Powder light emitting crystal material of antimony-doped wide band gap zirconium-based chloride and preparation method and application thereof

Abstract

This invention discloses an antimony-doped wide-bandgap zirconium chloride powder-emitting crystal material, its preparation method, and its application. The chemical formula of the powder-emitting crystal material is (C9H). 15 N3)2ZrCl8:Sb 3+ It belongs to the monoclinic crystal system, with space group P21 / c; in the described photoluminescent crystal material, each zirconium atom is coordinated with 8 chlorine atoms to form [ZrCl8]. 4‑ Polyhedral structure, organic cation (C9H) 15 N3) + It is linked to inorganic anions via C–N–H···Cl bonds, forming discrete [ZrCl8]. 4‑ The octahedral structure is replaced by organic cations (C9H). 15 N3) + Complete isolation is achieved, forming a zero-dimensional ionic crystal structure. This invention overcomes the problems of single luminescent center, limited emission wavelength, and insufficient luminescence intensity in undoped zirconium-based chlorides by introducing antimony. Antimony, as an effective luminescent center, can promote the radiative recombination process and achieve high-brightness broadband emission.

Description

Technical Field

[0001] This invention relates to an antimony-doped wide-bandgap zirconium chloride powder luminescent crystal material, its preparation method and application, belonging to the field of luminescent functional materials. Background Technology

[0002] Organic-inorganic hybrid lead-free halide perovskite materials, as a typical class of optoelectronic functional materials, are constructed by coordination between organic cations and inorganic halide anions. With their core advantages such as high quantum yield, excellent X-ray absorption, high carrier mobility, and good luminous efficiency, they have become a research hotspot in photovoltaic cells, photodetectors, light-emitting diodes, and sensors. The tunability of these materials' structure can be achieved by controlling the ratio of organic / inorganic components or their chemical structure to customize performance. Furthermore, their lead-free nature avoids the environmental pollution risks of traditional lead-based materials, further expanding their application scenarios. However, the inherent defects of these materials severely restrict their industrialization process: firstly, poor environmental stability, easily undergoing phase transformation or decomposition under practical application conditions such as high humidity and high temperature; secondly, the fabrication process of high-efficiency devices is complex, involving multiple control steps and making it difficult to guarantee quality consistency; and thirdly, the volatility of organic cations leads to performance degradation during long-term use, affecting service reliability.

[0003] Zirconium chloride-based photoluminescent crystals, as an important branch of wide-bandgap halide crystals, have demonstrated unique advantages in the ultraviolet-visible light emission field in recent years. Their core performance advantages stem from their structural characteristics: a large bandgap (typically >3 eV) effectively suppresses self-absorption effects, reducing light energy loss; the synergy of low self-absorption and good structural stability makes them potentially valuable for applications in solid-state lighting, display technology, and other fields, especially suitable for scenarios requiring environmental tolerance. Nevertheless, undoped zirconium chloride materials still face key performance bottlenecks: a single luminescent center leads to a narrow emission spectrum, failing to meet the requirements for wide-spectrum emission; insufficient luminescence intensity makes them unsuitable for high-brightness applications; and the low photoluminescence quantum efficiency of pure-phase materials limits their application in high-performance optoelectronic devices. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides an antimony-doped wide-bandgap zirconium chloride powder-emitting crystal material, its preparation method, and its applications. By introducing antimony, the invention specifically overcomes the problems of undoped zirconium chloride, such as a single luminescent center, limited emission wavelength, and insufficient luminescence intensity. Antimony, as an effective luminescent center, can promote the radiative recombination process, achieving high-brightness, wide-spectrum emission (covering the 390-820nm visible light range), exhibiting unique advantages, especially in the field of powder-emitting materials. At the same time, the coordination effect of antimony with the matrix can further enhance the stability of the crystal structure and improve the thermal stability and environmental tolerance of the material.

[0005] To achieve the above objectives, this invention employs an antimony-doped, wide-bandgap zirconium-based photoluminescent crystal material, the chemical formula of which is (C9H). 15 N3)2ZrCl8:Sb 3+ It belongs to the monoclinic crystal system and has the space group P21 / c;

[0006] In the aforementioned photoluminescent crystal material, each zirconium atom is coordinated with eight chlorine atoms to form [ZrCl8]. 4- Polyhedral structure, organic cation (C9H) 15 N3) + It is linked to inorganic anions via C–N–H···Cl bonds, forming discrete [ZrCl8]. 4- The octahedral structure is covered by organic cations (C9H). 15 N3) + Complete isolation forms a zero-dimensional ionic crystal structure.

[0007] As an improvement, the cell parameters of the light-emitting crystal material are a = 8.9385 Å, b = 12.7386 Å, c = 12.5600 Å, α = 90°, β = 101.188°, γ = 90°, Z = 2, V = 1402.9531 Å. 3 .

[0008] As an improvement, the photoluminescent crystal material has a band gap of 3.2 eV and exhibits good light absorption characteristics in the 250-390 nm ultraviolet region; it displays a bimodal emission spectrum under 349 nm ultraviolet excitation, and the bimodal emission spectrum covers the 390-820 nm visible light range, wherein Sb 3+ The induced characteristic emission peak is located at 635 nm.

[0009] As an improvement, the photoluminescence color coordinates of the photoluminescence emitting crystal material are (0.326, 0.197).

[0010] A second aspect of the present invention also provides a method for preparing the antimony-doped wide-bandgap zirconium chloride photoluminescent crystal material, comprising the following steps:

[0011] 1) Dissolve zirconium tetrachloride and antimony trichloride in hydrochloric acid, add N,N-dimethylformamide, and heat and stir until the solution is clear;

[0012] 2) Add 1-(2-pyridyl)piperazine ligand to the clear solution from step 1), and stir under controlled temperature until the solution becomes clear again;

[0013] 3) Transfer the clear solution obtained in step 2) into a polytetrafluoroethylene liner, seal it, and place it in a high-pressure reactor for solvothermal reaction;

[0014] 4) After the reaction is complete, the temperature is lowered to room temperature, the product is filtered, washed with ethanol and dried to obtain the target crystal material.

[0015] As an improvement, in step 1), the amount of zirconium tetrachloride is 0.1-0.3g, the amount of antimony trichloride is 0.01-0.03g, the amount of hydrochloric acid is 1-5mL, the amount of N,N-dimethylformamide is 0.5-2mL, and the heating and stirring temperature is 80-100℃.

[0016] As an improvement, in step 2), the amount of 1-(2-pyridyl)piperazine ligand added is 150-180 μL, the stirring temperature is maintained at 80-100℃, and the stirring speed is ≤300 r / min.

[0017] As an improvement, in step 3), the temperature of the solvothermal reaction is 80-100℃ and the time is 8-12 hours.

[0018] A third aspect of the present invention also provides the application of the antimony-doped wide bandgap zirconium chloride powder emitting crystal material or the antimony-doped wide bandgap zirconium chloride powder emitting crystal material prepared by the preparation method in fluorescent anti-counterfeiting labels, fluorescent marking devices, photodetectors, display devices, fluorescent sensors or flexible wearable devices.

[0019] A fourth aspect of the present invention also provides a fluorescent anti-counterfeiting label, which is prepared by the following method:

[0020] The antimony-doped wide bandgap zirconium chloride powder emitting crystal material or the antimony-doped wide bandgap zirconium chloride powder emitting crystal material prepared by the preparation method is ground into powder, compounded with polydimethylsiloxane, curing agent and diluent, and then vacuum degassed and cured at 80-100℃ for 8-12 hours to obtain a luminescent pattern film, which is the fluorescent anti-counterfeiting label.

[0021] Mechanism of the invention:

[0022] Employing zero-dimensional structural designs with organic-inorganic hybrids (such as...) Figure 1 As shown): the inorganic phase is discrete [ZrCl8]. 4- Coordination octahedron, organic phase is (C9H) 15 N3) + The cations are tightly linked by C–N–H···Cl bonds, forming a spatial structure of isolated polyhedra and organic insulating layers. The core function of this zero-dimensional structure is to achieve quantum confinement effects: discrete [ZrCl8] 4-The octahedron is completely encapsulated by organic cations, and photogenerated excitons (electron-hole pairs) are confined within independent inorganic polyhedra, preventing them from migrating long distances within the crystal. This significantly increases the radiative recombination probability of excitons, laying the structural foundation for subsequent optimization of luminescence performance.

[0023] Sb 3+ Doping is the core means by which this invention achieves performance breakthroughs, and its working principle is reflected in three aspects:

[0024] (1) Construction of luminescent centers: Sb 3+ By replacing Zr 4+ The lattice sites in [ZrCl8] 4- Isolated Sb forms in the octahedron 3+ Light-emitting center. Sb 3+ The energy level transition probability is much higher than that of Zr. 4+ This introduces new, highly efficient radiative recombination channels into the matrix, solving the problems of single luminescent centers and low luminescence intensity in pure matrices.

[0025] (2) Light absorption enhancement mechanism: The band gap of the crystal material is 3.2 eV (e.g. Figure 5 As shown), it has weak absorption only in the 250-390nm ultraviolet region; while Sb 3+ The introduction of Sb 3+ The associated localized electronic states, located between the conduction and valence bands of the matrix, lower the energy threshold for light absorption, resulting in enhanced and more continuous absorption in the ultraviolet region of the doped material (e.g., Figure 5 As shown in the figure, it also expands the near-band edge absorption range, providing a prerequisite for efficient excitation.

[0026] (3) Structural stability enhancement: Sb 3+ With surrounding Cl - The coordination effect of Sb complements the bonding strength of the matrix lattice, and Sb 3+ Ionic radius and Zr 4+ Similarly, doping does not destroy the original crystal lattice structure of the matrix (e.g.) Figure 2 The XRD pattern is shown in the image). Meanwhile, Sb 3+ By optimizing the lattice charge distribution through coordination, the C–N–H···Cl bond interaction between organic cations and inorganic anions is indirectly enhanced, thereby improving the thermal stability and environmental tolerance of the crystal.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] (1) This invention utilizes Sb 3+By constructing highly efficient luminescent centers in a wide-bandgap zirconium-based chloride matrix, a systematic optimization of photoelectric properties was achieved. The material emits bright 635nm phosphor light under 349nm UV excitation, with a bimodal emission spectrum covering the entire visible light range of 390-820nm, completely solving the problems of narrow emission wavelength and single luminescent center in undoped zirconium-based chlorides. The photoluminescence quantum efficiency was significantly improved from 35.4% in the pure matrix to 93.5%, reaching the application standard for high-performance luminescent materials and meeting the practical requirements of high brightness and broad-spectrum emission. Meanwhile, Sb... 3+ The localized electronic states introduced by doping lower the light absorption energy threshold, enhancing and continuating the absorption of the crystal material in the 250-390 nm ultraviolet region. This expands the near-band edge absorption range and creates the advantage of synergistic excitation through dual absorption channels from the matrix and dopant centers, effectively addressing the shortcomings of weak light absorption and low excitation efficiency in pure matrices, thus providing a sufficient energy basis for efficient luminescence. Furthermore, the C–N–H···Cl bonds and Sb bonds in the zero-dimensional structure... 3+ The coordination effect synergistically strengthens the crystal structure. After the material is placed in the air for 1 month, there is no significant change in the luminescence intensity and spectrum. It overcomes the problems of poor environmental stability and easy volatilization of organic-inorganic hybrid perovskite materials, while maintaining high crystallinity and structural integrity, and can be adapted to complex application environments such as high temperature and high humidity.

[0029] (2) This invention employs a mild and controllable solvothermal synthesis method, possessing significant technological advantages and industrialization prospects. The entire reaction is carried out under mild conditions, eliminating the need for harsh processes such as high-temperature calcination and high-pressure treatment. The steps are clear and concise (dissolution-coordination-solvothermal-post-treatment), making operation convenient and efficient. Each reaction parameter (raw material dosage, temperature, time, etc.) is clearly controllable, and the XRD pattern of the product perfectly matches the single-crystal simulation, exhibiting good crystallinity and high purity. It can achieve large-scale stable production with excellent repeatability. The raw materials selected are conventional zirconium tetrachloride, antimony trichloride, and organic ligands, eliminating the need for rare earth elements. Compared with traditional rare earth doping systems, this significantly reduces the material preparation cost. At the same time, the preparation process produces no toxic gas emissions, and the product is free of lead pollution, meeting environmental protection requirements and achieving a balance between economic and environmental benefits. By precisely controlling the reaction conditions, high-purity colorless blocky crystals can be stably obtained, and Sb 3+ The material is uniformly dispersed in the crystal (verified by elemental mapping) without agglomeration, effectively ensuring the consistency and reliability of its luminescent properties.

[0030] (3) The crystal material of this invention has a wide range of applications and is suitable for the actual needs of multiple core fields. Its comprehensive advantages of wide-spectrum high-efficiency luminescence, high quantum efficiency and good stability make it have significant application potential in fields such as fluorescent anti-counterfeiting, fluorescent marking, photoelectric detection, display devices, and fluorescent sensors; in particular, the 635nm characteristic powder light and wide-spectrum emission characteristics can be used to construct a dual anti-counterfeiting logic of specific wavelength excitation and unique emission color in the field of anti-counterfeiting, which greatly increases the difficulty of counterfeiting. In terms of application forms, in addition to bulk crystals, the material can be combined with PDMS to prepare customized luminescent pattern films. With the help of the flexibility and light transmittance of PDMS, flexible and structured applications can be realized, further expanding to flexible displays, wearable devices, personalized anti-counterfeiting labels and other scenarios, enriching the application forms and implementation forms of the material. In addition, the excitation wavelength (349nm) of the material is highly matched with the existing ultraviolet light source technology, and the emission spectrum covers the entire visible light band. It is compatible with existing photoelectric detection devices, display modules and other technology systems, reducing the adaptation cost at the application end and facilitating the acceleration of industrialization.

[0031] (4) This invention constructs a "zero-dimensional organic-inorganic hybrid and Sb 3+ The "site-doped" composite system utilizes the synergistic effect of quantum confinement and doping modification to modulate optoelectronic properties, providing a novel paradigm for performance optimization of wide-bandgap halide materials; simultaneously, it clarifies the Sb 3+ The mechanism of action of the luminescent center provides solid theoretical support for the doping modification research of similar materials. A key breakthrough has been achieved in balancing performance and cost. While ensuring high quantum efficiency, broad-spectrum emission, and high stability, low-cost preparation is achieved through low-cost raw materials and mild processes, resolving the contradiction of "high performance and low cost being mutually exclusive" in traditional high-efficiency luminescent materials, and significantly enhancing the material's market competitiveness. Addressing the core industry pain points of insufficient luminescence performance of undoped zirconium-based chlorides and poor stability of perovskite materials, this invention provides a novel material solution that combines broad-spectrum high-efficiency luminescence with excellent stability, enriching the category of lead-free luminescent functional materials and promoting technological progress in the field of optoelectronic functional materials. Attached Figure Description

[0032] Figure 1 It is the (C9H) prepared in Example 1 of the present invention. 15 Schematic diagram of the crystal structure of the N3)2ZrCl8 sample;

[0033] Figure 2 This is a comparison of the single-crystal fitted XRD patterns and powder XRD patterns before and after doping of the samples prepared in Examples 1 and 2 of this invention;

[0034] Figure 3 It is the (C9H) prepared in Example 2 of the present invention. 15 N3)2ZrCl8:Sb3+ SEM image of the sample;

[0035] Figure 4 It is the (C9H) prepared in Example 2 of the present invention. 15 N3)2ZrCl8:Sb 3+ Mapping images of the samples; where (a) is an EDS layered image showing the superimposed distribution of each element; (b) is a single distribution map of the Cl element; (c) is a single distribution map of the Zr element; and (d) is a single distribution map of the Sb element.

[0036] Figure 5 These are the ultraviolet-visible diffuse reflectance images of the samples prepared in Examples 1 and 2 of the present invention; wherein, (a) is the ultraviolet-visible diffuse reflectance image of the sample prepared in Example 1; and (b) is the ultraviolet-visible diffuse reflectance image of the sample prepared in Example 2.

[0037] Figure 6 These are the excitation and emission spectra of the samples prepared in Examples 1 and 2 of the present invention; wherein (a) and (b) are respectively (C9H 15 The excitation and emission spectra of N3)2ZrCl8, (c) and (d) are respectively (C9H 15 N3)2ZrCl8:Sb 3+ The excitation and emission spectra;

[0038] Figure 7 It is the (C9H) prepared in Example 2 of the present invention. 15 N3)2ZrCl8:Sb 3+ CIE coordinate plot of the sample;

[0039] Figure 8 This is a physical image of the PDMS sample prepared in Example 3 of the present invention. Detailed Implementation

[0040] The following embodiments are further illustrations of the present invention and serve as explanations of the technical content of the present invention. However, the essence of the present invention is not limited to the embodiments described below. Those skilled in the art can and should know that any simple changes or substitutions based on the spirit of the present invention should fall within the protection scope claimed by the present invention.

[0041] Example 1

[0042] This embodiment prepares a product with the chemical formula (C9H). 15 The broad bandgap zirconium-based chloride crystals of N3)2ZrCl8 are obtained through the following steps:

[0043] (1) Weigh 0.233 g of zirconium tetrachloride (ZrCl4), add it to 3 mL of hydrochloric acid, stir until initially dispersed, then add 1 mL of N,N-dimethylformamide (DMF) as an auxiliary solvent; place the mixture in a constant temperature environment of 90 °C, add a magnetic stirring bead and continue stirring and heating until the solution is completely clear;

[0044] (2) Add 160 μL of 1-(2-pyridyl)piperazine ligand to the above clear solution, keep the temperature at 90℃ and the stirring speed ≤300 r / min, and continue stirring until the solution becomes clear again to obtain a homogeneous and stable coordination reaction solution;

[0045] (3) Transfer the clarified coordination reaction solution into a polytetrafluoroethylene liner, seal it, put it into a high-pressure reactor and tighten it; put the reactor into an oven, set the temperature to 90°C, keep it at the temperature for 10 hours, and then let it cool down to room temperature naturally.

[0046] (4) Open the reactor, filter and collect the product, wash the product three times with anhydrous ethanol to remove residual impurities, and dry it in a vacuum drying oven to obtain high-purity colorless block crystals, which are the target matrix crystals (C9H). 15 N3)2ZrCl8.

[0047] Example 2

[0048] This embodiment prepares a product with the chemical formula (C9H). 15 N3)2ZrCl8:Sb 3+ The specific steps for producing antimony-doped, wide-bandgap zirconium chloride crystals are as follows:

[0049] (1) Accurately weigh 0.2097 g ZrCl4 and 0.0228 g antimony trichloride (SbCl3), add them together to 3 mL hydrochloric acid, stir until initially dispersed, then add 1 mL LDM as an auxiliary solvent; place the mixture in a constant temperature environment of 90℃, add a magnetic stirring bead and continue stirring and heating until the solution is completely clear;

[0050] (2) Add 160 μL of 1-(2-pyridyl)piperazine ligand to the above clear solution, keep the temperature at 90℃ and the stirring speed ≤300 r / min, and continue stirring until the solution becomes clear again to obtain a homogeneous and stable coordination reaction solution;

[0051] (3) Transfer the clarified coordination reaction solution into a polytetrafluoroethylene liner, seal it, put it into a high-pressure reactor and tighten it; put the reactor into an oven, set the temperature to 90°C, keep it at the temperature for 10 hours, and then let it cool down to room temperature naturally.

[0052] (4) Open the reactor, filter and collect the product, wash the product three times with anhydrous ethanol to remove residual impurities, and dry it in a vacuum drying oven to obtain high-purity colorless block crystals, which are the target doped crystals (C9H). 15 N3)2ZrCl8:Sb 3+ .

[0053] Example 3

[0054] This embodiment provides a customized luminescent pattern film for anti-counterfeiting applications. The specific preparation steps are as follows:

[0055] (1) The (C9H) prepared in Example 2 15 N3)2ZrCl8:Sb 3+ The crystals were ground into a uniform powder, and 1g of this powder was weighed out as a luminescent filler. 5g of polydimethylsiloxane (PDMS), 0.7g of methyl vinylcyclosiloxane curing agent, and 0.1g of dimethyl silicone oil diluent were weighed out in sequence for later use.

[0056] (2) Place the above-mentioned luminescent filler, PDMS, curing agent and diluent together in a sealed container and stir continuously at 300 r / min for 30 minutes to form a uniformly dispersed suspension;

[0057] (3) Select a custom mold in the shape of a butterfly, spray the release agent evenly on its inner surface and let it dry; slowly inject the prepared suspension into the mold to ensure that the suspension completely fills the mold cavity;

[0058] (4) Place the mold containing the suspension in a vacuum device and maintain the vacuum state for 30 minutes to completely remove the air bubbles in the suspension; after degassing, take out the mold and visually inspect to confirm that there are no visible air bubbles remaining;

[0059] (5) Transfer the mold to an oven, set the temperature to 80℃, and heat to cure for 10 hours; after curing, turn off the oven and allow the mold to cool naturally to room temperature. Then peel the film off the mold to obtain a well-formed (C9H) mold with a clear luminescent pattern. 15 N3)2ZrCl8:Sb 3+ / PDMS composite fluorescent film.

[0060] The (C9H) prepared in Example 1 15 X-ray single-crystal diffraction analysis of N3)2ZrCl8 crystal (e.g.) Figure 1 (As shown). The results indicate that this crystal is a typical organic-inorganic hybrid ionic crystal, with the inorganic framework consisting of discrete [ZrCl8]. 4- Composed of coordination polyhedra, organic cations (C9H) 15 N3) +Complete isolation forms a zero-dimensional structure; organic cations and inorganic anions interact through C–N–H···Cl bonds, stabilizing crystal stacking and structural integrity. This structural feature is beneficial for photophysical behaviors such as exciton localization and broadband emission, and also facilitates the formation of Sb 3+ The preferential replacement of Zr sites and the formation of isolated luminescent centers provide a clear structural basis.

[0061] Figure 2 The images show the single-crystal fitted XRD patterns and powder XRD comparison diagrams of Example 1 (matrix crystal) and Example 2 (doped crystal). The results show that the diffraction peak positions and intensities of both types of crystals are in good agreement with the simulated single-crystal structure patterns, and no impurity peaks appear, indicating that the synthesized crystals have high purity and excellent crystallinity; and Sb 3+ The doping process did not alter the lattice structure of the matrix crystal, proving that the doping process did not destroy the structural integrity of the crystal.

[0062] Example 2 prepared (C9H 15 N3)2ZrCl8:Sb 3+ SEM images of the crystal (e.g.) Figure 3 As shown in the figure, the target crystal exhibits a regular polyhedral morphology and good crystallization. Elemental EDS Mapping (as shown in the figure) Figure 4 In the image shown, (a) is the superimposed distribution image of Cl, Zr, and Sb elements, and (b)-(d) are the individual distribution images of Cl, Zr, and Sb elements, respectively. The results show that Sb element is spatially uniformly distributed with Cl and Zr elements in the crystal, and their positions highly overlap, proving that Sb... 3+ It has been successfully doped into the matrix crystal and uniformly dispersed without agglomeration.

[0063] Figure 5 This is a comparison of the UV-Vis diffuse reflectance spectra of samples from Example 1 and Example 2. The results show that the matrix crystal (C9H) 15 N3)2ZrCl8 exhibits characteristic absorption in the 250-390 nm ultraviolet region, with a calculated band gap of 3.2 eV, consistent with the optical characteristics of a wide bandgap semiconductor; Sb 3+ After doping, the reflectance of the sample in the ultraviolet region decreased significantly and the fluctuations weakened, indicating enhanced light absorption and a tendency towards continuity. Simultaneously, near the absorption edge (390-450 nm), the reflectance of the doped sample in the visible region was slightly lower and the increase was gradual, indicating enhanced absorption near the band edge and a slight narrowing of the band gap or the appearance of a band tail effect. This change confirms that the Sb in Example 2... 3+ Doping can effectively optimize the light absorption characteristics of matrix materials, laying the foundation for improving the luminescence performance in the visible light region.

[0064] Figure 6The figures show a comparison of the excitation and emission spectra of the samples from Example 1 and Example 2, where (a) and (b) are the excitation spectrum (monitoring wavelength 392 nm) and emission spectrum (excitation wavelength 280 nm) of the matrix crystal, respectively, and (c) and (d) are the excitation spectrum (monitoring wavelength 635 nm) and emission spectrum (excitation wavelength 349 nm) of the doped crystal, respectively. Figure 6 (a) It can be seen that the excitation band of the matrix crystal is located in the 250-370nm ultraviolet region, which is broadband and tails towards the long wavelength side, which is consistent with the characteristics of charge transfer (such as halogen → metal / ligand → metal) or exciton state absorption. Figure 6 (b) shows that the matrix crystal produces broadband emission centered at 392 nm under 280 nm excitation, extending into the long-wavelength side of the visible region, which is attributed to the self-trapped excitons (STE) / defect-trapped excitons in the matrix or [ZrCl8]. 4- Broadband radiative recombination of coordination units. Figure 6 (c) indicates that the main excitation peak of the doped crystal is located at 349 nm, and a broadband background exists in the short-wave ultraviolet region, proving that the photoluminescence emission can be effectively excited by near-ultraviolet light, which is attributed to Sb. 3+ Doping-induced localized exciton states or energy transfer from the matrix to the Sb center; Figure 6 (d) shows that the doped crystal exhibits a bimodal emission characteristic under 349 nm excitation: a 395 nm blue peak (corresponding to the matrix emission at 392 nm) and a 635 nm broadband red peak, forming a broad spectrum emission covering 390-820 nm; and the photoluminescence quantum efficiency increases from 35.4% in the matrix to 93.5%, confirming that Sb 3+ A new, highly efficient radiative recombination channel was introduced, which significantly optimized the luminescence performance.

[0065] Figure 7 The CIE color coordinate diagram of the doped crystal in Example 2 is shown, with color coordinates of (0.326, 0.197), clearly indicating that the crystal is a bright phosphor emitter with a unique emission color characteristic.

[0066] Figure 8 The image shown is of the composite fluorescent film prepared in Example 3. This film presents a customized luminescent pattern in the shape of a butterfly, with the luminescent color being pink. This pattern, combining specific wavelength excitation, unique pink light emission, and unique shape, can enhance the difficulty of counterfeiting through dual anti-counterfeiting logic, making it suitable for the field of anti-counterfeiting labels. At the same time, leveraging the flexible properties of PDMS, it can be extended to scenarios such as flexible clothing and wearable devices.

[0067] Example 4

[0068] This embodiment prepares a product with the chemical formula (C9H). 15 N3)2ZrCl8:Sb 3+ The specific steps for producing antimony-doped, wide-bandgap zirconium chloride crystals are as follows:

[0069] (1) Weigh 0.15g zirconium tetrachloride ZrCl4 and 0.015g SbCl3, add them together to 2mL hydrochloric acid, stir until initially dispersed, then add 0.8mL LDM as an auxiliary solvent; place the mixture in a constant temperature environment of 85℃, add a magnetic stirring bead and continue stirring and heating until the solution is completely clear;

[0070] (2) Add 155 μL of 1-(2-pyridyl)piperazine ligand precisely to the above clear solution, keep the temperature at 85℃ and the stirring speed at 280 r / min, and continue stirring until the solution becomes clear again to obtain a homogeneous and stable coordination reaction solution;

[0071] (3) Transfer the clarified coordination reaction solution into a polytetrafluoroethylene liner, seal it, put it into a high-pressure reactor and tighten it; put the reactor into an oven, set the temperature to 85°C, keep it at the temperature for 9 hours, and then let it cool naturally to room temperature.

[0072] (4) Open the reactor, filter and collect the product, wash the product three times with anhydrous ethanol to remove residual impurities, and dry it in a vacuum drying oven to obtain high-purity colorless block crystals, which are the target doped crystals (C9H). 15 N3)2ZrCl8:Sb 3+ .

[0073] Example 5

[0074] This embodiment prepares a product with the chemical formula (C9H). 15 N3)2ZrCl8:Sb 3+ The specific steps for producing antimony-doped, wide-bandgap zirconium chloride crystals are as follows:

[0075] (1) Accurately weigh 0.28g ZrCl4 and 0.028g SbCl3, add them together to 4mL hydrochloric acid, stir until initially dispersed, then add 1.8mL LDM as an auxiliary solvent; place the mixture in a constant temperature environment of 95℃, add a magnetic stirring bead and continue stirring and heating until the solution is completely clear;

[0076] (2) Add 175 μL of 1-(2-pyridyl)piperazine ligand precisely to the above clear solution, keep the temperature at 95℃ and the stirring speed at 250 r / min, and continue stirring until the solution becomes clear again to obtain a homogeneous and stable coordination reaction solution;

[0077] (3) Transfer the clarified coordination reaction solution into a polytetrafluoroethylene liner, seal it, put it into a high-pressure reactor and tighten it; put the reactor into an oven, set the temperature to 95°C, keep it at the temperature for 11 hours, and then let it cool naturally to room temperature.

[0078] (4) Open the reactor, filter and collect the product, wash the product three times with anhydrous ethanol to remove residual impurities, and dry it in a vacuum drying oven to obtain high-purity colorless block crystals, which are the target doped crystals (C9H). 15 N3)2ZrCl8:Sb 3+ .

[0079] This invention uses zero-dimensional discrete [ZrCl8] 4- Coordination polyhedra serve as the inorganic host unit, coupled with organic cations via C–N–H···Cl bonds to construct a monoclinic wide-bandgap zirconium-based chloride matrix, through Sb 3+ By preferentially replacing Zr sites to introduce independent luminescent centers with high transition probabilities, precise control over the absorption and luminescence behavior of materials can be achieved.

[0080] Implementation examples demonstrate that the obtained (C9H) 15 N3)2ZrCl8:Sb 3+ The crystal exhibits good absorption in the 250-390nm ultraviolet region and produces bright pink light dominated by 635nm under 349nm excitation. Its bimodal emission covers the 390-820nm visible light range, with a photoluminescence quantum efficiency of 93.5%, combining the advantages of high-efficiency luminescence and broad-spectrum emission. The preparation process adopts a mild solvothermal method, which is simple, low-cost, and highly reproducible, making it easy to scale up production. Customized luminescent films can be prepared by combining it with PDMS, expanding its application scenarios to include anti-counterfeiting labels, fluorescent markers, and flexible devices. Furthermore, the material shows no significant change in luminescence intensity and spectrum after being placed in air for one month, demonstrating excellent chemical and air stability, providing a reliable guarantee for practical applications.

[0081] 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 or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An antimony-doped wide-bandgap zirconium chloride photoluminescent crystal material, characterized in that, The chemical formula of the photoluminescent crystal material is (C9H). 15 N3)2ZrCl8:Sb 3+ It belongs to the monoclinic crystal system and has the space group P21 / c; In the aforementioned photoluminescent crystal material, each zirconium atom is coordinated with eight chlorine atoms to form [ZrCl8]. 4- Polyhedral structure, organic cation (C9H) 15 N3) + It is linked to inorganic anions via C–N–H···Cl bonds, forming discrete [ZrCl8]. 4- The octahedral structure is replaced by organic cations (C9H). 15 N3) + Complete isolation, forming a zero-dimensional ionic crystal structure; The unit cell parameters of the light-emitting crystal material are a = 8.9385 Å, b = 12.7386 Å, c = 12.5600 Å, α = 90°, β = 101.188°, γ = 90°, Z = 2, V = 1402.9531 Å. 3 .

2. The antimony-doped wide-bandgap zirconium-based photoluminescent crystal material as described in claim 1, characterized in that, The photoluminescent crystalline material has a band gap of 3.2 eV and exhibits good light absorption characteristics in the 250-390 nm ultraviolet region; it displays a bimodal emission spectrum under 349 nm ultraviolet excitation, and the bimodal emission spectrum covers the 390-820 nm visible light range, wherein Sb 3+ The induced characteristic emission peak is located at 635 nm.

3. The antimony-doped wide-bandgap zirconium chloride photoluminescent crystal material as described in claim 1, characterized in that, The photoluminescence color coordinates of the photoluminescence emitting crystal material are (0.326, 0.197).

4. The method for preparing antimony-doped wide-bandgap zirconium-based photoluminescent crystal material according to any one of claims 1-3, characterized in that, Includes the following steps: 1) Dissolve zirconium tetrachloride and antimony trichloride in hydrochloric acid, add N,N-dimethylformamide, and heat and stir until the solution is clear; 2) Add 1-(2-pyridyl)piperazine ligand to the clear solution from step 1), and stir under controlled temperature until the solution becomes clear again; 3) Transfer the clear solution obtained in step 2) into a polytetrafluoroethylene liner, seal it, and place it in a high-pressure reactor for solvothermal reaction; 4) After the reaction is complete, the temperature is lowered to room temperature, the product is filtered, washed with ethanol and dried to obtain the target crystal material.

5. The method for preparing the antimony-doped wide-bandgap zirconium-based photoluminescent crystal material as described in claim 4, characterized in that, In step 1), the amount of zirconium tetrachloride is 0.1-0.3g, the amount of antimony trichloride is 0.01-0.03g, the amount of hydrochloric acid is 1-5mL, the amount of N,N-dimethylformamide is 0.5-2mL, and the heating and stirring temperature is 80-100℃.

6. The method for preparing the antimony-doped wide-bandgap zirconium-based photoluminescent crystal material as described in claim 4, characterized in that, In step 2), the amount of 1-(2-pyridyl)piperazine ligand added is 150-180 μL, the stirring temperature is maintained at 80-100℃, and the stirring speed is ≤300 r / min.

7. The method for preparing the antimony-doped wide-bandgap zirconium-based photoluminescent crystal material as described in claim 4, characterized in that, In step 3), the temperature of the solvothermal reaction is 80-100℃ and the time is 8-12 hours.

8. The application of the antimony-doped wide bandgap zirconium chloride powder emitting crystal material as described in any one of claims 1-3 or the antimony-doped wide bandgap zirconium chloride powder emitting crystal material prepared by the preparation method described in any one of claims 4-7 in fluorescent labeling devices, photodetectors, display devices, fluorescent sensors or flexible wearable devices.

9. A fluorescent anti-counterfeiting label, characterized in that, The fluorescent anti-counterfeiting label is prepared by the following method: the antimony-doped wide bandgap zirconium chloride powder emitting crystal material as described in any one of claims 1-3 or the antimony-doped wide bandgap zirconium chloride powder emitting crystal material prepared by the preparation method described in any one of claims 4-7 is ground into powder, compounded with polydimethylsiloxane, curing agent and diluent, and then vacuum degassed and cured at 80-100℃ for 8-12 hours to obtain a luminescent pattern film, which is the fluorescent anti-counterfeiting label.

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