MgS: Nd, Sm ultraviolet charging infrared up-conversion fluorescent powder

Abstract

The invention discloses a preparation method of MgS: Nd < 3 + >; according to the Sm < 3 + > up-conversion fluorescent powder, Nd < 3 + > ions are adopted as a light-emitting center and Sm < 3 + > ions are adopted as a trap center, the Sm < 3 + > ions can effectively capture excited state electrons of the Nd < 3 + > ions after being excited by ultraviolet light, and when the Sm < 3 + > ions are irradiated by infrared light again, the electrons stored by a trap energy level are released, so that visible light is emitted; a novel and efficient material is provided for the fields of energy storage, photoelectric conversion and the like.

Description

Technical Field

[0001] The invention relates to a Nd and Sm co-doped magnesium sulfide (MgS) up-conversion phosphor, which can emit orange-red light under near-infrared light excitation and belongs to the technical field of photoelectric functional materials. Background Art

[0002] With the rapid development of modern science and technology, especially in the fields of energy, communication and sensors, infrared upconversion phosphors, as an important optoelectronic functional material, have attracted widespread attention. Infrared upconversion phosphors not only have the unique property of converting low-energy infrared light into high-energy visible light, but also have broad application prospects in a variety of high-tech fields due to their light emission characteristics in the visible light region, especially in the field of energy storage infrared upconversion phosphors. With the increasing demand for high-efficiency, low-energy consumption energy conversion materials, the research of this type of phosphors has become an important direction in the fields of optical materials, energy storage and utilization.

[0003] Ultraviolet energy storage type infrared upconversion phosphors combine energy storage function with infrared upconversion characteristics, that is, they can absorb and store energy under ultraviolet light excitation, and convert it into light through infrared light excitation when needed. This type of phosphor can store energy under certain special conditions and release this energy through external excitation (such as infrared light irradiation). The working principle of ultraviolet energy storage type infrared upconversion phosphors mainly includes energy storage process and energy release process. Rare earth ions (such as europium (Eu 2+ ), cerium (Ce 3+ ) absorbs energy under ultraviolet light excitation and passes through thulium (Tm 3+ ), Dy 3+ ) and samarium (Sm 3+ ) The trapped energy levels created by the plasma store the absorbed photons. Under appropriate conditions, such as when exposed to infrared light, the energy storage phosphor releases the stored energy and converts it into infrared light or visible light.

[0004] The uniqueness of ultraviolet energy storage type infrared upconversion phosphors lies in that they can simultaneously possess energy storage function, upconversion luminescence and downconversion luminescence characteristics. However, existing ultraviolet energy storage type infrared upconversion phosphors still face certain challenges in terms of energy conversion efficiency, stability and material cost. In particular, in terms of energy storage capacity and energy release control, many materials perform unsatisfactorily. In order to overcome these problems, the present invention proposes a new type of MgS:Nd 3+ ,Sm 3+ Up-conversion phosphors exhibit excellent luminescence properties under infrared light excitation and have high energy storage capacity. 3+ ions as luminescence centers, Sm 3+ions as trap centers, after being excited by ultraviolet light, Sm 3+ Ions can effectively capture Nd 3+ The electrons excited by the ions are stored. When irradiated by infrared light again, the electrons stored in the trapped energy level are released and emit visible light, providing a new and efficient material for energy storage and photoelectric conversion. Summary of the invention

[0005] The present invention provides a method using MgS as a matrix and Nd 3+ Ions are luminescent levels, Sm 3+ Energy storage infrared up-conversion phosphor with ions as trap centers. The up-conversion phosphor can be excited by near-infrared light to emit visible light under the condition of ultraviolet light charging. The composition of the fluorescent material is MgS:Nd 3+ ,Sm 3+ The synthesis steps of the fluorescent material are as follows: firstly, high-purity anhydrous MgSO4, sulfur powder (S), Nd2O3, Sm2O3 are selected as raw materials, C powder is used as a reducing agent, and the stoichiometric ratio of Mg 1-(x+y) S:xNd,ySm, (where x and y are both in the range of 0.001 to 0.04 mol) calculate the required amount of each raw material, grind them evenly in an agate mortar and put them into a thumb crucible. Then, mix the weighed carbon powder and sulfur powder in a certain proportion and put them into a porcelain boat. Finally, put the thumb crucible into the porcelain boat and place it in a tubular atmosphere furnace. Heat from room temperature to the synthesis temperature (900-1200℃) at a heating rate of 5℃ / min and keep warm for 1-3 hours. During heating, CS2 gas is formed by the reaction of S and C to achieve the goal of reduction, and finally MgS:Nd,Sm phosphor is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] · Figure 1 MgS:Nd 3+ ,Sm 3+ X-ray diffraction pattern of phosphor.

[0007] · Figure 2 MgS:Nd 3+ ,Sm 3+ Phosphors are excited in the UV spectrum.

[0008] · Figure 3 MgS:Nd 3+ ,Sm 3+ Phosphors emit in the ultraviolet spectrum.

[0009] · Figure 4 MgS:Nd 3+ ,Sm 3+ Phosphors are excited in the infrared spectrum.

[0010] · Figure 5 MgS:Nd 3+ ,Sm 3+ Emission spectrum of phosphor under infrared excitation. DETAILED DESCRIPTION

[0011] The sample preparation in the present invention adopts a high temperature solid phase method. The specific process is described in detail as follows:

[0012] (1) First, according to Mg 1-(x+y) S: xNd, ySm chemical formula design formula, where the value range of x and y is between 0.001 and 0.04 mol;

[0013] (2) Weigh the corresponding MgSO4, Nd2O3, and Sm2O3 using a precision electronic balance, and place the weighed raw materials into an agate mortar;

[0014] (3) Grinding the raw materials uniformly by wet grinding, and then drying them in an oven;

[0015] (4) The dried powder is placed in a thumb crucible and the sample is prepared using a double crucible method;

[0016] (5) Accurately weigh the corresponding carbon powder, sulfur powder and aluminum oxide, mix them evenly and put them into a porcelain boat;

[0017] (6) Place the thumb crucible into a porcelain boat and then into a tubular atmosphere furnace and heat from room temperature to

[0018] 1100℃, heating rate 5℃ / min, keep warm for 1h: finally cool down with the furnace, and get the final sample after cooling to room temperature.

[0019] Figure 1 MgS:Nd 3+ ,Sm 3+ The X-ray diffraction pattern of the phosphor is consistent with the standard card PDF#35-0730, indicating that the crystal structure of the material is cubic and the doping of rare earth ions does not change the original structure of the MgS matrix.

[0020] Figure 2 MgS:Nd 3+ ,Sm 3+ The ultraviolet excitation spectrum of the phosphor. From the figure, we can see that its excitation peak is 280nm, and it can be effectively charged with ultraviolet energy in the range of 200-350nm.

[0021] Figure 3 MgS:Nd 3+ ,Sm 3+The emission spectrum of the phosphor under ultraviolet excitation. It has strong emission peaks at 570nm and 610nm, and also has a relatively strong emission peak at 650nm.

[0022] Figure 4 MgS:Nd 3+ ,Sm 3+ Infrared excitation spectrum of phosphor. The sample exhibits a single broad spectrum excitation with a peak at 930nm.

[0023] Figure 5 MgS:Nd 3+ ,Sm 3+ The emission spectrum of the phosphor under infrared excitation. From the figure, we can see that it has relatively strong emission peaks at 570nm, 610nm, and 650nm, which is consistent with the ultraviolet emission spectrum.

Claims

1. A rare earth ion dual-doped MgS:Nd 3+ ; Sm 3+ UV-charged infrared up-conversion phosphor, the phosphor is based on MgS, Nd 3+ ions as luminescence centers, with a doping amount of 0.01 to 4%, Sm 3+ ions as trap centers, with a doping level of 0.01 to 4%. After being excited by ultraviolet light, Sm 3+ Ions can effectively capture Nd 3+ When the excited electrons of the ions are irradiated by infrared light again, the electrons stored in the trap energy levels are released and then emit visible light, providing a new and efficient material for fields such as energy storage and photoelectric conversion.

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