An antimony-based double-ligand metal halide perovskite crystal, a preparation method and application thereof

Abstract

The application relates to the technical field of artificial functional crystal materials, in particular to a Sb-based double-ligand metal halide perovskite crystal as well as a preparation method and application thereof, the chemical formula of the crystal is (C7H 10 N)2(C5H7N)Sb2I9, the Sb-based double-ligand metal halide perovskite crystal is of an orthorhombic system and has the structural characteristics of a P212121 space group, and exhibits excellent photoelectric response characteristics. Under the driving of an applied bias (such as 50V), efficient separation and directional transmission of carriers can be realized in the crystal, so that the crystal exhibits extremely high detection sensitivity and is suitable for the preparation of high-performance X-ray detectors.

Description

Technical Field

[0001] This invention relates to the field of artificial functional crystal materials technology, and in particular to an antimony-based dual-ligand metal halide perovskite crystal, its preparation method, and its application. Background Technology

[0002] In recent years, metal halide perovskite materials have shown great application potential in photodetectors, solar cells, and light-emitting diodes due to their excellent light absorption coefficient, tunable band gap, and high carrier mobility. However, many technical bottlenecks remain to achieve the large-scale and commercial application of these materials. The problems in existing technologies and their evolutionary logic are as follows: First, traditional high-performance metal halide perovskite materials (such as MAPbI3) usually rely on the toxic element lead (Pb). The high toxicity of lead not only poses a serious threat to the ecological environment and human health, but also seriously violates the global trend of green environmental protection and related regulatory restrictions. Therefore, developing environmentally friendly lead-free metal halide perovskites has become the primary problem to be solved in this field. Among many alternative elements, Sb³... + With Pb² + Antimony (Sb) has a similar electronic configuration to lead, but with over 90% less toxicity. It has attracted attention due to its environmental friendliness, chemical stability, and ease of forming diverse halide structures. Antimony (Sb) has an outer electron configuration (ns) similar to lead. 2 Furthermore, it has low toxicity and abundant natural reserves, making it an ideal metal cation candidate for constructing high-performance lead-free perovskites.

[0003] Although antimony-based perovskites have solved the toxicity problem, traditional three-dimensional (3D) or two-dimensional (2D) antimony-based perovskites still face fatal weaknesses in practical applications, such as poor environmental stability and severe "ion migration." Particularly in the field of photoelectric detection, the continuous three-dimensional / two-dimensional inorganic framework provides channels for the transport of ions and electrons in the dark state, leading to extremely high dark current and baseline noise, severely limiting detection sensitivity. To address this issue, reducing the material's dimension to zero (0D) has become a key strategy. Zero-dimensional perovskites are crystallographically composed of completely isolated metal halide polyhedra (such as [SbI6]³). - The material is composed of inorganic polyhedra that are completely spatially isolated by organic cations. This molecular-level spatial confinement effect effectively cuts off ion migration pathways and leakage current channels in the dark state, thereby endowing the material with extremely low dark current and excellent intrinsic environmental stability (moisture resistance, heat resistance, and light resistance).

[0004] Single-ligand zero-dimensional antimony-based perovskites (such as the traditional A3Sb2I9 type 0D structure) can achieve low dark current and high stability, but they face new technical bottlenecks. A single, large-volume organic ligand often leads to excessive steric hindrance, making the material prone to generating numerous surface / bulk defects (such as iodine vacancies) during crystallization. More seriously, the excessively thick insulating barrier constructed by a single ligand not only blocks the dark current but also significantly hinders the effective dissociation and transport of photogenerated carriers, resulting in excessively high exciton binding energy and low photoelectric conversion efficiency. This creates the dilemma of traditional zero-dimensional materials having low dark current but also limited sensitivity (photocurrent). Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art by proposing an antimony-based dual-ligand metal halide perovskite crystal, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: an antimony-based zero-dimensional dual-ligand metal halide perovskite crystal, wherein the chemical formula of the antimony-based zero-dimensional dual-ligand metal halide perovskite crystal is (C7H). 10 N)2(C5H7N)Sb2I9, the dual ligands of this crystal include piperidine and benzylamine. Derivatives of piperidine can also serve as ligands. These are saturated six-membered cyclic amines with C1-C3 lower alkyl or heteroatom substitutions. Derivatives of benzylamine can also serve as ligands, possessing R-C6H4CH2NH3. + A benzylamine derivative of the structure, wherein R is selected from hydrogen, halogen atoms, or lower alkyl groups of C1-C3.

[0007] Furthermore, antimony-based zero-dimensional dual-ligand metal halide perovskite crystals belong to the orthorhombic crystal system with space group P212121.

[0008] Furthermore, the cell parameters of the antimony-based dual-ligand metal halide perovskite crystal are: a=8.5712(10)Å, b=21.2406(4)Å, c=21.5149(4)Å, α=90°, β=90°, γ=90°, V=3916.9477Å3, Z=4.

[0009] A method for preparing antimony-based dual-ligand metal halide perovskite crystals includes the following steps: mixing antimony trioxide, benzylamine, and piperidine, adding hydroiodic acid aqueous solution, heating and stirring until the reaction is complete; performing crystallization post-treatment on the obtained solution, and obtaining the desired crystals after sufficient growth, thus obtaining the antimony-based metal halide perovskite crystals.

[0010] The method is simple and efficient, and can produce high-quality crystals. By controlling the reaction conditions, crystal growth can be optimized, thereby improving its stability and performance.

[0011] Further, the post-crystallization treatment, after sufficient growth to obtain the desired crystals, includes the following specific steps: placing the solution obtained from the complete reaction in an oven at a temperature of 90-100℃, and cooling the solution to room temperature using a cooling growth method at a rate of 1-2℃ per day. The oven program is set; the slower the cooling rate, the better the quality of the crystals produced. This continues until the oven temperature drops to room temperature (25℃), at which point the crystals are removed.

[0012] Furthermore, the molar ratio of antimony trioxide, benzylamine, and piperidine is 1:2:2.

[0013] This molar ratio ensures the complete progress of the reaction while optimizing the structure and properties of the crystal. An appropriate molar ratio can improve the stability and X-ray absorption capacity of the crystal.

[0014] Furthermore, the molar ratio of antimony trioxide to HI is 1:1.

[0015] Furthermore, the HI aqueous solution has a mass fraction of 55-58%, and the heating temperature is 90-100℃. The 55-58% HI aqueous solution concentration is suitable, ensuring the smooth progress of the reaction while avoiding the corrosiveness and hazards caused by excessively high concentrations. This temperature range also ensures efficient reaction while avoiding side reactions and crystal structure damage caused by excessively high temperatures. Appropriate temperature can improve the growth quality and stability of the crystals.

[0016] Furthermore, antimony-based dual-ligand metal halide perovskite crystals are used to prepare X-ray detectors.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This antimony-based dual-ligand metal halide perovskite crystal is orthorhombic, exhibiting the structural characteristics of space group P212121, which significantly influences its physical properties (such as optical and electrical properties). It displays excellent photoelectric response characteristics. Under an applied bias voltage (e.g., 50V), efficient carrier separation and directional transport can be achieved within the crystal, resulting in extremely high detection sensitivity, making it suitable for the fabrication of high-performance X-ray detectors.

[0018] 2. This invention utilizes a dual-ligand synergistic strategy, taking advantage of the natural differences in spatial configuration, hydrogen bonding mode, and stacking tilt angle between piperidine cations (PD) and benzylamine cations (PMA), to achieve [SbI] x ] n- Orientation, anchoring, and encapsulation of zero-dimensional polyhedral elements.

[0019] First, the synergistic effect of rigid aromatic PMA and flexible heterocyclic PD constructs a dense organic isolation layer. Through asymmetric π-π stacking and a multidimensional hydrogen bond network, it effectively anchors the zero-dimensional inorganic units, greatly enhancing the structural stability of the crystal lattice. This synergistic effect not only improves the fatigue resistance of the crystal under long-term X-ray irradiation but also significantly inhibits the migration of impurity ions.

[0020] Secondly, the strong confinement effect of the zero-dimensional structure not only cuts off the leakage current path in the dark state, but more importantly, under an applied bias voltage of 50V, the dense network formed by the dual ligands effectively suppresses charge injection and ion drift, thus achieving extremely low baseline noise and excellent current stability. This extremely low drift current ensures that the X-ray detector maintains an ultra-high signal-to-noise ratio even under long-term high-voltage operation. Finally, by relying on the optimization of the charge transport path by the dual ligands and the effective passivation of crystal defects, high-performance and high-stability direct detection of antimony-based X-rays is achieved.

[0021] 3. The crystal of this invention exhibits excellent performance in the field of X-ray detection, such as high detection sensitivity, low detection limit, and high stability. These characteristics make it promising for wide applications in medical testing, security inspection, and scientific research. Attached Figure Description

[0022] Figure 1 The (C7H) prepared in Example 2 of this invention 10 Structure diagram of N)2(C5H7N)Sb2I9 crystal; Figure 2 The (C7H) prepared in Example 2 of this invention 10 Photograph of N)2(C5H7N)Sb2I9 crystal; Figure 3 The (C7H) prepared in Example 2 of this invention 10 X-ray powder diffraction pattern of N)2(C5H7N)Sb2I9 crystal; Figure 4 The (C7H) prepared in Example 2 of this invention 10 The ultraviolet-visible absorption spectrum of N)2(C5H7N)Sb2I9 crystal; Figure 5 The (C7H) prepared in Example 2 of this invention 10 The real-time current density response curves of a device made of N)2(C5H7N)Sb2I9 crystal to different dose rates under a 50V bias voltage; Figure 6 The (C7H) prepared in Example 2 of this invention 10A comparison of the sensitivity of a device made from N)2(C5H7N)Sb2I9 crystal under a 50V bias voltage and the sensitivity of the device after one month of storage. Figure 7 The (C7H) prepared in Example 2 of this invention 10 Devices made from N)2(C5H7N)Sb2I9 crystals were exposed to continuous, long-term X-ray irradiation (60.1 μGy / s) at a bias voltage of 50 V. -1 Operational stability results; Figure 8 The (C7H) prepared in Example 2 of this invention 10 Devices made from N)2(C5H7N)Sb2I9 crystals exhibit drift current at a 50V bias.

[0023] Table 1 shows the (C7H) prepared in Example 2. 10 The drift current of the N)2(C5H7N)Sb2I9 crystal under a 50V bias voltage is compared with the drift current of other low-dimensional perovskite devices. Detailed Implementation The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0024] Example 1 The preparation, synthesis, and crystal growth of antimony-based dual-ligand metal halide perovskite include the following steps: Antimony trioxide, benzylamine, and piperidine are placed in a beaker at a molar ratio of 1:2:2. Then, a 55% (w / w) aqueous solution of HI is added to the beaker, wherein the molar ratio of antimony trioxide to HI is 1:1. The mixture is heated to 100°C and stirred until the solution becomes a colorless and clear solution. The resulting colorless and clear solution is naturally cooled to room temperature to obtain 1-2 mm deep red needle-like microcrystals. These microcrystals are filtered and dried to obtain antimony-based dual-ligand metal halide perovskite crystals (C7H4H4O). 10 N)2(C5H7N)Sb2I9).

[0025] Example 2 The preparation, synthesis, and crystal growth of antimony-based dual-ligand metal halide perovskites include the following steps: Antimony trioxide, benzylamine, and piperidine are placed in a beaker at a molar ratio of 1:2:2. Then, a 55% (w / w) aqueous solution of HI is added to the beaker, with a molar ratio of antimony trioxide to HI of 1:1. The mixture is heated to 100°C and stirred until the solution becomes a colorless and clear solution, indicating that the reaction is complete. While still hot, the colorless and clear solution is placed in an oven at 100°C. The solution is then slowly cooled to room temperature using a slow cooling growth method, with a cooling rate of 1-2°C per day, resulting in rod-shaped antimony-based dual-ligand metal halide perovskite crystals (C7H4H4O) with a size of approximately 10-20 mm. 10 N)2(C5H7N)Sb2I9).

[0026] Crystals meeting the requirements can be obtained with a HI aqueous solution mass fraction of 55-58%.

[0027] Figure 1 The (C7H) prepared in Example 2 of this invention 10 Structure diagram of N)2(C5H7N)Sb2I9 crystal. From Figure 1 As can be seen from this, (C7H 10 N)2(C5H7N)Sb2I9 has a unique crystal structure. 10 N)2(C5H7N)Sb2I9 adopts a typical OD dual-ligand crystal structure, consisting of two [SbI6] ligands. 3- An octahedron sharing a triangular face forms an isolated [Sb2I9]. 3- The dimer serves as the basic structural unit, with the NH bond between the organic cations PMA and PD and the inorganic anion [Sb₂I₉]. 3- Forming NH…I hydrogen bonds, long-chain PMA + The flexibility of the material allows it to wrap around the surface of the dimer, while the short-chain PD+ fills the gaps, together achieving close packing. This enables (C7H) 10 The stability of Sb₂I₉ is sufficiently high. The inorganic framework of Sb₂I₉ is linked to the organic cations through ionic interactions and possible hydrogen bonds. This structure results in relatively regular interlayer spacing, which is beneficial for electron migration. Simultaneously, the interaction between the organic cations and the inorganic framework enhances the structural stability of the crystal, enabling it to exhibit excellent performance in photoelectric detection and radiation measurement.

[0028] Figure 2 The (C7H) prepared in Example 2 of this invention 10 A photograph of a C5H7N)Sb2I9 crystal. X-ray single-crystal diffraction results indicate that the molecular formula of this compound is C5H7N. 19 H 27N3Sb2I9, structural formula is (C7H 10 N)2(C5H7N)Sb2I9. At room temperature (C7H 10 N)2(C5H7N)Sb2I9 crystal belongs to the orthorhombic crystal system, space group P21212. 11 The unit cell parameters are: a=8.5712(10)Å, b=21.2406(4)Å, c=21.5149(4)Å, α =90°, β =90°, γ =90°, V=3916.9477Å3, Z=4.

[0029] Figure 3 The (C7H) prepared in Example 2 of this invention 10 The X-ray powder diffraction pattern of the N)2(C5H7N)Sb2I9 crystal, obtained through structural simulation, matches the experimentally measured results, indicating that its phase purity is very high and there are no other obvious impurities.

[0030] The (C7H) prepared in Example 2 was analyzed by UV-Vis absorption spectroscopy. 10 The optical absorption of the N)2(C5H7N)Sb2I9 crystal was analyzed, and the results are as follows: Figure 4 As shown. Figure 4 Display (C7H) 10 The absorption cutoff edge of N)2(C5H7N)Sb2I9 is ​​600 nm. Based on the Tauc formula, the optical band gap of this compound can be derived to be 2.14 eV.

[0031] Example 3 The (C7H) prepared in Example 2 10 Single-crystal X-ray detectors are constructed using N)2(C5H7N)Sb2I9 crystals. The specific method involves selecting crystals with a size of approximately 3×2×1mm. 3 A high-quality single crystal is placed on a glass slide, and Ag electrodes are uniformly coated on both ends of the crystal (along the polar axis: crystallographic c-axis). Then, wires are led out from both ends to form a complete current path.

[0032] The (C7H) prepared in Example 2 10 The detection performance of a single-crystal X-ray detector constructed from N)2(C5H7N)Sb2I9 crystal was tested, and the results are as follows: Figure 5 As shown, the test results demonstrate that the device possesses a wide dynamic range capability, even at the lowest setting of 1.0 μGy / s. -1At the specified dose rate, the current response remains significantly higher than the baseline noise, demonstrating excellent sensitivity. Traditional detectors are susceptible to noise interference at low dose rates, making it difficult to accurately capture minute current changes and resulting in low statistical efficiency at low dose rates. The high sensitivity of this device enables its application in low-dose medical scenarios, improving diagnostic accuracy and safety.

[0033] Figure 6 The (C7H) prepared in Example 2 10 The photoresponse of the N)2(C5H7N)Sb2I9 crystal under high X-ray irradiation dose decreased only slightly after one month. The calculated sensitivity was 113.7 μC Gy. -1 cm -2 It maintained 78% of its original value. All of the above demonstrates the excellent stability of the detection device.

[0034] Figure 7 The (C7H) prepared in Example 2 10 N)2(C5H7N)Sb2I9 crystal was subjected to continuous, long-term X-ray irradiation (60.1 μGy s) at a bias voltage of 50 V. -1 Dark current and photocurrent remain stable.

[0035] Figure 8 The (C7H) prepared in Example 2 10 The drift current of N)2(C5H7N)Sb2I9 crystal under a 50V bias voltage is such a stable drift current due to the synergistic effect of the dual-ligand organic cations, which promotes close packing, thus endowing the material with excellent structural stability, effectively suppressing ion migration while maintaining low dark current and ultra-high stability.

[0036] Table 1 shows the (C7H) prepared in Example 2. 10 The drift current of the N)2(C5H7N)Sb2I9 crystal under a 50V bias voltage is compared with that of other low-dimensional perovskite devices at the same drift current.

[0037]

[0038] Table 1 The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made without departing from the spirit and scope of the invention, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents. The system is activated when the gas storage tank is nearly full, efficiency decreases, and the fuel cell requires or can accept the use of the stored hydrogen, maximizing the utilization of the stored hydrogen. Through dynamic timing coordination between the valve and the pressurization device, and a delay compensation algorithm, smooth airflow during mode switching is ensured, preventing hydrogen leakage or pressure surges caused by improper valve opening and closing, thus guaranteeing the effective utilization of hydrogen.

Claims

1. An antimony-based zero-dimensional dual-ligand metal halide perovskite crystal, characterized in that, The chemical formula of antimony-based zero-dimensional dual-ligand metal halide perovskite crystals (C7H) 10 N)2(C5H7N)Sb2I9.

2. The antimony-based dual-ligand metal halide perovskite crystal according to claim 1, characterized in that, The antimony-based zero-dimensional dual-ligand metal halide perovskite crystals described above belong to the orthorhombic crystal system, with space group P212121.

3. The antimony-based dual-ligand metal halide perovskite crystal according to claim 1, characterized in that, The cell parameters of the antimony-based dual-ligand metal halide perovskite crystal are: a=8.5712(10)Å, b=21.2406(4)Å, c=21.5149(4)Å, α=90°, β=90°, γ=90°, V=3916.9477Å3, Z=4.

4. A method for preparing antimony-based dual-ligand metal halide perovskite crystals as described in any one of claims 1-3, characterized in that, The process includes the following steps: mixing antimony trioxide, benzylamine, and piperidine, then adding an aqueous solution of hydroiodic acid, heating and stirring until the reaction is complete; crystallizing the resulting solution, and after sufficient growth, obtaining the desired crystal, i.e., obtaining the antimony-based metal halide perovskite crystal.

5. The method for preparing antimony-based dual-ligand metal halide perovskite crystals according to claim 4, characterized in that, The specific steps of the post-crystallization treatment, which allows for sufficient growth to obtain the desired crystals, include: placing the solution obtained after complete reaction in an oven at a temperature of 90-100℃ to cool the solution to room temperature at a rate of 1-2℃ per day.

6. The method for preparing antimony-based dual-ligand metal halide perovskite crystals according to claim 5, characterized in that, The molar ratio of antimony trioxide, benzylamine, and piperidine is 1:2:

2.

7. The method for preparing antimony-based dual-ligand metal halide perovskite crystals according to claim 5, characterized in that, The molar ratio of antimony trioxide to HI is 1:

1.

8. The method for preparing antimony-based dual-ligand metal halide perovskite crystals according to claim 5, characterized in that, The mass fraction of the HI aqueous solution is 55-58%.

9. The method for preparing antimony-based dual-ligand metal halide perovskite crystals according to claim 5, wherein the heating temperature is 90-100℃.

10. The application of any one of the antimony-based dual-ligand metal halide perovskite crystals as claimed in claims 1 to 3, characterized in that, The antimony-based dual-ligand metal halide perovskite crystals are used to prepare X-ray detectors.

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