Sm-doped zinc gallate multi-color luminescent material and its temperature sensing and multi-mode anti-counterfeiting applications

Abstract

This application relates to the field of luminescent materials technology, and in particular to a rare-earth samarium-doped zinc gallate multicolor luminescent material and its temperature sensing and multimode anti-counterfeiting applications, comprising a ZnGa2O4 matrix and co-doped Sm 3+ It is prepared by reacting boric acid with the material in a high-temperature solid-state reaction. This material can achieve continuous color change from blue to red light under different ultraviolet excitation wavelengths or temperatures, and has both long red afterglow and enhanced near-infrared luminescence, making it suitable for anti-counterfeiting, temperature-sensitive detection, and bio-imaging.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials technology, specifically a rare-earth samarium-doped zinc gallate multicolor luminescent material and its temperature sensing and multimode anti-counterfeiting applications. Background Technology

[0002] Rare-earth-doped luminescent materials have wide applications in lighting, displays, bioimaging, and anti-counterfeiting due to their excellent optical properties. Among them, zinc gallate has become a hot research topic in recent years because of its chemical stability, the ability to replace gallium and zinc cation sites with rare-earth luminescent ions to construct luminescent materials, and the presence of numerous intrinsic defects in its crystal lattice that allow for the design of multimode luminescent materials. Samarium ions (Sm...) 3+ As a typical rare-earth luminescent ion, samarium (Sm) exhibits multiple characteristic emission peaks in the visible light region (such as 570 nm, 615 nm, and 654 nm), displaying orange-red to red luminescence. Sm-doped luminescent materials have been extensively studied in white LED lighting, sensing, and anti-counterfeiting applications. However, existing technologies for multicolor luminescent materials based on Sm doped zinc gallate systems still suffer from problems such as low excitation efficiency, limited color coordinate control range, and complex fabrication processes. In this invention, zinc gallate-doped rare-earth Sm ions, under 264 nm ultraviolet light excitation, exhibit a broad blue light at 433 nm (originating from charge migration in the matrix Ga-O), and near-infrared peaks at 698 nm and 714 nm (V2). O * →O 2- Sm at 570 nm, 615 nm and 654 nm 3+ The composite emission spectrum is composed of characteristic emissions; after excitation stops, the material continues to emit red afterglow at 713 nm for several minutes; when the excitation wavelength gradually increases from 264 nm to 294 nm, the intensity of blue light at 433 nm decreases significantly, while the relative intensity of red light at 713 nm increases, causing the overall emission color to transition from blue through yellow-green to red; in addition, within the temperature range of 25℃ to 120℃, as the temperature increases, the intensity of blue light emission at 433 nm decreases monotonically, while the intensity of red light emission at 713 nm continues to increase, realizing dynamic color coordinate shift based on temperature response.

[0003] Patent CN102277172B discloses rare-earth luminescent materials and their preparation methods, with the general formula Y2. 3-x Ln x (Al1-yGay)5O12@M (Ln is Ce or Tb, M is Au, Ag, or other metal nm particles) enhances luminescence efficiency through surface plasmon resonance. Although this material exhibits high luminescence intensity under specific wavelength excitation, its activated ions are mainly limited to Ce. 3+ and Tb3+ Sm was not involved. 3+ The doped system, whose emission color is concentrated in the green or yellow-green region, failed to achieve Sm 3+ Its unique multi-peak red-orange emission is not designed for multi-color adjustability.

[0004] Patent CN101016456A discloses a rare-earth multi-element co-activated long-afterglow luminescent material with the chemical composition aMO·bAl2O3·cSiO2·dGa2O3:xEu·yB·zN (M=Ca or Sr, N=Dy or Nd). Ga2O3 is introduced as a matrix component to improve water resistance. Although this material contains gallium and possesses long afterglow characteristics, its activator is Eu. 2+ / Eu 3+ With Dy 3+ / Nd 3+ The combination did not use Sm 3+ As the light-emitting center, it cannot display Sm 3+ It exhibits a unique multicolor emission spectrum. Furthermore, this system relies on the synergistic effect of multiple co-activating ions, resulting in a complex composition that hinders precise control of multicolor luminescence behavior under a single activator system.

[0005] In summary, while existing technologies include luminescent materials involving gallium carbonate matrices or samarium ion doping, none have yet been found to incorporate Sm... 3+ Reports have documented the introduction of gallium salt systems as the sole or primary activator to achieve efficient, tunable multicolor emission. Summary of the Invention

[0006] This invention provides a multicolor luminescent material of gallate doped with rare-earth samarium ions and its preparation method, aiming to introduce Sm into a ZnGa2O4 spinel matrix. 3+ A novel photoluminescent material with multimodal luminescence response characteristics was constructed by using ions and boric acid (H3BO3) as co-dopersants. This material exhibits blue photoluminescence at a specific ultraviolet excitation wavelength, produces a long red afterglow after excitation stops, and can achieve a continuous color transition from blue to red light under different excitation wavelengths or temperatures, while enhancing the luminescence intensity in the near-infrared region.

[0007] In a first aspect, the present invention provides a method for preparing a rare-earth samarium ion-doped gallium carbonate multicolor luminescent material, comprising the following steps: S10: Weigh the zinc-containing precursor, gallium-containing precursor, samarium-containing precursor, and boric acid according to the stoichiometric ratio; wherein, the general formula of the luminescent material is ZnGa 2-x O4:xSm 3+ ,yH3BO3, where x ranges from 0.01 to 0.19 and y is 0.09; S20: Place the above raw materials in a mortar, add organic solvent and wet grind to ensure that all components are fully mixed and uniform; the ratio of the total mass of raw materials to the volume of organic solvent is 1g:1ml to 1.5ml, and the grinding time is 0.5h to 2h. S30: Transfer the ground slurry to an oven and dry it at 55℃ to 65℃ for 1-5 hours to obtain a dry powder; S40: The dry powder is placed in a corundum crucible and placed in a tube furnace. It is heated to 1200°C in air at a heating rate of 1°C to 10°C per minute and held at this temperature for 4 hours. S50: After naturally cooling to room temperature, the sintered product is ground again to obtain powder with a particle size of 3 to 5 micrometers, which is the rare earth samarium ion-doped gallium salt multicolor luminescent material.

[0008] According to the present invention, ZnGa2O4 is used as the matrix material. Its spinel structure possesses good thermal stability and chemical inertness, and its wide bandgap characteristics (4.4 to 5.0 eV) are beneficial for reducing the reabsorption of light emitted by doped ions. Sm 3+ Ions occupy Zn 2+ or Ga 3+ After the lattice sites are established, an effective energy transfer channel is formed between its 4f electronic level and the matrix conduction band or valence band. Simultaneously, the introduction of boric acid not only acts as a flux to lower the synthesis temperature and promote grain densification, but also influences the Sm group by regulating the local coordination environment. 3+ The crystal field splits, thereby modulating its luminescence properties. Furthermore, cation antisite defects (such as Zn) formed during high-temperature solid-state reactions... 2+ Entering the octahedral position, Ga 3+ Intrinsic defects such as tetrahedral sites and oxygen vacancies constitute effective electron / hole trap energy levels, providing the physical basis for carrier storage and slow release for long afterglow luminescence.

[0009] In some embodiments, in step S10, the zinc-containing precursor is selected from at least one of zinc oxide (ZnO), zinc carbonate (ZnCO3), or zinc nitrate (Zn(NO3)2·6H2O).

[0010] In some embodiments, in step S10, the gallium-containing precursor is selected from at least one of gallium trioxide (Ga2O3), gallium phosphate (GaPO4), or gallium hydrogen phosphate (GaHPO4).

[0011] In some embodiments, in step S10, the samarium-containing precursor is selected from at least one of samarium trioxide (Sm2O3) or samarium nitrate (Sm(NO3)3·6H2O).

[0012] In some embodiments, in step S20, the organic solvent is anhydrous ethanol.

[0013] In some embodiments, in step S40, the protective atmosphere inside the tube furnace is any one of air, nitrogen, argon, hydrogen, or oxygen, with air atmosphere being the preferred condition.

[0014] In some implementations, in step S10, the value of x is further limited to 0.01-0.15, within which Sm 3+ The doping concentration can effectively avoid concentration quenching effect while maximizing the red light emission intensity at 713 nm.

[0015] In some embodiments, in step S10, the amount of boric acid added is fixed at 0.09 molar equivalents. This ratio, relative to the ZnGa2O4 matrix, has been experimentally verified to significantly improve the crystallinity of the material and optimize the trap energy level distribution.

[0016] In some embodiments, in step S50, grinding is carried out using an agate mortar or ball mill, and the average particle size of the final product is controlled to be between 3-5 μm, so as to balance luminescence efficiency and dispersion performance.

[0017] Secondly, this invention provides a rare-earth samarium ion-doped gallium salt multicolor luminescent material, whose general chemical formula is ZnGa 2-x O4:xSm 3+ The composition is 0.09H3BO3, where x ranges from 0.01 to 0.15. This material belongs to the cubic crystal system with space group Fd3m. Its X-ray diffraction pattern perfectly matches the standard ZnGa2O4 card, and no impurity peaks were detected. Under 264 nm ultraviolet excitation, the material exhibits a broadband blue light at 433 nm (originating from charge migration in the matrix Ga-O), and near-infrared peaks at 698 nm and 714 nm (V2). O * →O 2- Sm at 570 nm, 615 nm and 654 nm 3+ The composite emission spectrum is composed of characteristic emissions; after excitation stops, the material continues to emit red afterglow at 713 nm for several minutes; when the excitation wavelength gradually increases from 264 nm to 294 nm, the intensity of blue light at 433 nm decreases significantly, while the relative intensity of red light at 713 nm increases, causing the overall emission color to transition from blue through yellow-green to red; in addition, within the temperature range of 25℃ to 120℃, as the temperature increases, the intensity of blue light emission at 433 nm decreases monotonically, while the intensity of red light emission at 713 nm continues to increase, realizing dynamic color coordinate shift based on temperature response.

[0018] According to the present invention, Sm 3+ Effective doping alters the defect types and concentration distribution in the ZnGa2O4 lattice. Specifically, Sm 3+ Replace Ga 3+ When entering the octahedral site, due to the difference in ionic radius (Sm) 3+ It is 1.08 Ga 3+ It is 0.62 This leads to local lattice distortion, promoting the formation of oxygen vacancies (V_O); simultaneously, to maintain electroneutrality, it may be accompanied by Zn... 2+ Vacancy (V) Zn ** ) or Ga 3+ The generation of vacancy (V_Ga), Ga 3+ Ions will occupy vacancy defects V Zn ** This results in the formation of Gazn with a positive valence of +1. These defect levels are located in the band gap at a moderate depth (approximately 0.6 to 1.0 electron volts), effectively trapping photogenerated electrons or holes, which are then slowly released under thermal perturbation and re-interact with Sm. 3+ The excited-state recombination produces a long afterglow. The introduction of boric acid further modulates the liquid phase behavior during sintering, inhibits abnormal grain growth, and through B... 3+ Some of these particles enter the crystal lattice or form a surface borate layer, passivating nonradiative recombination centers and improving luminescence quantum efficiency.

[0019] In some embodiments, the emission spectrum of the multicolor luminescent material under 264 nm excitation includes three main peaks: 433 nm (HWHM of approximately 80 nm), 698 nm (HWHM of approximately 5 nm), and 714 nm (HWHM of approximately 6 nm), wherein the 433 nm peak originates from octahedral Ga coordinated in the ZnGa2O4 matrix. 3+ -O 2- The charge transfer bands at 570 nm, 615 nm, and 654 nm are attributed to Sm 3+ of 4 G 5 / 2 → 6 H 5 / 2 , 4 G 5 / 2 → 6 H 7 / 2 and 4 G 5 / 2 → 6 H 9 / 2 The 698 nm and 714 nm peaks are attributed to the V in the distorted oxygen vacancy octahedron in the matrix, respectively. O * Towards the surrounding O 2-The resulting electric dipole transition.

[0020] In some embodiments, the afterglow decay curve of the material conforms to a double exponential decay model, with an initial rapid decay component ( ≈10 seconds) corresponds to the release of a shallow trap, with a slow decaying component ( (≈120 seconds) corresponds to the release of the deep trap, and both contribute to the visible red afterglow.

[0021] In some embodiments, the chromaticity coordinates of the material cover a region from (0.16, 0.12) (blue) to (0.58, 0.40) (red) in the CIE1931 chromaticity diagram as a function of excitation wavelength, thus possessing wide color gamut control capability.

[0022] In some embodiments, the material exhibits a decrease of over 80% in 433 nm emission intensity and an increase of approximately 40% in 713 nm emission intensity as the temperature rises from 25°C to 120°C. This thermochromic behavior stems from the higher temperature sensitivity of matrix defect state emission to temperature compared to Sm... 3+ The ff transition, which has better thermal stability due to parity forbidment.

[0023] In some embodiments, the integrated intensity of the near-infrared emission (700 to 800 nm) of the material is in the range of Sm 3+ The doping concentration x=0.05 reaches a maximum value of 18395 (in any unit), which is more than two orders of magnitude higher than the undoped sample, indicating that Sm 3+ It effectively enhances the near-infrared emission channel.

[0024] Thirdly, this invention provides applications of the rare-earth samarium ion-doped gallate multicolor luminescent material in anti-counterfeiting labels, temperature sensing, bioimaging, and multicolor display devices. In advanced anti-counterfeiting, utilizing its distinctly different emission colors (blue vs. red) and the presence or absence of afterglow under 264 nm and 294 nm ultraviolet light, dual optical anti-counterfeiting labels that are difficult to replicate can be designed. In temperature sensing, based on its continuously changing thermoluminescent color, non-contact optical temperature probes can be fabricated. In bioimaging, its near-infrared long afterglow characteristic can avoid tissue autofluorescence interference, achieving high signal-to-noise ratio imaging.

[0025] According to the present invention, the preparation method employs a conventional high-temperature solid-state method, requiring no complex equipment or expensive reagents. The raw materials are all industrial-grade chemicals, resulting in low cost, good process repeatability, and suitability for large-scale production. By precisely controlling Sm... 3+ Doping concentration, boric acid addition amount, and calcination parameters can be used to directionally control the luminescence color, afterglow performance, and thermal response characteristics of materials, solving the problems of single color, weak afterglow, and lack of Sm in existing gallium salt luminescent materials. 3+Technical bottlenecks in multicolor emission and temperature response functions. Attached Figure Description

[0026] Figure 1 The phosphor samples in Example 1 and Comparative Examples 1-3 of this invention were subjected to a temperature range of 400-2000 cm⁻¹. -1 FTIR spectra within the range; Figure 2 The XRD patterns of the samples calcined in air atmosphere according to the present invention (x=0, 0.01, 0.003, 0.05, 0.07, 0.09, 0.13, 0.15); Figure 3 The morphology and particle size characteristics of Example 1 of the present invention are shown below; (a) SEM spectra at different scales; (b) EDS scan of the selected object and the scan spectrum of each element; (c) EDS scan of the full spectrum. Figure 4 The excitation spectrum of the sample (x=0, 0.01, 0.003, 0.05, 0.07, 0.09, 0.13, 0.15) calcined in air atmosphere at 433 nm is shown. Figure 5 The excitation spectrum of the sample (x=0, 0.01, 0.003, 0.05, 0.07, 0.09, 0.13, 0.15) calcined in air at 713 nm is shown below. Figure 6 The emission spectra of the samples (x=0, 0.01, 0.003, 0.05, 0.07, 0.09, 0.13, 0.15) calcined in air atmosphere at 264 nm are shown. Figure 7 The emission spectra of Embodiment 1 of the present invention at different excitation wavelengths; Figure 8 This is a CIE coordinate diagram of Embodiment 1 of the present invention under different excitation wavelengths; Figure 9 These are photoluminescence images of Embodiment 1 of the present invention at different temperatures; Figure 10 These are images taken by an electronic device at different temperatures in Embodiment 1 of the present invention; Figure 11 This is the afterglow spectrum of Embodiment 1 of the present invention; Figure 12 This is an afterglow image taken with an electronic device in Embodiment 1 of the present invention. Detailed Implementation

[0027] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] As described in the background section above, most gallium-based luminescent materials currently rely on single rare-earth ion doping, resulting in fixed emission colors, a lack of dynamic color-changing capabilities in response to excitation wavelength or temperature, and generally weak afterglow performance. 3+ Although it possesses abundant ff transition energy levels, its direct excitation efficiency is low due to parity-forbidden characteristics, requiring matrix sensitization. Furthermore, the defect manipulation methods in the ZnGa2O4 spinel structure are limited, making it difficult to construct electron / hole traps of suitable depth to support long afterglow. In addition, existing preparation methods lack sufficient control over the type and ratio of co-dopers, resulting in poor crystallinity and numerous non-radiative recombination centers, thus limiting near-infrared emission intensity and quantum efficiency.

[0031] Based on this, the present invention provides a rare-earth samarium ion-doped gallate multicolor luminescent material and its preparation method, by precisely introducing Sm into a ZnGa2O4 matrix. 3+ By using a fixed ratio of boric acid (H3BO3) and a high-temperature solid-state reaction, a luminescent system with controllable defect structure and optimized coordination environment is constructed, achieving blue-red composite emission under ultraviolet excitation, long red afterglow after excitation cessation, wavelength-dependent color tunability, and temperature-induced thermochromic behavior.

[0032] In a first aspect, the present invention provides a method for preparing a rare-earth samarium ion-doped gallium carbonate multicolor luminescent material, comprising the following steps: S10: Weigh the zinc-containing precursor, gallium-containing precursor, samarium-containing precursor, and boric acid according to the stoichiometric ratio; wherein, the general formula of the luminescent material is ZnGa 2-X O4:xSm 3+,yH3BO3, where x ranges from 0.01 to 0.15 and y is 0.09; S20: Place the above raw materials in a mortar, add organic solvent and wet grind to ensure that all components are fully mixed and uniform; the ratio of the total mass of raw materials to the volume of organic solvent is 1g:1 ml to 1.5 ml, and the grinding time is 0.5 h to 2 h; S30: Transfer the ground slurry to an oven and dry it at 55°C to 65°C for 1 to 5 hours to obtain a dry powder; S40: The dry powder is placed in a corundum crucible and placed in a tube furnace. It is heated to 1200°C in air at a heating rate of 1°C to 10°C per minute and held at this temperature for 4 hours. S50: After naturally cooling to room temperature, the sintered product is ground again to obtain powder, which is the rare earth samarium ion-doped gallium salt multicolor luminescent material.

[0033] According to the present invention, in step S10, the zinc-containing precursor is selected from at least one of zinc oxide (ZnO), zinc carbonate (ZnCO3), or zinc nitrate (Zn(NO3)2·6H2O). The gallium-containing precursor is selected from at least one of gallium trioxide (Ga2O3), gallium phosphate (GaPO4), or gallium hydrogen phosphate (GaHPO4). The samarium-containing precursor is selected from at least one of samarium trioxide (Sm2O3) or samarium nitrate (Sm(NO3)3·6H2O). Boric acid (H3BO3) is used as a co-doperant, and its molar addition relative to the ZnGa2O4 matrix is ​​fixed at 0.09. This ratio has been verified by numerous experiments to effectively promote grain growth, suppress impurity phase formation, and optimize the trap energy level distribution.

[0034] In step S20, the organic solvent is preferably anhydrous ethanol with a purity of not less than 99.7% to avoid introducing moisture or other impurities that could affect the subsequent calcination process. Wet grinding is performed using an agate mortar. During the grinding process, a small amount of anhydrous ethanol needs to be continuously added to maintain the fluidity of the slurry and prevent dry grinding from causing localized overheating or component segregation. The grinding time is controlled between 0.5 and 2 hours to ensure that the precursor particles are fully dispersed and mixed at the molecular level.

[0035] In step S30, the drying temperature is set within the range of 55℃ to 65℃ to avoid excessively high temperatures causing premature decomposition of nitrate precursors, which would produce gas, resulting in loose powder or loss of components. The drying time is adjusted according to the slurry thickness; typically, 1 to 5 hours is sufficient to completely remove the solvent and obtain a loose, easily pulverized dry powder.

[0036] Step S40 is the critical calcination step. The corundum crucible needs to be pre-calcined at 1200°C for 2 hours to remove surface adsorbates. The heating rate of the tube furnace is controlled at 1°C per minute to 10°C per minute, preferably 5°C per minute, to balance thermal stress and reaction kinetics. The calcination atmosphere is air, and the oxygen partial pressure is favorable for Sm 3+ It exists stably in the +3 oxidation state and promotes the formation of oxygen vacancies. The holding time is fixed at 4 hours to ensure complete reaction and sufficient grain development. Using inert atmospheres such as nitrogen or argon may lead to Sm... 2+ The formation and destruction of luminescent centers can occur; if a reducing atmosphere such as hydrogen is used, the matrix may be over-reduced, reducing luminescence efficiency.

[0037] In step S50, the sintered block becomes hard after natural cooling and requires secondary grinding using an agate mortar or planetary ball mill. The grinding media is zirconia balls, with a ball-to-material ratio of 10:1, a rotation speed of 300 rpm, and a grinding time of 30 minutes, ultimately obtaining powder with an average particle size between 3-5 μm. This particle size range ensures good light scattering properties and facilitates subsequent coating or dispersion applications.

[0038] In some implementations, the value of x is further limited to 0.01-0.15. When x is less than 0.01, Sm 3+ Insufficient concentration results in weak red light emission intensity; when x is higher than 0.05, Sm 3+ The shortening of the inter-wavelength distance leads to cross-relaxation, resulting in concentration quenching and a decrease in the 713 nm emission intensity. Experiments show that the near-infrared integrated intensity reaches a peak of 18395 (in arbitrary units) when x=0.05.

[0039] In other embodiments, the amount of boric acid added is strictly controlled to 0.09 molar equivalents. If y < 0.09, the fluxing effect is insufficient, resulting in fine grains with many defects; if y > 0.09, excess boric acid will volatilize at high temperatures, potentially corroding the furnace tube or forming a glassy phase that encapsulates the grains, reducing luminescence efficiency.

[0040] Secondly, this invention provides a rare-earth samarium ion-doped gallium salt multicolor luminescent material, whose general chemical formula is ZnGa 2-x O4:xSm 3+ The material contains 0.09H₃BO₃, where x ranges from 0.01 to 0.15. X-ray diffraction (XRD) analysis showed that the diffraction peak positions perfectly matched those of the JCPDS No. 38-1240 standard card. It has space group Fd₃m, a cubic crystal system, and no Sm₂O₃, B₂O₃, or other impurity phase peaks were observed, indicating that Sm₂O₃ is the precursor. 3+ Element B successfully enters the crystal lattice or forms an amorphous interface layer.

[0041] Under 264 nm ultraviolet light excitation, the material's emission spectrum includes a broad peak at 433 nm (HWHM of approximately 80 nm), a narrow peak at 698 nm (HWHM of approximately 5 nm), and a narrow peak at 714 nm (HWHM of approximately 6 nm). The 433 nm peak originates from octahedral Ga coordination in the ZnGa2O4 matrix. 3+ -O 2- The charge transfer band; the small peaks appearing at 570 nm, 615 nm and 654 nm are respectively attributed to Sm 3+ of 4 G 5 / 2 → 6 H 5 / 2 , 4 G 5 / 2 → 6 H 7 / 2 and 4 G 5 / 2 → 6 H 9 / 2 The 698 nm and 714 nm peaks are attributed to the V in the distorted oxygen vacancy octahedron in the matrix, respectively. O * Towards the surrounding O 2- The resulting electric dipole transition. When the excitation wavelength is switched to 294 nm, the intensity of the 433 nm peak decreases to less than 5% of the initial value, while Sm... 3+ The emission peak remained stable, and the overall emission was orange-red. Afterglow testing showed that emission at 713 nm continued for several minutes after excitation ceased.

[0042] The CIE 1931 chromaticity coordinates shift continuously from (0.16, 0.12) to (0.58, 0.40) as the excitation wavelength increases from 264 nm to 294 nm, covering the blue, cyan, green, yellow, orange, and red regions. During a temperature increase from 25℃ to 120℃, the emission intensity at 433 nm decreases by more than 80%, while the intensity at 713 nm increases by approximately 40%, and the chromaticity coordinates shift along the red light direction.

[0043] The following describes embodiments of the present invention. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0044] Example 1 S10 is calculated by weighing ZnO: 0.814 g, Ga2O3: 1.826 g, Sm2O3: 0.087 g, H3BO3: 0.055 g, x=0.05, y=0.09; S20: Place the above powder in an agate mortar, add 2.7 ml of anhydrous ethanol, and wet grind for 1 h; S30: Dry the slurry in an oven at 60℃ for 3 hours; S40: Place in a corundum crucible and heat to 1200 ℃ at 5 ℃ per minute in air atmosphere, and hold for 4 h; S50: After cooling, ball mill for 30 minutes to obtain powder.

[0045] Example 2 S10: Weigh out ZnO: 0.814 g, Ga2O3: 1.865 g, Sm2O3: 0.017 g, H3BO3: 0.055 g, corresponding to x=0.01, y=0.09; the remaining steps are the same as in Example 1.

[0046] Example 3 S10: Weigh out ZnO: 0.814 g, Ga2O3: 1.790 g, Sm2O3: 0.157 g, H3BO3: 0.055 g, x=0.09, y=0.09; the remaining steps are the same as in Example 1.

[0047] Example 4 S10: Weigh out ZnO: 0.814 g, Ga2O3: 1.734 g, Sm2O3: 0.262 g, H3BO3: 0.055 g, x=0.15, y=0.09; the remaining steps are the same as in Example 1.

[0048] Comparative Example 1 S10 weighs out ZnO: 0.814 g, Ga2O3: 1.826 g, Sm2O3: 0.087 g, x=0.05, y=0; the remaining steps are the same as in Example 1.

[0049] Comparative Example 2 S10 weighs out 0.814 g of ZnO, 1.826 g of Ga2O3, x=0, y=0; the remaining steps are the same as in Example 1.

[0050] Comparative Example 3 S10 weighs out 0.814 g of ZnO, 1.8744 g of Ga2O3, x=0, y=0; the remaining steps are the same as in Example 1.

[0051] Comparative Example 4 S10: Weigh out ZnO: 0.814 g, Ga2O3: 1.874 g, Sm2O3: 0.087 g, H3BO3: 0.110 g (y=0.18); the remaining steps are the same as in Example 1.

[0052] The above samples were subjected to XRD, photoluminescence (PL), afterglow, and thermoluminescence tests. The results are shown in the table below:

[0053] As shown in the table, Examples 1 to 4 all exhibited strong red light emission, long afterglow, and wide color gamut control capabilities, with Example 2 showing the best performance. Comparative Example 1, lacking boric acid, had poor crystallinity, numerous defects, and weak luminescence; Comparative Example 2, with excessive boric acid, formed a non-radiative channel, resulting in a significant decrease in performance.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rare-earth samarium-doped zinc gallate multicolor luminescent material and its temperature sensing and multimode anti-counterfeiting applications, characterized in that, Includes the following steps: S10: take the zinc-containing precursor, the gallium-containing precursor, the samarium-containing precursor and boric acid according to the stoichiometric ratio; wherein the composition general formula of the luminescent material is ZnGa 2-x O4:xSm 3+ yH3BO3, x is in the range of 0.01 to 0.19, and y is 0.

09. S20: Place the above raw materials in a mortar, add organic solvent and wet grind to ensure that all components are fully mixed and uniform; the ratio of the total mass of raw materials to the volume of organic solvent is 1 g: 1 ml to 1.5 ml, and the grinding time is 0.5 h to 2 h. S30: Transfer the ground slurry to an oven and dry it at 55 ℃ to 65 ℃ for 1 h to 5 h to obtain a dry powder; S40: The dry powder is placed in a corundum crucible and placed in a tube furnace. It is heated to 1200°C in air at a heating rate of 1°C to 10°C per minute and held at this temperature for 4 hours. S50: After naturally cooling to room temperature, the sintered product is ground again to obtain powder, which is the rare earth samarium ion-doped gallium salt multicolor luminescent material.

2. The preparation method according to claim 1, characterized in that, In step S10, the zinc-containing precursor is selected from at least one of zinc oxide, zinc carbonate, or zinc nitrate.

3. The preparation method according to claim 1, characterized in that, In step S10, the gallium-containing precursor is selected from at least one of gallium trioxide, gallium phosphate, or gallium hydrogen phosphate.

4. The preparation method according to claim 1, characterized in that, In step S10, the samarium-containing precursor is selected from at least one of samarium trioxide or samarium nitrate.

5. The preparation method according to claim 1, characterized in that, In step S20, the organic solvent is anhydrous ethanol.

6. The preparation method according to claim 1, characterized in that, In step S40, the atmosphere inside the tubular furnace is either air or oxygen.

7. The preparation method according to claim 1, characterized in that, In step S10, the value of x ranges from 0.01 to 0.

15.

8. The preparation method according to claim 1, characterized in that, In step S50, grinding is performed using an agate mortar and pestle or a ball mill.

9. A rare-earth samarium ion-doped gallium salt multicolor luminescent material, the general chemical formula of which is ZnGa 2-x O4:xSm 3+ ,0.09H3BO3, where x is between 0.01 and 0.19.

Images