One-dimensional hybrid perovskite single crystal based on tryptamine ions and pressed sheet, preparation method and application in preparing X-ray imaging plate

Abstract

A one-dimensional hybrid perovskite single crystal and tablet based on tryptamine ions, a preparation method thereof, and an application thereof in the preparation of an X-ray imaging plate, belonging to the technical field of X-ray imaging. The perovskite tablet material based on tryptamine ions provided by the present invention can achieve a reversible transformation between one-dimensional and two-dimensional dimensions. Due to the strong hydrophobic interaction between organic cations of tryptamine ions and the defect-free perovskite structure with microstrain relaxation, the hybrid perovskite material has super water stability, realizes aqueous-phase processing directly on the surface of the perovskite material, and further prepares an X-ray imaging plate with microarray pixel points through ultraviolet lithography of microarray electrodes. The sensitivity of the X-ray imaging plate under 120 kV hard X-rays is as high as 106129 μC / Gy air / cm 2 , the minimum detection limit reaches 5 nGyair / s, and the imaging resolution reaches 3.0 lp / mm.

Description

Technical Field

[0001] The invention belongs to the technical field of X-ray imaging, and in particular relates to a one-dimensional hybrid perovskite single crystal and a pressed sheet based on tryptamine ions, a preparation method and an application in preparing an X-ray imaging plate. Background Art

[0002] Sensitive and stable X-ray detectors have been widely used in our daily life and military applications, such as medical imaging, security inspection, academic research, industrial product quality inspection, etc. However, their sensitivity is still unsatisfactory considering the high doses applied in X-ray generators and the subsequent damage to the human body. Although scintillators are more compatible with commercial readout systems and dominate the current market, semiconductors in direct detection mode are attractive for higher spatial resolution and lower dose X-ray imaging. Conventional semiconductors such as silicon (Si) and amorphous selenium (a-Se) have limited absorption of hard X-rays, thus resulting in low sensitivity. Cadmium zinc telluride (CdZnTe) and high-purity germanium (Ge) single crystals are usually obtained by the Bridgman method, which is difficult to control their intrinsic defects and subsequent integration on large-area readout circuit substrates in a low-cost manner. High-purity germanium must even be operated in a liquid nitrogen atmosphere, which greatly limits the development of X-ray detectors in direct detection mode.

[0003] Halide perovskite X-ray detectors have seen unprecedented development in recent years due to their strong stopping power, large charge carrier mobility (μ) and charge carrier lifetime (τ) product (μτ product), and tunable compositions to meet desired physical / chemical properties. Their single-crystalline counterparts can be grown via low-cost solution processes with abundant raw materials. The low trap density of perovskite single-crystalline devices enables higher sensitivity than conventional a-Se detectors, and their corresponding μτ values ​​are even comparable to those of state-of-the-art conventional CdZnTe single crystals. However, the commercialization of growing large-area perovskite single crystals for X-ray flat panels from low-cost solution processes is limited due to time-consuming and reproducibility issues. To target practical X-ray imaging applications, large-area perovskite sheets, sintered sheets, and scraped polycrystalline films with different compositions have shown promising performance in a more rapid and economical manner, although their sensitivity is lower than their single-crystalline counterparts due to the inevitable lattice microstrain during crystallization and processing. In addition, the ionic nature of perovskite materials leads to inherent instability in water, moisture, electric fields, and other complex conditions. Along with structural instability, the polarization effect known as ion migration can seriously cause leakage current drift, and the photoelectric signal will also be damaged and submerged in noise fluctuations during low-dose detection. Low-dimensional perovskites (including two-dimensional (2D), one-dimensional (1D) and zero-dimensional (0D) structures), whose inorganic skeletons are separated by organic cations, are effective in suppressing ion migration and improving their water stability. But at the same time, long-chain organic cations are partially harmful to efficient charge carrier collection. In addition, the water stability or long-term water stability of perovskite materials remains one of the biggest challenges in building future commercial multifunctional optoelectronic devices, which also limits its compatibility with many powerful and typical semiconductor technologies, such as lithography, wet etching, ion implantation, crystal polishing, etc. Summary of the invention

[0004] The purpose of the present invention is to provide a one-dimensional hybrid perovskite single crystal based on tryptamine ions and a pressed sheet, a preparation method and an application of the same in the preparation of an X-ray imaging plate.

[0005] The present invention provides a one-dimensional TA4Pb3I based on tryptamine ions. 10 Hybrid perovskite single crystal and pressed sheet and two-dimensional TA2PbI4 hybrid perovskite crystal and pressed sheet. The perovskite pressed sheet material based on tryptamine ions can achieve reversible transformation in two dimensions. Heating can make one-dimensional TA4Pb3I 10 The pressed material of the hybrid perovskite is converted into a two-dimensional TA2PbI4 hybrid perovskite material. Water treatment can convert the two-dimensional TA2PbI4 hybrid perovskite material into a one-dimensional TA4Pb3I 10Hybrid perovskite material. In addition, we demonstrated that the structural microstrain of the material was gradually relaxed during the reversible transformation of the tryptamine ion-based perovskite sheet material in two dimensions. Due to the strong hydrophobic forces between organic cationic tryptamine ions and the defect-free perovskite structure with relaxed microstrain, the hybrid perovskite material has super strong water stability, which enables direct water phase processing on the surface of the perovskite material, and further prepares an X-ray imaging plate with microarray pixels by ultraviolet etching of microarray electrodes. The sensitivity of this X-ray imaging plate is as high as 106129 μC / Gy under 120 kV hard rays. air / cm 2 The minimum detection limit reached 5 nGyair / s and the imaging resolution reached 3.0 lp / mm.

[0006] The method for synthesizing tryptamine iodine (TAI) of the present invention comprises the following steps:

[0007] (a) Weigh 1:1 molar ratio of tryptamine (TA) and HI (aq), then dissolve TA in ethanol (EtOH) and stir magnetically to dissolve it completely;

[0008] (b) placing the solution obtained in step (a) under an ice bath, and dripping HI (aq) into the solution dropwise, stirring continuously for 2 to 8 hours, and rotary evaporating the reaction solution to dryness;

[0009] (c) dissolving the dried product obtained in step (b) in a small amount of ethanol under reflux, cooling it after it is completely dissolved, and slowly precipitating it with dichloromethane anti-solvent;

[0010] (d) filtering the precipitate obtained in step (c) and drying it;

[0011] (e) Repeat the recrystallization operation of steps (c) to (d) 2 to 3 times;

[0012] (f) drying the product of step (e) to obtain tryptamine iodine (TAI);

[0013] The one-dimensional TA4Pb3I 10 The controllable growth method of a single crystal (1D single crystal) comprises the following steps:

[0014] (a) TAI and PbI2 were weighed in a molar ratio of 2:1 and then added into acetonitrile (ACN) in sequence;

[0015] (b) subjecting the solution obtained in step (a) to ultrasonic treatment at room temperature until the solution is completely dissolved, and filtering to obtain a clear solution;

[0016] (c) The clarified solution obtained in step (b) is allowed to stand at 20-70°C for 1-10 h, during which crystals are precipitated from the solution, namely, one-dimensional TA4Pb3I 10 Single crystal (triclinic P system, a=9.48, b=11.83, c=13.71; α=75.258, β=83.018, γ=78.937; density ρ=2.891g / cm 3 ).

[0017] The controllable growth method of the two-dimensional TA2PbI4 crystal (2D crystal) of the present invention comprises the following steps:

[0018] (a) TAI and PbI2 were weighed in a molar ratio of 2:1 and then added into acetonitrile (ACN) in sequence;

[0019] (b) subjecting the solution obtained in step (a) to ultrasonic treatment at room temperature until the solution is completely dissolved, and filtering to obtain a clear solution;

[0020] (c) adding ethyl acetate (EA) in an amount of 1 to 10 times the volume of acetonitrile to the clear solution obtained in step (b), mixing the mixture evenly to obtain a uniform solution;

[0021] (d) The uniform solution obtained in step (c) is allowed to stand at 20-70°C for 3-60 min, during which time crystals are precipitated from the solution, namely, two-dimensional TA2PbI4 crystals ( Figure 1 The photo on the lower right side in a shows that a 2D crystal is obtained; Figure 1 The XRD peak positions in b are 5, 10, 15, 20, 25, and 30 degrees, which are typical peak characteristics of two-dimensional layered materials).

[0022] The one-dimensional TA4Pb3I 10 The perovskite material, through single crystal structure testing and theoretical optimization, directly proved for the first time that the organic cationic tryptamine ion is directly involved in the band edge construction of the perovskite material. The specific experiment is as follows:

[0023] (a) obtaining a 1D single crystal according to the controllable growth method of a 1D single crystal as described above in the present invention;

[0024] (b) From the single crystals obtained in step (a), a perfect crystal without bubbles, cracks, or impurities is selected under a microscope, and a single crystal X-ray diffraction test is performed. The obtained results are subjected to single crystal analysis to obtain microscopic crystal structure data of the 1D single crystal;

[0025] (c) importing the crystal structure data obtained in step (b) into the VASP calculation software to perform structure optimization through density functional theory (DFT);

[0026] (d) Import the optimized structure obtained in step (c) into the VESTA software, and the differential charge distribution of the crystal microstructure can be seen (e.g. Figure 4 and Figure 5 As shown in Figure 2), from the differential charge distribution, it can be determined that the organic cation TA participates in the one-dimensional TA4Pb3I 10 The construction of the band edge structure of perovskite materials. This makes it easier to regulate the band edge structure of perovskite materials by adjusting the intermolecular forces, and the direct participation of organic cations in the band edge construction greatly improves the charge transport capacity of the perovskite material.

[0027] The 1D perovskite material and the 2D perovskite material of the present invention can achieve reversible dimensional transformation. After the perovskite material based on tryptamine ions is pressed, the microstrain increases significantly. The pressed material is heated and water-immersed to cause the dimensional transformation. In the process of dimensional transformation, the microstrain is gradually relaxed and eventually stabilized. The specific experiment is as follows:

[0028] (a) The obtained one-dimensional TA4Pb3I 10 The single crystal (1D single crystal) was dried and ground to obtain one-dimensional TA4Pb3I 10 Perovskite powder (1D powder), completely dried;

[0029] (b) Weigh a certain amount of one-dimensional TA4Pb3I 10 Perovskite powder (1D powder) is evenly sprinkled into the tablet press mold for extrusion molding, and demolding to obtain a one-dimensional TA4Pb3I with a certain shape and thickness. 10 Perovskite tablet material (A-1D tablet);

[0030] (c) The one-dimensional TA4Pb3I 10 The perovskite pressed material (A-1D pressed material) was heated at 120-150 °C for 2-10 hours. The color of the perovskite pressed material changed from light yellow-green to orange-yellow. XRD test confirmed that the color change represented the one-dimensional TA4Pb3I 10 The perovskite sheet material (A-1D sheet) is transformed into a two-dimensional TA2PbI4 perovskite sheet material (T-2D sheet) under heating;

[0031] (d) Soaking the two-dimensional TA2PbI4 perovskite pressed material obtained in step (c) in water, or by steam fumigation, to achieve the conversion of the two-dimensional TA2PbI4 perovskite pressed material into a one-dimensional TA4Pb3I 10 The dimensional transformation of the perovskite sheet material can be observed by changing the color of the perovskite sheet material from orange-yellow to light yellow-green, and the XRD test further confirms this transformation;

[0032] (e) The dimensional reversible transformation process of step (c) and step (d) is performed 1 to 8 times, and finally the perovskite sheet material is stabilized in one-dimensional TA4Pb3I 10 Perovskite tablet material (F-1D tablet) status;

[0033] (f) The reversible conversion process of step (c) and step (d) was monitored by XRD test, and the XRD data (such as Figure 2 b and Figure 3 b) performing fitting processing, we found that after the perovskite material was extruded, it induced a larger internal microstrain, and observed that during the reversible conversion process of step (c) and step (d), the internal microstrain had a continuous relaxation process and eventually stabilized, reaching a perfect stable structure with almost no internal microstrain, which achieved the high performance of the X-ray imaging plate of the present invention;

[0034] (g) The one-dimensional TA4Pb3I obtained in step (e) 10 The perovskite tablet material (F-1D tablet) can be stable for several months without decomposition when immersed in water.

[0035] The direct photolithography preparation steps of the X-ray imaging plate of the present invention are as follows:

[0036] (a) In one-dimensional TA4Pb3I 10 The upper and lower surfaces of the perovskite sheet material (F-1D sheet) are respectively deposited with Au electrodes with a thickness of 50-80 nm;

[0037] (b) Spin coating a positive photoresist aqueous solution on the Au electrode surfaces on both sides of the pressed material at 2000-4000 rpm for 20-40 s, and annealing at 80-90 °C for 20-40 min in the dark;

[0038] (c) placing the pressed sheet material obtained in step (b) under a mercury lamp of a UV lithography machine (wavelength of 365 nm, power of 350 W), and exposing the Au electrode on one side of the pressed sheet material under a mask of a gridded microarray pattern mask (the shading area is a square grid with a side length of 100 to 300 μm or a circular grid with a diameter of 100 to 300 μm) for 10 to 15 s;

[0039] (d) soaking the pressed material obtained in step (c) in a sodium hydroxide solution having a mass fraction of 0.5% to remove the positive photoresist that has undergone exposure reaction, shaking for 5 to 10 seconds, taking it out, immediately rinsing it with running water for 20 to 30 seconds, and then drying it with N2;

[0040] (e) immersing the pressed material obtained in step (d) in a gold etching solution to remove the Au electrode layer without photoresist protection, taking it out after 15 to 30 seconds, immediately rinsing it with running water for 20 to 30 seconds, and then drying it with N2 to obtain a pressed material with a gridded microarray pattern Au electrode on one surface;

[0041] (f) soaking the pressed material obtained in step (e) in an ethanol solution for 1 to 2 minutes, taking it out and immediately rinsing it with running water for 20 to 30 seconds and then drying it with N2 to remove the positive photoresist coated on the surface of the Au electrodes on both sides of the pressed material that has not undergone exposure reaction;

[0042] (g) heating the pressed sheet material obtained in step (f) at 90-110° C. to dry it, thereby obtaining an X-ray array imaging plate.

[0043] The steps of X-ray imaging described in the present invention are as follows:

[0044] (a) Customized probes with the same size and spacing as the grid-shaped microarray pattern Au electrodes in the X-ray array imaging plate;

[0045] (b) placing the probes of step (a) in close contact with the Au electrodes in the X-ray array imaging plate one by one;

[0046] (c) Fix the probe connected to the X-ray imaging board in step (b) on a circuit board that reads the Au electrode signal by collecting fixed-value resistor voltage divider through pin headers and cables, and introduce the signal into the NI-9205 acquisition card;

[0047] (d) placing the X-ray imaging plate connected in step (c) directly below the X-ray source in the X-ray cabin, and placing the object to be measured directly above the X-ray imaging plate and close to the X-ray imaging plate; turning on the X-ray generator to irradiate the object to be measured with X-rays, and using the NI-9205 acquisition card to read the signal values ​​of each Au electrode of the X-ray imaging plate when the X-rays are irradiated;

[0048] (e) The signal values ​​of each Au electrode obtained in step (d) are imported into Matlab software for image visualization processing, and the transmission image of the object under X-ray can be obtained, thereby completing X-ray imaging.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] The sensitivity of the tryptamine ion-based perovskite X-ray detector described in the present invention is as high as 96480 μC / Gy under 120 keV hard rays. air / cm 2The minimum detection limit reached 5 nGyair / s. It has a series of advantages such as high detection performance and high-quality X-ray imaging applications, which has made unprecedented breakthroughs in the commercial processing and integration of perovskite materials and solved the problem of water immersion stability of perovskite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 a is a schematic diagram and crystal photo of the growth of one-dimensional and two-dimensional perovskite single crystals based on tryptamine ions. As shown in the figure, when slowly crystallized, the perovskite precursor solution based on tryptamine ions precipitates a one-dimensional single crystal TA4Pb3I 10 , and when rapidly crystallized, the precursor solution precipitates two-dimensional crystals TA2PbI4;

[0052] Figure 1 b is Figure 1 a The corresponding powder X-ray diffraction structure data diagram, the upper curve in the figure is the powder XRD diffraction diagram of a one-dimensional single crystal, and the lower curve in the figure is the powder XRD diffraction diagram of a two-dimensional crystal, which is a typical characteristic peak of a two-dimensional growth crystal;

[0053] Figure 2 a is a photo of the dimensional transformation between the one-dimensional perovskite single crystal, powder and pressed sheet based on tryptamine ions. The left photo is a comparison of the one-dimensional single crystal before and after heating at 120°C for 4 hours. After heating, the yellow-green crystal turns into brown crystal; the middle photo is a comparison of the one-dimensional perovskite powder before and after heating for 4 hours. After heating, the light yellow-green powder turns into orange; the right photo is a comparison of the one-dimensional perovskite pressed sheet before and after heating for 4 hours. After heating, the yellow-green pressed sheet turns into orange, and the A-1D pressed sheet is converted to T-2D pressed sheet (heating); after hydrolysis of the T-2D pressed sheet, the color changes from orange to yellow-green, and the T-2D pressed sheet is converted to F-1D pressed sheet (water immersion); unlike single crystals and powders, we found that the perovskite pressed sheet can undergo a limited number of reversible dimensional transformations from one-dimensional to two-dimensional and from two-dimensional to one-dimensional;

[0054] Figure 2 b is Figure 2 a is the data diagram of the powder XRD diffraction of the one-dimensional perovskite tablet that undergoes a reversible dimensional transformation. From the figure, it can be seen that the characteristic peaks of the two-dimensional perovskite appear and enhance after heating and disappear after water immersion; T-2D tablet (heating) means that it is obtained by heating the A-1D tablet, and F-1D tablet (water immersion) means that it is obtained by water immersion the T-2D tablet; the dimensional transformation will finally stabilize in the F-1D state, and even if it is heated again, it will no longer become a two-dimensional tablet, that is, Figure 2 b The state corresponding to the top curve F-1D (heating).

[0055] Figure 3a is a photo of the process of a one-dimensional perovskite based on tryptamine ions changing from powder state to extrusion molding to a one-dimensional perovskite tablet, and the reversible dimensional transformation of the perovskite tablet under heating and water immersion treatment, as well as a schematic diagram of the microstrain relaxation process. From the figure, we can see that the powder state perovskite material obtained by crystal grinding is free of microstrain. When the perovskite powder is extruded into a tablet material, the external extrusion force brings anisotropic microstress inside the structure, resulting in a large microstrain inside the structure ( Figure 3 The microstrain data listed in b can prove that when we heat and water-immerse the pressed material for dimensional transformation, the microstrain is gradually relaxed, and the internal crystal structure of the material reaches a near-perfect state;

[0056] Figure 3 b is a characterization data diagram of microstrain relaxation during the reversible dimensional transformation of a one-dimensional perovskite sheet based on tryptamine ions; it can be seen from the figure that the microstrain of the perovskite material based on tryptamine ions has increased significantly after the sheet is pressed, and the microstrain is gradually relaxed and eventually stabilized during the process of heating and water immersion of the sheet material to make it undergo dimensional transformation;

[0057] Figure 4 a is the differential charge distribution diagram after the structure optimization of the one-dimensional perovskite material based on tryptamine ions; from the charge distribution in the figure, we can see that the organic cation tryptamine ions contribute to the valence band of the one-dimensional perovskite material, proving that the organic cation tryptamine ions participate in the construction of the band edge structure of the one-dimensional perovskite, which is consistent with the reported article ( Science , 375, 6583 (2022)) mentioned that the organic cations affect the band edge structure but do not directly participate in the construction of the perovskite band edge;

[0058] Figure 4 b is the differential charge distribution diagram of the two-dimensional perovskite material based on tryptamine ions after structural optimization; from the charge distribution in the figure, we can see that the band edge structure of the two-dimensional perovskite material based on tryptamine ions has no direct participation of organic cationic tryptamine ions, and the band edge structure is only related to the inorganic octahedron Pb-I of the perovskite;

[0059] Figure 4 c is the energy band spectrum of the one-dimensional perovskite material after structure optimization based on tryptamine ions; from the figure we can see that the one-dimensional perovskite is a direct band gap material, and its band gap width is 2.8eV;

[0060] Figure 4 d is the energy band spectrum of the optimized structure of the two-dimensional perovskite material based on tryptamine ions; from the figure we can see that the two-dimensional perovskite is a direct band gap material, and its band gap width is 2.24eV;

[0061] Figure 5 a is the fluorescence emission spectrum of the tryptamine ion-based perovskite sheet material during the dimensional transformation process; from the figure, it can be seen that the fluorescence intensity of the one-dimensional perovskite material (A-1D sheet and F-1D sheet) is very weak, almost in the fluorescence quenching state, but the fluorescence intensity of the two-dimensional perovskite material (T-2D sheet) is much higher than that of the one-dimensional one;

[0062] Figure 5 b is based on Figure 5 aThe change of fluorescence intensity and Figure 4 Schematic diagram of the mechanism of almost quenched one-dimensional fluorescence and strong two-dimensional fluorescence intensity, which is derived from the conclusion of band edge structure construction; in one-dimensional perovskite materials, excited electrons undergo more non-radiative transition processes such as energy dissipation when returning to the ground state, which makes the fluorescence intensity of radiative transition almost quenched, while the radiative transition process of two-dimensional perovskite materials is far more than non-radiative transition, so it has stronger fluorescence intensity;

[0063] Figure 5 c and d are diagrams showing the molecular forces in the structure of one-dimensional perovskite materials based on tryptamine ions. By importing the single crystal structure into Maestro software, the forces are visualized using the software's built-in functions. The force lines and action distances in the figure prove that there are multiple strong Pi forces between organic cation tryptamine ions, and the one-dimensional perovskite molecules based on tryptamine ions are arranged very closely, which is conducive to charge transfer.

[0064] Figure 6 The data graph is a graph showing the change in fluorescence intensity of a one-dimensional perovskite sheet material based on tryptamine ions during the dimensional transformation to a two-dimensional perovskite sheet material and the corresponding change in molecular arrangement. From the trend of change in the graph, it can be concluded that the reason why the one-dimensional perovskite has a very weak fluorescence intensity that is almost quenched is due to the face-to-face close stacking of organic cationic tryptamine ions. This face-to-face close stacking produces an aggregation-induced quenching effect, which almost quenches the fluorescence intensity. The fluorescence intensity of the two-dimensional perovskite material is greatly increased because when the perovskite sheet material is heated, due to the internal stress and microstress brought about by the extrusion forming process, the organic cationic tryptamine ions undergo greater thermal vibrations and stabilize in a two-dimensional structural state that is more loosely arranged than the one-dimensional structure. From the intermolecular forces shown in the figure, we can also see that the heating process destroys the face-to-face close stacking of tryptamine ions, which is a relatively loose arrangement, so that there is no aggregation-induced quenching effect in this two-dimensional state, and the fluorescence intensity is greatly increased.

[0065] Figure 7 a is a diagram in which each hydrogen in a different chemical environment of the tryptamine ion is labeled with a different letter;

[0066] Figure 7 b is a characterization diagram of the 1D selective NOESY test of the tryptamine ion-based perovskite material in a deuterated acetonitrile solution when different equivalents of deuterated water were added for titration experiments. We excited the hydrogen atom b with a chemical shift of 3.2ppm in the figure. From the figure, we can see that with the increase in the amount of deuterated water added, the correlation peaks of hydrogen i and hydrogen d gradually increase and tend to stabilize, proving that the addition of water will not only not decompose the perovskite material, but also make the arrangement of the perovskite material more compact. This proves that our tryptamine ion-based perovskite material is a water-stable material, and also explains why the two-dimensional material is transformed into one-dimensional during the water immersion process because the water drives the arrangement of the organic cationic tryptamine ions to become more compact, promoting the structural transformation;

[0067] Figure 7 c is a schematic diagram of the dimensional transformation process of one-dimensional and two-dimensional perovskites based on tryptamine ions. From the figure, we can see that the organic cation part of the one-dimensional perovskite material based on tryptamine ions presents a tightly packed stacking mode. When subjected to heat treatment, this stacking mode is transformed into a relatively loose two-dimensional arrangement mode based on tryptamine ions, accompanied by the occurrence of a dimensional transformation from A-1D to T-2D. Finally, when this relatively loose arrangement mode is subjected to water immersion treatment, driven by strong hydrophobic forces, the relatively loose two-dimensional stacking mode is transformed into a tighter one-dimensional stacking mode, which also brings about a dimensional transformation from T-2D to F-1D.

[0068] Figure 8 a is a characterization diagram of the thermal stability of one-dimensional and two-dimensional perovskite sheet materials based on tryptamine ions at various stages of dimensional transformation; it can be seen from the figure that the thermal decomposition temperature of tryptamine iodine TAI is only 131°C, while the thermal decomposition temperatures of perovskite materials A-1D, T-2D, and F-1D based on tryptamine ions have been greatly improved, reaching 217°C, 235°C, and 242°C, respectively, and it can be clearly seen that the thermal decomposition temperature of the directly prepared one-dimensional sheet (A-1D) material is 217°C, which is lower than the 242°C of the one-dimensional sheet material (F-1D) after the dimensional transformation process. This is also a major advantage brought by the fact that our material can undergo a dimensional transformation process and relax micro-strain. During the dimensional transformation and strain relaxation process, the material repairs some defect states, making the material more stable, thus achieving a higher performance X-ray detector imaging plate;

[0069] Figure 8b is a hardness characterization diagram of the classic pure inorganic perovskite cesium silver bismuth bromide (Cs2AgBiBr6) tablet, the classic organic-inorganic hybrid three-dimensional perovskite methylamine lead iodine (MAPbI3) tablet, the classic organic-inorganic hybrid two-dimensional perovskite phenylethylamine lead iodine (PEA2PbI4) tablet, and the one-dimensional two-dimensional perovskite tablet material based on tryptamine ions at various stages of dimensional transformation (A-1D, T-2D and F-1D). From the figure, it can be seen that the hardness of the perovskite tablet material based on tryptamine ions is generally higher than that of the classic reported materials, which also shows that the perovskite material based on tryptamine ions itself has fewer lattice defect states. And from the figure, it can be seen that the hardness of the A-1D, T-2D and F-1D tablet materials gradually increases, which also shows that the strain relaxation process does occur during the dimensional transformation process, which makes up for some lattice defects and achieves high-performance X-ray detector imaging plates;

[0070] Fig. 9 a is the X-ray sensitivity of the one-dimensional perovskite sheet material (F-1D) based on tryptamine ions at different immersion times (measure the current output by each Au electrode pixel on the imaging plate under a specific radiation dose. The area of ​​the Au electrode pixel is known, and the current density of each pixel can be obtained (nA / cm 2 ); Set 5 to 7 X-rays with different dose rates to irradiate the imaging plate, and obtain 5 to 7 corresponding current densities. Use this current density to plot the X-ray dose rate (μGy / s), and use linear fitting. The slope × 1000 is the sensitivity of the material to the X-ray response curve. It can be seen from the figure that with the increase of water immersion time, the radiation performance of the detector imaging plate has not decayed, but has increased to a small extent.

[0071] Fig. 9 b is the X-ray sensitivity change curve of the one-dimensional perovskite sheet material based on tryptamine ions before and after the dimensional transformation at different working temperatures. It can be seen from the figure that with the increase of working temperature, the X-ray detection performance of the A-1D sheet decreases, and the absolute value of the sensitivity at different temperatures is less than 5×10 4 μC Gy -1 cm -2 , while the X-ray detection performance of the F-1D pressed sheet that has undergone the dimensional transformation process has not weakened with the increase of temperature, but has increased to a certain extent. In addition, the absolute value of the sensitivity is also greater than that of A-1D, reaching 7×10 4 μC Gy -1 cm -2 above;

[0072] Fig.10a is a photo of an X-ray imaging plate of a surface microarray obtained by the present invention; the square Au electrode pixel points with a side length of 100 μm on the surface of the perovskite have clear outlines, which is also the result that the perovskite material based on tryptamine ions is water-stable and cannot be decomposed by water;

[0073] Fig.10 b is Fig.10 a A magnified photo of Au electrode pixels in a microarray; the Au electrode pixels are clearly spaced apart and have clear outlines. This is the first time that a perovskite surface has been directly processed in water and an X-ray imaging plate of Au electrode pixels in a microarray has been fabricated using traditional semiconductor technology - UV etching technology.

[0074] Fig.11 a is a photo of the front and back of the probe taken with a mobile phone and a microscope photo of the needle tip; the probe tip size is 50μm, and the needle arm center distance is 300μm, which can fit well with the 200μm side length and 100μm spacing Au electrode pixel points of our final imaging plate;

[0075] Fig.11 b The photo of the probe in close contact with the X-ray imaging board shows the circuit design diagram of X-ray imaging; from the photo, it can be seen that the probe and the Au electrode pixel of the imaging board are closely attached, which can well derive the electrical signal, and then input the electrical signal into the signal receiving end NI-9205 acquisition card through the circuit shown in the figure;

[0076] Fig.11 c is a photo of the actual circuit diagram of X-ray imaging, which is obtained by taking a photo with a mobile phone; the current signal generated under X-ray irradiation is transmitted from the Au electrode pixel through the probe, and then the signal is collected from the NI-9205 acquisition card at the probe input signal receiving end;

[0077] Fig.12 a is an optical reflection photo of a tooth used for X-ray imaging, which is obtained by taking a photo with a mobile phone; the tooth is the object we use for X-ray imaging;

[0078] Fig.12 b is a high-quality X-ray transmission photo of teeth obtained by the prepared imaging plate and the designed corresponding circuit; it can be clearly seen from the figure that the outline of the tooth is well restored through the difference in electrical signals of different Au electrode pixels, which shows that our perovskite material based on tryptamine ions has high sensitivity and can detect current signals passing through different positions of the teeth. In addition, the current signals of teeth with different thicknesses at different positions are obviously different, which is shown as the depth of color in the figure;

[0079] Fig.12c is a high-quality dental imaging resolution curve obtained by the prepared imaging plate and the designed corresponding circuit; as can be seen from the figure, X-rays penetrate the teeth and irradiate on our imaging plate, and the imaging plate can well sense the current signals at different positions of the teeth and use the data for digital imaging, which can achieve an imaging resolution of 3.0lp / mm. DETAILED DESCRIPTION

[0080] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.

[0081] The present invention provides a method for growing one-dimensional and two-dimensional hybrid perovskite single crystals based on tryptamine ions, such as Figure 1 As shown, the same raw materials and ratio of precursor solution precipitate perovskite structures with different structural arrangement dimensions at different crystallization rates, and the two different structures are further confirmed by XRD testing. Embodiment 1:

[0082] The present embodiment provides the synthesis of tryptamine iodide ion based on tryptamine molecule, and the specific steps are as follows:

[0083] a) Weigh tryptamine (TA) and HI (aq) in a molar ratio of 1:1, then dissolve TA in ethanol (EtOH) and stir magnetically to completely dissolve it;

[0084] (b) placing the solution obtained in step (a) under an ice bath, and dripping HI (aq) into the solution dropwise, stirring for 3 hours, and rotary evaporating the reaction solution to dryness;

[0085] (c) dissolving the dried product obtained in step (b) in a small amount of ethanol under reflux, cooling it to room temperature after it is completely dissolved, and slowly precipitating it with dichloromethane anti-solvent;

[0086] (d) filtering the precipitate obtained in step (c) and drying it;

[0087] (e) Repeat the recrystallization operation of steps (c) to (d) three times;

[0088] (f) drying the product of step (e) to obtain the product tryptamine iodine (TAI). Embodiment 2:

[0089] This embodiment provides a controllable growth method of a one-dimensional perovskite single crystal based on tryptamine ions. The specific steps are as follows:

[0090] (a) TAI and PbI2 were weighed in a molar ratio of 2:1 and then added into acetonitrile (ACN) in sequence;

[0091] (b) subjecting the solution obtained in step (a) to ultrasonic treatment at room temperature until the solution is completely dissolved, and filtering to obtain a clear solution;

[0092] (c) The clear solution was placed on a 30 °C hot plate / oven for 5 h, during which crystals precipitated from the solution, namely the one-dimensional TA4Pb3I 10 Single crystal (triclinic P system, a=9.48, b=11.83, c=13.71; α=75.258, β=83.018, γ=78.937; density ρ=2.891g / cm 3 ). Embodiment 3:

[0093] This embodiment provides a controllable growth method of two-dimensional perovskite crystals based on tryptamine ions, and the specific steps are as follows:

[0094] (a) TAI and PbI2 were weighed in a molar ratio of 2:1 and then added into acetonitrile (ACN) in sequence;

[0095] (b) subjecting the solution obtained in step (a) to ultrasonic treatment at room temperature until the solution is completely dissolved, and filtering to obtain a clear solution;

[0096] (c) adding ethyl acetate (EA) in an amount equal to that of acetonitrile to the clear solution obtained in step (b), and shaking the solution to mix it evenly;

[0097] (d) The homogeneous solution obtained in step (c) is placed on a hot plate / oven at 65°C for 60 min, during which crystals are precipitated from the solution, namely two-dimensional TA2PbI4 crystals.

[0098] The present invention provides a reversible dimensional transformation process of one-dimensional and two-dimensional hybrid perovskite single crystals based on tryptamine ions, such as Figure 2 As shown, one-dimensional perovskite sheet materials can undergo cyclically reversible dimensional transformation between one-dimensional and two-dimensional structures, which was further confirmed by XRD testing. Embodiment 4:

[0099] This embodiment provides a one-dimensional TA4Pb3I 10 The perovskite material has been directly proved for the first time through single crystal structure testing and theoretical optimization that cationic tryptamine ions are directly involved in the band edge construction of the perovskite material. The specific steps are as follows:

[0100] (a) 1D TA4Pb3I according to the present invention 10 A controllable growth method of a single crystal (1D single crystal) to obtain a 1D single crystal;

[0101] (b) From the single crystals obtained in step (a), select perfect crystals without bubbles, cracks, or impurities under a microscope, perform single crystal X-ray diffraction tests, and perform single crystal analysis on the results to obtain microscopic crystal structure data of the 1D single crystal;

[0102] (c) importing the crystal structure data obtained in step (b) into the VASP calculation software to perform structure optimization through density functional theory (DFT);

[0103] (d) The optimized structure obtained in step (c) is imported into the VESTA software, where the differential charge distribution of the crystal microstructure can be seen. From the differential charge distribution, we can preliminarily determine that the organic cation TA participates in the construction of the band edge structure of its one-dimensional structure. Embodiment 5:

[0104] This embodiment provides a hybrid perovskite material based on tryptamine ions, wherein the organic cation tryptamine ions directly participate in the construction of the band edge structure of the hybrid perovskite. The hybrid perovskite material based on tryptamine ions can undergo a reversible dimensional transition between one dimension and two dimensions, and has super strong water immersion stability. The specific experimental steps are as follows:

[0105] (a) The obtained one-dimensional TA4Pb3I 10 After drying the single crystal, it was ground to obtain one-dimensional TA4Pb3I 10 The perovskite powder is dried thoroughly;

[0106] (b) Weigh a certain amount of one-dimensional TA4Pb3I 10 The perovskite powder is evenly sprinkled into the tablet press mold for extrusion molding, and demolding is performed to obtain a one-dimensional TA4Pb3I with a certain shape and thickness. 10 Perovskite tablet material (A-1D tablet);

[0107] (c) The one-dimensional TA4Pb3I 10 After the pressed material was heated at 120 °C for 4 hours, the color of the perovskite pressed material changed from light yellow-green to orange-yellow. XRD test confirmed that the color change represented that the tryptophan-based one-dimensional perovskite (A-1D) was transformed into a two-dimensional TA2PbI4 (T-2D) perovskite under heating, and the one-dimensional TA4Pb3I 10 The converted two-dimensional TA2PbI4 perovskite pressed material;

[0108] (d) Soaking the two-dimensional TA2PbI4 perovskite pressed material obtained in step (c) in water or by steam fumigation to achieve the conversion of the two-dimensional TA2PbI4 pressed material into the one-dimensional TA4Pb3I 10The dimensional transformation of the tablet material can be observed, with the orange-yellow color changing back to light yellow-green, and the XRD test further confirmed this transformation;

[0109] (e) The dimensional reversible transformation process of step (c) and step (d) is performed three times, and finally the perovskite sheet material is stabilized in one-dimensional TA4Pb3I 10 Tableting material status (F-1D);

[0110] (f) By monitoring the reversible transformation process of step (c) and step (d) through XRD testing and fitting the XRD data using Williamson-Hall (WH) calculation, we found that the perovskite material induced a larger intrinsic microstrain after extrusion molding, and observed that during the reversible transformation process of step (c) and step (d), this intrinsic microstrain had a continuous relaxation process and eventually stabilized, reaching a perfect stable structure with almost no internal microstrain;

[0111] (g) The one-dimensional TA4Pb3I obtained in step (e) 10 The tablet material (F-1D tablet) is stable for several months when immersed in water without decomposition. Embodiment 6:

[0112] This embodiment provides a hybrid perovskite material based on tryptamine ions, which has super strong water immersion stability and can be integrated through traditional semiconductor processing technology. We have performed wet polishing and UV etching on the surface of the perovskite material, such as Fig.10 As shown, a microarray surface with a certain pattern etched was obtained, and an X-ray imaging plate was prepared. The specific experimental steps are as follows:

[0113] (a) In one-dimensional TA4Pb3I 10 Au electrodes are deposited on the upper and lower surfaces of the pressed material with a thickness of 60 nm;

[0114] (b) The pressed sheet material obtained in step (a) was fixed on a glass substrate with Kapton tape, and a positive photoresist aqueous solution (SU-8 photoresist) was spin-coated at 3000 rpm for 30 seconds on the Au electrode surfaces on both sides of the pressed sheet material, and annealed at 88°C for 30 minutes in the dark;

[0115] (c) placing the pressed material obtained in step (b) under a mercury lamp of an ultraviolet photolithography machine (wavelength of 365 nm, power of 350 W), and irradiating the Au electrode on one side of the pressed material for 12 s under a mask of a gridded microarray pattern mask; the light-shielding area of ​​the mask is a square grid with a side length of 200 μm, and the spacing of the square grid is 100 μm;

[0116] (d) immersing the photoetched pressed sheet obtained in step (c) in a 0.5% by mass sodium hydroxide solution to remove the positive photoresist that has undergone exposure reaction, shaking for 10 seconds, taking it out, immediately rinsing it with running water for 25 seconds, and then blowing it dry with N2;

[0117] (e) The pressed material obtained in step (d) is immersed in a gold etching solution again to remove the gold plating layer without photoresist protection, and is taken out after 20 seconds, and is immediately rinsed with running water for 25 seconds and then blown dry with N2 to obtain a pressed material with gridded microarray Au electrode pixel points on one side of the surface;

[0118] (f) soaking the pressed material with the microarray Au electrode pixel points obtained in step (e) in an ethanol solution for 2 minutes, taking it out and immediately rinsing it with running water for 25 seconds and then blowing it dry with N2 to remove the positive photoresist that has not undergone exposure reaction and is coated on the surface of the Au electrodes on both sides of the pressed material;

[0119] (g) The pressed sheet material with the microarray Au electrode pixel points obtained in step (f) is heated at 110° C. to be dried, thereby obtaining an X-ray array imaging plate. Embodiment 7:

[0120] This embodiment provides a hybrid perovskite material based on tryptamine ions, which has super strong water immersion stability and can be integrated through traditional semiconductor processing technology. We wet polished the perovskite material and processed it by ultraviolet etching. Fig.11 As shown in a, a probe card matching the array is designed to lead the pixel points as the input end for signal reading; Fig.11 b and Fig.11 c shows the circuit design schematic diagram and physical diagram of the output end and receiving end of the signal reading, which is used to complete X-ray imaging. The specific experimental steps are as follows:

[0121] (a) Customized probes with sizes and spacing corresponding to the Au electrodes in the microarray pattern in the X-ray array imaging plate;

[0122] (b) placing the probe of step (a) in close contact with the array Au electrode pixel points of the X-ray array imaging plate one by one;

[0123] (c) Fix the probe connected to the X-ray imaging board in step (b) to a circuit board designed to read pixel signals by collecting fixed-value resistor voltage dividers through pin headers and cables, introduce the signal into the NI-9205 acquisition card, and use software to read the signal to obtain the signal value of each pixel;

[0124] (d) In step (c), the object to be imaged is a tooth. The signal value of each pixel point obtained in step (c) is imported into Matlab software for image visualization processing to obtain the transmission image of the tooth under X-ray. Fig.12 Optical reflection photos of teeth used for X-ray imaging, and high-quality X-ray transmission photos of teeth obtained at low doses through the prepared imaging plate and the designed corresponding circuit, as well as the corresponding imaging resolution.

Claims

1. A one-dimensional TA4Pb3I based on tryptamine ions 10 The controllable growth method of a single crystal comprises the following steps: (a) Weigh TAI and PbI2 in a molar ratio of 2:1 and then add them into acetonitrile in sequence; (b) subjecting the solution obtained in step (a) to ultrasonic treatment at room temperature until the solution is completely dissolved, and filtering to obtain a clear solution; (c) The clarified solution obtained in step (b) is allowed to stand at 20-70°C for 1-10 h, during which crystals are precipitated from the solution, namely, one-dimensional TA4Pb3I 10 Single crystal, triclinic P system, a=9.48, b=11.83, c=13.71; α=75.258, β=83.018, γ=78.937; density ρ=2.891g / cm 3 .

2. A one-dimensional TA4Pb3I based on tryptamine ions as claimed in claim 1 10 A controllable growth method of a single crystal, characterized in that: The synthesis steps of tryptamine iodine TAI are as follows: (a) Weigh tryptamine TA and HI aq in a molar ratio of 1:1, then dissolve TA in ethanol and stir magnetically to completely dissolve it; (b) placing the solution obtained in step (a) under an ice bath, and dripping HI aq into the solution dropwise, stirring continuously for 2 to 8 hours, and rotary evaporating the reaction solution to dryness; (c) dissolving the dried product obtained in step (b) in a small amount of ethanol under reflux, cooling it after it is completely dissolved, and slowly precipitating it with dichloromethane anti-solvent; (d) filtering the precipitate obtained in step (c) and drying it; (e) Repeat the recrystallization operation of steps (c) to (d) 2 to 3 times; (f) drying the product of step (e) to obtain tryptamine iodine TAI.

3. A one-dimensional TA4Pb3I based on tryptamine ions 10 A single crystal, characterized in that: The method is prepared by the method of claim 1 or 2.

4. A one-dimensional TA4Pb3I based on tryptamine ions 10 The preparation method of the tablet is as follows: (a) One-dimensional TA4Pb3I 10 After drying the single crystal, it was ground to obtain one-dimensional TA4Pb3I 10 The perovskite powder, denoted as 1D powder, is then completely dried; (b) Weigh a certain amount of one-dimensional TA4Pb3I 10 The perovskite powder is evenly sprinkled into the tablet press mold for extrusion molding, and demolding to obtain a one-dimensional TA4Pb3I with a certain shape and thickness. 10 Perovskite tablet material, denoted as A-1D tablet; (c) The one-dimensional TA4Pb3I 10 The perovskite pressed material is heated at 120-150°C for 2-10 hours to obtain a two-dimensional TA2PbI4 perovskite pressed material, which is referred to as T-2D pressed material. (d) Soaking the two-dimensional TA2PbI4 perovskite pressed material obtained in step (c) in water, or by steam fumigation, to achieve the conversion of the two-dimensional TA2PbI4 perovskite pressed material into a one-dimensional TA4Pb3I 10 Dimensional transformation of perovskite sheet materials; (e) The dimensional reversible transformation process of step (c) and step (d) is performed 1 to 8 times, and finally the perovskite sheet material is stabilized in one-dimensional TA4Pb3I 10 The state of the perovskite sheet material is a one-dimensional TA4Pb3I based on tryptamine ions. 10 Tableting, recorded as F-1D tableting.

5. A one-dimensional TA4Pb3I based on tryptamine ions 10 Tableting, characterized in that: The F-1D tablet is prepared by the method described in claim 4.

6. A one-dimensional TA4Pb3I based on tryptamine ions as claimed in claim 5 10 Application of pressed sheets in the preparation of X-ray imaging plates.

7. A one-dimensional TA4Pb3I based on tryptamine ions as claimed in claim 6 10 The application of the pressed sheet in the preparation of X-ray imaging plates, the preparation steps are as follows: (a) In one-dimensional TA4Pb3I 10 Au electrodes are deposited on the upper and lower surfaces of the perovskite sheet material, with a thickness of 50-80 nm. (b) Spin coating a positive photoresist aqueous solution on the Au electrode surfaces on both sides of the pressed material at 2000-4000 rpm for 20-40 s, and annealing at 80-90 °C for 20-40 min in the dark; (c) placing the pressed material obtained in step (b) under a mercury lamp of an ultraviolet photolithography machine, and exposing the Au electrode on one side of the pressed material under a mask of a gridded microarray pattern mask for 10 to 15 seconds; the mask shielding area is a square grid with a side length of 100 to 300 μm or a circular grid with a diameter of 100 to 300 μm; (d) soaking the pressed material obtained in step (c) in a sodium hydroxide solution having a mass fraction of 0.5% to remove the positive photoresist that has undergone exposure reaction, shaking for 5 to 10 seconds, taking it out, immediately rinsing it with running water for 20 to 30 seconds, and then drying it with N2; (e) immersing the pressed material obtained in step (d) in a gold etching solution to remove the Au electrode layer without photoresist protection, taking it out after 15 to 30 seconds, immediately rinsing it with running water for 20 to 30 seconds, and then drying it with N2 to obtain a pressed material with a gridded microarray pattern Au electrode on one surface; (f) soaking the pressed material obtained in step (e) in an ethanol solution for 1 to 2 minutes, taking it out and immediately rinsing it with running water for 20 to 30 seconds and then drying it with N2 to remove the positive photoresist coated on the surface of the Au electrodes on both sides of the pressed material that has not undergone exposure reaction; (g) heating the pressed sheet material obtained in step (f) at 90-110° C. to dry it, thereby obtaining an X-ray array imaging plate.

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