Nitride deep red light-emitting material, preparation method and device thereof

Abstract

The application provides a nitride deep red light material and a preparation method and application thereof. The chemical general formula of the nitride deep red light material is La2BaSiAl 2‑x Cr x N6, wherein 0

Description

Technical Field

[0001] This invention relates to the field of luminescent material preparation technology, and in particular to a nitride deep red light material and its preparation method and device. Background Technology

[0002] All living things depend on the sun for growth, and plants have an essential need for light. However, only a very small portion of the sunlight radiation spectrum can affect photosynthesis. As data disclosed in Patent Document 1 (Chen Xiaodong, Lan Yanting, Chu Qingquan, Zhao Wenxiang, Zhao Peng, Ma Xiaoping, Plant Growth Lamp and Plant Growth System, CN204901494U) shows, red / deep red light and blue light have the greatest effect on plant growth.

[0003] Since red and blue light are essential for plant growth, plant lighting sources should provide red and blue light. The simplest and most reliable way to achieve red and blue light output is to use a combination of blue LEDs and red LEDs, as disclosed in patent document 2 (Liu Deguang, Liu Xinmao, Liao Benyu, Plant Lighting Control System Based on LED Light Source, CN204201522U). This plant lighting control system includes: a lamp, comprising: a first LED module; and a second LED module, wherein the first LED module and the second LED module emit different spectra; and a control module that controls the first LED module and the second LED module according to the lighting conditions. However, the all-LED red and blue light solution also has certain limitations. First, red LEDs have shorter lifespans and lower reliability than blue LEDs, which can lead to premature device failure. Second, red LEDs operate at different voltages than blue LEDs, making the power input control of a full LED red and blue light solution more complex. Finally, the half-width at half-maximum (WHM) of a single type of red LED is narrow, making it difficult to fully cover all the red light components required for plant growth. Increasing the variety of red LEDs would reduce the reliability and cost of plant lighting devices.

[0004] As an improved technical solution, using blue diodes to excite red / deep red fluorescent materials to achieve red and blue light output is currently the most popular plant lighting technology solution. Therefore, developing deep red fluorescent materials suitable for blue light excitation and intended for plant lighting is of extremely important practical significance. Recently, some patents for red / deep red fluorescent materials have been published, such as patent document 3 (Xiao Siguo, Wang Wenbo, An Improved Mn...). 4+ CN109810708B discloses a method for preparing and applying Mn-doped calcium lanthanum tungstate deep red fluorescent materials. 4+ A deep-red fluorescent material doped with calcium lanthanum tungstate. The general chemical formula of this fluorescent material is Ca. 3-2x-2 YLa 2+2x+2 YW 2-X-Y Mn X RY O 12 This material emits deep red light at 650–800 nm, which coincides with the main absorption wavelength (650–760 nm) of plant phytochrome PFR. However, this material uses Mn... 4+ As the luminescent center, the half-width at half maximum (FWHM) of the emission spectrum is less than 20 nm, and the area where energy is concentrated cannot fully cover the needs of plant growth.

[0005] Patent document 4 (Yang Xiaoliang, Chen Tiejin, Xiao Siguo, A broadband deep red light conversion material and its preparation method, CN106634970A) discloses a broadband deep red light conversion material with the chemical formula Li2MgTiO4:xCr, where 0.003≤x≤0.015. This deep red light conversion material has a wide excitation bandwidth and an emission wavelength of 726nm. However, due to the presence of Li, the material exhibits poor stability and is not water-resistant, making its application in plant lighting challenging.

[0006] Patent document 5 (Wang Ting, Xiu Liang, Wang Shaoqing, Yu Xue, Guo Longchao, Li Ziyang, Ma Qianrui, Guo Haihong, A deep red niobate phosphor for agricultural lighting and its preparation method, CN112625684A) discloses a deep red niobate phosphor for agricultural lighting, with the general chemical formula Ba. 2-x LuNbO6:xMn 4+ Where 0 < x ≤ 0.02; this red fluorescent material has broad ultraviolet and blue light absorption, can produce reflection in the 600-800nm ​​range, and its luminescence center is located at 700nm, making it applicable in white LED lighting and red LED lights for plant growth. Similar to patent document 3, this material uses Mn 4+ As the luminescent center, the half-width at half maximum (FWHM) of the emission spectrum is less than 20 nm, and the area where energy is concentrated cannot fully cover the needs of plant growth.

[0007] Patent document 6 (Xiao Siguo, Long Zheng, A Deep Red Emitting Fluorescent Material for Plant Cultivation LEDs Excited by Ultraviolet and Blue Light and Its Preparation Method, CN112760094A) discloses a deep red fluorescent material for plant cultivation LEDs that can be excited by ultraviolet and blue light. The general chemical formula of this fluorescent material is K. 0.5 La 0.5 AMgW 1-x O6: xMn 4+Where 0.001≤x≤0.03, and A is Sr or Ca. This fluorescent material emits far-red light at 650–800 nm when excited by light in the 300–570 nm wavelength range, coinciding with the main absorption wavelength (650–760 nm) of plant phytochrome PFRs. However, due to the presence of potassium (K), this material exhibits poor stability and is not water-resistant, posing challenges for its application in plant lighting.

[0008] Patent document 7 (Qiao Juan, Jia Zhen, A Deep Red-Near Infrared Light Emitting Device, CN113097403A) discloses a deep red-near infrared light emitting device based on deep red-near infrared light emitting quantum dot material. However, it is well known that the instability of quantum dot materials reduces the reliability of the device.

[0009] Patent document 8 (Li Juan, Li Guanwei, Che Shenglei, Zheng Jingwu, Qiao Liang, Ying Yao, Li Wangchang, Yu Liang, Cai Wei, A manganese-doped deep red phosphor material and its preparation method, CN112480918A) discloses a manganese-doped deep red phosphor material with the general chemical formula: A 2-2x CaB' 1-x O6: 2xR 3+ ,xMn 4+ Where: A is one of Sr or Ba; B' is one of Mo or W; R is one of La, Gd, Eu, Y, Sm, Nd, or Dy; and x ranges from 0.001 to 0.130. This phosphor can be used in LED lighting and artificial light sources to aid plant growth, as described in patent document 3, etc. This material uses Mn... 4+ As the luminescent center, the half-width at half maximum (FWHM) of the emission spectrum is less than 20 nm, and the area where energy is concentrated cannot fully cover the needs of plant growth.

[0010] Patent document 9 (You Hongpeng, Zhang Liang, Yin Shuwen, A Mn-doped deep red luminescent material for LED plant growth and its preparation method and application, CN113528137A) discloses a Mn4+-doped deep red luminescent material for LED plant growth, with the structural formula: Sr2InSb 1-x O6: xMn 4+ Where 0.0005 ≤ x ≤ 0.015. The emission wavelength range of this deep red luminescent material is within 600–750 nm. Similar to Patent Document 3, this material uses Mn... 4+ As the luminescent center, the half-width at half maximum (FWHM) of the emission spectrum is less than 20 nm, and the area where energy is concentrated cannot fully cover the needs of plant growth.

[0011] Patent document 10 (Chang Gui, Li Zhiyong, Zhao Xiaoxia, Wang Yuhua, Seto Takatoshi, Liu Dongwei, Wang Lin, A light conversion membrane that can promote plant growth and its preparation method and application, CN110698811A) discloses a light conversion membrane that can promote plant growth. This light conversion membrane is Al2O3:Cr 3+ Mixed Y3Al5O 12 Ce 3+ Light conversion film. Although this material uses Cr... 3+ As the luminescent center, but Cr 3+ In a strong crystal field environment, the emission spectrum is narrow-band emission, with a full width at half maximum (FWHM) of less than 5 nm. The area where energy is concentrated cannot fully cover the needs of plant growth.

[0012] Patent document 11 (Xia Mao, Zhou Zhi, Zeng Shaobo, Jiang Kuiming, Liu Qingling, A deep red phosphor and its application, CN105154080A) discloses a deep red phosphor having the following molecular formula (M 1-y Ln y ) 14 Al 10-x (Zn 1- z Mg z )6O 35 :xMn 4+ Where M is one or more of the alkaline earth metals Ca, Sr, and Ba; Ln is one or more of Y, La, Gd, and Lu; 0 < x ≤ 0.5, 0 ≤ y ≤ 0.3, and 0 ≤ z ≤ 0.2. This phosphor can be excited by light in the wavelength range of 380–520 nm, emitting far-red light in the 650–750 nm range. It can be applied to LED plant growth lights to improve plant growth efficiency, reduce energy consumption, and save costs. Similar to patent document 3, this material uses Mn... 4+ As the luminescent center, the half-width at half maximum (FWHM) of the emission spectrum is less than 20 nm, and the area where energy is concentrated cannot fully cover the needs of plant growth.

[0013] Patent document 12 (V. Wöhler PJ Schmitt, Narrow-band red-emitting fluorosilicate for coating semiconductor LEDs, CN104114671B) discloses a Mn 4+ Doped M′ x M 2-2x The phosphor of AX6, wherein M′ comprises an alkaline earth metal cation, M comprises an alkali metal cation, and x is in the range of 0-1, wherein A comprises a tetravalent cation, including at least silicon, and wherein X comprises a monovalent anion, including at least fluorine. Similar to patent document 3, this material utilizes Mn... 4+As the luminescent center, the half-width at half-maximum (FWHM) of the emission spectrum is less than 20 nm. The region where the energy is concentrated cannot fully cover the needs of plant growth, and the F contained in the phosphor may be harmful to plant growth.

[0014] Patent document 13 (Wang Yuhua, Seto Takatoshi, Yan Mengwen, A fluorescent powder for plant growth and its preparation method, CN110157430A) discloses a fluorescent powder for plant growth, the chemical formula of which is Y. 2-x BaAl 4-y SiO 12 :xCe 3+ yCr 3 + The excitation spectrum of this phosphor basically covers the entire visible light region, effectively converting sunlight into red light required by plants, improving the utilization rate of sunlight by plants, and promoting plant growth. However, its red light emission depends on Cr. 3+ The light emitted, and Ce was present. 3+ To Cr 3+ Energy transfer is impaired, which results in the phosphor having low luminous efficiency.

[0015] Patent document 14 (Shao Qiyue, Shi Meiling, Dong Yan, Jiang Jianqing, A deep red phosphor for LED plant growth lights and its preparation method, CN110358537A) discloses a deep red fluorescent material for LED plant growth lights, RX3(BO3)4:yCr; wherein R is at least one of La, Lu, Gd, Y, and Nd, and X is at least one of Al, Ga, and Sc, and 0.005≤y≤0.2. This phosphor can be effectively excited by blue light and emits deep red and near-infrared light in the range of 650nm to 900nm. However, the main peak of the emission spectrum of the fluorescent material is above 740nm, which has a low matching degree with the main absorption wavelength (650-760nm) of plant phytochrome PFR.

[0016] Patent document 15 (Liu Xinfang, Tao Dejie, Yuan Xianglong, Li Yiqun, Nitride-based Red Phosphor, CN102066522B) discloses a nitride-based deep red phosphor: the phosphor has the general formula M a M b B c (N, D): Eu 2+ M a Divalent alkaline earth metals, such as Mg, Ca, Sr, Ba; M b It is a trivalent metal, such as Al, Ga, Bi, Y, La, and Sm; and M cThe elements are tetravalent, such as Si, Ge, P, and B; N is nitrogen, and D is a halogen, such as F, Cl, or Br. Because this material contains halogens, the corrosive nature of halogens can accelerate the failure of silver wires and reflectors in the packaged devices.

[0017] Patent document 16 (Xia Zhiguo, Liu Gaochao, A near-infrared luminescent material and its preparation method and conversion type LED light-emitting device, CN112251226A) discloses a near-infrared luminescent material, which contains a material of general formula A x B y C z O q D p The material is an inorganic compound, where A is Li or Na, B is In, Lu, Sc, Ga, Al, Zr, Ti, Hf, Sn, or Ge, C is Sb, Nb, Ta, Zr, Ti, Hf, Sn, or Ge, O is oxygen, and D is Mn, Cr, Ni, Bi, Pr, Nd, Tm, Eu, Yb, Er, or Ho; 0.8≤x≤1.2, 1.5≤y≤2, 0.5≤Z≤1, 5≤q≤7, 0<p≤0.2. However, due to the presence of Li, this material exhibits poor stability and is not water-resistant, making its application in plant lighting challenging.

[0018] Patent document 17 (Xia Zhiguo, Yang Zhiyu, Gallate Red Fluorescent Material and Preparation Method and White LED Light Emitting Device, CN112480924A) discloses a gallate red fluorescent material with the chemical formula Sr2Sc 0.5 Ga 1.5 O5: xEu 2+ Where 0.02≤x≤0.15. Although the material has high luminous efficiency, the raw material contains volatile Ga2O3, which can easily lead to deviations in the chemical composition of the material, making its synthesis difficult; moreover, the material has poor thermal quenching characteristics, with luminous intensity at 150℃ being only 22% of that at room temperature (Non-Patent Document 1: Zhiyu Yang, Yayun Zhou, Jianwei Qiao, Maxim S. Molokeev, Zhiguo Xia, Rapid Synthesis of Red-Emitting Sr2Sc 0.5 Ga 1.5 O5: Eu 2+ Phosphors and the Tunable Photoluminescence Via Sr / BaSubstitution, Advanced Optical Materials, DOI: 10.1002 / adom.202100131).

[0019] Patent document 18 (Xia Zhiguo, Yang Zhiyu, A red phosphor that can be excited by blue light and its preparation method, CN113416542A) discloses a method using SrLaScO4 oxide as the phosphor matrix and doping with Eu. 2+ A technical solution for achieving red light emission was developed, and by adding an S-containing compound as an additive during the synthesis process, Eu effectively promoted the emission of red light. 3+ To a greater extent, it is reduced to Eu. 2 + To increase the Eu content in phosphors 2+ The actual content of sulfur powder is adjusted to improve the luminous efficiency of the red phosphor. However, sulfur powder is added during the synthesis process, and sulfur powder is highly corrosive to the silicone used in encapsulation, which inevitably leads to a decrease in the reliability of the encapsulated device.

[0020] Patent document 19 (Lei Bingfu, Li Mingcai, Zhang Haoran, Liu Yingliang, Zhang Xuejie, A far-infrared fluorescent glass ceramic, its preparation method and plant lamp, CN108314332B) discloses a structure with the structural formula ZnGa 2-x O4:xCr 3+ The far-red fluorescent material has a value of 0.002 < x < 0.0016. However, due to the presence of volatile Ga2O3 in the raw materials, the chemical composition of the material is easily deviated, making its synthesis quite difficult.

[0021] Patent document 20 (Wang Dajian, Li Guanghao, Mao Zhiyong, Song Weiwei, Sun Taolu, Zhijuan, A fluorescent microcrystalline glass for plant laser illumination and its preparation method, CN104402231B) discloses a fluorescent microcrystalline glass for plant laser illumination, composed of a glass matrix and red phosphor, wherein the content of red phosphor is 5-30 wt%, and the balance is the glass matrix. However, the synthesis of this fluorescent microcrystalline glass requires mixing the glass powder and fluorescent material evenly, heating to 500-650℃, holding at that temperature for 60-180 minutes until completely melted, and finally annealing at 300℃ for 30 minutes to eliminate internal stress. Such a high preparation temperature and holding time will lead to the oxidation of the fluorescent material, which will reduce the luminescence intensity of the final fluorescent microcrystalline glass.

[0022] In summary, existing literature reveals a severe lack of deep red fluorescent materials that simultaneously possess a broad emission spectrum, excellent thermal quenching properties, and stable chemical properties. Therefore, it is essential to develop a deep red fluorescent material with these characteristics and to fabricate a device using this material for application in plant lighting. Summary of the Invention

[0023] The primary objective of this invention is to protect a nitride deep-red light-emitting material. The general chemical formula of this nitride deep-red light-emitting material is: La₂BaSiAl 2-x Cr x N6, where 0 < x ≤ 0.2; under blue light excitation, the deep red luminescent material produces an emission wavelength with a main peak range between 680 and 730 nm and a full width at half maximum (FWHM) of the emission spectrum greater than or equal to 180 nm. Preferably, in the general chemical formula of the nitride deep red luminescent material, x = 0.02; optionally, the luminescence intensity of the nitride deep red luminescent material at 200°C is not less than 50% of its luminescence intensity at room temperature.

[0024] A second objective of this invention is to provide a method for preparing a nitride deep red light-emitting material. The method includes mixing a La precursor, a Ba precursor, a Si precursor, an Al precursor, and a Cr precursor, and then performing a high-temperature solid-state reaction under a reducing atmosphere to obtain a nitride deep red light-emitting material. Specifically, the molar ratio of the La precursor, Ba precursor, Si precursor, Al precursor, and Cr precursor is 2∶1∶1∶(2-x)∶x, and the chemical formula of the obtained material is: La₂BaSiAl 2-x Cr x N6, where 0 < x ≤ 0.2.

[0025] This invention also provides a deep red fluorescent glass and its preparation method. The deep red fluorescent glass is obtained by mixing the nitride deep red light material with glass powder and then carrying out a high-temperature solid-state reaction. Specifically, the high-temperature solid-state reaction is carried out in an air atmosphere. The temperature of the high-temperature solid-state reaction is 450-550°C and the time of the high-temperature solid-state reaction is 0.1-1h.

[0026] The present invention also provides a red light device for plant growth, the device comprising a blue light diode and a light-emitting layer, the light-emitting layer comprising the deep red fluorescent glass.

[0027] The specific plan is as follows:

[0028] A nitride deep red light material, the general chemical formula of which is:

[0029] Ba 1-x Eu x LnSiO3N

[0030] Where 0 < x ≤ 0.2.

[0031] Preferably, x = 0.02.

[0032] A second objective of this invention is to provide a method for preparing a nitride deep red light material. The preparation method comprises the following steps:

[0033] The La precursor, Ba precursor, Si precursor, Al precursor and Cr precursor are mixed and subjected to a high-temperature solid-state reaction under a reducing atmosphere to obtain the nitride deep red light material.

[0034] Preferably, in this step, the molar ratio of La, Ba, Si, Al and Cr in the La precursor, Ba precursor, Si precursor, Al precursor and Cr precursor is 2∶1∶1∶(2-x)∶x.

[0035] Preferably, in the above steps, the La precursor is selected from LaN; optionally, the Ba precursor is selected from Ba3N2; optionally, the Si precursor is one or more of Si and Si3N4, wherein Si is mandatory; optionally, the Al precursor is AlN; optionally, the Cr precursor is CrN.

[0036] Preferably, the purity of the La precursor, Ba precursor, Si precursor, Al precursor and Cr precursor is not less than 99.5 wt%.

[0037] Preferably, in the above steps, the temperature of the high-temperature solid-phase reaction is between 1000 and 1200°C, and the time of the high-temperature solid-phase reaction under a reducing atmosphere is between 4 and 10 hours.

[0038] This invention also protects a fluorescent glass based on a nitride deep red light-emitting material. The manufacturing method is as follows: the nitride deep red light-emitting material is mixed with glass powder and then subjected to a high-temperature solid-state reaction under a nitrogen atmosphere to obtain the nitride deep red light-emitting glass.

[0039] Preferably, the mass ratio of nitride deep red light material to glass powder is 1:1 to 1:2.

[0040] Preferably, the melting point of the glass powder is 450–550°C.

[0041] Preferably, the temperature for the high-temperature solid-state reaction between the nitride deep red light material and the glass powder is 450–550°C, and the reaction time is 0.1–1 h.

[0042] This invention also protects a light-emitting device based on fluorescent glass made of nitride deep-red light-emitting material. The light-emitting device includes a blue light-emitting diode and a light-emitting layer, the light-emitting layer comprising the nitride deep-red light-emitting glass, and the light-emitting layer is excited by the blue light-emitting diode to emit deep-red light.

[0043] Beneficial effects

[0044] This invention provides a nitride deep red light material, its preparation method, and its application. The chemical formula of the nitride deep red light material is La2BaSiAl. 2-x Cr xN6, where 0 < x ≤ 0.2; under blue light excitation, the deep red fluorescent material produces an emission wavelength peak range between 680 and 730 nm, and a full width at half maximum (FWHM) of the emission spectrum greater than or equal to 180 nm. Compared with existing technologies, the nitride deep red fluorescent material prepared in this invention has a novel chemical composition, a broad emission spectrum, good thermal quenching characteristics, and stable chemical properties, thus enabling the application of this luminescent material in the plant lighting industry. Attached Figure Description

[0045] Figure 1 The emission spectrum of the luminescent material obtained in Example 3 of this invention;

[0046] Figure 2 The excitation spectrum of the luminescent material obtained in Example 3 of this invention; Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0048] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0050] The general chemical formula of the nitride deep red light material is as follows:

[0051] La2BaSiAl 2-x Cr x N6

[0052] Where 0 < x ≤ 0.2.

[0053] In some embodiments provided by the present invention, x is preferably 0.001, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.005, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.02, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.04, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.08, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.1, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.15, and the precursor of Si is preferably Si; in some embodiments provided by the present invention, x is preferably 0.2, and the precursor of Si is preferably Si; in some embodiments provided by the present invention... In some embodiments, x is preferably 0.02, and the precursor of Si is preferably Si and Si3N4, wherein the molar ratio of Si and Si3N4 is 1:1; in some embodiments provided by the present invention, x is preferably 0.02, and the precursor of Si is preferably Si and Si3N4, wherein the molar ratio of Si and Si3N4 is 1:2; in some embodiments provided by the present invention, x is preferably 0.02, and the precursor of Si is preferably Si and Si3N4, wherein the molar ratio of Si and Si3N4 is 1:5; in some embodiments provided by the present invention, x is preferably 0.02, and the precursor of Si is preferably Si and Si3N4, wherein the molar ratio of Si and Si3N4 is 1:9; in other embodiments provided by the present invention, x is preferably 0.02, and the precursor of Si is preferably Si and Si3N4, wherein the molar ratio of Si and Si3N4 is 1:20.

[0054] The specific steps of the method for preparing the nitride deep red light material are as follows:

[0055] A deep red nitride material was obtained by mixing La, Ba, Si, Al, and Cr precursors and carrying out a high-temperature solid-state reaction under a reducing atmosphere.

[0056] In the aforementioned steps, the molar ratio of La, Ba, Si, Al, and Cr is 2∶1∶1∶(2-x)∶x, and the chemical formula of the resulting material is: La₂BaSiAl 2-x Cr x N6, where 0 < x ≤ 0.2.

[0057] In the steps described, the La precursor is selected from LaN; the Ba precursor is selected from Ba3N2; the Si precursor is one or more of Si and Si3N4, wherein Si is mandatory; the Al precursor is AlN; and the Cr precursor is CrN.

[0058] The purity of the La precursor, Ba precursor, Si precursor, Al precursor, and Cr precursor is not less than 99.5%. The higher the purity, the fewer impurities are in the resulting luminescent material.

[0059] The reducing atmosphere in the above steps can be ammonia or a nitrogen-ammonia mixture (dry) atmosphere, which is well known to those skilled in the art. The nitrogen volume content in the nitrogen-ammonia mixture is 25-75%, and there are no other special restrictions. In this invention, ammonia is preferred.

[0060] In the above steps, the temperature of the high-temperature solid phase is preferably 1000-1200°C, and the atmosphere is ammonia. In some embodiments provided by the present invention, the temperature of the high-temperature solid phase is preferably 1100°C.

[0061] The preferred time for the high-temperature solid phase in the above steps is 4 to 10 hours, more preferably 5 to 8 hours; in some embodiments provided by the present invention, the preferred time for the high-temperature solid phase is 6 hours.

[0062] The high-temperature solid reaction phase is preferably carried out in a high-temperature furnace. After the reaction is carried out, the furnace is cooled to room temperature to obtain a nitride deep red light material.

[0063] This invention utilizes a high-temperature solid-state reaction to successfully prepare a nitride deep red light material.

[0064] The plant lighting device made of a nitride deep red light-emitting material comprises at least a blue light-emitting diode and a light-emitting layer. The light-emitting layer is a deep red fluorescent glass.

[0065] The aforementioned deep red fluorescent glass uses a chemical formula: La₂BaSiAl 2-x Cr x The N6 nitride deep red light material (where 0 < x ≤ 0.2) is mixed with low melting point glass powder and then subjected to a high-temperature solid-state reaction to finally prepare the material.

[0066] The deep red fluorescent glass is prepared under a nitrogen atmosphere. The temperature of the high-temperature solid-state reaction is preferably 450-550°C. In some embodiments of the present invention, the temperature of the high-temperature solid-state reaction is preferably 500°C. The time of the high-temperature solid-state reaction is preferably 0.1-1 h. In some embodiments of the present invention, the time of the high-temperature solid-state reaction is preferably 0.5 h, and a deep red fluorescent glass is finally obtained.

[0067] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a nitride deep red light material and its preparation method provided by the present invention.

[0068] All reagents used in the following comparative examples and embodiments are commercially available.

[0069] The following comparative examples and embodiments use an ammonia atmosphere.

[0070] The chemical stability of fluorescent materials was evaluated using a method described in Chinese Patent CN104422676A (Jie Rongjun, Zhou Tianliang, Rapid Aging Equipment, CN104422676A). First, the luminescence intensity of the corresponding fluorescent material at 25°C was recorded and defined as 100 (relative intensity). Then, the samples were aged in a rapid aging equipment at 200°C for 48 hours. After aging, the luminescence intensity of the aged fluorescent material was measured. Generally, if the rapid aging method is used to age the fluorescent material, and the luminescence intensity remains at 75 (relative intensity) after aging at 200°C for 48 hours, the fluorescent material is considered to have good chemical stability.

[0071] The thermal quenching characteristics of phosphors were tested using a phosphor thermal quenching measurement instrument. The measurement temperature range was 25–200℃, with a temperature control accuracy of ±1℃. First, the luminescence intensity of the phosphor at 25℃ was recorded and defined as 100 (relative intensity). Then, the sample temperature was raised to 200℃, and the luminescence intensity of the phosphor was recorded again. The relative intensity was then converted from the luminescence intensity at 25℃. Generally, if the luminescence intensity of the phosphor at 200℃ reaches or exceeds 50% of the luminescence intensity of the sample at 25℃ (i.e., when the relative intensity is 50), the phosphor is considered to have good thermal quenching characteristics.

[0072] The La, Ba, Si, Al, and Cr precursors used in the comparative examples and embodiments are merely illustrative and do not constitute a limitation on the precursor raw materials. The purity of the precursors is not less than 99.5 wt%.

[0073] Comparative Example 1

[0074] The material described in this comparative example contains the compound with the chemical formula: La2BaSiAl 1.98 Cr 0.02 N6. Using LaN, BaN, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Comparative Example 1 is a nitride deep-red fluorescent material. The luminescence intensity at 25℃ was measured and defined as 100 (relative intensity). The material was then heated to 200℃, and its luminescence intensity was recorded, revealing a low intensity (see Table 1 for details). The luminescence intensity at 25℃ was measured and defined as 100 (relative intensity). The material was then placed in a rapid aging apparatus and aged at 200℃ for 48 hours. The luminescence intensity before and after aging was measured, revealing a luminescence intensity of 37. Therefore, the material corresponding to Comparative Example 1 is a deep-red fluorescent material with a broad emission spectrum, moderate thermal quenching characteristics, and unstable chemical properties.

[0075] Example 1

[0076] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.999 Cr 0.001 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.999 Cr 0.001 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.999 Cr 0.001 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 1 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded, revealing a high luminescence intensity (see Table 1). The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then placed in a rapid aging apparatus and aged at 200°C for 48 hours. The luminescence intensity before and after aging was measured, revealing a luminescence intensity of 78. This indicates that the material corresponding to Example 1 is a deep-red fluorescent material with a broad emission spectrum, good thermal quenching characteristics, and stable chemical properties.

[0077] Example 2

[0078] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.995 Cr 0.005 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.995 Cr 0.005The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.995 Cr 0.005 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 2 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that the luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 2 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0079] Example 3

[0080] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.98 Cr 0.02 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 3 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 3 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0081] Example 4

[0082] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.96 Cr 0.04 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.96 Cr 0.04 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.96 Cr 0.04N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 4 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that the luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 4 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0083] Example 5

[0084] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.92 Cr 0.08 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.92 Cr 0.08 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.92 Cr 0.08 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 5 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 5 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0085] Example 6

[0086] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.9 Cr 0.1 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.9 Cr 0.1 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.9 Cr 0.1N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 6 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 6 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0087] Example 7

[0088] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.85 Cr 0.15 N6. Using LaN, BaN, Si, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.85 Cr 0.15 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.85 Cr 0.15 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 7 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 7 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0089] Example 8

[0090] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.8 Cr 0.2 N6. Using LaN, BaN, Si, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.8 Cr 0.2 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.8 Cr 0.2N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 8 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 8 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0091] Example 9

[0092] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.98 Cr 0.02 N6. Using LaN, BaN, Si, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 9 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 9 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0093] Example 10

[0094] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.98 Cr 0.02 N6. Using LaN, BaN, Si, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 10 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that the luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 10 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0095] Example 11

[0096] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.98 Cr 0.02 N6. Using LaN, BaN, Si, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 11 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 11 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0097] Example 12

[0098] The material described in this embodiment contains a compound with the chemical formula La2BaSiAl. 1.98 Cr 0.02 N6. Using LaN, BaN, Si, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 12 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded. It was found that its luminescence intensity was relatively high, as detailed in Table 1. Therefore, the material corresponding to Example 12 is a deep-red fluorescent material with a broad emission spectrum and good thermal quenching characteristics.

[0099] Example 1.3

[0100] The material described in this embodiment contains the compound with the chemical formula: La2BaSiAl 1.98 Cr 0.02 N6. Using LaN, BaN, Si, Si3N4, AlN, and CrN as raw materials, according to its composition La2BaSiAl 1.98 Cr 0.02 The raw materials were accurately weighed according to the stoichiometric ratio of N6, and sintered at 1100℃ in a nitrogen-hydrogen mixed atmosphere for 6 hours. After cooling, the material with the nominal chemical composition La2BaSiAl was obtained. 1.98 Cr 0.02 N6. The emission spectrum of the obtained luminescent material was measured using a fluorescence spectrometer. The full width at half maximum (FWHM) and the position of the main peak of the emission spectrum are shown in Table 1. Table 1 shows that the material prepared in Example 13 is a nitride deep-red fluorescent material. The luminescence intensity at 25°C was measured and defined as 100 (relative intensity). The material was then heated to 200°C, and its luminescence intensity was recorded, revealing a high intensity, as detailed in Table 1. Therefore, the material corresponding to Example 13 is a deep-red fluorescent material with a broad emission spectrum, good thermal quenching characteristics, and stable chemical properties.

[0101] Example 14

[0102] The chemical composition of the synthesized material in Example 3 was selected as La2BaSiAl. 1.98 Cr 0.02 N6 deep red fluorescent material. The above material is mixed with low-melting-point glass powder at a mass ratio of 1:1. The mixture is placed in a flat-bottomed crucible made of titanium with a bottom diameter of 10 mm and sintered at 500°C for 0.5 h under a nitrogen atmosphere. After cooling, a deep red fluorescent glass is obtained. Encapsulating this deep red fluorescent glass with a blue light-emitting diode with an emission wavelength of 450 nm yields a deep red plant lighting source.

[0103] Table 1. Emission Spectrum Data of Materials (Excited with 450 nm Blue Light)

[0104]

[0105] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0106] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0107] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A nitride deep red light material, characterized in that, The general chemical formula of the nitride deep red light material is: La2BaSiAl 2-x Cr x N6, where 0 <x≤0.2。 2. The nitride deep red light material according to claim 1, characterized in that: In the general chemical formula of the nitride deep red light material, x = 0.02; optionally, the preparation method of the nitride deep red light material includes mixing La precursor, Ba precursor, Si precursor, Al precursor and Cr precursor, and carrying out a high-temperature solid-state reaction under a reducing atmosphere to obtain the nitride deep red light material, wherein the temperature of the high-temperature solid-state reaction is 1000~1200℃ and the time of the high-temperature solid-state reaction is 4~10h.

3. The nitride deep red light material according to claim 1 or 2, characterized in that: Under blue light excitation, the emission wavelength of the nitride deep red light material is in the range of 680~730 nm and the half width at half maximum (FWHM) of the emission spectrum is greater than or equal to 180 nm; optionally, the luminescence intensity of the nitride deep red light material at 200 °C is not less than 50% of the luminescence intensity at room temperature.

4. A method for preparing a nitride deep red light material as described in any one of claims 1-3, characterized in that: The La precursor, Ba precursor, Si precursor, Al precursor and Cr precursor are mixed and subjected to a high-temperature solid-state reaction under a reducing atmosphere to obtain the nitride deep red light material.

5. The method for preparing the nitride deep red light material according to claim 4, characterized in that... The molar ratio of La, Ba, Si, Al, and Cr in the La precursor, Ba precursor, Si precursor, Al precursor, and Cr precursor is 2:1:1:(2-x):x; the La precursor is selected from LaN; optionally, the Ba precursor is selected from Ba3N2; optionally, the Si precursor is one or more of Si and Si3N4, wherein Si is mandatory; optionally, the Al precursor is AlN. Optionally, the Cr precursor is CrN; optionally, the purity of the La precursor, Ba precursor, Si precursor, Al precursor and Cr precursor is not less than 99.5 wt%.

6. The method for preparing the nitride deep red light material according to claim 4 or 5, characterized in that: The temperature of the high-temperature solid-phase reaction is 1000~1200℃, and the reaction time is 4~10 h; Optionally, the reducing atmosphere is ammonia or a mixture of nitrogen and ammonia, wherein the nitrogen volume content in the nitrogen-ammonia mixture is 25-75%.

7. A nitride deep red fluorescent glass, characterized in that: The nitride deep red fluorescent glass is obtained by mixing the nitride deep red light material according to any one of claims 1-3, or the nitride deep red light material prepared by the preparation method according to any one of claims 4-6, with glass powder and then carrying out a high-temperature solid-state reaction. The mass ratio of the nitride deep red light material to the glass powder is 1:1 to 1:2; the melting point of the glass powder is 450 to 550°C.

8. A method for preparing the nitride deep red fluorescent glass according to claim 7, characterized in that: The nitride deep red light material according to any one of claims 1-3, or the nitride deep red light material prepared by the preparation method according to any one of claims 4-6, is mixed with glass powder and subjected to a high-temperature solid-state reaction under a nitrogen atmosphere to obtain the nitride deep red fluorescent glass.

9. The method for preparing the nitride deep red fluorescent glass according to claim 8, characterized in that: The high-temperature solid-state reaction is carried out at a temperature of 450~550℃ and for a time of 0.1~1 h; optionally, the mass ratio of the nitride deep red light material to the glass powder is 1:1~1:2; the melting point of the glass powder is 450~550℃.

10. A red light device for plant growth, characterized in that: The red light device includes a blue light-emitting diode and a light-emitting layer. The light-emitting layer includes the nitride deep red fluorescent glass of claim 7, or the nitride deep red fluorescent glass prepared by the preparation method of claim 8 or 9.

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