Preparation method of aluminum-manganese co-doped Ca2YTaO6-based fluorescent powder

Abstract

The invention discloses a preparation method of aluminum-manganese co-doped Ca2YTaO6-based fluorescent powder. The preparation method comprises the steps of preparation of manganese-doped Ca2YTaO6-based fluorescent powder and fluorescence intensity analysis, and preparation of aluminum-manganese co-doped Ca2YTaO6-based fluorescent powder and fluorescence intensity analysis. According to the method, the optimal manganese doping concentration is tested firstly, the influence of the manganese concentration on the fluorescence intensity is verified, then aluminum-manganese co-doping is achieved, the influence of co-doping on the fluorescence intensity, the thermal stability of the fluorescence intensity and the service life decay time of the fluorescence intensity is verified, the luminous intensity and the luminous efficiency of the Ca2YTaO6-based fluorescent powder are remarkably improved through aluminum-manganese double doping, and the luminous efficiency of the Ca2YTaO6-based fluorescent powder is remarkably improved. A new thought is provided for design and development of the high-performance Mn < 4 + >-doped fluorescent powder, and a foundation is laid for application of the high-performance Mn < 4 + >-doped fluorescent powder in the fields of LEDs, anti-counterfeiting and plant cultivation.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent materials, and in particular to a method for preparing aluminum-manganese co-doped Ca2YTaO6-based phosphor. Background Art

[0002] With the rapid development of modern agricultural technology, the impact of light on plant growth is receiving increasing attention. Fluorescence, as an important light source, has spectral characteristics that can significantly influence plant photosynthesis, morphological development, and physiological metabolism. Research has shown that fluorescence of specific wavelengths can effectively promote plant growth and development, especially in conditions lacking natural light. Fluorescent light sources have become a crucial tool in greenhouse cultivation and plant factories. Compared with traditional light sources, fluorescent LEDs offer advantages such as low energy consumption, long lifespan, and spectral tunability. They can precisely match the spectral range required for plant photosynthesis, thereby improving light energy utilization efficiency. In contrast, traditional light sources such as high-pressure sodium lamps and metal halide lamps, while offering higher light intensity, have a wide and uncontrollable spectral range, resulting in significant energy waste and heat generation, which adversely affects the plant growth environment.

[0003] In the research of fluorescent luminescent materials, although fluoride has high luminescence efficiency, its poor chemical stability, easy oxidation, high cost and certain harm to the environment and human health limit its application in practical environments. 4+ Doped phosphors have attracted much attention due to their unique luminescence properties and low cost and ease of production. 4+ The ions usually exist in the form of [MnO6] octahedron in the oxide matrix, and the luminescence principle is mainly due to 2 E g → 4 A 2g The transition of Mn 4+ Doped materials have broad application prospects in anti-counterfeiting technology, optical thermometers, display screens, and indoor and outdoor plant cultivation. For example, in the field of anti-counterfeiting, Mn 4+ The high color purity and stability of doped materials make them ideal for high-end anti-counterfeiting labels; in optical thermometers, Mn 4+ The fluorescence intensity of Mn is sensitive to temperature and can be used for high-precision temperature sensing. 4+ Doped materials can provide high brightness and high contrast red light, improving the display effect; in the field of indoor and outdoor plant cultivation, the use of doped Mn 4+ The matrix is used to make fill lights to broaden its emission spectrum and provide more red light wavelengths, thereby improving photosynthesis efficiency and promoting plant growth and flowering.

[0004] However, despite the Mn 4+Doped materials have many advantages, but they still face some challenges in practical applications. For example, single-doped Mn 4+ In some cases, the material has the problem of insufficient luminescence intensity or poor thermal stability. Therefore, researchers began to explore the dual doping strategy by introducing other ions (such as Al 3+ ) to improve the luminescence properties of the material. 3+ The doping of Mn can not only improve the structural stability of the matrix, but also enhance the 4+ luminous efficiency.

[0005] In recent years, Mn 4+ Single doping and Mn 4+ and Al 3+ Significant progress has been made in the development of dual-doped perovskites and double perovskite materials. For example, in the CaTiO3:Mn 4+ In the 4+ The doping of Ca2InNbO6:Mn 4+ In, Al 3+ The introduction of further optimizes the luminescence intensity and thermal stability of the material; in Ba2LaNbO6:Mn 4+ In this study, the dual-doping strategy achieved efficient red light emission and excellent temperature sensing performance. 4+ With Al 3+ The synergistic effect of Mn provides a new idea for optimizing the performance of fluorescent materials. 4+ , Al 3+ The research on co-doped CYTO phosphors has not been conducted by any scholar.

[0006] Nevertheless, Mn 4+ and Al 3+ The dual-doping experiment still has some shortcomings. Excessively high doping concentrations can lead to fluorescence quenching, reducing luminescence efficiency. Furthermore, the luminescence properties vary significantly in different matrices, requiring further optimization of matrix selection and preparation processes. Summary of the Invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor comprises the following steps:

[0010] S1. Preparation of manganese-doped Ca2YTaO6-based phosphor:

[0011] CaCO3, Y2O3, Ta2O5 and MnCO3 were weighed in a certain molar ratio, evenly mixed in an agate mortar and fully ground for two hours. The ground mixture was then transferred to a corundum crucible and pre-sintered in a muffle furnace at 600°C for 5 hours. After cooling, it was ground for 30 minutes and calcined in a muffle furnace at 1350°C for 5 hours. Finally, the calcined product was naturally cooled to ambient temperature and ground into powder. The obtained fine powder was the synthesized Ca2YTa 1-x O6:xMn 4+ Phosphor sample, wherein x = 0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% or 6.0%;

[0012] S2. Fluorescence intensity analysis of manganese-doped Ca2YTaO6-based phosphor:

[0013] Sequentially detect each Ca2YTa with x=0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% or 6.0% 1-x O6:xMn 4+ The PLE excitation spectrum and PL emission spectrum of the phosphor sample show that x = 3.0% Ca2YTa 1-x O6:xMn 4+ Phosphor sample (i.e. Ca2YTaO6:0.3%Mn 4+ Phosphor, abbreviated as CYTO:0.3%Mn 4+ ) has a higher fluorescence intensity;

[0014] S3. Preparation of Al-Mn co-doped Ca2YTaO6-based phosphor:

[0015] On the basis of S2, with a manganese doping amount of x=0.3%, an aluminum-manganese co-doped Ca2YTaO6-based phosphor was prepared by a high-temperature solid-phase reaction method. CaCO3, Y2O3, Ta2O5, MnCO3 and Al2O3 were weighed according to a certain molar ratio, uniformly mixed in an agate mortar and fully ground for two hours. The ground mixture was then transferred to a corundum crucible and pre-sintered in a muffle furnace at 600°C for 5 hours. After cooling, it was ground for 30 minutes; it was calcined in a muffle furnace at 1350°C for 5 hours, and finally the calcined product was naturally cooled to ambient temperature and ground into powder. The obtained fine powder is the synthesized Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Phosphor, wherein y=0.4%, 0.8%, 1.2%, 1.6%, 2.0% or 2.4%.

[0016] The aforementioned method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor further comprises:

[0017] S4, Fluorescence intensity analysis of Al-Mn co-doped Ca2YTaO6-based phosphors:

[0018] The Ca2YTa prepared by S1 with x=3.0% 1-x O6:xMn 4+ The phosphor sample is Ca2YTa with y=0% 1-0.3％- y O6:0.3%Mn 4+ ,yAl 3+ Phosphor blank sample, sequentially detect y = 0%, 0.4%, 0.8%, 1.2%, 1.6%, 2.0% or 2.4% of each Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The PLE excitation spectrum and PL emission spectrum of the phosphor sample show that y=1.2% Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Phosphor sample (i.e. Ca2YTa 98.5％ O6:0.3%Mn 4+ ,1.2%Al 3+ , abbreviated as CYTO:0.3%Mn 4+ ,1.2%Al 3+ ) has a strong fluorescence intensity.

[0019] Preferably, the Ca2YTa obtained in S3 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The phosphor was subjected to crystal structure analysis before preparation, and the specific analysis is as follows:

[0020] 1) Through unit cell analysis, the target compound is in the monoclinic space group P21 / n, and the cell parameters are α=γ=90°, β=89.9859°, R p 2.99%, R wp 10.85%;

[0021] 2) Using crystal group modeling software to analyze the Ca2YTaO6:0.2%Mn 4+ The crystal structure of the compound was analyzed. 3+ and Ta 5+ The ions are surrounded by 6 O atoms, thus sharing one oxygen atom to form [YO6] and [TaO6] octahedrons, while Ca 2+ ions are located at the center of the alternating octahedrons. The presence of [TaO6] octahedrons may make Mn 4+ and Al3+ Ions can easily enter the Ca2YTaO6 host lattice, so it can be predicted that Mn doping 4+ Can make phosphor emit red light;

[0022] 3) It has been determined by research that the radius difference between the substituted ion and the original host dopant ion should be less than 30%. Therefore, in a specific octahedral environment, the substituted Mn 4+ and Al 3+ The ratio of ions can be determined by the following given expression (1):

[0023]

[0024] Among them, CN is the coordination number, R m (CN) and R d (CN) are the radii of the substitutional ions and dopant ions in the original matrix, respectively. (coordination number CN = 6), (coordination number CN = 6), (coordination number CN = 6) and (coordination number CN = 6);

[0025] 4) Through calculation, Mn 4+ and Ta 5+ 、Y 3+ The radius percentage difference between r ) were 17.2% and 41.1%, respectively, Al 3+ and Ta 5+ 、Y 3+ The radius percentage difference between r ) were 16.4% and 40.6% respectively, Mn 4+ and Al 3+ The ionic radius is closer to Ta 5+ Therefore, in CYTO:Mn 4+ In phosphor, Mn 4+ and Al 3+ Dopants tend to replace Ta 5+ The ions form [MnO6] and [AlO6] octahedra.

[0026] Preferably, the Ca2YTa obtained by testing the S3 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+The XRD pattern of the phosphor is the result of the lack of PDF standard card data for Ca2YTaO6 compounds. The pattern of Ca2GdTaO6 compounds is selected as a reference because Ca2YTaO6 and Ca2GdTaO6 have the same crystal structure type, which means that their atomic arrangement and space group are very similar. 4+ and Al 3+ The doping has no significant effect on the crystal structure of the Ca2GdTaO6 matrix.

[0027] Preferably, by detecting x=0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% or 6.0% of Ca2YTa 1- x O6:xMn 4+ Phosphor samples and Ca2YTa with y=1.2% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Fluorescence decay curve of phosphor, and fitted with double exponential function:

[0028]

[0029] Where A1 and A2 are constants, I(t) represents the PL intensity at time t, τ1 and τ2 represent the short and long lifetimes of the exponential component, respectively. s Further calculated by the following formula:

[0030]

[0031] Ca2YTa 1-x O6:xMn 4+ Average lifetime τ of phosphor samples s The calculated values are as follows: 0.249ms when x=0.1%, 0.215ms when x=0.2%, 0.177ms when x=0.3%, 0.139ms when x=0.4%, 0.127ms when x=0.5%, and 0.124ms when x=0.6%. It can be seen that as Mn 4+ With the increase of doping concentration, the average fluorescence lifetime decreases from 0.249ms to 0.124ms. 4+ In phosphor, Mn 4+ Only one site is occupied. Therefore, the observed biexponential decay curve can be attributed to the Mn 4+ The energy transfer process between ions provides an additional luminescence decay channel. 4+ The increase of ion concentration, Mn 4+ The distance between ions decreases, resulting in the Mn 4+ -Mn4+ The number of ions increases, and thus, Mn 4+ The non-radiative energy transfer between ions becomes more frequent, resulting in a continuous decrease in the lifetime of the phosphor.

[0032] With Al 3+ After ion co-doping, the average decay time changes from Ca2YTa 1-x O6:xMn 4+ The 0.177ms of the phosphor sample was extended to y = 1.2% Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The phosphor sample has a value of 0.203ms, which indicates that Al 3+ The introduction of Mn 4+ -Al 3+ ion pairs, thereby inhibiting the Mn 4+ -Mn 4+ The formation of ion pairs reduces non-radiative transitions, thereby enhancing the luminescence intensity of CYTO and extending the average life of the phosphor.

[0033] Preferably, by detecting x=3.0% Ca2YTa 1-x O6:xMn 4+ Phosphor samples and Ca2YTa with y=1.2% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Photoluminescence (PL) spectrum of phosphor in the temperature range of 308-468K, to test Mn 4 + and Al 3+ The doping of α-D has a significant effect on the thermal stability of fluorescence intensity.

[0034] Preferably, x=3.0% of Ca2YTa is calculated by detection 1-x O6:xMn 4+ Phosphor samples and Ca2YTa with y=1.2% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The quantum yield (QY) of the phosphor measured under 304nm excitation is as follows:

[0035]

[0036] Where Z is represented by QY, L S is the emission spectrum of the phosphor, E S and E R The excitation spectra of the phosphor and BaSO4 reference are respectively. 1-0.3％-yO6:0.3%Mn 4+ ,yAl 3+ The QY of the phosphor sample reaches 6.13%, which is the Ca2YTa with x=3.0%. 1-x O6:xMn 4+ 1.71 times that of the phosphor sample;

[0037] The quantum yield (QY) is an important indicator for evaluating the performance of fluorescent materials, reflecting the efficiency of the material in converting light into light after absorbing light. For applications with high luminous efficiency requirements (such as LEDs, lasers, and display technologies), improving the quantum yield is crucial. Therefore, CYTO:0.3% Mn 4+ ,1.2%Al 3+ As an optimal phosphor, it is a potential candidate in the field of plant growth lighting.

[0038] The aluminum-manganese co-doped Ca2YTaO6-based phosphor obtained by the above preparation method is applied in LED devices by coating CYTO: 0.3% Mn on a 365nm ultraviolet LED chip. 4+ ,1.2%Al 3+ Phosphor, successfully prepared LED devices for plant cultivation lighting, LED devices can produce stable deep red light at different driving currents, and the luminous intensity gradually increases with the increase of driving current. These findings prove that CYTO: 0.3% Mn 4+ ,1.2%Al 3+ The excellent performance of the phosphor indicates that it is suitable for LED devices used in plant cultivation. By using these LEDs, ultraviolet light can be converted into deep red light, making this phosphor potentially useful in agriculture.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention aims to explore Al 3+ Doping of Ca2YTaO6:Mn 4+ The influence of the luminescence properties of oxide phosphors, by optimizing the material properties, improving its luminescence intensity, regulating the luminescence wavelength, and revealing the Al 3+ The mechanism of doping provides theoretical support for its application in LED, anti-counterfeiting and increasing crop yields;

[0041] 2. The present invention adopts high temperature solid phase method to prepare a series of different Al 3+ Doping concentration of Ca2YTaO6:Mn 4+Phosphor samples. The crystal structure, luminescence properties, concentration quenching, and lifetime decay of the samples were systematically characterized using X-ray diffraction (XRD), photoluminescence spectroscopy (PL), photoluminescence spectroscopy (PLE), quantum yield (QY), thermal stability analysis, and fluorescence lifetime testing.

[0042] 3. The present invention first tests the optimal manganese doping concentration and verifies the effect of manganese concentration on fluorescence intensity. The experimental results show that the synthesized sample can be effectively excited under ultraviolet light and blue light of 250-600nm, producing strong far-red emission. The emission peak of the sample is about 680nm. When the doping concentration Mn 4+ When x = 0.3%, the fluorescence intensity reaches the best due to concentration quenching of the dipole-dipole reaction;

[0043] 4. Based on the optimal manganese doping concentration, the present invention tests different contents of Al 3+ Doping was performed to achieve aluminum-manganese co-doping, and the effect of co-doping on the fluorescence intensity, thermal stability and lifetime decay time was verified. Double doping can significantly improve the fluorescence intensity of Ca2YTaO6:Mn 4+ The luminous intensity of the phosphor is improved and its luminous efficiency is optimized, wherein the optimal doping concentration of Al 3+ 1.2%, CYTO: 0.3% Mn 4+ ,1.2%Al 3+ The PL intensity of CYTO:0.3%Mn is about 4+ In addition, Al 3+ Doping also improves the thermal stability and QY of the material;

[0044] 5. In summary, the present invention utilizes Al 3+ Doping of Ca2YTaO6:Mn 4+ The luminescence performance of phosphors has been significantly optimized, mainly because Al 3+ ions can interrupt Mn 4+ The energy transfer between ions improves the luminous intensity and efficiency of the phosphor by regulating the crystal field environment and improving the material structure. 4+ The design and development of doped phosphors provide new ideas and lay the foundation for their application in LED, anti-counterfeiting and plant cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is the XRD spectrum of the phosphor, where Figure 1 (a)CYTO:xMn 4+ (x=0-0.6%) XRD spectrum of phosphor, Figure 1 (b) CYTO:0.3%Mn 4+ ,yAl3+ (y=0-2.4%) XRD spectrum of phosphor.

[0046] Figure 2 This is the crystal structure analysis diagram of CYTO, where Figure 2 (a) CYTO: 0.3% Mn 4+ Rietveld refinement of phosphor XRD, Figure 2 (b) Schematic diagram of the CYTO crystal structure.

[0047] Figure 3 is the excitation spectrum of the manganese-doped phosphor, where Figure 3 (a) is CYTO:xMn 4+ The excitation spectrum of phosphor at room temperature (λ em =680nm), Figure 3 (b) CYTO:0.3%Mn 4+ Gaussian fitting of the excitation spectrum of the phosphor.

[0048] Figure 4 is the emission spectrum of the manganese-doped phosphor, where Figure 4 (a) is CYTO:xMn 4+ The emission spectrum of the sample at room temperature (λ ex =304nm), Figure 4 (b) is CYTO:xMn 4+ The comprehensive emission intensity of phosphors and Mn 4+ The concentration change relationship diagram, Figure 4 (c) is CYTO:xMn 4+ Linear fitting relationship between log(I / x) and log(x) in phosphor.

[0049] Figure 5 is the emission spectrum of the manganese-aluminum co-doped phosphor, where Figure 5 (a) is CYTO:xMn 4+ ,yAl 3+ PLE spectra of the samples at room temperature (λ em =680nm), Figure 5 (b) CYTO:0.3%Mn 4+ ,1.2%Al 3+ Gaussian fitting excitation spectrum of phosphor, Figure 5 (c) is CYTO:xMn 4+ ,yAl 3+ PL spectra of the samples at room temperature (λ ex =304nm), Figure 5 (d) CYTO: 0.3% Mn 4+ ,yAl 3+(y=0-2.4%) The PL intensity of phosphor varies with Al 3+ Concentration variation histogram.

[0050] Figure 6 is the fluorescence attenuation curve of the phosphor, where Figure 6 (a) is CYTO:xMn 4+ The decay curve (λ ex =304nm,λ em =680nm), Figure 6 In (a), from top to bottom, the curves are x = 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6%. Figure 6 (b) CYTO:0.3%Mn 4+ and CYTO:0.3%Mn 4+ ,1.2%Al 3+ (λ ex =304nm,λ em =680nm) phosphor attenuation curve comparison.

[0051] Figure 7 CYTO: 0.3% Mn 4+ and CYTO:0.3%Mn 4+ ,1.2%Al 3+ Tanabe-Sugano energy level diagram and corresponding transition path diagram.

[0052] Figure 8 is a schematic diagram of the change of phosphor emission spectrum with temperature, where Figure 8 (a) CYTO: 0.3% Mn 4+ The emission spectrum of phosphor changes with temperature, Figure 8 (b) CYTO:0.3%Mn 4+ ,1.2%Al 3+ The emission spectrum of phosphor changes with temperature, Figure 8 (a) and Figure 8 In (b), from top to bottom, the emission spectrum curves are at temperatures of 308K, 328K, 348K, 368K, 388K, 408K, 428K, 448K and 468K. Figure 8 (c) CYTO: 0.3% Mn 4+ Normalized integrated intensity as a function of temperature, Figure 8 (d) CYTO: 0.3% Mn 4+ ,1.2%Al 3+ Normalized integrated intensity as a function of temperature.

[0053] Figure 9 is the quantum yield diagram of the phosphor, where Figure 9(a) CYTO: 0.3% Mn 4+ The quantum yield of the phosphor, Figure 9 (b) CYTO:0.3%Mn 4+ ,1.2%Al 3+ Quantum yield of phosphors.

[0054] Figure 10 CYTO: 0.3% Mn 4+ ,1.2%Al 3+ The color purity of the phosphor and its electroluminescence (EL) spectrum, where Figure 10 (a) CYTO: 0.3% Mn 4+ ,1.2%Al 3+ CIE diagram of phosphor, Figure 10 (b) is the electroluminescence (EL) spectrum of the LED device under different driving currents (100-200mA). Figure 10 (b) From bottom to top are the electroluminescence (EL) spectra at driving currents of 100mA, 120mA, 140mA, 160mA, 180mA, and 200mA. Figure 10 The inset in (b) is a digital photograph of the fabricated LED device at a current of 100 mA. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the existing known technologies. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0056] Embodiment 1:

[0057] 1 Materials and Methods

[0058] 1.1 Phosphor Preparation

[0059] All samples were prepared by high temperature solid phase reaction method, where the raw materials are CaCO3 (99.99%), Y2O3 (99.99%), Ta2O5 (99.99%), MnCO3 (99.99%) and Al2O3 (99.99%). Produced by Shanghai Aladdin Company. Synthetic sample Ca2YTa 1-x O6:xMn 4+ Phosphors (x = 0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% and 6.0%) and Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+Phosphor (y = 0%, 0.4%, 0.8%, 1.2%, 1.6%, 2.0%, and 2.4%). First, the above raw materials were weighed according to the specified molar ratios, uniformly mixed in an agate mortar, and thoroughly ground for two hours. The ground mixture was then transferred to a corundum crucible and pre-sintered in a muffle furnace at 600°C for 5 hours. After cooling, it was ground for 30 minutes. It was then calcined in a muffle furnace at 1350°C for 5 hours. Finally, the calcined product was naturally cooled to ambient temperature and ground into a powder. The resulting fine powder was the phosphor required for the experiment.

[0060] 1.2 Sample characterization

[0061] X-ray powder diffractometer (XRD, Shimadzu XRD-6100, Japan, Cu target Kα radiation, 40 kV, 30 mA, λ = 0.15406 nm) was used for all phosphor samples. The scanning speed was 10° / min and the scanning angle range was 10° to 80°. The excitation (PL) and emission (PLE) spectra, as well as the luminescence lifetime decay curves, were acquired using an FLS980 spectrometer (Edinburgh, Livingston, UK) equipped with a 450 W continuous microsecond pulsed xenon lamp. The quantum yield of the phosphors was measured using a barium sulfate-coated integrating sphere connected to the spectrophotometer.

[0062] 2 Results and Analysis

[0063] 2.1 Phase analysis and crystal structure

[0064] Figure 1 (a) and (b) show the CYTO:xMn 4+ (x = 0%, 0.10%, 0.20%, 0.30%, 0.40%, 0.50% and 0.60%) and CYTO: 0.3% Mn 4+ ,yAl 3+ (y=0%,0.40%,0.80%,1.20%,1.60%,2.00% and 2.4%). Due to the lack of PDF standard card data for Ca2YTaO6 compounds, we chose the spectrum of Ca2GdTaO6 compounds as a reference because Ca2YTaO6 and Ca2GdTaO6 have the same crystal structure type, which means that their atomic arrangements and space groups are very similar. Figure 1 (a) and (b) show that CYTO:xMn 4+ and CYTO:0.3%Mn 4+ ,yAl 3+ The diffraction peaks of the phosphor samples are highly consistent with those of the standard card PDF#73-0085, indicating that we have successfully synthesized single-doped Ca2YTaO6:Mn4+ and dual-doped Ca2YTaO6:Mn 4+ , Al 3+ Compounds, and Mn 4+ and Al 3+ The doping did not significantly affect the host crystal structure.

[0065] For Ca2YTaO6:0.3%Mn 4+ The XRD pattern of the phosphor was subjected to Rietveld refinement, and the results were as follows Figure 2 (a) Crystal structure analysis shows that the target compound is in the monoclinic space group P21 / n, with a cell parameter of α=γ=90°, β=89.9859°, R p 2.99%, R wp It is 10.85%.

[0066] like Figure 2 As shown in (b), for Ca2YTaO6:0.2%Mn 4+ The crystal structure of the compound was analyzed. 3+ and Ta 5+ The ions are surrounded by 6 O atoms, thus sharing one oxygen atom to form [YO6] and [TaO6] octahedrons, while Ca 2+ ions are located at the center of the alternating octahedrons. The presence of [TaO6] octahedrons may make Mn 4+ and Al 3+ Ions can easily enter the Ca2YTaO6 host lattice, so it can be predicted that Mn doping 4+ Can make phosphor emit red light.

[0067] It has been determined that the radius difference between the substitution ion and the original host dopant ion should be less than 30%. Therefore, in a specific octahedral environment, the substituted Mn 4+ and Al 3+ The ratio of ions can be determined by the following given expression (1):

[0068]

[0069] Among them, CN is the coordination number, R m (CN) and R d (CN) are the radii of the substitutional ions and dopant ions in the original matrix, respectively. (coordination number CN = 6), (coordination number CN = 6), (coordination number CN = 6) and (Coordination number CN=6). By calculation, Mn 4+ and Ta5+ , Y 3+ The radius percentage difference between r ) were 17.2% and 41.1%, respectively, Al 3+ and Ta 5+ , Y 3+ The radius percentage difference between r ) are 16.4% and 40.6% respectively, and the ionic radius is closer. Therefore, in CYTO:Mn 4+ In phosphor, Mn 4+ and Al 3+ Dopants tend to replace Ta 5+ The ions form [MnO6] and [AlO6] octahedra.

[0070] 2.2 PLE and PL spectral analysis

[0071] Ca2YTaO6:xMn 4+ Phosphor(λ em =680nm) of the PLE spectrum is as follows Figure 3 (a) shows a broad excitation band in the ultraviolet and blue-green regions within the 250-600 nm wavelength range. The excitation band around 304 nm is particularly prominent. Therefore, 304 nm was selected as the excitation wavelength in subsequent studies. Figure 3 (b) CYTO:0.3%Mn 4+ The Gaussian fitting excitation spectrum can be fitted into four Gaussian bands, corresponding to the Mn-O charge transfer band (CTB) and the Mn 4+ Ionic 4 A 2g - 4 T 1g 、 4 A 2g - 2 T 2g and 4 A 2g - 4 T 2g The transitions have peaks at 273, 300, 326 and 512 nm respectively.

[0072] CYTO:xMn 4+ The emission spectrum of phosphor is as follows Figure 4 (a) As shown. Under 350nm excitation, due to the Mn 4+ Spin inhibition of ions 2 E g → 4 A 2g Transition, showing a bright narrow-band deep red light in the wavelength range of 635-770nm, with the emission peak at 680nm. In order to determine the critical value of doping, different concentrations of Mn4+ ions are doped into CYTO. 4+ When the concentration increases from 0.1 to 0.3%, the luminescence intensity gradually increases, but decreases after exceeding 0.3%. Figure 4 (b) shows the CYTO:xMn 4+ The comprehensive emission intensity of phosphors is closely related to the Mn 4+ Dependence of doping concentration. CYTO: 0.3% Mn 4+ The luminescence intensity of the phosphor is the highest, so 0.3% is the best concentration for subsequent optimization experiments. The decrease in emission intensity is due to concentration quenching, which is caused by Mn 4+ In order to clarify the energy transfer process between Mn 4+ -Mn 4+ Energy transfer mechanism, critical distance (R c ) is calculated by using the Blasse equation:

[0073]

[0074] Where V represents the unit cell volume; x c is the critical concentration of the dopant; N is the number of available sites for activated ions per unit cell. x c =0.3%, N=2, then determine R c Approximately Much greater than It can be seen that the electric multipolar interaction is the 4+ -Mn 4+ The main mechanism of energy transfer. In addition, the detailed type of interaction can be determined using the Dexter equation:

[0075] I / x=K[1+β(x) θ / 3 ] -1 (3)

[0076] Where I is the emission intensity, x is the dopant concentration; K and β are constants, and θ = 6, 8, and 10 represent dipole-dipole, dipole-quadrupole, and quadrupole-quadrupole interactions, respectively. The relationship between log(x) and log(I / x) is shown in the figure below: Figure 4 (c) This graph can be well fitted by a straight line with a slope of -θ / 3 = -2.24, so the θ value is 6.72, which is close to 6. It can be seen that the dipole-dipole interaction is the main 4+ -Mn 4+ The main mechanism of energy transfer between ions.

[0077] Figure 5 (a) and (c) depict the CYTO:0.3%Mn 4+,yAl 3+ PLE and PL spectra of (y = 0, 0.4%, 0.8%, 1.2%, 1.6%, 2.0% and 2.4%) phosphors. 3+ With the participation of , there is no obvious change in the position and characteristics of the PLE and PL spectra. Figure 5 (d) shows Al 3+ Doping effect of CYTO:0.3%Mn 4+ The influence of the PL intensity of the phosphor. It is worth noting that the Al-doped 3+ Can significantly increase CYTO:0.3%Mn 4+ PL intensity. When Al 3+ When the doping concentration is y=1.2%, CYTO:0.3%Mn 4+ ,1.2%Al 3+ The PL intensity of CYTO:0.3%Mn 4+ 5.92 times of Al 3+ ions tend to occupy Ta 5+ vacancy, because Al 3+ The radius is much smaller than Y 3+ , but with Ta 5+ ions are similar. Therefore, a pair of Ta 5+ -Ta 5+ ions can be separated by a pair of Mn 4+ -Al 3+ ions. Figure 5 (d) shows the dependence of PL intensity on dopants. 4+ Energy transfer between ions can be controlled by Mn 4+ -Al 3+ The ion pairs are effectively interrupted, resulting in CYTO:0.3%Mn 4+ ,1.2%Al 3+ The ions have higher luminescence performance. The significance of this result is that it provides an effective strategy to enhance luminescence.

[0078] 2.3 Lifespan decay analysis

[0079] Generally speaking, regardless of the intensity of the excitation light, the fluorescence lifetime is directly affected by the environment surrounding the luminescent center. Figure 5 (a) shows the CYTO:xMn 4+ Phosphor(λ ex =304nm,λ em =680nm) of fluorescence decay curve. It was found that these decay curves can be well fitted with a double exponential function:

[0080]

[0081] Where A1 and A2 are constants, I(t) represents the PL intensity at time t, τ1 and τ2 represent the short and long lifetimes of the exponential component, respectively. s Further calculated by the following formula

[0082]

[0083] CYTO:xMn 4+ The average lifespan of phosphor (τ s )Calculated value is as follows Figure 6 As shown in (a), CYTO:xMn 4+ The average decay life of the samples is as follows: 0.249ms when x=0.1%, 0.215ms when x=0.2%, 0.177ms when x=0.3%, 0.139ms when x=0.4%, 0.127ms when x=0.5%, and 0.124ms when x=0.6%. It can be seen that with the increase of Mn 4+ With the increase of doping concentration, the average fluorescence lifetime decreases from 0.249ms to 0.124ms. 4+ In phosphor, Mn 4+ Only one site is occupied. Therefore, the observed biexponential decay curve can be attributed to the Mn 4+ The energy transfer process between ions provides an additional luminescence decay channel. 4+ The increase of ion concentration, Mn 4+ The distance between ions decreases, resulting in the Mn 4+ -Mn 4+ The number of ions increases, and thus, Mn 4+ The non-radiative energy transfer between ions becomes more frequent, resulting in a continuous decrease in the life of the phosphor. Figure 6 (b) It can be clearly seen that 3+ After ion co-doping, CYTO:0.3%Mn 4+ The average decay time of the phosphor was extended from 0.177ms to 0.203ms, which indicates that the Al 3+ The introduction of Mn 4+ -Al 3+ ion pairs, thereby inhibiting the Mn 4+ -Mn 4+ The formation of ion pairs reduces non-radiative transitions, thereby enhancing the luminescence intensity of CYTO and extending the average life of the phosphor.

[0084] 2.4 Crystal Field Analysis

[0085] Figure 7 (a) is Mn 4+ Energy level transition diagram of Mn4+ The energy level transition of Mn has a great dependence on its crystal field environment. 4+ When in an octahedral environment, its energy level diagram can be represented by the Tanabe-Sugano diagram. Under the excitation of ultraviolet light or blue light, Mn 4+ The electrons can be taken from the ground state 4 A 2g Transition to excited state 4 T 1g , 2 T 2g and 4 T 2g Afterwards, the electron returns to the lowest excited state via a non-radiative path 2 E g , and then jump back to the ground state through radiation 4 A 2g , producing deep red light. This figure is obtained by the crystal field intensity (D q ) and Racah parameters (B) obtained. D q It can be calculated by the following formula 4 A 2g - 4 T 2g Energy difference:

[0086] D q =E( 4 T 2g → 4 A 2g ) / 10 (6)

[0087] use 4 A 2g - 4 T 1g and 4 A 2g - 4 T 2g The energy difference between transitions, the Racah parameter, can be calculated using the following formula:

[0088]

[0089] according to Figure 3 (b) CYTO: 0.3% Mn 4+ From the excitation and emission spectra, we can see that 4 A 2g - 4 T 1g and 4 A 2g - 4 T 2g The energies are 28736cm -1 (348nm) and 19608cm -1(510nm). In addition, according to Figure 5 (b), CYTO: 0.3% Mn 4+ ,1.2%Al 3+ middle 4 A 2g -4T 1g and 4 A 2g -4T 2g The energies are 27933 cm -1 (358nm) and 19417cm -1 (515nm). Using the above equation, the crystal field parameters D of single doping and double doping can be calculated respectively. q / B values are 2.02 and 2.21 respectively. It can be concluded that in this system, Mn 4+ Placed in a strong crystal field environment and in Al 3+ Under the dual-doping condition, the crystal field parameter increases from 2.02 to 2.21, indicating that Al 3+ It successfully occupied the CYTO matrix lattice and effectively formed Mn 4+ -Al 3+ Ion pairs increase the Mn 4+ The radiation energy transfer between them.

[0090] 2.5 Thermal Stability Analysis and Quantum Yield (QY)

[0091] CYTO:0.3%Mn 4+ and CYTO:0.3%Mn 4+ ,1.2%Al 3+ The temperature-dependent photoluminescence (PL) spectra of phosphors were studied in the range of 308–468 K, e.g. Figure 8 (a) and (b). As the temperature increases, the profile and peak position of the PL spectrum remain basically unchanged. However, the PL intensity decreases with increasing temperature, that is, the temperature quenching effect occurs. For LEDs, especially high-power LED devices, the thermal quenching characteristics of phosphors are a key issue. Figure 8 (c) and (d) show that at the operating temperature of high-power white light LED at 368K, CYTO:0.3%Mn 4+ The PL intensity of the phosphor dropped to 49.9% of the initial PL intensity. 3+ When ion co-doping, CYTO:0.3%Mn 4+ ,1.2%Al 3+ The PL intensity of the phosphor increased from 49.9% to 51.8%, and the thermal stability of the phosphor was enhanced.

[0092] Quantum yield (QY) is an important indicator for evaluating the performance of fluorescent materials, reflecting the efficiency of the material in converting light into light after absorbing light. For applications with high luminous efficiency requirements (such as LEDs, lasers, and display technologies), improving quantum yield is crucial. 4+ and CYTO:0.3%Mn 4+ ,1.2%Al 3+ The QY can be determined using the following formula:

[0093]

[0094] Where Z is represented by QY, L S is the emission spectrum of the phosphor, E S and E R The excitation spectra of phosphor and BaSO4 reference are respectively. 3+ (y=1.2%) After the merger, QY reaches 6.13%, which is CYTO:0.3%Mn 4+ 1.71 times of Figure 9 (a) and (b). Therefore, CYTO: 0.3% Mn 4+ ,1.2%Al 3+ As an optimal phosphor, it is a potential candidate in the field of plant growth lighting.

[0095] 2.6 CIE Chromaticity Coordinates and LED Applications

[0096] Calculate and plot CYTO:0.3%Mn 4+ ,1.2%Al 3+ The CIE chromaticity coordinates of the phosphor, such as Figure 10 As shown in (a), when excited by 365nm light, the CIE chromaticity coordinates of the phosphor are located at (0.6473, 0.3326), which is in the far red region. 4+ ,1.2%Al 3+ The color purity of the sample is as high as 98.7%, indicating that CYTO:0.3%Mn 4+ ,1.2%Al 3+ It has excellent color purity. It can be concluded that the phosphor can emit far-red light under near-ultraviolet light or blue light excitation, and has great application potential in the field of deep red LED for plant growth.

[0097] By coating CYTO:0.3%Mn on the 365nm UV LED chip 4+ ,1.2%Al 3+ Phosphors have been successfully used to prepare LED devices for plant cultivation lighting, such as Figure 9 (b) is shown in the illustration. In addition, Figure 10 (b) shows the EL spectra of the LED device at different driving currents. It can be observed that the LED device can produce stable deep red light at different driving currents, and the luminous intensity gradually increases with the increase of driving current. These findings prove that CYTO:0.3%Mn 4+ ,1.2%Al 3+ The excellent properties of the phosphor indicate its suitability for LED devices used in plant cultivation. By using these LEDs, ultraviolet light can be converted into deep red light, making this phosphor of potential application value in agriculture.

[0098] 3 Conclusion and Discussion

[0099] In summary, CYTO:0.3%Mn was synthesized by high temperature solid phase method. 4+ Phosphor. The phase analysis of the phosphor was carried out by X-ray diffraction. These samples were crystallized in the monoclinic space group P21 / n, and their crystal structure contained abundant [TaO6] octahedrons to provide Mn 4+ In the range of 250-600nm, the excitation spectrum shows several wide PLE bands, which match the emission of commercial near-ultraviolet LED chips. The emission spectrum shows a deep red emission band with a maximum wavelength of 680nm and a FWHM of 32.8nm. The CIE chromaticity coordinates are located at (0.6473, 0.3326) and the color purity is 98.7%. When doped with Mn 4+ When the concentration of Al reaches x = 0.3%, concentration quenching occurs, which is caused by the dipole-dipole reaction. More importantly, Al 3+ Dopants can replace Ta 5+ sites and significantly enhanced the Mn 4+ The emission intensity is mainly due to the Mn 4+ -Mn 4+ ions can be separated by a pair of Mn 4+ -Al 3+ Ion replacement, interruption of Mn 4+ -Mn 4+ Energy transfer between ions. Impressively, CYTO:0.3%Mn 4+ ,1.2%Al 3+ The PL intensity of CYTO:0.3%Mn is about 4 + 5.92 times of that in the experiment. CYTO:0.3%Mn 4+ and CYTO:0.3%Mn 4+ ,1.2%Al 3+ The temperature dependence of the PL spectrum, quantum yield (QY), and lifetime decay of the phosphors showed that the latter were improved to varying degrees compared to the former. These conclusions indicate that the prepared CYTO: 0.3% Mn4+ ,1.2%Al 3+ Phosphors have potential application prospects in the fields of plant cultivation and LED growth, and have certain guiding significance for improving phosphors by doping ions.

[0100] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor, characterized in that: The following steps are involved: S1. Preparation of manganese-doped Ca2YTaO6-based phosphor: CaCO3, Y2O3, Ta2O5 and MnCO3 were weighed in a certain molar ratio, evenly mixed and fully ground in an agate mortar for two hours, and then the ground mixture was transferred to a corundum crucible and pre-sintered in a muffle furnace at 600℃ for 5 hours. After cooling, it was ground for 30 minutes. The product was calcined in a muffle furnace at 1350 ° C for 5 hours, and finally the calcined product was naturally cooled to ambient temperature and ground into powder. The fine powder obtained was the synthesized Ca2YTa 1-x O6:xMn 4+ Phosphor sample, wherein x = 0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% or 6.0%; S2. Fluorescence intensity analysis of manganese-doped Ca2YTaO6-based phosphor: Sequentially detect each Ca2YTa with x=0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% or 6.0% 1-x O6:xMn 4+ The PLE excitation spectrum and PL emission spectrum of the phosphor sample show that x = 3.0% Ca2YTa 1-x O6:xMn 4+ Phosphor sample, namely Ca2YTaO6:0.3%Mn 4+ The fluorescence intensity of phosphor is high; S3. Preparation of Al-Mn co-doped Ca2YTaO6-based phosphor: Based on S2, an aluminum-manganese co-doped Ca2YTaO6-based phosphor was prepared by a high-temperature solid-phase reaction method with a manganese doping content of x=0.3%. CaCO3, Y2O3, Ta2O5, MnCO3, and Al2O3 were weighed according to a certain molar ratio, uniformly mixed in an agate mortar and fully ground for two hours. The ground mixture was then transferred to a corundum crucible and pre-sintered in a muffle furnace at 600°C for 5 hours. After cooling, it was ground for 30 minutes. The product was calcined in a muffle furnace at 1350 ° C for 5 hours, and finally the calcined product was naturally cooled to ambient temperature and ground into powder. The fine powder obtained was the synthesized Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Phosphor, wherein y=0.4%, 0.8%, 1.2%, 1.6%, 2.0% or 2.4%.

2. The method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor according to claim 1, characterized in that: Also includes: S4, Fluorescence intensity analysis of Al-Mn co-doped Ca2YTaO6-based phosphors: The Ca2YTa prepared by S1 with x=3.0% 1-x O6:xMn 4+ The phosphor sample is Ca2YTa with y=0% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Phosphor blank sample, sequentially detect y = 0%, 0.4%, 0.8%, 1.2%, 1.6%, 2.0% or 2.4% of each Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The PLE excitation spectrum and PL emission spectrum of the phosphor sample show that y=1.2% Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Phosphor sample, namely Ca2YTa 98.5％ O6:0.3%Mn 4+ ,1.2%Al 3+ The fluorescence intensity is strong.

3. The method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor according to claim 1, characterized in that: The Ca2YTa obtained in S3 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The phosphor was subjected to crystal structure analysis before preparation, and the specific analysis is as follows: 1) Through unit cell analysis, the target compound is in the monoclinic space group P21 / n, and the cell parameters are α=γ=90°, β=89.9859°, R p 2.99%, R wp 10.85%; 2) Using crystal group modeling software to analyze the Ca2YTaO6:0.2%Mn 4+ The crystal structure of the compound was analyzed. 3+ and Ta 5+ The ions are surrounded by 6 O atoms, thus sharing one oxygen atom to form [YO6] and [TaO6] octahedrons, while Ca 2+ The ions are located at the center of the alternating octahedra; 3) It has been determined by research that the radius difference between the substituted ion and the original host dopant ion should be less than 30%. Therefore, in a specific octahedral environment, the substituted Mn 4+ and Al 3+ The ratio of ions can be determined by the following given expression (1): Among them, CN is the coordination number, R m (CN) and R d (CN) are the radii of the substitutional ions and dopant ions in the original matrix, respectively. (coordination number CN = 6), (coordination number CN = 6), (coordination number CN = 6) and (coordination number CN = 6); 4) By calculation, Mn 4+ and Ta 5+ 、Y 3+ The radius percentage differences between the two are 17.2% and 41.1%, respectively. 3+ and Ta 5+ 、Y 3 + The radius percentage differences between the two groups are 16.4% and 40.6%, respectively. 4+ and Al 3+ The ionic radius is closer to Ta 5+ ,,Mn 4+ and Al 3+ Dopants tend to replace Ta 5+ The ions form [MnO6] and [AlO6] octahedra.

4. The method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor according to claim 1, characterized in that: The Ca2YTa obtained by testing the S3 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The XRD pattern of the phosphor is selected as a reference to verify the XRD pattern of the Mn 4+ and Al 3+ The doping has no significant effect on the crystal structure of the Ca2GdTaO6 matrix.

5. The method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor according to claim 1, characterized in that: By detecting x = 0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0% or 6.0% of Ca2YTa 1-x O6:xMn 4+ Phosphor samples and Ca2YTa with y=1.2% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Fluorescence decay curve of phosphor, and fitted with double exponential function: Where A1 and A2 are constants, I(t) represents the PL intensity at time t, τ1 and τ2 represent the short and long lifetimes of the exponential component, respectively; the average lifetime τ s Further calculated by the following formula: Ca2YTa 1-x O6:xMn 4+ Average lifetime τ of phosphor samples s The calculated values are as follows: 0.249ms when x=0.1%, 0.215ms when x=0.2%, 0.177ms when x=0.3%, 0.139ms when x=0.4%, 0.127ms when x=0.5%, and 0.124ms when x=0.6%; With Al 3+ After ion co-doping, the average decay time changes from Ca2YTa 1-x O6:xMn 4+ The 0.177ms of the phosphor sample was extended to y = 1.2% Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ 0.203ms for the phosphor sample.

6. The method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor according to claim 1, characterized in that: By detecting x=3.0% Ca2YTa 1-x O6:xMn 4+ Phosphor samples and Ca2YTa with y=1.2% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ Photoluminescence spectrum of phosphor in the temperature range of 308-468K, test Mn 4+ and Al 3+ The doping of α-D has a significant effect on the thermal stability of fluorescence intensity.

7. The method for preparing an aluminum-manganese co-doped Ca2YTaO6-based phosphor according to claim 1, characterized in that: Calculation of x=3.0% of Ca2YTa by detection 1-x O6:xMn 4+ Phosphor samples and Ca2YTa with y=1.2% 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The quantum yield of the phosphor measured under 304nm excitation is as follows: Among them L S is the emission spectrum of the phosphor, E S and E R The excitation spectra of phosphor and BaSO4 reference respectively, y = 1.2% Ca2YTa 1-0.3％-y O6:0.3%Mn 4+ ,yAl 3+ The QY of the phosphor sample reaches 6.13%, which is the Ca2YTa with x=3.0%. 1-x O6:xMn 4+ 1.71 times that of the phosphor sample.

8. Use of the aluminum-manganese co-doped Ca2YTaO6-based phosphor obtained by the preparation method according to claims 1-7 in LED devices, characterized in that: By coating CYTO:0.3%Mn on the 365nm UV LED chip 4+ ,1.2%Al 3+ Phosphor is used to prepare LED devices for plant cultivation lighting. The LED devices can produce stable deep red light at different driving currents, and the light intensity gradually increases with the increase of driving current.

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