrode, wherein the transparent ceramic is arranged on the bottom electrode, and the top electrode is arranged on the transparent ceramic; The input end of the detector structure is also provided with a light-shielding shutter which is opaque to visible light.

2. The visible light-X-ray detector structure according to claim 1, characterized in that: The thickness of the transparent ceramic is >100 μm.

3. A visible light-X-ray detector structure according to claim 2, characterized in that: The transparent ceramic is APbX3 transparent ceramic.

4. The visible light-X-ray detector structure according to claim 3, characterized in that: The transparent ceramic includes a transparent ceramic 1 and a transparent ceramic 2 which are laminated and pressed.

5. The visible light-X-ray detector structure according to claim 4, characterized in that: The transparent ceramic 1 and the transparent ceramic 2 have energy band barriers.

6. The visible light-X-ray detector structure according to claim 5, characterized in that: The energy band barriers of the transparent ceramic 1 and the transparent ceramic 2 are greater than 0.2 eV.

Images