Binary metal hybrid halide material as well as preparation method and application thereof

Abstract

The invention discloses a binary metal hybrid halide material and a preparation method and application thereof, and belongs to the field of direct X-ray detectors. The molecular formula of the binary metal hybrid halide material is (EDA) 4MIMIII X12, EDA is ethylenediamine (C2H8N2), MI is selected from monovalent metal elements, MIII is selected from trivalent metal elements, and X is selected from halogen elements; the crystal structure of the binary metal hybrid halide material is a layered structure containing a halide ion layer. According to the method, a specific cooling rate is adopted in the cooling process, so that the high-quality crystal is prepared. The direct X-ray detector prepared on the basis of the binary metal hybrid halide material (EDA) 4MIMIII X12 has excellent radiation sensitivity under different electric field intensities, and the maximum radiation sensitivity is 5250 [mu] CGy <-1 > cm <-2 >.

Description

Technical Field

[0001] This application relates to binary metal hybrid halide materials, their preparation methods, and applications, and belongs to the field of direct X-ray detectors. Background Technology

[0002] X-rays are widely used in numerous fields such as medical CT imaging, security inspection, industrial non-destructive testing, and national defense, making X-ray detectors a focus of significant attention for research institutes and companies worldwide. Most commercial scintillators are fabricated into indirect X-ray detectors, where the detection signal is obtained by converting the incident X-rays twice, once through the scintillator and once through a photodetector. As an alternative, direct detection using scintillation semiconductors (directly converting X-rays into electrical signals) holds greater potential for developing compact CT devices with high-quality X-ray imaging. Due to their excellent compatibility with mature micro / nano manufacturing technologies, traditional semiconductors, such as crystalline silicon, germanium, and amorphous selenium, dominate the commercial market for direct X-ray detection. However, most commercial semiconductor materials currently suffer from intrinsic defects or material preparation problems. Therefore, finding a semiconductor scintillation material with a high atomic number and stable physicochemical properties is of great significance.

[0003] Lead-based hybrid halides have attracted significant attention as semiconductor-type scintillation materials in direct X-ray detection due to their structural diversity and excellent electrical transport properties. Their structure can be manipulated to fabricate X-ray detectors with high sensitivity and low detection limits. In recent years, to avoid the lead-containing problem of B-site metal cations, researchers have attempted to replace lead with various other non-toxic elements to obtain lead-free halide materials. Among these, binary metal hybrid halide materials formed by replacing divalent lead with monovalent and trivalent metals have achieved significant progress in X-ray detection. Summary of the Invention

[0004] According to the first aspect of this application, a binary metal hybrid halide material (EDA)4M is provided. Ⅰ M Ⅲ X 12 In this context, EDA is ethylenediamine (C2H8N2), and M... Ⅰ Selected from monovalent metallic elements, M Ⅲ The elements are selected from trivalent metals, and X is selected from halogen elements. The use of metals with high atomic numbers as cations ensures the material's cutoff capability and constructs a layered structure containing halide ions. This results in binary metal hybrid halides exhibiting excellent charge transport and stable physicochemical properties, enabling the fabrication of direct X-ray detectors that are sensitive and stable to X-rays, with significant application potential.

[0005] A binary metal hybrid halide material, wherein the molecular (EDA) of the binary metal hybrid halide material is 4M Ⅰ M Ⅲ X 12 EDA is ethylenediamine (C4H2O) 12 N2), M Ⅰ Selected from monovalent metallic elements, M Ⅲ X is selected from trivalent metal elements, and X is selected from at least one of Cl, Br, and I.

[0006] Optionally, the crystal structure of the binary metal hybrid halide material is a layered structure containing a halide ion layer.

[0007] Optionally, the crystal phase structure of the binary metal hybrid halide material is either a monoclinic phase or a triclinic phase.

[0008] Optionally, M Ⅰ It is selected from at least one of Cu, Ag, and Au.

[0009] Optionally, M Ⅲ It is selected from at least one of Sb, Bi, Ga, Bi, Ru, and Mo.

[0010] Optionally, X is selected from at least one of Cl, Br, and I.

[0011] Optionally, the binary metal hybrid halide material is a single crystal ranging from micrometer to millimeter in size.

[0012] Optionally, the size of the binary metal hybrid halide material is 0.1 mm to 2 mm.

[0013] Optionally, the size of the single crystal of the binary metal hybrid halide material is 0.3 mm to 2 mm.

[0014] Optionally, the size of the single crystal of the binary metal hybrid halide material is independently selected from any value of 0.10 mm, 0.15 mm, 0.30 mm, 0.35 mm, 1.55 mm, 2.00 mm, or a range between any two of the above.

[0015] Optionally, the effective atomic number of the binary metal hybrid halide material is 37.1 to 38.6.

[0016] Optionally, the resistivity of the binary metal hybrid halide material is 9.3 × 10⁻⁶. 9 ~1.3×10 10 Ω cm.

[0017] According to a second aspect of this application, a binary metal hybrid halide material (EDA) 4M is provided. Ⅰ MⅢ X 12 The preparation method involves a solvothermal process, specifically employing a particular cooling rate during the cooling process to obtain high-quality crystals.

[0018] A method for preparing a binary metal hybrid halide material, the method comprising: In a closed reactor, a mixture containing an ethylenediamine organic source, monovalent and trivalent metal sources, and a halogen source solvent is reacted to obtain the binary metal hybrid halide material.

[0019] Optionally, the ethylenediamine organic source is selected from at least one of ethylenediamine, ethylenediamine hydroiodide, ethylenediamine hydrobromide, and ethylenediamine hydrochloride.

[0020] Optionally, the monovalent metal source is selected from metal halides and / or metal oxides.

[0021] Optionally, the monovalent metal source is selected from at least one of metal iodides, metal bromides, metal chlorides, and metal oxides.

[0022] Optionally, the trivalent metal source is selected from metal halides and / or metal oxides.

[0023] Optionally, the trivalent metal source is selected from at least one of metal iodides, metal bromides, metal chlorides, and metal oxides.

[0024] Optionally, the mass ratio of the monovalent metal source to the ethylenediamine organic source is 1:1 to 3.

[0025] Optionally, the mass ratio of the monovalent metal source to the ethylenediamine organic source is 1:2.

[0026] Optionally, the mass ratio of the monovalent metal source to the ethylenediamine organic source is independently selected from any value among 1:1, 1:1.25, 1:1.5, 1:1.75, 1:2, or any range between the two.

[0027] Optionally, the mass ratio of the ethylenediamine organic source to the trivalent metal source is 1:1 to 3.

[0028] Optionally, the mass ratio of the ethylenediamine organic source to the trivalent metal source is 1:1.5.

[0029] Optionally, the mass ratio of the ethylenediamine organic source to the trivalent metal source is independently selected from any value among 1:1, 1:1.15, 1:1.3, 1:1.45, 1:1.5, or any range between the two.

[0030] The mixture also includes hypophosphoric acid.

[0031] Optionally, the volume ratio of hypophosphoric acid to halogen source solvent is 1:2 to 5.

[0032] Optionally, the concentration of the ethylenediamine organic source is 0.0000001 mol / L ~ 0.000001 mol / L, and the concentration of the ethylenediamine organic source is measured as the molar concentration of organic molecules in the mixture.

[0033] Optionally, the concentration of the ethylenediamine organic source is independently selected from any value among 0.0000001 mol / L, 0.0000003 mol / L, 0.0000006 mol / L, 0.0000009 mol / L, 0.000001 mol / L, or a range between any two of the above.

[0034] Optionally, the concentration of the monovalent metal source is 0.0000001 mol / L ~ 0.000001, and the concentration of the monovalent metal source is measured by the molar concentration of the monovalent metal element in the mixture.

[0035] Optionally, the concentration of the monovalent metal source is independently any value among 0.0000001 mol / L, 0.0000003 mol / L, 0.0000006 mol / L, 0.0000009 mol / L, 0.000001 mol / L, or a range between any two of the above.

[0036] Optionally, the concentration of the trivalent metal source is 0.0000001 mol / L ~ 0.000001, and the concentration of the trivalent metal source is measured by the molar concentration of the trivalent metal element in the mixture.

[0037] Optionally, the concentration of the trivalent metal source is independently any value among 0.0000001 mol / L, 0.0000003 mol / L, 0.0000006 mol / L, 0.0000009 mol / L, 0.000001 mol / L, or a range between any two of the above.

[0038] Optionally, the phosphoric acid and halogen source solvent are of chemical purity.

[0039] Optionally, the reaction temperature is 100℃~120℃, and the reaction time is 10h~30h.

[0040] Optionally, the temperature of the reaction is independently selected from any value of 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, or a range between any two of the above.

[0041] Optionally, the temperature is lowered after the reaction is complete; The cooling rate is 0.1 ℃ / hour to 2 ℃ / hour.

[0042] Optionally, the cooling rate is independently selected from any value among 0.1 ℃ / hour, 0.5 ℃ / hour, 1.0 ℃ / hour, 1.5 ℃ / hour, 2 ℃ / hour, or a range between any two of the above.

[0043] According to a third aspect of this application, an application of the aforementioned binary metal hybrid halide material in a direct X-ray detector is provided. The direct X-ray detector based on the binary metal hybrid halide material possesses high sensitivity.

[0044] Application of a binary metal hybrid halide material in a direct X-ray detector.

[0045] A direct X-ray detector, the direct X-ray detector comprising electrodes and a light-absorbing layer; The light-absorbing layer is selected from one of the binary metal hybrid halide materials described above.

[0046] Optionally, the direct X-ray detector includes an upper electrode, a light-absorbing layer, and a lower electrode.

[0047] Optionally, the light-absorbing layer is selected from single-crystal or polycrystalline pressed binary metal hybrid halide materials.

[0048] Optionally, the thickness of the upper electrode and the lower electrode is 5 µm to 10 µm.

[0049] Optionally, the thickness of the light-absorbing layer is 0.1 mm to 2 mm.

[0050] Optionally, the upper electrode and the lower electrode are independently selected from at least one of Ag, Au, Cu, Cr, and ITO.

[0051] Optionally, the sensitivity of the direct-type X-ray detector is 3388 μCGy. -1 cm -2 ~ 5250 μCGy -1 cm -2 .

[0052] Optionally, the sensitivity of the direct-type X-ray detector is independently selected from 3388 μCgy. -1 cm -2 3952 μCGy - 1 cm -2 4338 μCGy -1 cm -2 4725 μCGy-1 cm -2 5250 μCGy -1 cm -2 Any value in or a range between any two of the above.

[0053] According to a fourth aspect of this application, a method for fabricating a direct-type X-ray detector is provided.

[0054] A method for fabricating a direct-type X-ray detector includes the following steps: Conductive silver paste is evenly applied to both sides of the binary metal hybrid halide material and allowed to dry naturally to obtain the device unit of electrode / binary metal hybrid halide material / electrode. The binary metal hybrid halide material is selected from the aforementioned binary metal hybrid halide material (EDA) 4M. Ⅰ M Ⅲ X 12 .

[0055] This invention proposes a method based on binary metal hybrid halide material (EDA) 4M Ⅰ M Ⅲ X 12 A direct-type X-ray detector and its fabrication method are described, which has high X-ray sensitivity.

[0056] The present invention describes a binary metal hybrid halide material (EDA) 4M Ⅰ M Ⅲ X 12 The direct-type X-ray detector has a top-to-bottom device structure of electrode / binary metal hybrid halide material / electrode, and binary metal hybrid halide material (EDA) 4M. Ⅰ M Ⅲ X 12 It serves as an absorbing layer for X-rays.

[0057] Furthermore, the electrode is made of metallic Ag with a thickness of 1 to 2 μm.

[0058] Based on binary metal hybrid halide material (EDA) 4M Ⅰ M Ⅲ X 12 The method for fabricating an X-ray detector includes the following steps: (a) Mix the three raw materials, ethylenediamine hydrobromide (EDABr2), silver bromide (AgBr), and bismuth bromide (BiBr3), in a mass ratio of 2:1:3; (b) Add the raw material mixture obtained in step (a) into the inner liner of the hydrothermal reactor containing hydrobromic acid solution, maintaining the concentration at 0.0000001 mol / L ~ 0.000001 mol / L, then insert the inner liner into the outer shell of the hydrothermal reactor, and place the hydrothermal reactor into a temperature-controlled forced-air drying oven. (c) The temperature-controlled drying oven is set to maintain a constant temperature of 110 °C and then slowly cooled to room temperature at a rate of 0.1 °C / hour to obtain millimeter-scale binary metal hybrid halide material single crystals. (d) The binary metal hybrid halide material single crystal obtained in step (c) is kept at 60 °C until dry.

[0059] The present invention describes a binary metal hybrid halide material (EDA) 4M Ⅰ M Ⅲ X 12 The fabrication method of the direct X-ray detector involves uniformly coating conductive silver paste onto a binary metal hybrid halide material (EDA) 4M. Ⅰ M Ⅲ X 12 The device structure of electrode / binary metal hybrid halide material / electrode is obtained by naturally drying the top and bottom surfaces of the single crystal.

[0060] The beneficial effects that this application can produce include: 1) The binary metal hybrid halide material (EDA) 4M provided in this application Ⅰ M Ⅲ X 12 It has a layered structure containing halide ions and a high atomic number, thus it has strong absorption cutoff and efficient conversion of X-rays, which is beneficial for the preparation of direct X-ray detectors that are sensitive to X-rays.

[0061] 2) The binary metal hybrid halide material (EDA) 4M provided in this application Ⅰ M Ⅲ X 12 The preparation method is carried out by hydrothermal method. In particular, a specific cooling rate is adopted during the cooling process to obtain high-quality crystals. It is simple, efficient and suitable for large-scale industrial production.

[0062] 3) The binary metal hybrid halide material (EDA) 4M provided in this application Ⅰ M Ⅲ X 12 In direct-type X-ray detectors, this detector exhibits excellent sensitivity under different electric field strengths, with a maximum sensitivity of 5250 μCy. -1 cm -2 . Attached Figure Description

[0063] Figure 1 In Example 1 of this application, (EDA)4AgBiBr 12 And in Example 2, (EDA)4CuBiBr 12 Crystal structure diagram.

[0064] Figure 2 In Example 1 of this application, (EDA)4AgBiBr 12 And in Example 2, (EDA)4CuBiBr 12 X-ray powder diffraction pattern.

[0065] Figure 3 In Example 1 of this application, (EDA)4AgBiBr 12 And in Example 2, (EDA)4CuBiBr 12 Photos of the actual product.

[0066] Figure 4 The curves show the temperature change over time during crystal growth in Examples 1-2 of this application.

[0067] Figure 5 The X-ray sensitivity changes of the direct X-ray detectors prepared in Examples 1-2 of this application under different electric field strengths. Detailed Implementation

[0068] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0069] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0070] The analysis method in the embodiments of this application is as follows: Detector performance analysis was performed using a Keithley 2450 high voltage source meter.

[0071] Example 1 This embodiment provides a binary metal hybrid halide material (EDA) 4AgBiBr. 12 Preparation method and (EDA)4AgBiBr 12 The specific steps for fabricating a direct-type X-ray detector using the material are as follows: (a) Mix 0.2 g of ethylenediamine hydrobromide (EDABr2), 0.1 g of silver bromide (AgBr), and 0.3 g of bismuth bromide (BiBr3) in a mass ratio of 2:1:3; (b) Add the raw material mixture obtained in step (a) into the inner liner of the hydrothermal reactor containing hydrobromic acid solution, maintain the concentration at 0.0000001 mol / L, then put the inner liner into the outer shell of the hydrothermal reactor, and place the hydrothermal reactor into a temperature-controlled forced-air drying oven. (c) A temperature-controlled drying oven was set to maintain a constant temperature of 120 °C for 20 h, and then slowly cooled to room temperature at a rate of 0.1 °C / hour to obtain (EDA)₂AgBiBr₂. 12 Crystals; (d) Take the (EDA)4AgBiBr obtained in step (c) 12 The crystals were kept at 60 °C until dry.

[0072] (e) Apply the conductive silver paste evenly to the (EDA)4AgBiBr obtained in step (d). 12 The top and bottom surfaces of the crystal are 8 μm and 8 μm respectively. The thickness of the binary metal hybrid halide crystal is 1 mm. The device structure of electrode / binary metal hybrid halide crystal / electrode is obtained by natural drying.

[0073] Example 2 This embodiment provides a binary metal hybrid halide material (EDA) 4CuBiBr. 12 Preparation method and (EDA)4CuBiBr 12 The specific steps for fabricating a direct-type X-ray detector using the material are as follows: (a) Mix 0.3 g of ethylenediamine hydrobromide (EDABr2), 0.07 g of cuprous bromide (AgCu), and 0.35 g of bismuth bromide (BiBr3) in a mass ratio of 4.2:1:5; (b) Add the raw material mixture obtained in step (a) into the inner liner of a hydrothermal reactor containing hydrobromic acid solution (the volume ratio of hydrobromic acid to hypophosphoric acid is 5:1) and maintain the concentration at 0.0000001 mol / L. Then, put the inner liner into the outer shell of the hydrothermal reactor and place the hydrothermal reactor into a temperature-controlled forced-air drying oven. (c) A temperature-controlled drying oven was set to maintain a constant temperature of 120 °C for 20 h, and then slowly cooled to room temperature at a rate of 0.1 °C / hour to obtain (EDA)₄CuBiBr₂. 12 Crystals; (d) Take the (EDA)4CuBiBr obtained in step (c) 12 The crystals were kept at 60 °C until dry.

[0074] (e) Apply the conductive silver paste evenly to the (EDA)4CuBiBr obtained in step (d). 12The top and bottom surfaces of the crystal are 8 μm and 8 μm respectively. The thickness of the binary metal hybrid halide crystal is 0.8 mm. The device structure of electrode / binary metal hybrid halide crystal / electrode is obtained by natural drying.

[0075] Test case In Example 1, (EDA)4AgBiBr 12 And in Example 2, (EDA)4CuBiBr 12 Crystal structure such as Figure 1 As shown, the crystal structure is a layered structure containing halide ion layers. The left-hand diagram corresponds to (EDA)4AgBiBr in Example 1. 12 As can be seen, its crystal structure is a two-dimensional layered structure. The figure on the right corresponds to (EDA)4CuBiBr in Example 2. 12 As can be seen, its crystal structure is a two-dimensional layered structure.

[0076] In Example 1, (EDA)4AgBiBr 12 And in Example 2, (EDA)4CuBiBr 12 X-ray powder diffraction pattern as follows Figure 2 As shown, the crystallinity of the products is very high.

[0077] In Example 1, (EDA)4AgBiBr 12 And in Example 2, (EDA)4CuBiBr 12 Real photos of the product, such as Figure 3 As shown, its crystallinity is good. The left-hand graph corresponds to (EDA)4AgBiBr in Example 1. 12 As can be seen, its size is on the millimeter scale. The figure on the right corresponds to (EDA)4CuBiBr in Example 2. 12 As can be seen, its size is on the order of millimeters.

[0078] The temperature-time variation curves for crystal growth in Examples 1-2 are shown below. Figure 4 As shown, the duration of the reaction and cooling processes corresponds to the temperature changes shown in the figure.

[0079] The X-ray sensitivity changes of the direct-type X-ray detectors prepared in Examples 1-2 under different electric field intensities are as follows: Figure 5 As shown, its sensitivity is 3388 μCGy. -1 cm -2 ~ 5250 μCGy -1 cm -2 .

[0080] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A binary metal hybrid halide material, characterized in that, The molecular formula of the binary metal hybrid halide material is (EDA)4M Ⅰ M Ⅲ X 12 ; Wherein, EDA is ethylenediamine, and M... Ⅰ Selected from monovalent metallic elements, M Ⅲ X is selected from trivalent metal elements, and X is selected from halogen elements.

2. The binary metal hybrid halide material according to claim 1, characterized in that, The crystal structure of the binary metal hybrid halide material is a layered structure containing a halide ion layer. Preferably, M Ⅰ Selected from at least one of Cu, Ag, and Au; Preferably, M Ⅲ Selected from at least one of Sb, Bi, Ga, Bi, Ru, and Mo; Preferably, X is selected from at least one of Cl, Br, and I; Preferably, the crystal phase structure of the binary metal hybrid halide material is either a monoclinic phase or a triclinic phase; Preferably, the binary metal hybrid halide material is a single crystal ranging from micrometer to millimeter in size; Preferably, the size of the binary metal hybrid halide material is 0.1 mm to 2 mm.

3. The binary metal hybrid halide material according to claim 1, characterized in that, The effective atomic number of the binary metal hybrid halide material is 37.1~38.6; Preferably, the resistivity of the binary metal hybrid halide material is 9.3 × 10⁻⁶. 9 ~1.3×10 10 Ω cm.

4. The method for preparing the binary metal hybrid halide material according to any one of claims 1 to 3, characterized in that, The preparation method includes: In a closed reactor, a mixture containing an ethylenediamine organic source, monovalent and trivalent metal sources, and a halogen source solvent is reacted to obtain the binary metal hybrid halide material.

5. The preparation method according to claim 4, characterized in that, The ethylenediamine organic source is selected from at least one of ethylenediamine, ethylenediamine hydroiodate, ethylenediamine hydrobromide, and ethylenediamine hydrochloride; Preferably, the monovalent metal source is selected from at least one of metal iodides, metal bromides, metal chlorides, and metal oxides; Preferably, the trivalent metal source is selected from at least one of metal iodides, metal bromides, metal chlorides, and metal oxides; Preferably, the halogen source solvent is selected from at least one of hydroiodic acid, hydrobromic acid, and hydrochloric acid.

6. The preparation method according to claim 4, characterized in that, The mass ratio of the monovalent metal source to the ethylenediamine organic source is 1:2 to 4.5, and the mass ratio of the ethylenediamine organic source to the trivalent metal source is 1:1 to 2. Preferably, the mass ratio of the monovalent metal source to the ethylenediamine organic source is 1:2; Preferably, the mass ratio of the ethylenediamine organic source to the trivalent metal source is 1:1.5; Preferably, the mixture further includes hypophosphoric acid; Preferably, the volume ratio of hypophosphorous acid to halogen source solvent is 1:2 to 5; Preferably, the concentration of the ethylenediamine organic source is 0.0000001 mol / L ~ 0.000001 mol / L, and the concentration of the ethylenediamine organic source is measured as the molar concentration of organic molecules in the mixture; Preferably, the concentration of the monovalent metal source is 0.0000001 mol / L ~ 0.000001, and the concentration of the monovalent metal source is measured by the molar concentration of the monovalent metal element in the mixture; Preferably, the concentration of the trivalent metal source is 0.0000001 mol / L ~ 0.000001, and the concentration of the trivalent metal source is measured by the molar concentration of the trivalent metal element in the mixture.

7. The preparation method according to claim 4, characterized in that, The reaction temperature is 100℃~120℃, and the reaction time is 10h~30h; Preferably, the temperature is lowered after the reaction is complete; The cooling rate is 0.1 ℃ / hour to 2 ℃ / hour.

8. A direct-type X-ray detector, characterized in that, The direct X-ray detector includes electrodes and a light-absorbing layer; The light-absorbing layer is selected from one of the binary metal hybrid halide materials according to any one of claims 1 to 3.

9. The direct-type X-ray detector according to claim 8, characterized in that, The direct X-ray detector includes an upper electrode, a light-absorbing layer, and a lower electrode; Preferably, the light-absorbing layer is selected from single-crystal or polycrystalline pressed sheets of binary metal hybrid halide materials; Preferably, the thickness of the upper electrode and the lower electrode is 5 µm to 10 µm; Preferably, the thickness of the light-absorbing layer is 0.1 mm to 2 mm; Preferably, the upper electrode and the lower electrode are independently selected from at least one of Ag, Au, Cu, Cr, and ITO; Preferably, the sensitivity of the direct-type X-ray detector is 3388 μCGy. -1 cm -2 ~ 5250 μCGy -1 cm -2 .

10. The method for preparing the direct-type X-ray detector according to claim 8, characterized in that, include: Conductive silver paste is evenly applied to both the upper and lower surfaces of the binary metal hybrid halide material and allowed to dry naturally to obtain the device unit of electrode / binary metal hybrid halide material / electrode. The binary metal hybrid halide material is selected from the binary metal hybrid halide materials described in any one of claims 1 to 3.

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