A crystalline compound, methods of making and use in x-ray direct detection and imaging

Abstract

This invention provides a crystalline compound, its preparation method, and its application in X-ray direct detection and imaging, relating to the field of crystal synthesis technology. Specifically, the molecular formula of the crystalline compound is [Pb(IQS)]. n ISQ 2‑ Formed by the loss of two hydrogen atoms from 7-iodo-8-hydroxyquinoline-5-sulfonic acid, it belongs to the tetragonal crystal system with space group P42bc and cell parameters α=90°, β=90°, γ=90°, Z=8. The cell volume is [missing information]. The preparation method of the crystal compound of this invention is simple. As a material for X-ray detectors, it has the characteristics of large mass attenuation coefficient for X-ray energy, large carrier mobility lifetime product, and high X-ray detection sensitivity. It can be applied to semiconductor materials, room temperature X-ray radiation direct detection materials, radiation detection dosimeters, X-ray semiconductor medical imaging, etc.

Description

Technical Field

[0001] This invention belongs to the field of crystal technology and relates to a crystal compound, its preparation method, and its application in X-ray direct detection and imaging. Background Technology

[0002] With the development of science and technology, radiation detection materials play a significant role in fields such as medical diagnosis and treatment, homeland security, astrophysics, and space exploration. Direct X-ray detection using semiconductor optoelectronic materials can directly convert X-ray photons into electrical signals. Compared to X-ray indirect detection materials based on scintillators, direct detection eliminates the visible light-to-electrical signal conversion process, reducing energy loss. Therefore, semiconductor-based direct detection offers advantages in terms of improved energy and spatial resolution. Advances in direct X-ray detection technology are closely related to the development of direct detection semiconductor materials. Currently, commercially available photodetectors are mainly based on high-purity silicon (Si) or high-purity germanium (Ge). However, due to the low X-ray absorption efficiency of these materials, crystalline silicon can only effectively respond to high-energy rays with energies below 20 keV. The bandgap of crystalline germanium is only 0.7 eV. This small bandgap leads to high leakage current during X-ray detection, therefore crystalline germanium radiation detection materials require strictly controlled cryogenic conditions to effectively detect high-energy rays. Second- and third-generation semiconductors, represented by GaAs, InSb, BN, and SiC, possess large band gaps, enabling effective detection of thermal neutrons. However, these materials are difficult to fabricate, hindering the synthesis of large-area detectors. Organic semiconductor materials can also be used for high-energy radiation (X-rays and gamma rays). However, these materials are primarily composed of light atoms such as C, H, O, and N. Compared to inorganic materials containing heavy atoms, organic semiconductors have very weak X-ray blocking capabilities, severely limiting their ability to detect high-energy radiation. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a crystalline compound that solves the problems of poor X-ray cutoff capability of traditional materials affecting detection performance, and the complex and costly synthesis process of commercial materials.

[0004] The present invention also provides a method for preparing crystalline compounds, which adopts a low-cost solution synthesis process and utilizes the synergistic advantages of self-assembly between inorganic and organic building blocks to solve the problem that a single inorganic or organic component cannot achieve the desired function.

[0005] Another object of the present invention is to provide an application of the crystalline compound.

[0006] The technical solution of the present invention is as follows:

[0007] A crystalline compound having the molecular formula [Pb(IQS)] n ISQ 2- It is formed by the loss of two hydrogen atoms from 7-iodo-8-hydroxyquinoline-5-sulfonic acid.

[0008] Preferably, the crystalline compound belongs to the tetragonal crystal system, with space group P42bc and cell parameters of [missing information]. α = 90°, β = 90°, γ = 90°, Z = 8, cell volume is

[0009] A method for preparing the crystalline compound according to any of the above embodiments, wherein a lead source, 7-iodo-8-hydroxyquinoline-5-sulfonic acid and a reaction medium are added to a reactor, and a solvothermal reaction is carried out at 90-120°C for 36-72 hours, followed by cooling, filtration, washing and drying to obtain the crystalline compound.

[0010] Preferably, the lead source is selected from at least one of Pb(CH3COO)2, Pb(NO3)2, PbCl2, PbBr2 and PbI2.

[0011] Preferably, the molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 0.8-3:1.

[0012] More preferably, the molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 1-2.5:1.

[0013] Preferably, the reaction medium is selected from water or a mixture of water-soluble organic solvent and water in a volume ratio of 9:1 to 1:9.

[0014] Preferably, the weight ratio of the lead source to the reaction medium is 1:50-2000.

[0015] More preferably, the weight ratio of the lead source to the reaction medium is 1:100-1500.

[0016] The crystalline compound described in any of the above embodiments or the crystalline compound obtained by the preparation method described in any of the above embodiments may be used as a semiconductor material, a direct X-ray detection material, and in radiation detection metrology and X-ray semiconductor medical imaging.

[0017] The beneficial effects of this invention are:

[0018] (1) This invention employs a low-cost solution synthesis method, utilizing the synergistic advantage of self-assembly between inorganic and organic building blocks, to obtain a compound [Pb(IQS)] with a crystal structure. nThis solves the problems of complex synthesis processes and high production costs of crystalline semiconductor materials for existing commercial X-ray detection.

[0019] (2) The [Pb(IQS)] of the present invention n The crystal exhibits a highly efficient photocurrent response under X-rays. Utilizing the synergistic effect of the self-assembly of inorganic and organic components into a supramolecular network, it displays a large product of carrier mobility and lifetime, as well as high X-ray detection sensitivity. Compared to traditional semiconductor materials silicon and germanium, the [Pb(IQS)] of this invention... n Crystals exhibit greater X-ray attenuation efficiency and stronger X-ray blocking ability compared to organic semiconductors. Therefore, the [Pb(IQS)] of this invention... n Crystals can be applied to semiconductor materials, room temperature X-ray radiation direct detection materials, radiation detection dosimeters, X-ray semiconductor medical imaging, and other fields. Attached Figure Description

[0020] Figure 1 [Pb(IQS)] for Example 1 n Pb 2+ A schematic diagram of the coordination environment;

[0021] Figure 2 [Pb(IQS)] for Example 1 n Pb 2+ 3D stacked image;

[0022] Figure 3 [Pb(IQS)] for Example 1 n X-ray powder diffraction pattern;

[0023] Figure 4 [Pb(IQS)] for Example 1 n Infrared absorption spectrum;

[0024] Figure 5 [Pb(IQS)] for Example 1 n The ultraviolet-visible absorption spectrum;

[0025] Figure 6 [Pb(IQS)] for Example 1 n The mass attenuation coefficient of X-ray energy when assembled into an X-ray detector;

[0026] Figure 7 [Pb(IQS)] for Example 1 n The carrier mobility lifetime product assembled into an X-ray detector;

[0027] Figure 8 [Pb(IQS)] for Example 1 nX-ray detection sensitivity diagram of an assembled X-ray detector. Detailed Implementation

[0028] The technical solution of the present invention will be further described and illustrated below through specific embodiments. The technical solution of the present invention will be further described and illustrated below based on various embodiments. Unless otherwise specified, the parts mentioned in the following embodiments are parts by weight.

[0029] In one aspect, this invention proposes a crystalline compound with the molecular formula [Pb(IQS)]. n ISQ 2- It is formed by the loss of two hydrogen atoms from 7-iodo-8-hydroxyquinoline-5-sulfonic acid. In the crystalline compound of this invention, Pb(IQS) simply represents one unit cell, [Pb(IQS)]. n The crystalline compounds representing this invention are not single entities, but rather are infinitely stacked from the smallest units.

[0030] The structural formula of 7-iodo-8-hydroxyquinoline-5-sulfonic acid (abbreviated as "H2IQS") is shown in formula (1) below, and its molecular formula is C9H6INO4S.

[0031]

[0032] The two hydrogen atoms lost from the above-mentioned 7-iodo-8-hydroxyquinoline-5-sulfonic acid are the hydrogen atoms on the sulfonic acid group and the hydrogen atoms on the phenolic group, respectively, thus becoming IQS. 2- .

[0033] In a preferred embodiment of the present invention, the crystalline compound belongs to the tetragonal crystal system, with space group P42bc and cell parameters of [missing information]. α = 90°, β = 90°, γ = 90°, Z = 8, cell volume is

[0034] In another aspect, the present invention provides a method for preparing the crystalline compound described in any of the above embodiments, wherein a lead source, 7-iodo-8-hydroxyquinoline-5-sulfonic acid and a reaction medium are added to a reactor, and a solvothermal reaction is carried out at 90-120°C for 36-72 hours, followed by cooling, filtration, washing and drying to obtain the crystalline compound.

[0035] In a preferred embodiment of the present invention, the lead source can be an inorganic lead source or an organic lead source, specifically selected from at least one of Pb(CH3COO)2, Pb(NO3)2, PbCl2, PbBr2, and PbI2. More preferably, the lead source is Pb(NO3)2 or PbCl2.

[0036] In a preferred embodiment of the present invention, the molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 0.8-3:1.

[0037] In a more preferred embodiment of the present invention, the molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 1-2.5:1. More preferably, the molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 1-2:1.

[0038] In a preferred embodiment of the present invention, the reaction medium is selected from water or a mixture of water-soluble organic solvent and water in a volume ratio of 9:1 to 1:9. In this invention, the water-soluble organic solvent is not particularly limited and can be selected from at least one of methanol, ethanol, DMF, DMAc, DMSO, 1,4-dioxane, tetrahydrofuran, ethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, acetonitrile, acetone, and ethyl acetate. More preferably, the reaction medium is selected from a mixture of water-soluble organic solvent and water in a volume ratio of 5:1 to 1:5. Even more preferably, the reaction medium is selected from a mixture of water-soluble organic solvent and water in a volume ratio of 3:1 to 1:3.

[0039] In a preferred embodiment of the present invention, the weight ratio of the lead source to the reaction medium is 1:50-2000.

[0040] In a more preferred embodiment of the present invention, the weight ratio of the lead source to the reaction medium is 1:100-1500. Even more preferably, the weight ratio of the lead source to the reaction medium is 1:100-1000.

[0041] In another aspect, the present invention proposes the use of the crystalline compound described in any of the above embodiments or the crystalline compound obtained by the preparation method described in any of the above embodiments as a semiconductor material, a direct X-ray detection material, and in radiation detection metrology and X-ray semiconductor medical imaging.

[0042] One application method of the crystalline compound of the present invention is as follows: the crystalline compound is cut into the required size or the crystal is ground and then pressed into a sheet at 8-10 MPa. Electrode material is then deposited on both ends of the cut crystal or the pressed sheet to obtain an X-ray detector. The electrode material used can be a conductive material such as gold, silver, copper, aluminum, graphite, or conductive carbon.

[0043] Example 1

[0044] 0.1 mmol of PbCl2 and 0.1 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 10 mL container, followed by the addition of 3 mL of DMA and 3 mL of deionized water for a solvothermal reaction at 100 °C for 72 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solid was washed three times with a 1:1 volume ratio of DMA and deionized water. The solid was then dried overnight in a 40 °C oven to obtain yellow rod-shaped crystals.

[0045] After X-ray diffraction (as shown in the attached image) Figure 3 (as shown), infrared absorption (as attached) Figure 4 (as shown) and ultraviolet-visible absorption (as attached) Figure 5 As shown in the image, testing confirmed that the chemical formula of the obtained yellow rod-shaped crystals is [Pb(IQS)]. n It belongs to the tetragonal crystal system, with space group P42bc and cell parameters of . α = 90°, β = 90°, γ = 90°, Z = 8, cell volume is [Pb(IQS)] n Pb 2+ The coordination environment is as follows Figure 1 As shown, Pb 2+ The 3D stacked diagram is attached. Figure 2 As shown.

[0046] Example 2

[0047] 0.1 mmol of PbCl₂ and 0.1 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 10 mL container, followed by 3 mL of DMA, 2 mL of methanol, and 1 mL of deionized water. A solvothermal reaction was initiated at 100 °C for 72 h. After the reaction, the mixture was cooled to room temperature, filtered, and the solid was washed three times with a 1:1 (v / v) mixture of DMA and deionized water. The solid was then dried overnight in a 40 °C oven to obtain yellow rod-shaped crystals [Pb(IQS)]. n .

[0048] Example 3

[0049] 0.2 mmol of PbCl₂ and 0.12 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 30 mL container, followed by 10 mL of DMF and 10 mL of deionized water. A solvothermal reaction was initiated at 120 °C for 36 h. After the reaction, the mixture was cooled to room temperature, filtered, and the solid was washed three times with a 1:1 (v / v) mixture of DMF and deionized water. The solid was then air-dried for 48 h to obtain yellow rod-shaped crystals [Pb(IQS)]. n .

[0050] Example 4

[0051] 0.2 mmol of PbBr2 and 0.12 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 30 mL container, followed by 5 mL of DMF and 15 mL of deionized water. A solvothermal reaction was initiated at 110 °C for 46 h. After the reaction, the mixture was cooled to room temperature, filtered, and the solid was washed three times with a 1:1 (v / v) mixture of DMF and deionized water. The solid was then air-dried for 48 h to obtain yellow rod-shaped crystals [Pb(IQS)]. n .

[0052] Example 5

[0053] 0.2 mmol of PbBr2 and 0.2 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 40 mL container, followed by 15 mL of DMF and 15 mL of deionized water. A solvothermal reaction was initiated at 110 °C for 50 h. After the reaction, the mixture was cooled to room temperature, filtered, and the solid was washed three times with a 1:1 (v / v) mixture of DMF and deionized water. The solid was then air-dried for 48 h to obtain yellow rod-shaped crystals [Pb(IQS)]. n .

[0054] Example 6

[0055] 0.1 mmol of Pb(NO3)2 and 0.1 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 20 mL container, followed by 12 mL of deionized water. A solvothermal reaction was initiated at 120 °C for 40 h. After the reaction, the mixture was cooled to room temperature, filtered, and the solid was washed three times with deionized water and air-dried for 48 h to obtain yellow rod-shaped crystals [Pb(IQS)]. n .

[0056] Example 7

[0057] 0.15 mmol of Pb(NO3)2 and 0.1 mmol of 7-iodo-8-hydroxyquinoline-5-sulfonic acid were added to a 20 mL container, followed by 13 mL of deionized water. A solvothermal reaction was initiated at 100 °C for 70 h. After the reaction, the mixture was cooled to room temperature, filtered, and the solid was washed three times with deionized water and air-dried for 48 h to obtain yellow rod-shaped crystals [Pb(IQS)]. n .

[0058] Application testing

[0059] The yellow rod-shaped crystals [Pb(IQS)] obtained in Example 1 nA crystal material was cut into pieces with dimensions of 40μm (width) × 40μm (length) × 210μm (height). Gold electrodes with a thickness of 40μm were deposited on the upper and lower surfaces along the length of the cut crystal material to obtain an X-ray detector.

[0060] After testing, [Pb(IQS)]... n A comparison of the mass attenuation coefficients of Cd(Zn)Te crystal, Si crystal, TiBr crystal, and α-Se to X-ray energy is attached. Figure 6 As shown.

[0061] The carrier mobility-lifetime product is commonly used to characterize carrier properties (mobility, drift length, etc.), indicating the semiconductor's ability to extract charge from its internal structure and reflecting the charge collection efficiency of the detection material. A larger carrier mobility-lifetime product value indicates higher charge collection efficiency and better photoelectric response. [Pb(IQS)] n The carrier mobility lifetime product is shown in the attached figure. Figure 7 As shown. The results show that [Pb(IQS)] n The carrier mobility lifetime product is 7.82 × 10⁻⁶. -6 cm 2 / V, a relatively large value.

[0062] High X-ray detection sensitivity indicates that a large change in X-ray induced current occurs at a given X-ray dose rate, which is beneficial for improving imaging quality. [Pb(IQS)] n The X-ray detection sensitivity is shown in the attached figure. Figure 8 As shown. The results show that [Pb(IQS)] n X-ray detection sensitivity = 18334.87 μCy air -1 cm -2 High sensitivity.

[0063] Therefore, the above tests show that the Pb(IQS) crystal compound of the present invention is suitable as a material for X-ray detectors, and has the characteristics of large mass attenuation coefficient for X-ray energy, large carrier mobility lifetime product and high X-ray detection sensitivity.

[0064] As described above, the basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments, which are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the scope of the patent and the description should still fall within the scope of the present invention. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. The use of a crystalline compound in the preparation of semiconductor materials or X-ray direct detection materials, characterized in that: The molecular formula of the crystalline compound is [Pb(IQS)]. n Among them, IQS 2- It is formed by the loss of two hydrogen atoms from 7-iodo-8-hydroxyquinoline-5-sulfonic acid; The crystalline compound belongs to the tetragonal crystal system, with space group _____. P 42bc, cell parameters are a = 17.5559 Å, b = 17.5559Å, c = 7.3135 Å, α = 90°, β = 90°, γ = 90°, Z = 8, cell volume is 2254.09(14) Å 3 .

2. The use according to claim 1, characterized in that: The method for preparing the crystalline compound is as follows: lead source, 7-iodo-8-hydroxyquinoline-5-sulfonic acid and reaction medium are added to a reactor, and a solvothermal reaction is carried out at 90-120 °C for 36-72 hours. After cooling, filtration, washing and drying, the crystalline compound is obtained.

3. The use according to claim 2, characterized in that: The lead source is selected from at least one of Pb(CH3COO)2, Pb(NO3)2, PbCl2, PbBr2 and PbI2.

4. The use according to claim 2, characterized in that: The molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 0.8-3:

1.

5. The use according to claim 4, characterized in that: The molar ratio of the lead source to the 7-iodo-8-hydroxyquinoline-5-sulfonic acid is 1-2.5:

1.

6. The use according to claim 2, characterized in that: The reaction medium is selected from water or a mixture of water-soluble organic solvent and water in a volume ratio of 9:1 to 1:

9.

7. The use according to claim 2, characterized in that: The weight ratio of the lead source to the reaction medium is 1:50-2000.

8. The use according to claim 7, characterized in that: The weight ratio of the lead source to the reaction medium is 1:100-1500.

9. The use according to claim 1, characterized in that: The semiconductor material or X-ray direct detection material is used in radiation detection metrology or X-ray semiconductor medical imaging.

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