A near-infrared fluorescent powder and an optical device

Abstract

The application discloses a near-infrared fluorescent powder and an optical device. The near-infrared fluorescent powder comprises an inorganic compound with a composition formula of A2D 1‑x‑y G y E 1‑ z J z O6: xNi, A elements include Y and Ca, D elements include Mg and / or Zn, E elements include one or two of Ti, Ge and Si, G elements include Sc, Lu, Li, Na or K, and J elements include Ga, Al, V or P; wherein, 0

Description

Technical Field

[0001] This invention relates to the field of luminescent materials technology, and in particular to a near-infrared phosphor and optical device. Background Technology

[0002] Highly efficient deep-red and near-infrared light is required for various applications, including supplemental lighting in modern agriculture and security monitoring, information detection lighting in food safety testing, and light conversion films in photovoltaics. Currently, the main methods for generating deep-red and near-infrared light are electroluminescent LED chips and photoluminescent fluorescence conversion technologies. Existing mainstream commercial gallium arsenide-based LED chips emit deep-red and near-infrared light with narrow spectra and poor tunability. Furthermore, their complex manufacturing processes and costs are several times higher than those of violet LED chips, limiting their application and widespread adoption. Currently, deep-red and near-infrared fluorescence conversion technology based on rare-earth luminescent materials shows great promise, and research on related material systems, preparation technologies, and applications has begun both domestically and internationally.

[0003] As one of the core materials for phosphor-converting near-infrared LEDs, near-infrared phosphors directly determine the luminous intensity, spectral continuity, and other performance characteristics of near-infrared LED devices, as well as their application scenarios. However, research on near-infrared phosphors is still in its early stages, with a lack of material types, limited spectral coverage, and low luminous intensity. In particular, there is a lack of high-efficiency near-infrared phosphors with emission peak wavelengths above 1300nm, or even up to 1500nm, and a full width at half maximum (FWHM) greater than 200nm. Summary of the Invention

[0004] The purpose of this invention is to provide a near-infrared phosphor and optical device. The near-infrared phosphor can be excited by violet light, red light, and short-wave near-infrared light, with an emission peak position in the range of 1500-1630nm and a half-width at half-maximum (WHM) of 240-295nm. This solves the technical problems in the prior art, such as the scarcity of near-infrared phosphor materials, the limited spectral coverage, the insufficient emission band, and the low luminous intensity.

[0005] To address the aforementioned technical problems, a first aspect of this invention provides a near-infrared phosphor, wherein the near-infrared phosphor comprises a compound with the formula A2D. 1-x-y G y E 1-z J z Inorganic compounds of O6:xNi, where A includes Y and Ca, D includes Mg and / or Zn, E includes one or two of Ti, Ge and Si, G includes Sc, Lu, Li, Na or K, and J includes Ga, Al, V or P.

[0006] Among them, 0 <x≤0.06,0<y≤0.2,0<z≤0.15。

[0007] Furthermore, the molar percentage of Ca in element A is i, 0%. <i≤30%。

[0008] Furthermore, element A also includes Gd or Sr.

[0009] Furthermore, element D includes Mg and Zn, with Zn accounting for 0% of the molar percentage of element D. <j≤50%。

[0010] Furthermore, element E contains Ti and Si, with Si accounting for k, 0% of the molar percentage of element E. <k≤20%。

[0011] Furthermore, when element G is Sc, element J is Al, and 0 <x=y≤0.12。

[0012] Furthermore, when element G is Li, element J is V, and 0 <x=y≤0.07。

[0013] Accordingly, a second aspect of the present invention provides an optical device comprising a light source and a light-emitting material, wherein the light-emitting material comprises any of the near-infrared phosphors described above.

[0014] Furthermore, the light source is a semiconductor chip with an emission peak wavelength range of 400nm-430nm or 600nm-700nm;

[0015] The luminescent material also includes visible light phosphors with an emission wavelength range of 500nm-780nm and near-infrared phosphors with an emission wavelength range of 780nm-1300nm.

[0016] Furthermore, the red phosphor with a wavelength of 600nm-700nm has the composition formula (Ca,Sr)AlSiN3:Eu.

[0017] Furthermore, the near-infrared phosphor in the 700nm-750nm range has the following composition: (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O 12 :Cr 3+ .

[0018] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0019] 1. A near-infrared phosphor with an emission peak wavelength in the range of 1500nm-1630nm and a half-width at half-maximum (WHM) of 240nm-295nm that can be excited by violet light, red light, and short-wave near-infrared light;

[0020] 2. This near-infrared phosphor can be matched with violet light chips, with peak positions covering 1500nm-1630nm, which can enrich the types of near-infrared phosphors in longer wavelength bands and solve the problem of material scarcity;

[0021] 3. This near-infrared phosphor has a broad emission spectrum with a full width at half maximum (FWHM) of 240nm-295nm that is adjustable. The emission band covered by a single phosphor is relatively wide, which is beneficial for obtaining hyperspectral LED devices with continuous spectra.

[0022] 4. This near-infrared phosphor has the advantage of higher luminescence intensity and can be effectively applied to water quality testing, fresh produce testing, grain testing, material testing, sweeping robots, semiconductor material flaw detection and other application scenarios;

[0023] 5. This near-infrared phosphor has absorption in the 680nm-1000nm deep red-short wave near-infrared domain, making it suitable for doping into fiber materials or ink materials for anti-counterfeiting or marking on commemorative coins. Attached Figure Description

[0024] Figure 1 This is the absorption spectrum of the near-infrared phosphor sample provided in the embodiments of the present invention;

[0025] Figure 2 This is the emission spectrum of the near-infrared phosphor sample provided in the embodiments of the present invention;

[0026] Figure 3 This is a schematic diagram of the optical device structure provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0028] A first aspect of this invention provides a near-infrared phosphor, the near-infrared phosphor comprising a composition of A2D 1-x-y G y E 1-z J z O6:xNi is an inorganic compound, where A includes Y and Ca, D includes Mg and / or Zn, E includes one or two of Ti, Ge, and Si, G includes Sc, Lu, Li, Na, or K, and J includes Ga, Al, V, or P; wherein, 0 <x≤0.06,0<y≤0.2,0<z≤0.15。

[0029] Near-infrared phosphors can be excited by violet light, red light, and short-wave near-infrared light, with emission peak positions in the range of 1500nm-1630nm and a half-width at half-maximum (WHM) of 240nm-295nm. This addresses the technical problems of existing near-infrared phosphors, such as the scarcity of material types, limited spectral coverage, insufficient emission band, and low luminescence intensity.

[0030] Among these, Ca and Y have similar radii, making it less likely to cause significant lattice distortion, thus ensuring the structural stiffness of the material and giving it excellent luminescence intensity and thermal stability. On the other hand, Ca and Y ions are heterovalent ions, which easily create defects such as oxygen vacancies, facilitating the formation of traps and further enhancing the material's luminescence intensity and thermal stability. Furthermore, the high reactivity of Y and Ca, along with the solubilizing effect of Ca raw materials (such as calcium carbonate), further contributes to improving the material's luminescence intensity. When the Ca content is too low, the luminescence intensity is low because Ca's effect on phosphor enhancement is not significant. Conversely, excessive Ca content may lead to impurities and significant lattice distortion, increasing the probability of non-radiative transitions in the phosphor and also resulting in low luminescence intensity. Further, the molar percentage of Ca in A is i, 0%. <i≤30%。

[0031] In addition, while element A contains Y and Ca, it can also contain one of Gd or Sr, forming certain structural changes that give the material richer optical properties.

[0032] The D element is one or both of Mg and Zn, and the G element is one of Sc, Lu, Li, Na, and K, with G replacing a portion of the D element. Li, Na, and K are reactive elements, which are beneficial for further nucleation and grain growth of the phosphor, thus improving luminescence intensity. The D and G ions are heterovalent ions with different ionic radii and coordination environments; doping can enrich the optical properties of the material. When the G element content is too low, the effect of G on phosphor enhancement is not significant, resulting in low luminescence intensity. When the G element content is too high, it may lead to impurities and significant lattice distortion, increasing the probability of non-radiative transitions in the phosphor, also resulting in low luminescence intensity. Therefore, a content of 0% is preferred. <y≤0.2。

[0033] Furthermore, Mg and Zn ions share the same outermost electrons and similar coordination environments. Mg and Zn simultaneously occupy the same lattice site, achieving equivalent ion substitution, which is beneficial for controlling defects in the material and improving its optical properties. Moreover, Zn has a high electronegativity, enabling it to form strong covalent bonds with O, thus enhancing luminescence intensity. However, when the Zn content is too low, its effect on phosphor enhancement is not significant, resulting in low luminescence intensity. Conversely, excessive Zn content may lead to impurities and significant lattice distortion, increasing the probability of non-radiative transitions in the phosphor and also resulting in low luminescence intensity.

[0034] Furthermore, when element D includes both Mg and Zn, the molar percentage of Zn in element D is j, 0%. <j≤50%。

[0035] Element E is one or two of Ti, Ge, and Si; element J is one of Ga, Al, V, and P. V and P are reactive elements, which are beneficial for further nucleation and grain growth of the phosphor, thus improving luminescence intensity. Element J replaces a portion of element E. The ions of element E and element J are heterovalent ions with different ionic radii and coordination environments, and doping can enrich the optical properties of the material. When the content of element J is too low, the effect of element J on improving the phosphor is not significant, resulting in low luminescence intensity. When the content of element J is too high, it may lead to impurities and significant lattice distortion, increasing the probability of non-radiative transitions in the phosphor, and also resulting in low luminescence intensity. Therefore, a content of 0% J is preferred. <z≤0.15。

[0036] Furthermore, Si doping into Ti sites, with its wide absorption band, is expected to increase the material's band gap, increase the probability of radiative transitions, and enhance luminescence intensity; it also shifts the emission wavelength to shorter wavelengths. Ti, with its large radius, easily expands the matrix lattice, thereby reducing the crystal field strength and shifting the phosphor emission wavelength to longer wavelengths. Furthermore, Ti's high reactivity is beneficial for nucleation and grain growth, enhancing luminescence intensity. Additionally, Ti's high electronegativity allows it to form strong covalent bonds with O, further improving luminescence intensity. Experimental studies have shown that when the Si content is too low, the effect of Si on phosphor enhancement is not significant, resulting in low luminescence intensity. Conversely, excessive Si content may lead to impurities and significant lattice distortion, increasing the probability of non-radiative transitions in the phosphor, also resulting in low luminescence intensity.

[0037] Furthermore, when element E contains both Ti and Si, the molar percentage of Si in element E is k, 0%. <k≤20%。

[0038] Furthermore, G and J elements simultaneously replace G and Z elements, achieving the substitution of non-equivalent ion pairs. While the lattice sites of the material do not change significantly, the substitution of non-equivalent ion pairs helps to control the generation of excessive lattice defects in the material, thereby enriching the optical properties of the material and further enhancing its luminescence intensity.

[0039] Further, when the G element is Sc, correspondingly, the J element is Al, and 0 < x = y ≤ 0.12. Sc ions and Al ions enter the divalent metal D and tetravalent E lattice sites respectively, forming a non-equivalent ion pair substitution. On the one hand, there is a difference in electronegativity between the Sc element and the Al element, one is large and the other is small, and it will not cause excessive covalent bond changes after entering the lattice sites, which is beneficial to stabilizing the bond force between chemical bonds. At the same time, the non-equivalent ion pair substitution is conducive to causing appropriate lattice distortion, which is beneficial to breaking the forbidden transition of the luminescence center Ni 2+ and resulting in enhanced absorption and improved luminescence intensity of the material. And x = y is beneficial to compensating for the charge imbalance caused by the elements entering the lattice sites, preventing the generation of too many vacancies, and is beneficial to improving the luminescence intensity of the material. On the premise of ensuring a pure phase structure, when the content of Sc and Al elements is too small, since the improvement effect of Sc and Al elements on the phosphor is not obvious and the luminescence intensity is low, when the content of Sc and Al elements is too high, it may lead to the generation of impurities and large lattice distortion, resulting in an increase in the non-radiative transition probability of the phosphor and a low luminescence intensity as well.

[0040] Further, when the G element is Li, correspondingly, the J element is V, and 0 < x = y ≤ 0.07. Li ions and V ions enter the divalent metal D and tetravalent E lattice sites respectively, forming a non-equivalent ion pair substitution. On the one hand, there is a difference in electronegativity between the Li element and the V element, one is large and the other is small, and it will not cause excessive covalent bond changes after entering the lattice sites, which is beneficial to stabilizing the bond force between chemical bonds. At the same time, the non-equivalent ion pair substitution is conducive to causing appropriate lattice distortion, which is beneficial to breaking the forbidden transition of the luminescence center Ni 2+ and resulting in enhanced absorption and improved luminescence intensity of the material. And x = y is beneficial to compensating for the charge imbalance caused by the elements entering the lattice sites, preventing the generation of too many vacancies, and is beneficial to improving the luminescence intensity of the material. Further, the doping of Li element is beneficial to forming covalent bonds, increasing the covalent bond property, and is beneficial to increasing the probability of radiative transition of the luminescence center; and Li and V elements, as active metals, have a co-dissolution effect, further improving the luminescence intensity. According to experimental verification, on the premise of ensuring a pure phase structure, when the content of Li and V elements is too small, since the improvement effect of Li and V elements on the phosphor is not obvious and the luminescence intensity is low, when the content of Li and V elements is too high, it may lead to the generation of impurities and large lattice distortion, resulting in an increase in the non-radiative transition probability of the phosphor and a low luminescence intensity as well.

[0041] The above near-infrared phosphor can be obtained by the following preparation method, and the specific steps are as follows:

[0042] Step 1: Using elemental substances, nitrides, oxides, fluorides or their alloys selected from different elements as raw materials, mixing the raw materials to obtain a mixture.

[0043] Step 2: Place the mixture obtained in Step 1 into a container and calcine it under a reducing atmosphere to obtain the calcined product. The maximum sintering temperature is 1250℃~1480℃ and the holding time is 3.5h-5.5h.

[0044] Step 3: The calcination product from Step 2 is sequentially crushed, washed, sieved, and dried to obtain fluorescent powder.

[0045] Phosphors composed of inorganic compounds with the above-mentioned composition can be excited by violet light, with emission peak positions covering 1500nm-1630nm and a tunable full width at half maximum (FWHM) of 240nm-295nm. They can be used in conjunction with (CaSr)AlSiN3:Eu red phosphor with an emission wavelength range of 620nm-660nm and (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O, a near-infrared phosphor with an emission wavelength range of 700nm-750nm. 12 :Cr 3+ This allows the optical device to have more efficient near-infrared emission, making it effective for applications such as water quality testing, fresh produce testing, and grain testing. In addition, it exhibits absorption in the 680nm-1000nm deep red-near-infrared domain, making it suitable for incorporating into fiber materials or inks for anti-counterfeiting or commemorative coin marking.

[0046] The following are specific embodiments illustrating the near-infrared phosphor involved in this invention, but this invention is not limited to the following embodiments.

[0047] Example 1

[0048] The near-infrared phosphor provided in this embodiment contains compounds with the formula Y. 1.99 Ca 0.01 Mg 0.98 Lu 0.0 1Ti 0.99 Ga 0.01 O6:0.01Ni. The oxide raw materials were ground and mixed according to the stoichiometric ratio of the chemical formula to obtain a mixture. The mixture was then calcined at 1380℃ for 4 hours after grinding and mixing. After cooling, the calcined product was obtained. The calcined product was then subjected to post-processing such as crushing, grinding, grading, and sieving to obtain the near-infrared phosphor intermediate.

[0049] The absorption and emission spectra of the obtained near-infrared samples were measured using a fluorescence spectrometer. The absorption and emission spectra of the near-infrared phosphor samples prepared in Example 1 are shown below. Figure 1 , Figure 2 As shown. From Figure 1 , Figure 2It can be seen that the obtained near-infrared phosphor samples have effective absorption in the wavelength ranges of 300 nm - 375 nm, 400 nm - 450 nm, and 600 nm - 800 nm, and the emission wavelength covers 1300 nm - 1700 nm, with the emission peak position at 1500 nm. The obtained results are listed in Table 1.

[0050] Table 1

[0051]

[0052]

[0053]

[0054] The materials and luminescence performance characterization results of the near-infrared phosphors prepared in the above Examples 1 - 41 and Comparative Examples are shown in Table 1. Note: Based on the luminescence intensity of the Comparative Example as the reference value of 100, the relative luminescence intensity of the Example is its actual luminescence intensity divided by the actual luminescence intensity of the Comparative Example, and then multiplied by 100%.

[0055] By comparing the data of the Examples and Comparative Examples in Table 1 above, it is not difficult to find that for the inorganic compound of LiA a Sc 1-a-p-d- c D d P p EO4:cCr, where A2D 1-x-y G y E 1-z J z O6:xNi, where the A element is two or three of Y, Gd, Ca, Sr, and must contain Y and Ca; the D element is one or two of Mg and Zn; the E element is one or two of Ti, Ge, and Si; the G element is one of Sc, Lu, Li, Na, and K; the J element is one of Ga, Al, V, and P; where 0 < x ≤ 0.06, 0 < y ≤ 0.2, 0 < z ≤ 0.15. The above methods can all achieve the regulation of the spectral peak position covering the range of 1300 nm - 1500 nm and the improvement of the luminescence intensity, resulting in a more efficient near-infrared broadband emission.

[0056] Comparing Example 1 with the comparative example, it is found that element A in the compound is Y and Ca. The radii of Ca and Y are similar, which is not likely to cause large lattice distortion, ensuring the structural stiffness of the material and endowing it with relatively excellent luminous intensity and thermal stability. On the other hand, Ca and Y ions are hetero-valent ions, which are likely to cause the generation of defects such as oxygen vacancies, facilitating the formation of traps and further enhancing the luminous intensity and thermal stability of the material. Moreover, Y and Ca elements have high activity, and the raw material of Ca (such as calcium carbonate) has a solubilizing effect, which is more conducive to enhancing the luminous intensity of the material.

[0057] Comparing Examples 12 - 15, when the content of Ca element is too low, since the improvement effect of Ca element on the phosphor is not obvious, the luminous intensity is low. When the content of Ca element is too high, it may lead to the generation of impurities and significant lattice distortion, resulting in an increase in the non-radiative transition probability of the phosphor and a low luminous intensity as well. Therefore, the molar percentage of Ca occupying element A is i, preferably 0% < i ≤ 30%, which is conducive to improving the light efficiency of the material.

[0058] Comparing Examples 15 - 20, element D must contain Mg and Zn. Mg and Zn ions have the same outermost electrons and similar coordination environments. Mg and Zn occupy the same lattice site simultaneously, achieving the substitution of equivalent ions alone, which is conducive to controlling the generation of defects in the material and improving the optical properties of the material. Moreover, Zn has a relatively large electronegativity and can form covalent bonds with excellent covalent bond properties with O, enhancing the luminous intensity.

[0059] Comparing Examples 20 - 26, element E must contain Ti and Si. Si is doped into the Ti position. Si element has the characteristic of a wide absorption band. When Si is doped, it is expected to increase the band gap of the material, increase the probability of radiative transition, and enhance the luminous intensity; and shift the emission band towards the short wavelength. The radius of Ti element is large, which is likely to expand the matrix lattice of the material, thereby reducing the crystal field strength and shifting the emission band of the phosphor towards the long wavelength. Moreover, Ti element has high activity, which is conducive to nucleation and grain growth, enhancing the luminous intensity. And Ti has a relatively large electronegativity and can form covalent bonds with excellent covalent bond properties with O, enhancing the luminous intensity.

[0060] Comparing Examples 26 - 33, when element G is Sc, element J is Al, and x = y. According to the claim item, Sc ions and Al ions enter the divalent metal D and tetravalent E lattice sites respectively, forming a substitution of non-equivalent ion pairs. On the one hand, there is a difference in electronegativity between Sc element and Al element, one is large and the other is small. After entering the lattice site, it will not cause excessive covalent bond changes, which is conducive to stabilizing the bond force between chemical bonds. At the same time, the substitution of non-equivalent ion pairs is conducive to causing appropriate lattice distortion, which is beneficial to breaking the luminescence center Ni 2+The prohibited transitions lead to enhanced absorption, thus increasing the luminescence intensity of the material. Furthermore, x = y helps compensate for the charge imbalance caused by elements entering lattice sites, preventing the generation of excessive vacancies and further enhancing the luminescence intensity of the material.

[0061] Comparing Examples 26 and 34-41, when G is Li, J is V, and x = y. According to the claims, Li ions and V ions enter the divalent metal D and tetravalent metal E sites respectively, forming non-equivalent ion-pair substitutions. On one hand, the electronegativity of Li and V differs, being significantly different; their entry into the sites does not cause excessive changes in covalent bonds, which is beneficial for stabilizing the bonding forces between chemical bonds. Simultaneously, non-equivalent ion-pair substitution is conducive to causing appropriate lattice site distortion, which is beneficial for breaking the luminescent center Ni. 2+ The prohibition of transitions leads to enhanced absorption and increased luminescence intensity. Furthermore, x = y helps compensate for the charge imbalance caused by elements entering lattice sites, preventing excessive vacancies and further enhancing luminescence intensity. Moreover, Li doping promotes covalent bond formation, increasing the probability of radiative transitions at the luminescence center; and Li and V, as active metals, act as fluxing agents, further improving luminescence intensity.

[0062] Accordingly, please refer to Figure 3 A second aspect of the present invention provides an optical device comprising a light source and a light-emitting material, wherein the light-emitting material comprises any of the aforementioned near-infrared phosphors.

[0063] Due to the advantages of near-infrared phosphors, such as high luminescence intensity and easy-to-control emission spectrum, optical devices containing near-infrared phosphors have high working stability, long service life, and are suitable for a variety of different needs.

[0064] Optionally, the light source can be a semiconductor light-emitting diode light source; preferably, the light source is a semiconductor chip with an emission peak wavelength of 400nm-430nm or 600nm-700nm.

[0065] Optical devices containing the aforementioned near-infrared luminescent materials can achieve efficient near-infrared emission under violet light excitation, thus solving the problems of low near-infrared luminescence intensity in existing infrared chip technology, especially the difficulty in realizing chip technology with emission peak wavelengths in the 1500-1630nm band and low luminescence intensity. This expands its application in water quality testing, fresh food testing, grain testing, material testing, sweeping robots, semiconductor material flaw detection, and other application scenarios.

[0066] Currently, commercial LED excitation sources have excitation wavelengths within this range, specifically two types of excitation sources. Utilizing light-emitting diodes within the aforementioned wavelength range is beneficial for the photoluminescence of phosphors.

[0067] Furthermore, the light source is a semiconductor chip with an emission peak wavelength range of 400nm-430nm or 600nm-700nm;

[0068] The luminescent materials also include visible phosphors with an emission wavelength range of 500nm-780nm and near-infrared phosphors with an emission wavelength range of 780nm-1300nm.

[0069] Specifically, visible light phosphors are phosphors with emission wavelengths in the range of 500-780 nm, including but not limited to (Mg,Zn)(Ca,Sr,Ba)3Si2O8:Eu 2+ (Ca,Sr,Ba)Si2N2O2:Eu 2+ β-SiAl ON:Eu 2+ (Lu,Y,Gd)3(Al,Ga)5O 12 :Ce 3+ ,Tb 3+ (Lu,Y,Gd)3(Al,Ga)5O 12 :Ce 3+ (La,Y,Lu)3Si6N 11 :Ce 3+ (Ca,Sr,Ba)2Si5N8:Eu 2+ (Ca,Sr)AlSiN3:Eu 2+ K2(Si,Ge)F6:Mn 4+ (Sr,Ca,Ba)4(Al,Sc,Ga,In) 14 O 25 :Mn 4+ (La,Y,Gd,Lu)3(Al,Ga)(Ge,Si)5O 16 :Mn 4+ , CaO·Al2O3·Ga2O3·ZnO·MnO2·Li2O and (Lu,Y,Gd)3(Al,Ga)5O 12 :M n 4+ One or more of them.

[0070] Specifically, near-infrared phosphors are phosphors with emission wavelengths in the range of 780nm-1300nm, including but not limited to (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O. 14 :Cr 3+ ,Yb 3+ ,Sc2O3·Ga2O3·(C r,Yb)2O3 and (La,Lu,Y,Gd)(Sc,Ga,Al,In)3B4O 12 :Cr 3+ ,Yb3 One or more of them.

[0071] Furthermore, the red phosphor with a wavelength range of 600nm-700nm has the formula (Ca,Sr)AlSiN3:Eu. In addition to the absorption of the aforementioned near-infrared phosphor in the red light region, the use of a (Ca,Sr)AlSiN3:Eu red phosphor with an emission wavelength range of 620nm-660nm further enhances the optical device's near-infrared emission efficiency (photoelectric conversion efficiency in the near-infrared band) and provides a unique spectrum tailored to the aforementioned applications.

[0072] Furthermore, the near-infrared phosphor with a wavelength of 700nm-750nm has the following composition: (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O 12 :Cr 3+ .

[0073] In this context, the comma in each substance indicates that the element within the parentheses can be a single component or a solid solution containing more than one element, for example: (Ca,Sr)AlSiN3:Eu 2+ Represented as CaAlSiN3:Eu 2+ SrAlSiN3:E u 2+ and Ca 1-α Sr α AlSiN3:Eu 2+ One or more of the following solid solutions: (0<α<1).

[0074] By combining the near-infrared phosphor of the present invention with the aforementioned phosphor, the light-emitting device emits light with high luminous efficiency, solving the problems of low near-infrared luminous intensity in existing infrared chip technology, especially the difficulty in realizing chip technology with emission peak wavelengths in the 1500nm-1630nm band, low luminous intensity, and poor continuity of the emission spectrum of optical devices. This satisfies the application needs of many traditional and emerging fields, including moisture detection, material detection, sweeping machines, and semiconductor material flaw detection.

[0075] The optical device, in addition to using near-infrared phosphors, also utilizes visible light phosphors with an emission wavelength range of 500nm-780nm and near-infrared phosphors with an emission wavelength range of 780nm-1300nm. Specifically, it leverages the near-infrared phosphor's absorption in the 680-1000nm deep red-near-infrared domain, combined with a (CaSr)AlSiN3:Eu red phosphor with an emission wavelength range of 620nm-660nm and a (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O near-infrared phosphor with an emission wavelength range of 700nm-750nm. 12 :Cr 3+This allows the optical device to have more efficient near-infrared emission (photoelectric conversion efficiency in the near-infrared band) and a unique spectrum for the above applications, further expanding its application range.

[0076] The following are specific embodiments illustrating the near-infrared phosphor involved in this invention, but this invention is not limited to the following embodiments.

[0077] LED light sources can experience peeling during storage or use under extreme conditions. Therefore, by controlling the centrifugation rate and time, the desired state of centrifugation can be effectively controlled to deposit the phosphor onto the chip surface. This reduces the distance between the excitation chip and the phosphor, improving the phosphor's conversion efficiency. Furthermore, it reduces color drift in the light source before and after drying caused by inconsistent phosphor settling speeds, thus improving the yield of this type of light source.

[0078] Example 42

[0079] The optical device described in this embodiment uses a semiconductor chip with a wavelength of 410 nm as the light source, and the luminescent material is a near-infrared phosphor with the chemical formula Y. 1.6 Ca 0.4 Mg 0.644 Zn 0.276 Li 0.05 Si 0.095 Ti 0.855 V 0.05 O6:0.03Ni, according to the stoichiometric ratio, the raw materials were accurately weighed and symmetrically ground and mixed to obtain a mixture; the mixture was calcined at 1450℃ for 5 hours, and after cooling, a calcined product was obtained; the obtained calcined product was crushed, ground, graded, sieved and washed to obtain near-infrared phosphor. In addition, in this embodiment, a Y-ray emission wavelength in the range of 500nm-780nm was selected. 0.85 Al5O 12 0.15Ce 3+ And near-infrared phosphors (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O with emission wavelengths in the range of 780nm-1300nm 14 :Cr 3+ ,Yb 3+The process involves using Sc2O3·Ga2O3·(Cr,Yb,Nd)2O3. In this embodiment, firstly, phosphor is deposited onto the chip surface. This reduces the distance between the excitation chip and the phosphor, improving the phosphor's conversion efficiency. It also reduces color drift in the light source before and after drying due to inconsistent phosphor deposition rates, thus improving the yield of this type of light source. Next, a visible light emitting material is uniformly mixed with silicone at a mass ratio of 0.2:1 and applied to the silicone surface. This mixture is then baked to solidify into a visible light phosphor layer. The visible light provided by the visible light emitting material and the visible light absorption by the near-infrared emitting material enhance the device's luminous efficiency, especially the photoelectric conversion efficiency in the near-infrared emission band. Subsequently, the near-infrared emitting material and silicone are uniformly mixed at a mass ratio of 1.87:1, stirred, and degassed to obtain a visible light phosphor conversion layer mixture. This mixture is then sprayed onto the surface of the visible light emitting material layer, cured, and encapsulated to obtain the desired LED optical device. Using a high-precision, fast spectroradiometer integrating sphere testing system, the light source of the optical device provided in each embodiment was lit with a constant current (forward voltage 3V, forward current 60.0mA). The test results showed that the optical power of the optical device described in this embodiment was 122mW and the photoelectric conversion efficiency in the near-infrared band was 73.3%.

[0080] The performance parameters of the optical devices obtained by encapsulating near-infrared luminescent materials in various embodiments of the present invention are shown in Table 2.

[0081] Table 2

[0082]

[0083]

[0084] As can be seen from Table 2, the phosphor in the optical device can be effectively excited by the LED chip. Through optical devices that combine visible light emitting materials and near-infrared emitting materials, dual emission of visible light in the 500nm-780nm band and near-infrared light in the 780nm-1550nm band can be achieved. Moreover, the device has suitable light flux and continuous emission spectrum or special waveform emission spectrum, which can be effectively applied to application scenarios such as water quality detection, fresh food detection, and grain detection.

[0085] In the aforementioned optical device, in addition to the near-infrared phosphor exhibiting absorption in the red light region, a (CaSr)AlSiN3:Eu red phosphor with an emission wavelength range of 620nm-660nm and a (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O near-infrared phosphor with a wavelength range of 700nm-750nm are also used. 12 :Cr 3+ The optical devices feature more efficient near-infrared emission (photoelectric conversion efficiency in the near-infrared band) and unique spectra for the aforementioned applications.

[0086] The embodiments of the present invention aim to protect a near-infrared phosphor and an optical device, and have the following effects:

[0087] 1. A near-infrared phosphor with an emission peak wavelength in the range of 1500nm-1630nm and a half-width at half-maximum (WHM) of 240nm-295nm that can be excited by violet light, red light, and short-wave near-infrared light;

[0088] 2. This near-infrared phosphor can be matched with violet light chips, with peak positions covering 1500nm-1630nm, which can enrich the types of near-infrared phosphors in longer wavelength bands and solve the problem of material scarcity;

[0089] 3. This near-infrared phosphor has a broad emission spectrum with a full width at half maximum (FWHM) of 240nm-295nm that is adjustable. The emission band covered by a single phosphor is relatively wide, which is beneficial for obtaining hyperspectral LED devices with continuous spectra.

[0090] 4. This near-infrared phosphor has the advantage of higher luminescence intensity and can be effectively applied to water quality testing, fresh produce testing, grain testing, material testing, sweeping robots, semiconductor material flaw detection and other application scenarios;

[0091] 5. This near-infrared phosphor has absorption in the 680nm-1000nm deep red-short wave near-infrared domain, making it suitable for doping into fiber materials or ink materials for anti-counterfeiting or marking on commemorative coins.

[0092] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A near-infrared fluorescent powder, characterized by, The near-infrared phosphor contains a composition of A2D. 1-x-y G y E 1-z J z Inorganic compounds of O6:xNi, where A is Y and Ca, D is Mg and / or Zn, E is one or two of Ti, Ge and Si, G is Sc, Lu, Li, Na or K, and J is Ga, Al, V or P. Among them, 0 <x≤0.06,0<y≤0.2,0<z≤0.15。 2. The near-infrared fluorescent powder according to claim 1, characterized by The molar percentage of Ca in element A is i, 0%. <i≤30%。 3. The near-infrared fluorescent powder according to claim 1, characterized by Element A also includes Gd or Sr.

4. The near-infrared phosphor according to claim 1, characterized in that, The element D is composed of Mg and Zn, with Zn accounting for 0% of the molar percentage of D. <j≤50%。 5. The near-infrared fluorescent powder according to claim 1, characterized by, Element E contains Ti and Si, with Si accounting for 0% of the molar percentage of element E. <k≤20%。 6. An optical device comprising a light source and a luminescent material, characterized in that The luminescent material comprises the near-infrared phosphor as described in any one of claims 1-5.

7. The optical device according to claim 6, characterized in that, The light source is a semiconductor chip with an emission peak wavelength range of 400 nm-430 nm or 600 nm-700 nm; The luminescent material also includes visible phosphors with an emission wavelength range of 500 nm to 780 nm and near-infrared phosphors with an emission wavelength range of 780 nm to 1300 nm.

8. The optical device of claim 7, wherein, The visible light phosphor with a wavelength of 500 nm to 780 nm has the composition formula (Ca,Sr)AlSiN3:Eu.

9. The optical device of claim 7, wherein, The near-infrared phosphor with a wavelength of 780 nm to 1300 nm has the following composition: (La,Y,Gd,Lu)3(Al,Ga)5(Ge,Si)O 12 :Cr 3+ .

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