Multivalent sulfide upconversion luminescent materials

Abstract

To provide a polysulfide upconversion luminescence material having higher upconversion luminescence efficiency and safety and wider application ranges compared with industrial NaYF4: Yb, Er materials.SOLUTION: The present invention employs a polysulfide as a host and rare earth ions as an activator, with the general formula of material being mA2S nBS kC2-xS3:Dx. The upconversion luminescence material provided in the present invention can emit ultraviolet, blue, blue-green, green, red and near-infrared light when excited by near infrared light at 750-1650 nm. The upconversion luminescence material provided in the present invention employs a polysulfide with low phonon energy and symmetry as a host material, the host material to be doped with, preferably, rare earth ions as the luminescence center.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the field of optically functional novel materials, and in particular to multivalent sulfide upconversion luminescent materials. [Background technology]

[0002] Luminescence can be classified into several types, such as photoluminescence, electroluminescence, cathode luminescence, radioluminescence, chemiluminescence, and bioluminescence, and photoluminescence can be further classified into conventional photoluminescence (hereinafter simply referred to as conventional luminescence) and upconversion luminescence. Conventional luminescence has the characteristics that the incident excitation light wavelength is smaller than the emission light wavelength, the luminescence efficiency is high, and the quantum efficiency can reach or even exceed 100%. Compared with conventional luminescence, upconversion luminescence can convert infrared light into ultraviolet or visible light, and its unique luminescence properties can be applied in the fields of biomedical, solar cells, infrared counterfeiting prevention, laser displays, etc., and therefore has attracted attention. To achieve upconversion luminescence, an energy transfer process between the activator or between the activator and the sensitizer must be carried out, which requires a long lifetime for the intermediate level of the luminescence ion. Currently, there are not many element species that can achieve upconversion luminescence at room temperature, and most of them are lanthanides. Compared to other lanthanides, the Yb ion has a large absorption cross section (11.7×10 -21 cm 2) is large, the energy level structure is simple, and high concentration doping can be easily achieved. When using 980 nm infrared light as an excitation source, Yb ions, as a sensitizer, can significantly enhance the upconversion luminescence of the material [(1) F. Auzel, Upconversion and anti-Stokes processes with f and d ions in solids, Chem.Rev., 2004, 104, 139-174]. Upconversion luminescence is difficult to achieve high luminescence efficiency because the incident excitation light wavelength is larger than the emission light wavelength. At present, the maximum quantum efficiency of upconversion luminescence materials has not reached 10%, and most are below 1%.

[0003] In order to further improve the luminescence efficiency of the upconversion luminescence material, in addition to selecting luminescence ions with high luminescence levels, sensitizing ions, and suitable excitation paths, it is necessary to reduce the non-radiative transition probability of the material, and selecting a suitable host material is the most direct way to improve the upconversion luminescence efficiency. The selection of the host lattice not only determines the relative spatial positions between the dopant ions, but also affects the anion species and coordination number around the dopant ions. The interaction between the host lattice and the dopant ions has a great impact on the upconversion luminescence properties and luminescence efficiency of the material. The selection criteria for the host material are roughly divided into: (1) by selecting a host material with a small phonon energy, the nonradiative relaxation of multiphonons can be reduced, the lifetime of the excited state can be extended, and the efficiency of upconversion luminescence can be improved; and (2) by selecting a host material with a low symmetry of the crystal structure, the ff electric dipole transition of upconversion luminescence can be suppressed by the odd-numbered terms of the electric field of the crystal, although the ff electric dipole transition is forbidden due to the euclidean selection rule of the electronic transition of lanthanides. nThis enables an electric dipole transition in the set state of , which can improve upconversion luminescence and luminescence efficiency.

[0004] Based on the above criteria, host materials with high upconversion luminescence efficiency were selected.

[0005] (1) Rare earth halides: Fluorides, chlorides, bromides, iodides, etc. have very low phonon energy and can achieve highly efficient upconversion luminescence. Chlorides, bromides, and iodides are chemically unstable and prone to deliquescence, and their manufacturing processes are complicated, limiting their practical use. Fluorides have to some extent solved the problem of being prone to deliquescence and retain the characteristic of low phonon energy, and are currently the most widely used and most widely studied hosts. Among them, β-NaYF 4 :Yb, Er and β-NaYF 4 :Yb,Tm are currently considered to be the upconversion luminescence materials with the highest luminescence efficiency [(2)KW Kramer,D.Biner,G.Frei,HUGudel,MPHehlen,SRLuthi,Hexagonal Sodium Yttrium Fluoride Based Green and Blue Emitting Upconversion Phosphors,Chem.Mater.,2004,16,1244].However, the environment required for the production of fluorides is also harsh, and it causes corrosion of equipment and environmental pollution during the production process.

[0006] (2) Rare earth oxysulfides: Oxysulfides not only have low phonon energy, but also have excellent chemical and thermal stability (high melting point: 2000-2200°C), high oxidation resistance, high resistance to radiation, low toxicity, and insolubility in water. 2 O 2 In S host, highly efficient upconversion luminescence, e.g. 980 nm excitation Y 2 O 2The upconversion luminescence brightness of S:Yb,Ho has been obtained, which may be the highest among known materials [(3)Luo XX, Cao WH,Upconversion luminescence of holmium and ytterbium co-doped yttrium oxysulfide phosphor,Mater.Lett.,2007,61 (17):3696-3700]. However, rare earth oxysulfides are difficult to produce due to their high covalent nature and complicated manufacturing process.

[0007] (3) Oxides: Oxides have high phonon energy, are mostly non-toxic, have good chemical stability, are easy to manufacture, and have low requirements for the production environment. In addition, oxide single crystals have a narrow active ion fluorescence spectrum, high gain, and are harder, more mechanically strong, and more thermally conductive than glass, so physicochemically stable oxide single crystals are often used as hosts for upconversion laser materials. 2 O 3 / Gd 2 O 3 , Bi 2 O 3 Although rare earth complex oxides such as phosphates exhibit good upconversion luminescence properties, they have the lowest upconversion luminescence efficiency among the above three types of materials.

[0008] JPEG0007680789000001.jpg72170JPEG0007680789000002.jpg67170JPEG0007680789000003.jpg124170

[0009] Rare earth polysulfides have low phonon energy equivalent to that of chlorides and have excellent chemical stability. For example, NaYS 2 The highest phonon energy is 279 cm -1 Currently, the most efficient upconversion luminescence is β-NaYF 4 (418cm -1) and belongs to a low symmetry crystal system, it meets the conditions as an ideal upconversion host material, and upconversion luminescence materials using it as a host should have higher upconversion luminescence efficiency. Conventionally, rare earth sulfides have been used in high-grade pigments and are often sensitized with Yb ions, but there are very few reports on upconversion luminescence of sulfide hosts.

[0010] Higuchi et al. first reported Ga 2 S 3 -GeS 2 -La 2 S 3 Er in glass 3+ reported that the green upconversion luminescence quantum efficiency of Er ions was less than half that of fluoride glasses [(23) H. Higuchi, M. Takahashi, Y. Kawamoto, Optical transitions and frequency upconversion emission of Er 3+ ions in Ga 2 S 3 -GeS 2 -La 2 S 3 glasses, J. Appl. Phys., 1998, 83, 19]. In addition, according to research by Pascal et al., in pure sulfides, S 2- →Yb 3+ The LMCT absorption edge of is 20000cm -1 Less than Er 3+ of 2 H 11 / 2 , 4 S 3 / 2 and 4 F 7 / 2 Level overlap, 980nm excitation Yb 3+ and Er 3+ Co-doped NaYS 2It was found that the luminescence intensity of the upconversion luminescence material is reduced by two orders of magnitude. Therefore, pure rare earth sulfides are not as good as conventional Yb 3+ It is generally believed that ZnO is not a suitable host material for enhanced upconversion luminescence [(24) Pascal Gerner, Hans U. Gudel, Absorption and upconversion light emission properties of Er 3+ and Yb 3+ / Er 3+ codoped NaYS 2 ,Chem.Phys.Lett.,413 (2005) 105-109.(25) Zhang Jisen, Zhang Liguo, Ren Jianyue et al., Yb 3+ and Er 3+ Doped NaYS 2 Stocks and Anti-Stocks Luminescence of Powder Materials at Room Temperature, Luminescence Reports, 2013, 34(7), 824-828]. Summary of the Invention

[0011] In view of the above-mentioned shortcomings of the prior art, the present invention provides a polyvalent sulfide upconversion luminescence material with high luminescence efficiency, which realizes upconversion luminescence of the three primary colors of red, green, and blue, as well as upconversion luminescence of ultraviolet and near-infrared light by multi-wavelength excitation. This material has the advantages of high upconversion luminescence brightness, chemical stability, and good biocompatibility.

[0012] The technical solutions of the present invention are as follows:

[0013] Polysulfide upconversion luminescence materials, which use polysulfides as hosts and rare earth ions as activators, have the general formula mA 2 S·nBS·kC 2-x S 3 :D xwherein A is one or more of Li, Na, K, Rb, Cs; B is one or more of Be, Mg, Sr, Ba, Zn, Cd, Cs; C is one or more of La, Gd, Lu, Y, Sc, Al, Ga, Bi; D is one or more of Ho, Er, Tm, Pr, and D is co-doped with Mo, W, Ce, Sm, Tb, Yb, Eu, or Nd; m, n, k, and x are mole fractions, m=0-2, n=0-6, K=0.3-2.5, and x=0.0001-2; and this material can emit ultraviolet, blue, blue-green, green, red, and near-infrared light when excited by near-infrared light of 750-1650 nm.

[0014] (1) The general formula is mA 2 S·nBS·kC 2-x S 3 :D x In the upconversion luminescent material of formula (I), where m=0-0.2 and n=0-0.1, the value of k is preferably 0.9-1.1.

[0015] (2) The general formula is mA 2 S·nBS·kC 2-x S 3 :D x The upconversion luminescent material preferably has an m value of 0.8-1.2 and k value of 0.4-0.6, when n=0-0.1.

[0016] (3) The general formula is mA 2 S·nBS·kC 2-x S 3 :D x The upconversion luminescent material preferably has a value of n of 0.8-1.2 and a value of k of 0.8-1.2, when m=0-0.2.

[0017] The general formula is mA 2 S·nBS·kC 2-x S 3 :D x The upconversion luminescent material preferably has an n value of 4.5-5.5 and k value of 1.8-2.2 when m=0-0.2.

[0018] (4) The general formula is mA 2 S·nBS·kC 2-x S 3 :D x In the upconversion luminescent material of the present invention, when D contains Er, the x value is preferably 0.05-2, and the excitation wavelength ranges are 1450-1600 nm, 920-1150 nm, and 780-860 nm, and these three excitation wavelengths can be used alone or simultaneously.

[0019] (5) The general formula is mA 2 S·nBS·kC 2-x S 3 :D x For the upconversion luminescent material, when D contains Ho, the optimum x value is 0.02-2, and the excitation wavelength range used is 1100-1190 nm.

[0020] (6) The general formula is mA 2 S·nBS·kC 2-x S 3 :D x For the upconversion luminescent material, when D contains Tm, the optimal x value is 0.01-2, and the excitation wavelength ranges used are 1180-1260 nm and 760-850 nm, and these two excitation wavelengths can be used alone or simultaneously.

[0021] The advantageous effects of the present invention are as follows:

[0022] The chemical formula of the present invention is mA 2 S·nBS·kC 2-x S 3 :D xThe polyvalent sulfides of NaYF have very low phonon energy and belong to a low symmetry crystal system, making them ideal host materials for upconversion luminescence. When doped with an appropriate concentration of ions, the spacing between dopant ions far exceeds that of conventional luminescent materials, allowing high concentration doping and reduced non-radiative relaxation, and their upconversion luminescence efficiency is much higher than that of conventional NaYF. 4 : Yb, Er, and can achieve multiple wavelengths of excitation simultaneously. In particular, infrared light in the range of 1450-1600 nm is a safe wavelength for the human eye, and even when a light source in this wavelength range is used as an excitation source, the present invention is particularly advantageous in application because it can reduce the protection level of the application site or expand the application range without using protection equipment, and has the highest brightness. [Brief description of the drawings]

[0023] [Figure 1] 1 is an emission spectrum of the NaY0.9S2:Er0.1 sample of Example 18 of the present invention at 1550 nm excitation. [Diagram 2] FIG. 14 shows data for NaY0.9S2:Er0.1 and NaYF4:Yb,Er of Example 18 of the present invention, where (a) is a comparative diagram of brightness data, (b) is a graph of the change in brightness versus laser excitation power at 980 nm and 1550 nm, and (c) is an emission photograph of NaY0.9S2:Er0.1 at 980 nm and 1550 nm laser excitation. [Diagram 3] 1 is an emission spectrum of the NaY0.9S2:Er0.1@NaY0.8S2:Yb0.1, Er0.1 sample of Example 60 of the present invention at 980 nm excitation. [Figure 4] 1 is an emission spectrum of the NaY0.9S2:Er0.1@NaGd0.78S2:Er0.18,Ho0.05 sample of Example 61 of the present invention at 980 nm excitation. [Diagram 5] 1 is an emission spectrum of the NaY0.8S2:Er0.10,Nd0.10@NaY0.89S2:Yb0.08,Nd0.01,Tm0.02 sample of Example 62 of the present invention at 980 nm excitation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, the different compositions of the polyvalent sulfides of the present invention and their luminescence performance will be described using specific examples.

[0025] Comparative Example 1: Commercially available β-NaYF 4 :Yb,Er green upconversion luminescent material. Comparative Example 2: Commercially available β-NaYF 4 :Yb,Tm blue upconversion luminescent material. Comparative Example 3: Commercially available Y 2 O 3 :Yb,Er red upconversion luminescent material.

[0026] The sample of the present invention is prepared by the solid-state reaction method, weighing the raw materials according to the molar ratio of the constituent elements, and the raw materials can be oxides, carbonates, oxalates, nitrates, acetates, and sulfates of the elements in the technical solution. By the dry mixing method, the raw materials are crushed, mixed uniformly, put into a crucible, and then placed in a high-temperature furnace, and then placed in a sulfurizing atmosphere (such as H 2 S, CS) at 900-1400°C for 1-50 hours. The firing time is adjusted according to the amount of material. To improve brightness, a small amount of auxiliary solvent, e.g. 0-20 wt% AF and / or BF 2 (NH 4 Cl, NH 4 F, MgF 2 , CaF 2 , SrF 2 , BaF 2 etc.) can be added to the feedstock to significantly improve the upconversion luminescence efficiency.

[0027] In the present invention, the luminescence efficiency is evaluated by measuring the luminescence brightness or luminescence intensity of the sample. Specifically, the luminescence brightness was measured by placing the sample in a black disk with a diameter of 10 mm and a depth of 5 mm, and flattening it with a piece of glass to remove the effects of scattering. A semiconductor laser was used as the excitation light source, and the sample was irradiated with the laser in a visible light source, and then the brightness of the sample was measured with a luminance meter. The test was performed using commercially available β-NaYF, which currently has the highest upconversion luminescence efficiency. 4 : Yb, Er (green), β-NaYF 4 : Yb, Tm (blue), Y 2 O 3 :Yb,Er (red) was used as a reference sample. In comparison with the method of measuring the luminescence intensity with a spectrometer for invisible samples, all test conditions were constant in one set of examples.

[0028] <Example 1> As a starting material, Y 2 O 3 (99.99%), Er 2 O 3 (99.99%) was used. The raw materials were in the stoichiometric ratio Y 1.9 S 3 :Er 0.01 Weigh it according to the method described above, polish it well for 30 minutes, place it in a quartz tube, and place the quartz tube in a resistance furnace. 2 Ar gas is entrained in the bubbles, or H containing Ar carrier gas is used. 2 Using S gas as is, the sample was heated to 1050°C at a rate of 10°C / min, kept at that temperature for 2 hours, cooled to room temperature, and polished to obtain the target product. A 1500 nm laser was used as the excitation source, and the performance is shown in the table below in comparison with Comparative Example 1.

[0029] By a similar method, Examples 2 to 17 can be obtained. JPEG0007680789000004.jpg64170JPEG0007680789000005.jpg18170

[0030] Parameters affecting the luminescence color, luminescence intensity, and thermal properties other than those listed in Example 1-17 can be determined in the same manner as in Example 1-17. When A=Rb or Cs, the results are similar to those when A=K, but Rb and Cs are expensive. When A is used in combination, the properties are better, as in the combination of A=Li and K, and the product particle size can be made more uniform, and it is also possible to appropriately lower the reaction temperature by about 50-100°C while maintaining the luminescence intensity. When B=Be, Ba, Cd, the results are similar to those when B=Ca, but it may be difficult to apply products containing these elements from the perspective of environmental protection. When B=Zn, it is necessary to control the flow rate and reducing property of the carrier gas atmosphere. When C=Al, Ga, Bi, it is usually used to replace 30% or less of La, Gd, Lu, Y, Sc, and in this case, the luminescence intensity can be improved by about 5-13%. In the case of D=Er, the excitation wavelengths are used in the ranges of 1450-1600 nm, 920-1150 nm, and 780-860 nm, and these three excitation wavelengths can be used alone or simultaneously, and the same effect as when a 1500 nm excitation light source is used can be obtained. The excitation light source wavelength is selected according to the application conditions and the laser wavelength that can be provided in large quantities on the market. The luminescence brightness is as follows: infrared light in the wavelength range of 1450-1600 nm>infrared light in the wavelength range of 920-1150 nm>infrared light in the wavelength range of 780-860 nm. In particular, infrared light in the range of 1450-1600 nm is particularly advantageous depending on the application, since it is a wavelength safe for the human eye and has the highest brightness. In addition, in the above embodiment, a small amount of auxiliary solvent, for example, 0-20 wt% NH 4 Cl, NH 4 F, MgF 2 , CaF 2 , SrF 2 , BaF 2 By adding these to the raw materials, the luminescence brightness can be increased by an additional 5-28%, and by using them in combination, the performance can be further improved.

[0031] In the case of D=Er, the material properties such as luminescence color and heat absorption characteristics can be changed by combining with other RE ions and co-doping. Adding a small amount of Mo and W (x=0.01-0.3) can significantly reduce the red luminescence component in the luminescence spectrum and improve the color purity of the green luminescence by 2-10 times. Adding Ho, Tm or Pr can increase the red luminescence component in the luminescence spectrum and improve the color purity of the red luminescence by 2-15 times, and the luminescence brightness is 110-180% of that of Comparative Example 3 under the same excitation conditions, and the color purity of the red luminescence is 200-300% of that of Comparative Example 3. Adding Yb, Ce, Sm, Tb, Eu or Nd can significantly increase the thermal properties and change the luminescence color, and improve the temperature rise of the sample by more than twice at the same power density.

[0032] When RE=Ho, the excitation wavelength can be changed to 1100-1190nm, and the color purity of the green luminescence is improved by more than 150% compared with RE=Er, and when RE=Tm, the excitation wavelength can be changed to 1180-1260nm, 760-850nm, and the brightness of the blue luminescence is 150-300% of that of Comparative Example 2 under the same excitation conditions, widening the range of application.Furthermore, by combining with other RE, full color luminescence can be obtained and color purity can be adjusted.

[0033] In addition, when the values ​​of m, n, k, and x are outside the range of Example 1-17, such as m=0.2-2, n=0.1-6, k=0.3-0.9, k=1.1-2.5, and x=0.2-2, the samples also exhibit good luminescence effects, but the luminescence intensity is reduced by 5-53% compared to Example 1-17 under the same conditions.

[0034] <Example 18> NaY 0.9 S 2 :Er 0.1 As a starting material, Y 2 O3 (99.99%), Er 2 O 3 (99.99%), Na 2 CO 3 (99.99%) was used. The raw material was stoichiometric NaY 0.9 S 2 :Er 0.1 Weigh it according to the method described above, polish it thoroughly for 30 minutes, place it in a quartz tube, and place the quartz tube in a resistance furnace. 2 Ar gas was entrained in the bubbles, and the sample was heated to 1050°C at a rate of 10°C / min, kept at that temperature for 2 hours, then cooled to room temperature and polished to obtain the target product.

[0035] Figure 1 shows the NaY 0.9 S 2 :Er 0.1 This is an upconversion luminescence spectrum of the sample at 1550 nm excitation. Sample NaY 0.9 S 2 :Er 0.1 shows green emission in the wavelength range of 512-578 nm and red emission in the wavelength range of 640-698 nm, respectively. 4 S 3 / 2 → 4 I 15 / 2 , 2 H 11 / 2 → 4 I 15 / 2 , 4 F 9 / 2 → 4 I 15 / 2 Er at the level of 3+ It can be seen that this corresponds to the transition of

[0036] In addition, NaY 0.9 S 2 :Er 0.1 In order to evaluate the upconversion luminescence characteristics of Comparative Example 1, NaY 0.9 S 2 :Er 0.1 The luminescence brightness data of the samples (Figure 2) were compared. 0.9 S 2 :Er 0.1is about 60 times that of the commercially available NaYF 4 : The luminescence efficiency was very high, with a brightness more than twice that of Yb,Er at 980 nm excitation.

[0037] By a similar method, Examples 19 to 37 can be obtained. JPEG0007680789000006.jpg88170

[0038] The parameters affecting the luminescence color, luminescence intensity, and thermal properties other than those listed in Examples 19-37 can be determined in the same manner as in Examples 1-17. The effects are similar to those of the following Examples 1-17, but the luminescence intensity is improved by 12-35% compared to the following Examples 1-17.

[0039] Examples 38 to 47 can be obtained by the same method as Examples 19 to 37. JPEG0007680789000007.jpg55170

[0040] The parameters affecting the luminescence color, luminescence intensity, and thermal properties other than those listed in Examples 38-47 can be determined in the same manner as in Examples 38-47. The effect is the same as that of the following Examples 1-17, but the luminescence intensity is improved by 7-23% compared to the following Examples 1-17.

[0041] Examples 48 to 59 can be obtained in the same manner as Examples 38 to 37. JPEG0007680789000008.jpg62170

[0042] The parameters affecting the luminescence color, luminescence intensity, and thermal properties other than those listed in Examples 48-59 can be determined in the same manner as in Examples 48-59, and the effects are the same as those in the following Examples 1-17.

[0043] <Example 60> NaY 0.9 S 2 :Er 0.1 @NaY 0.8 S 2 :Yb 0.1 ,Er 0.1 Y 2 O 3 (99.99%) and Er 2 O 3 (99.99%) in the stoichiometric ratio NaY 0.9 S 2 :Er 0.1 The rare earth chloride was formed by adding an appropriate amount of water and 6 mol / L hydrochloric acid and stirring. An appropriate amount of oleic acid and octadecene was taken, and a certain amount of sulfur powder and sodium oleate was weighed and mixed with the above rare earth chloride, and water and other low boiling point impurities were removed at 120°C under a vacuum atmosphere. After that, the solution was quickly heated to 300°C and kept at that temperature for 1 hour. The sample was washed several times with water and ethanol, then dried and dissolved in NaY 0.9 S 2 :Er 0.1 The sample was obtained. 2 O 3 (99.99%), Yb 2 O 3 (99.99%) and Er 2 O 3 (99.99%) was weighed to produce rare earth chloride, and the above steps were repeated to produce NaY 0.9 S 2 :Er 0.1 was added to the mixture and incubated at 300 °C for 1 h to obtain the core-shell structure NaY 0.9 S 2 :Er 0.1 @NaY 0.8 S 2 :Yb 0.1 ,Er 0.1 A sample was formed.

[0044] Figure 3 shows the NaY 0.9 S 2 :Er 0.1 @NaY 0.8 S 2 :Yb 0.1 ,Er 0.1The upconversion luminescence spectrum of the sample. The spectrum consists of two spectral bands in the visible light part: green emission in the wavelength range of 512-578 nm and red emission in the wavelength range of 640-698 nm. 3+ Ion 4 S 3 / 2 → 4 I 15 / 2 , 2 H 11 / 2 → 4 I 15 / 2 , 4 F 9 / 2 → 4 I 15 / 2 It corresponds to the transition of NaY 0.9 S 2 :Er 0.1 In comparison with the sample, NaY 0.9 S 2 :Er 0.1 @NaY 0.8 S 2 :Yb 0.1 ,Er 0.1 The peak types are similar, but the relative emission intensities in the red and green wavelength regions are significantly different. 0.9 S 2 :Er 0.1 shows strong green and weak red light, while NaY 0.9 S 2 :Er 0.1 @NaY 0.8 S 2 :Yb 0.1 ,Er 0.1 shows strong red light and weak green light. Under the same excitation conditions, the heat generation of this sample is three times that of Example 18, making it applicable when both light and heat effects are required simultaneously.

[0045] <Example 61> NaGd 0.9 S 2 :Er 0.1 @NaGd 0.78 S 2 :Er 0.18 ,Ho 0.05 Y 2 O 3 (99.99%) and Er 2 O3 (99.99%) in the stoichiometric ratio NaGd 0.9 S 2 :Er 0.1 A certain amount was weighed according to the method described above, and an appropriate amount of water and 6 mol / L hydrochloric acid were added and stirred to form rare earth chlorides. Appropriate amounts of oleic acid and octadecene were taken, and certain amounts of sulfur powder and sodium oleate were weighed and mixed with the above rare earth chlorides, and water and other low boiling point impurities were removed at 120°C under a vacuum atmosphere. The solution was then quickly heated to 300°C and kept at that temperature for 1 hour. The sample was washed several times with water and ethanol, then dried and dissolved in NaY 0.9 S 2 :Er 0.1 The sample was obtained. 2 O 3 (99.99%), Er 2 O 3 (99.99%) and Ho 2 O 3 (99.99%) was weighed to produce rare earth chloride, and the above steps were repeated to produce NaY 0.9 S 2 :Er 0.1 was added to the mixture and incubated at 300°C for 1 hour to obtain the core-shell structure NaGd 0.9 S 2 :Er 0.1 @NaGd 0.78 S 2 :Er 0.18 ,Ho 0.05 A sample was formed.

[0046] Figure 4 shows the NaY 0.9 S 2 :Er 0.1 @NaGd 0.78 S 2 :Er 0.18 ,Ho 0.05 The emission spectrum of the sample under 980 nm laser excitation is shown in Figure 3. The emission spectrum in Figure 3 shows: 1) a red luminescence band in the wavelength range of 646-666 nm: there are three emission peaks at 650, 654, and 661 nm, respectively, which are due to Ho 3+ Ion 5 F 5 → 5 I 82) A green luminescence band in the wavelength range of 535-565 nm: There are two emission peaks at 543 and 548 nm, respectively, which correspond to the transition of Ho 3+ Ion 5 F 4 → 5 I 8 and 5 S 2 → 5 I 8 It consists of two spectral bands, corresponding to transitions.

[0047] <Example 62> NaY 0.8 S 2 :Er 0.10 ,Nd 0.10 @NaY 0.89 S 2 :Yb 0.08 ,Nd 0.01 ,Tm 0.02 Y 2 O 3 (99.99%), Er 2 O 3 (99.99%) and Nd 2 O 3 (99.99%) in stoichiometric ratio NaY 0.8 S 2 :Er 0.10 ,Nd 0.10 A certain amount was weighed according to the method described above, and an appropriate amount of water and 6 mol / L hydrochloric acid were added and stirred to form rare earth chlorides. Appropriate amounts of oleic acid and octadecene were taken, and certain amounts of sulfur powder and sodium oleate were weighed and mixed with the above rare earth chlorides, and water and other low boiling point impurities were removed at 120°C under a vacuum atmosphere. The solution was then quickly heated to 300°C and kept at that temperature for 1 hour. The sample was washed several times with water and ethanol, then dried and dissolved in NaY 0.8 S 2 :Er 0.10 ,Nd 0.10 The sample was obtained. 2 O 3 (99.99%) and Tm 2 O 3 (99.99%) was weighed to produce rare earth chloride, and the above steps were repeated to produce NaY 0.8 S2 :Er 0.10 ,Nd 0.10 was added to the mixture and incubated at 300 °C for 1 h to obtain the core-shell structure NaY 0.8 S 2 :Er 0.10 ,Nd 0.10 @NaY 0.89 S 2 :Yb 0.08 ,Nd 0.01 ,Tm 0.02 A sample was formed.

[0048] Figure 5 shows the NaY 0.8 S 2 :Er 0.10 ,Nd 0.10 @NaY 0.89 S 2 :Yb 0.08 ,Nd 0.01 ,Tm 0.02 The emission spectrum of the sample excited by a 980 nm laser. The emission spectrum in the figure shows that 1) the wavelength range is 460-499 nm, with a peak at 476 nm, and 2) Tm 3+ of 1 G 4 → 3 H 6 2) a blue luminescence band in the wavelength range of 639-654 nm, with a peak at 650 nm, belonging to the Tm transition 3+ Ion 1 G 4 → 3 F 4 3) a red luminescence band in the wavelength range of 670-726 nm, with a peak at 698 nm, belonging to the transition 3+ Ion 3 F 3 → 3 H 6 The blue emission band is obviously stronger than the two red emission bands, so that it is not visible to the naked eye. 0.8 S 2 :Er 0.10 ,Nd 0.10 @NaY 0.89 S 2 :Yb 0.08 ,Nd0.01 ,Tm 0.02 The sample exhibited bright blue luminescence.

[0049] <Example 63> NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Nd 0.02 Y 2 O 3 (99.99%) and Er 2 O 3 (99.99%) in stoichiometric ratio NaY 0.9 S 2 :Er 0.10 A certain amount was weighed according to the method described above, and an appropriate amount of water and 6 mol / L hydrochloric acid were added and stirred to form rare earth chlorides. Appropriate amounts of oleic acid and octadecene were taken, and certain amounts of sulfur powder and sodium oleate were weighed and mixed with the above rare earth chlorides, and water and other low boiling point impurities were removed at 120°C under a vacuum atmosphere. The solution was then quickly heated to 300°C and kept at that temperature for 1 hour. The sample was washed several times with water and ethanol, then dried and dissolved in NaY 0.9 S 2 :Er 0.10 The sample was obtained. 2 O 3 (99.99%), Y 2 O 3 (99.99%) and Nd 2 O 3 (99.99%) was weighed to produce rare earth chloride, and the above steps were repeated to produce NaY 0.9 S 2 :Er 0.10 ,Nd 0.10 was added to the mixture and incubated at 300 °C for 1 h to obtain the core-shell structure NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Nd 0.02 A sample was formed.

[0050] NaY 0.9 S2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Nd 0.02 The upconversion luminescence spectra of the samples are Er, 3+ Ion 4 S 3 / 2 → 4 I 15 / 2 , 2 H 11 / 2 → 4 I 15 / 2 , 4 F 9 / 2 → 4 I 15 / 2 transitions, and Nd 3+ Ion 4 F 7 / 2 / 4 F 5 / 2 / 4 F 3 / 2 → 4 I 9 / 2 It consists of three spectral bands: green emission in the 510-570 nm wavelength range, red emission in the 640-700 nm wavelength range, and infrared emission in the 710-900 nm range, which correspond to the transitions in NaY. 0.9 S 2 :Er 0.1 Compared with the sample, NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Nd 0.02 The heat generation capacity of the sample is clearly improved.

[0051] <Example 64> NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Sm 0.02 Y 2 O 3 (99.99%) and Er 2 O 3 (99.99%) in stoichiometric ratio NaY 0.9 S 2:Er 0.10 A certain amount was weighed according to the method described above, and an appropriate amount of water and 6 mol / L hydrochloric acid were added and stirred to form rare earth chlorides. Appropriate amounts of oleic acid and octadecene were taken, and certain amounts of sulfur powder and sodium oleate were weighed and mixed with the above rare earth chlorides, and water and other low boiling point impurities were removed at 120°C under a vacuum atmosphere. The solution was then quickly heated to 300°C and kept at that temperature for 1 hour. The sample was washed several times with water and ethanol, then dried and dissolved in NaY 0.9 S 2 :Er 0.10 The sample was obtained. 2 O 3 (99.99%), Yb 2 O 3 (99.99%) and Sm 2 O 3 (99.99%) was weighed to produce rare earth chloride, and the above steps were repeated to produce NaY 0.9 S 2 :Er 0.10 was added to the mixture and incubated at 300 °C for 1 h to obtain the core-shell structure NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Sm 0.02 A sample was formed.

[0052] NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Sm 0.02 The upconversion luminescence spectra of the samples are 3+ Ion 4 G 5 / 2 → 6 H 5 / 2 , 4 G 5 / 2 → 6 H 7 / 2 , 4 G 5 / 2 → 6 H 9 / 2It consists of three spectral bands: green emission in the 550-580 nm wavelength range, red emission in the 580-630 nm and 630-675 nm wavelength ranges, which correspond to the transitions in NaY. 0.9 S 2 :Er 0.1 Compared with the sample, NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,Sm 0.02 The sample can generate a large amount of heat.

[0053] <Example 65> NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :EU 0.02 Y 2 O 3 (99.99%) and Er 2 O 3 (99.99%) in stoichiometric ratio NaY 0.9 S 2 :Er 0.10 A certain amount was weighed according to the method described above, and an appropriate amount of water and 6 mol / L hydrochloric acid were added and stirred to form rare earth chlorides. Appropriate amounts of oleic acid and octadecene were taken, and certain amounts of sulfur powder and sodium oleate were weighed and mixed with the above rare earth chlorides, and water and other low boiling point impurities were removed at 120°C under a vacuum atmosphere. The solution was then quickly heated to 300°C and kept at that temperature for 1 hour. The sample was washed several times with water and ethanol, then dried and dissolved in NaY 0.9 S 2 :Er 0.10 The sample was obtained. 2 O 3 (99.99%), Yb 2 O 3 (99.99%) and Eu 2 O 3 (99.99%) was weighed to produce rare earth chloride, and the above steps were repeated to produce NaY 0.9 S 2 :Er 0.10was added to the mixture and incubated at 300 °C for 1 h to obtain the core-shell structure NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,EU 0.02 A sample was formed.

[0054] NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,EU 0.02 The upconversion luminescence spectrum of the sample consists of three spectral bands: green emission in the 510-580 nm wavelength range, and red emissions in the 580-630 nm and 630-675 nm wavelength ranges. 0.9 S 2 :Er 0.1 Compared with the sample, NaY 0.9 S 2 :Er 0.10 @NaY 0.9 S 2 :Yb 0.08 ,EU 0.02 The red luminescence of the sample is significantly enhanced.

[0055] In a similar manner, upconversion luminescence samples co-doped with Pr, Tb, etc. can be obtained.

[0056] The above description is merely a preferred implementation of the present invention, and the scope of protection of the present invention is not limited to the above embodiment, and any technical solution included in the concept of the present invention belongs to the scope of protection of the present invention. In addition, any improvements and modifications made without departing from the principle of the present invention should be regarded as being within the scope of protection of the present invention.

Claims

1. A polysulfide upconversion luminescent material for green and red emission in the excitation wavelength range of 1450-1600 nm or 920-1150 nm or 780-860 nm, The general composition formula is mA ２ S.n.S.k.C. ２－ｘ S ３ :D ｘ Among them, A is Li, Na or K; B is Mg, Ca or Sr; C is La, Gd, Lu, Y or Sc; D is Er; m, n, k, and x are mole fractions; When m=0 and n=0, the value of k is 0.9-1.1 and the value of x is 0.05-0.40; When m=0, the value of n is 0.02-0.08, the value of k is 1-1.1, and the value of x is 0.20; When n=0, the value of m is 0.05-0.20, the value of k is 1, and the value of x is 0.20; When the values ​​of m and n are greater than 0, the value of m is 0.05, the value of n is 0.02, the value of k is 0.9-1, and the value of x is 0.20; The excitation wavelength range is 1450-1600 nm, 920-1150 nm, or 780-860 nm, and one or more of the above excitation wavelengths are adopted. Polysulfide upconversion luminescent materials.

2. A polysulfide upconversion luminescent material for green and red emission in the excitation wavelength range of 1100-1190 nm, comprising: The general composition formula is mA ２ S.n.S.k.C. ２－ｘ S ３ :D ｘ Among them, A is Li, Na or K; B is Mg, Ca or Sr; C is La, Gd, Lu, Y or Sc; D is Er and is co-doped in combination with Ho; m, n, k, and x are mole fractions; When m=0 and n=0, the value of k is 0.9-1.1 and the value of x is 0.05-0.40; When m=0, the value of n is 0.02-0.08, the value of k is 1-1.1, and the value of x is 0.20; When n=0, the value of m is 0.05-0.20, the value of k is 1, and the value of x is 0.20; When the values ​​of m and n are greater than 0, the value of m is 0.05, the value of n is 0.02, the value of k is 0.9-1, and the value of x is 0.20; The excitation wavelength range is 1100-1190 nm, and one or more of the above excitation wavelengths are employed. Polysulfide upconversion luminescent materials.

3. A polysulfide upconversion luminescent material for blue, green and red emission in the excitation wavelength range of 1180-1260 nm or 760-850 nm, comprising: The general composition formula is mA ２ S.n.S.k.C. ２－ｘ S ３ :D ｘ Among them, A is Li, Na or K; B is Mg, Ca or Sr; C is La, Gd, Lu, Y or Sc; D is Er and is co-doped in combination with Tm; m, n, k, and x are mole fractions; When m=0 and n=0, the value of k is 0.9-1.1 and the value of x is 0.05-0.40; When m=0, the value of n is 0.02-0.08, the value of k is 1-1.1, and the value of x is 0.20; When n=0, the value of m is 0.05-0.20, the value of k is 1, and the value of x is 0.20; When the values ​​of m and n are greater than 0, the value of m is 0.05, the value of n is 0.02, the value of k is 0.9-1, and the value of x is 0.20; The excitation wavelength range is 1180-1260 nm or 760-850 nm, and one or more of the above excitation wavelengths are employed. Polysulfide upconversion luminescent materials.

4. A polysulfide upconversion luminescent material for green and red emission in the excitation wavelength range of 1450-1600 nm or 920-1150 nm or 780-860 nm, The general composition formula is mA ２ S.n.S.k.C. ２－ｘ S ３ :D ｘ Among them, A is Li, Na or K; B is Mg, Ca or Sr; C is La, Gd, Lu, Y or Sc; D is Er; m, n, k, and x are mole fractions; When m=0 and n=0, C is Y, k is 0.9-1.1, and x is 0.05-0.40; When m=0, B is Mg, Ca or Sr, the value of n is 0.02-0.08, C is Y, the value of k is 1-1.1, and the value of x is 0.20; When n=0, A is Li, Na or K, m is 0.05-0.20, C is Y, k is 1, and x is 0.20; When the value of m and the value of n are greater than 0, A is Li, Na or K, the value of m is 0.05, B is Mg, the value of n is 0, 02, the value of k is 0.9-1, C is La, Gd, Lu, Y or Sc, and the value of x is 0.20; The excitation wavelength range is 1450-1600 nm, 920-1150 nm, or 780-860 nm, and one or more of the above excitation wavelengths are adopted. Polysulfide upconversion luminescent materials.

5. A polysulfide upconversion luminescent material for green and red emission in the excitation wavelength range of 1100-1190 nm, comprising: The general composition formula is mA ２ S.n.S.k.C. ２－ｘ S ３ :D ｘ Among them, A is Li, Na, or K; B is Mg, Ca or Sr; C is La, Gd, Lu, Y or Sc; D is Er and is co-doped in combination with Ho; m, n, k, and x are mole fractions; When m=0 and n=0, C is Y, k is 0.9-1.1, and x is 0.05-0.40; When m=0, B is Mg, Ca or Sr, the value of n is 0.02-0.08, C is Y, the value of k is 1-1.1, and the value of x is 0.20; When n=0, A is Li, Na or K, m is 0.05-0.20, C is Y, k is 1, and x is 0.20; When the value of m and the value of n are greater than 0, A is Li, Na or K, the value of m is 0.05, B is Mg, the value of n is 0, 02, the value of k is 0.9-1, C is La, Gd, Lu, Y or Sc, and the value of x is 0.20; The excitation wavelength range is 1100-1190 nm, and one or more of the above excitation wavelengths are employed. Polysulfide upconversion luminescent materials.

6. A polysulfide upconversion luminescent material for blue, green and red emission in the excitation wavelength range of 1180-1260 nm or 760-850 nm, comprising: The general composition formula is mA ２ S.n.S.k.C. ２－ｘ S ３ :D ｘ Among them, A is Li, Na, or K; B is Mg, Ca or Sr; C is La, Gd, Lu, Y or Sc; D is Er and is co-doped in combination with Tm; m, n, k, and x are mole fractions; When m=0 and n=0, C is Y, k is 0.9-1.1, and x is 0.05-0.40; When m=0, B is Mg, Ca or Sr, the value of n is 0.02-0.08, C is Y, the value of k is 1-1.1, and the value of x is 0.20; When n=0, A is Li, Na or K, m is 0.05-0.20, C is Y, k is 1, and x is 0.20; When the value of m and the value of n are greater than 0, A is Li, Na or K, the value of m is 0.05, B is Mg, the value of n is 0, 02, the value of k is 0.9-1, C is La, Gd, Lu, Y or Sc, and the value of x is 0.20; The excitation wavelength range is 1180-1260 nm or 760-850 nm, and one or more of the above excitation wavelengths are employed. Polysulfide upconversion luminescent materials.

7. 7. The polysulfide up-conversion luminescent material according to claim 1, wherein D is Er, and D is further doped with Mo and W at x=0.01-0.3.

Images