Two-dimensional perovskite single crystal, slurry, preparation method of two-dimensional perovskite single crystal and slurry, and application of two-dimensional perovskite single crystal and slurry in integrated X-ray detector

Abstract

The invention discloses a two-dimensional perovskite single crystal, slurry, a preparation method of the two-dimensional perovskite single crystal and application of the two-dimensional perovskite single crystal and the slurry in an integrated X-ray detector, and belongs to the technical field of X-ray detection. A two-dimensional perovskite single crystal and slurry are successfully prepared through a simple preparation process, the chemical structural formula of the two-dimensional perovskite single crystal is [M (O3S-(CH2) 2-NH3) 2] PbX4, M is Cu, Zn, Ni, Co or Cd, and X is Cl or Br, meanwhile, integration of a two-dimensional perovskite active material and a functional array panel is realized, and the two-dimensional perovskite single crystal with high sensitivity, high sensitivity, high sensitivity, high sensitivity, high sensitivity, high sensitivity, high sensitivity and high stability is successfully prepared. The integrated X-ray detector is excellent in imaging quality and stable in work. The detector is low in preparation cost and can be used in the fields of industrial flaw detection and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of X-ray detection, and in particular relates to a two-dimensional perovskite single crystal, a slurry and a preparation method thereof, and an application in an integrated X-ray detector. Background Art

[0002] The unique penetrability of X-rays makes them widely used in many fields such as medical CT imaging, industrial non-destructive testing, national defense and food safety, and X-ray detectors are one of the core products to achieve the above X-ray applications. Currently, the minimum detection dose of commercial X-ray detectors is limited and cannot meet the needs of daily detection. Therefore, the development of X-ray detector materials with high sensitivity, low detection dose limit and low cost is an important research direction in the field of X-ray detection technology.

[0003] In recent years, two-dimensional perovskite materials have shown high air stability and high ion migration activation energy, while their preparation process is simple and the raw materials are cheap. This makes two-dimensional perovskite materials widely used in the field of X-ray detection, and they show extremely high working stability. However, the limited interlayer carrier transport limits its X-ray detection sensitivity; in addition, how to integrate two-dimensional perovskite materials with functionalized array panels to prepare X-ray detectors also faces severe challenges. The above factors seriously restrict the application of two-dimensional perovskite materials in commercial X-ray detectors. Therefore, it is of great significance to develop new two-dimensional perovskites to further improve interlayer carrier transport, solve the preparation process problems of their integration with functionalized array panels, and realize the preparation of integrated X-ray detectors with high sensitivity, low detection dose limit and stable operation. Summary of the invention

[0004] The purpose of the present invention is to provide a two-dimensional perovskite single crystal, slurry and preparation method thereof and application in an integrated X-ray detector. The two-dimensional perovskite single crystal, slurry preparation process and device integration process are simple; at the same time, the prepared X-ray detector has the advantages of high sensitivity, low X-ray dose detection limit, good stability and low cost.

[0005] Based on the above purpose, the present invention adopts the following technical solution: A method for preparing a two-dimensional perovskite single crystal, wherein the chemical structure of the two-dimensional perovskite single crystal is [M (O3S-(CH2)2-NH3)2]PbX4, M=Cu, Zn, Ni, Co or Cd, X=Cl or Br, and the specific preparation process is as follows: (a) HO3S-(CH2)2-NH2, MX2 and PbX2 were added to deionized water, the molar ratio of HO3S-(CH2)2-NH2 to MX2 was (1-10):1, the molar ratio of HO3S-(CH2)2-NH2 to PbX2 was (4-10):1, the concentration of 2-aminoethanesulfonic acid was 0.1-0.4 mol / L, and the solution was stirred at 50-90 °C until the solution was saturated; (b) based on the saturated solution obtained in step (a), filtering the supernatant, cooling the filtered saturated solution at a cooling rate of 5 to 15 °C / h until seed crystals are precipitated from the solution, and finally removing the seed crystals, drying them for later use; (c) filtering the saturated solution obtained in step (a), preheating the filtered saturated solution at 90-100°C for 5-15 minutes, then placing the seed crystal obtained in step (b) into the preheated saturated solution, and lowering the solution temperature at a cooling rate of 0.2-1 o C / h, and finally crystals were obtained.

[0006] The two-dimensional perovskite single crystal prepared by the above preparation method.

[0007] The method for preparing slurry using the above two-dimensional perovskite single crystal is as follows: (1) grinding the obtained crystals to obtain crystal powder; (2) Mixing the crystal powder with a solvent, wherein the concentration of the crystal powder is 0.1-0.8 g / mL; (3) Add a thickener to the slurry obtained in step (2), wherein the volume of the thickener is 1% to 15% of the volume of the solvent, and stir the slurry thoroughly for later use.

[0008] Furthermore, the solvent in step (2) is one or a mixture of any proportion of two or more of H2O, DMF, DMSO, 2-methoxyethanol, and γ-butyrolactone.

[0009] Furthermore, the thickener in step (3) is one or a mixture of any proportion of two or more of silicone oil, terpineol, and polyethylene glycol (molecular weight of 3000-10000).

[0010] The two-dimensional perovskite polycrystalline slurry is prepared by the above method.

[0011] The above-mentioned two-dimensional perovskite polycrystalline slurry is used in the preparation of an integrated X-ray detector. The two-dimensional perovskite polycrystalline slurry is coated on a substrate, annealed, and the spin coating and annealing steps are repeated if necessary until a two-dimensional perovskite film of a target thickness is obtained, and an anode is prepared on the two-dimensional perovskite film.

[0012] Preferably, the substrate is one of TFT or CMOS.

[0013] Preferably, the annealing temperature is 100-150°C, and the thickness of the two-dimensional perovskite film is 0.1-1.2 mm.

[0014] Preferably, the anode is one of Cr, Au, Ag, and Cu, and the thickness of the anode is 60-120 nm.

[0015] The two-dimensional perovskite single crystal, slurry, preparation method thereof and application in integrated X-ray detector provided by the present invention have the following advantages compared with the existing technology: The two-dimensional perovskite single crystal [M(M=Cu, Zn, Ni, Co, Cd) (O3S-(CH2)2-NH3)2]PbX4(X=Cl, Br) described in the present invention can be prepared in large quantities by a seed crystal assisted cooling method, and the crystal has high quality, large size and excellent performance.

[0016] The two-dimensional perovskite [M(M=Cu, Zn, Ni, Co, Cd) (O3S-(CH2)2-NH3)2]PbX4(X=Cl, Br) slurry described in the present invention can be prepared in large quantities by directly mixing and stirring the two-dimensional perovskite single crystal powder with a solvent and a thickener. The slurry is suitable for preparing integrated X-ray detectors by scraping, meeting practical application requirements.

[0017] The integrated X-ray detector based on two-dimensional perovskite [M(M=Cu, Zn, Ni, Co, Cd) (O3S-(CH2)2-NH3)2]PbX4(X=Cl, Br) of the present invention has a high sensitivity of 120 Vmm -1 The device has low dark current and dark current drift under high field strength, showing excellent stability. -1 The sensitivity to 50 keV X-rays is as high as 7020 μC Gy-1 air cm -2 , the lowest detectable X-ray dose is 817.5 nGy air s -1 , which is much lower than the currently commercially available α-Se X-ray detectors. In addition, the imaging resolution of the detector reaches 2.2 lp mm -1 Finally, the detector has a simple preparation process, low cost and high commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1This is the powder XRD spectrum and theoretical XRD diffraction peak of the two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 slurry after drying described in the present invention. The slurry shows excellent phase purity. The inset is the corresponding new two-dimensional perovskite slurry.

[0019] Figure 2 Schematic diagram of the structure of the prepared integrated X-ray detector, which includes an anode 1, a two-dimensional perovskite [M(M=Cu, Zn, Ni, Co, Cd) (O3S-(CH2)2-NH3)2]PbX4(X=Cl, Br) thin film active layer 2, and a TFT substrate 3.

[0020] Figure 3 This is the dark current stability test of the prepared [Cu(O3S-(CH2)2-NH3)2]PbCl4 thin film device. The horizontal axis is time and the vertical axis is the dark current of the device.

[0021] Figure 4 This is the sensitivity test of the prepared [Cu(O3S-(CH2)2-NH3)2]PbCl4 thin film integrated device to X-rays. The horizontal axis is the X-ray dose rate and the vertical axis is the device response current density.

[0022] Figure 5 This is the X-ray imaging of the [Cu(O3S-(CH2)2-NH3)2]PbCl4 thin film integrated device against the standard lead wire pair card. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] The present invention provides a two-dimensional perovskite single crystal, a slurry preparation method and applications thereof in an integrated X-ray detector. Figure 1 Shown is the powder XRD and theoretical XRD comparison of the [Cu(O3S-(CH2)2-NH3)2]PbCl4 perovskite slurry after drying. The results show that the prepared [Cu(O3S-(CH2)2-NH3)2]PbCl4 perovskite slurry maintains good phase purity.

[0025] Embodiment 1: This embodiment provides a method for preparing a two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 single crystal, and the specific steps are as follows: (a) 2-aminoethanesulfonic acid (HO3S-(CH2)2-NH2), CuCl2 metal halide and lead halide PbCl2 are added to deionized water, the molar ratio of 2-aminoethanesulfonic acid to CuCl2 is 5:1, the molar ratio of 2-aminoethanesulfonic acid to PbCl2 is 6:1, and the concentration of 2-aminoethanesulfonic acid is 0.2 mol / L, and stirred at 70°C until a saturated solution is obtained; (b) Based on the saturated solution obtained in step (a), the supernatant is filtered, and the filtered saturated solution is cooled at a cooling rate of 10°C / h until seed crystals are precipitated from the solution, and the seed crystals are removed and dried for later use; (c) The saturated solution obtained in step (a) is filtered, and the filtered saturated solution is preheated on a hot plate at 100°C for 10 min, and then the seed crystal obtained in step (b) is slowly placed into the saturated solution, and the solution temperature is slowly lowered at a cooling rate of 0.5°C / h to finally obtain a crystal with a length × width × height of 3 mm × 2 mm × 0.7 mm.

[0026] Embodiment 2: This embodiment provides a method for preparing a two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 slurry, and the specific steps are as follows: (1) Grind the prepared crystals to obtain crystal powder, which is then set aside.

[0027] (2) Mixing the [Cu(O3S-(CH2)2-NH3)2]PbCl4 crystal powder obtained in step (1) with H2O, the single crystal powder concentration being 0.4 g / mL; (3) Add silicone oil (viscosity 10000 cSt, 25°C) as thickener to the slurry obtained in step (2). The volume of the thickener introduced is 2% of the volume of the solvent. Then, stir the slurry thoroughly for later use.

[0028] Embodiment 3: This embodiment provides a method for preparing a two-dimensional perovskite [Cu(O2C-CH2-NH2)2]Pb2Cl4 thin film integrated X-ray detector, and the specific steps are as follows: (a) The two-dimensional perovskite slurry [Cu(O3S-(CH2)2-NH3)2]PbCl4 is deposited on the TFT backplane substrate by blade coating; (b) performing a hot-pressing assisted pre-annealing treatment on the two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 film obtained in step (a), wherein the pre-annealing temperature is 70 °C and the annealing time is 20 min; (c) Based on the two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 film obtained in step (b), step (a) and step (b) are continued to be cycled twice, and finally the prepared perovskite film is annealed on a hot plate at 120°C for 30 min. The thickness of the two-dimensional perovskite film is 0.5 mm; (d) Based on the two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 film obtained in step (c), an anode Au with a thickness of 80 nm is prepared on its upper surface by thermal evaporation, and finally an integrated X-ray detector with a structure of TFT / [Cu(O3S-(CH2)2-NH3)2]PbCl4 film / anode is obtained.

[0029] Figure 2 The schematic diagram of the structure of the prepared [M(M=Cu, Zn, Ni, Co, Cd) (O3S-(CH2)2-NH3)2]PbX4(X=Cl, Br) thin film integrated X-ray detector. The detector includes: an anode 1, which can be one of Cr, Au, Ag or Cu, and the present application takes the Au anode as an example; a two-dimensional perovskite thin film active layer 2; and a TFT backplane 3.

[0030] Figure 3 The dark current stability test data of the two-dimensional perovskite [Cu(O3S-(CH2)2-NH3)2]PbCl4 thin film device show that at 120 V mm -1 The device continued to work for 3500 s under a field strength of , and the dark current drift was only 1.2×10 -9 nV - 1 mm -1 s -1 , showing excellent working stability and negligible ion movement, which is very beneficial for low-dose X-ray detection.

[0031] Figure 4 Integrated X-ray detector for [Cu(O3S-(CH2)2-NH3)2]PbCl4 thin film at 120 V mm -1 The response data of 50 keV X-rays under a field strength of 1.5 keV can be seen in this embodiment. The sensitivity of the integrated X-ray detector prepared by the present invention is as high as 7020 μC Gy-1 air cm -2 , far exceeding the commercial α-Se X-ray detector (20 μC Gy-1 air cm -2 ). Therefore, the integrated X-ray detector prepared by the present invention has broad application prospects in the fields of industrial flaw detection and the like.

[0032] Figure 5The X-ray imaging performance test of the [Cu(O3S-(CH2)2-NH3)2]PbCl4 thin film integrated X-ray detector shows that the imaging resolution of the integrated X-ray detector prepared by the present invention can reach 2.2 lp mm -1 .

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a two-dimensional perovskite single crystal, characterized in that: The chemical structure of the two-dimensional perovskite single crystal is [M (O3S-(CH2)2-NH3)2]PbX4, M=Cu, Zn, Ni, Co or Cd, X=Cl or Br, and the specific preparation process is as follows: (a) HO3S-(CH2)2-NH2, MX2 and PbX2 were added to deionized water, the molar ratio of HO3S-(CH2)2-NH2 to MX2 was (1-10):1, the molar ratio of HO3S-(CH2)2-NH2 to PbX2 was (4-10):1, the concentration of 2-aminoethanesulfonic acid was 0.1-0.4 mol / L, and the solution was stirred at 50-90 °C until the solution was saturated; (b) based on the saturated solution obtained in step (a), filtering the supernatant, cooling the filtered saturated solution at a cooling rate of 5 to 15 °C / h until seed crystals are precipitated from the solution, and finally removing the seed crystals, drying them for later use; (c) filtering the saturated solution obtained in step (a), preheating the filtered saturated solution at 90-100° C. for 5 min to 15 min, then placing the seed crystal obtained in step (b) into the preheated saturated solution, and lowering the solution temperature at a cooling rate of 0.2 to 1 o C / h, and finally crystals were obtained.

2. The two-dimensional perovskite single crystal obtained by the preparation method according to claim 1.

3. A method for preparing slurry using the two-dimensional perovskite single crystal according to claim 2, characterized in that: The process is as follows: (1) grinding the obtained crystals to obtain crystal powder; (2) Mixing the crystal powder with a solvent, wherein the concentration of the crystal powder is 0.1-0.8 g / mL; (3) Add a thickener to the slurry obtained in step (2), wherein the volume of the thickener is 1% to 15% of the volume of the solvent, and stir the slurry thoroughly for later use.

4. The method according to claim 3, characterized in that The solvent is one of H2O, DMF, DMSO, 2-methoxyethanol, and γ-butyrolactone, or a mixture of two or more of them in any proportion.

5. The method according to claim 3, characterized in that: The thickener is one of silicone oil, terpineol and polyethylene glycol or a mixture of two or more of them in any proportion.

6. A two-dimensional perovskite polycrystalline slurry prepared by the method according to any one of claims 3 to 5.

7. Use of the two-dimensional perovskite polycrystalline slurry according to claim 6 in preparing an integrated X-ray detector, characterized in that: The two-dimensional perovskite polycrystalline slurry is coated on a substrate and annealed to obtain a two-dimensional perovskite film, and an anode is prepared on the two-dimensional perovskite film.

8. The use according to claim 7, characterized in that: The substrate is TFT or CMOS.

9. The use according to claim 7, characterized in that: The annealing temperature is 100~150 ℃, and the thickness of the two-dimensional perovskite film is 0.1~1.2 mm.

10. The use according to claim 7, characterized in that: The anode is one of Cr, Au, Ag and Cu, and the thickness of the anode is 60-120 nm.

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