CN108728088B

CN108728088B - Europium ion excited silicate white light fluorescent powder and preparation method thereof

Info

Publication number: CN108728088B
Application number: CN201810441348.2A
Authority: CN
Inventors: 于立新; 钟检林; 高震宇; 满孝琴; 郭琪煌; 邹颖璇
Original assignee: Nanchang University
Current assignee: Nanchang University
Priority date: 2018-05-10
Filing date: 2018-05-10
Publication date: 2021-09-28
Anticipated expiration: 2038-05-10
Also published as: CN108728088A

Abstract

Europium ion excited silicate white light fluorescent powder and preparation method thereof, wherein the chemical formula is BaSn_xSi₃O_7+2x：Eu²⁺，Eu³⁺(x = 0.2-1), wherein the europium ion is an activator ion; with BaCO₃、SnO₂、SiO₂、Eu₂O₃Mixing the raw materials according to a stoichiometric ratio, ball-milling, filling the mixture into a corundum crucible, putting the corundum crucible into a muffle furnace to perform high-temperature solid-phase reaction at 1200-1400 ℃ for 10-14 h in an air atmosphere, and taking out the corundum crucible and cooling the corundum crucible to room temperature when the furnace is cooled to 950 ℃. The product emits strong white light under the excitation of ultraviolet light (250 nm-410 nm), has high color purity, and solves the problems of low color rendering index, poor color reducibility, energy loss and the like of the traditional WLED. The ultraviolet light absorption material has strong absorption to near ultraviolet light with the wavelength of 380 nm-410 nm, and is suitable for fluorescent lamps and WLED chips emitting ultraviolet light and near ultraviolet light.

Description

Europium ion excited silicate white light fluorescent powder and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of solid photoluminescence materials. Relates to white light fluorescent powder excited by ultraviolet light and a preparation method thereof.

Background

The white light emitting diode is a novel light source which has high luminous efficiency, low energy consumption, long service life and environmental protection. At present, white light LEDs are mainly realized by 1) blue light chips (In-GaN) activating yellow phosphor powder yttrium aluminum garnet (YAG: Ce), so that blue light and yellow light are mixed to form white light; 2) assembling red, green and blue tricolor LED chips together, and realizing white light by controlling the current of the tricolor chips; 3) the near ultraviolet chip activates the red, green and blue three-primary-color fluorescent powder to obtain white light. The method 1) has disadvantages such as low color rendering index, poor color reproducibility, and high-temperature quenching. Mode 2) the output voltage, temperature characteristics, and light-induced degradation degree of different chips are different, resulting in a complicated control circuit. Mode 3) the three-primary-color mixed fluorescent powder has the problems of proportioning regulation and color reabsorption, so that the luminous efficiency and the color reduction performance are greatly influenced. The color developing method aims to solve the problems of low color developing index, poor color reducibility, energy loss and the like. Therefore, it is necessary to develop a simple, environment-friendly and efficient single-matrix phosphor.

Disclosure of Invention

The invention aims to provide europium ion excited BaSn_xSi₃O_7+2xHigh-efficiency white light fluorescent powder. Partial Eu in air atmosphere³⁺High temperature self-reduction to Eu²⁺And by changing SnO₂The doping amount of the Eu is effectively adjusted³⁺/Eu²⁺The relative intensity of the light source is used for modulating the light emitting color, and therefore the white light fluorescent powder is obtained.

The invention is realized by the following technical scheme.

The invention relates to europium ion excited silicate white light fluorescent powder, which comprises the following chemical components: BaSn_xSi₃O_7+2x：Eu²⁺，Eu³⁺(wherein x = 0.2-1).

The invention relates to a preparation method of europium ion excited silicate white light fluorescent powder, which comprises the following steps:

(1) weighing the raw material BaCO according to the stoichiometric ratio₃、SnO₂、SiO₂、Eu₂O₃Wherein europium ion (Eu)²⁺+Eu³⁺) The molar concentration of the alkaline earth metal cation is 1 to 6 percent of that of the alkaline earth metal cation.

(2) The raw materials are mixed and put into a clean and dry ball mill (agate balls) with a corundum lining for ball milling uniformly and then put into a corundum crucible.

(3) High-temperature self-reduction process: and (3) placing the mixture in a muffle furnace to perform high-temperature solid-phase reaction at 1200-1400 ℃ for 10-14 h in an air atmosphere, taking out the mixture when the furnace is cooled to 950 ℃, and cooling the mixture to room temperature to obtain a sample.

The purity of the raw materials in the step (1) of the invention is respectively as follows: BaCO₃For analytical purification; SnO₂99.5%; SiO 2₂99.99%; eu (Eu)₂O₃The content was 99.99%.

The preparation method has the advantages of cheap raw materials, simple process, safety and environmental protection in the preparation process. The product can emit strong white light under the excitation of wide ultraviolet light and near ultraviolet light spectral range (250 nm-410 nm), has high color purity, and can be widely used as WLED white light fluorescent powder.

Drawings

FIG. 1 is an X-ray diffraction chart of a sample of the fluorescent material in examples 1 and 2.

FIG. 2 is a graph showing the emission spectra of the samples of the fluorescent materials of examples 1 and 2 under 395 nm ultraviolet excitation.

FIG. 3 is a color coordinate graph of emission spectra of fluorescent material samples of examples 1 and 2 under 395 nm ultraviolet excitation.

Detailed Description

The invention will be further illustrated by the following examples.

Examples 1-2 europium ion-excited silicate high efficiency white phosphors were prepared according to the procedure of the inventive concept.

Example 1.

Weighing BaCO₃：1.9730 g、SnO₂：0.6030 g、SiO₂：1.8025 g、Eu₂O₃: 0.0352 g. The raw materials are put into a clean and dry ball mill (agate balls) for ball milling uniformly and then are put into a corundum crucible. In the embodiment, the heat treatment temperature is set as 1300 ℃, after the reaction time is 10 hours, the switch of the furnace is closed, and the corundum crucible is taken out and cooled to room temperature when the corundum crucible is cooled to 950 ℃. And finally, putting the mixture in the corundum crucible into an agate mortar, and uniformly grinding to obtain the sample. As a result of X-ray diffraction (as shown in fig. 1), when X =0.4, the substance contained BaSi₂O₅And BaSnSi₃O₉And (4) phase(s). After grinding the sample, the room temperature emission spectrum was measured using an F-4600 fluorescence spectrophotometer (see FIG. 2). From FIG. 2, it can be seen that under the excitation of 395 nm near ultraviolet light, the excitation is carried outThe main emission peak of the emission spectrum is 496 nm, and the emission peak is derived from Eu²⁺5d → 4f broad band (446 nm-575 nm) emission, another emission peak at 620nm, the emission peak is derived from Eu³⁺：⁵D₀−⁷F_J(J =0, 1,2,3,4) line emission. The result of the chromoscope color coordinate is shown in figure 3, wherein the emission spectrum color coordinate positions are as follows: x =0.3352 y =0.2984 (as shown in fig. 3), positioned in the region of the white light, the fluorescent material being visible to the naked eye as emitting highly efficient white light.

Example 2.

Weighing BaCO₃：1.9730 g、SnO₂：1.2056 g、SiO₂：1.8025 g、Eu₂O₃: 0.0352 g. The raw materials are put into a clean and dry ball mill (agate balls) for ball milling uniformly and then are put into a corundum crucible. In the embodiment, the heat treatment temperature is set as 1300 ℃, the furnace is closed after the reaction time is 10 hours, and the corundum crucible is taken out and cooled to room temperature when the corundum crucible is naturally cooled to 950 ℃. And finally, putting the mixture in the corundum crucible into an agate mortar, and uniformly grinding to obtain a sample. As a result of X-ray diffraction (as shown in fig. 1), when X =0.8, the substance contained BaSni₃O₉And BaSi₅O₁₃Phase (1); with SnO₂When x =0.8, the amount of the doped metal oxide particles increases, and not only the phase present at x =0.4 but also a small amount of SnO appears₂And (4) new phase. After grinding the sample, the room temperature emission spectrum was measured using an F-4600 fluorescence spectrophotometer (see FIG. 2). From FIG. 2, it can be seen that under 395 nm near ultraviolet excitation, the main emission peak of the excitation spectrum is 495nm, which is derived from Eu²⁺5d → 4f, another emission peak at 620nm, the emission peak being derived from Eu³⁺：⁵D₀−⁷F_J(J =0, 1,2,3,4) line emission. The color coordinate results are shown in fig. 3: the emission spectrum color coordinate positions are as follows: x =0.2834 y =0.2734 (as shown in fig. 3), located in the region of the white light, the fluorescent material emitting intense white light visible to the naked eye.

Claims

1. Europium ion excited silicate white light fluorescent powderCharacterized by comprising the following chemical components: BaSn_xSi₃O_7+2x：Eu²⁺，Eu³⁺Wherein x = 0.2-1.

2. The method of claim 1, wherein the method comprises the steps of:

(1) weighing the raw material BaCO according to the stoichiometric ratio₃、SnO₂、SiO₂、Eu₂O₃Wherein the europium ion Eu²⁺+Eu³⁺The molar concentration of the alkaline earth metal is 1 to 6 percent of that of the alkaline earth metal cations;

(2) mixing the raw materials, putting the mixture into a clean and dry ball mill with a corundum lining for ball milling uniformly, and then putting the mixture into a corundum crucible;

(3) high-temperature self-reduction process: and placing the mixture in a muffle furnace to perform high-temperature solid-phase reaction at 1200-1400 ℃ for 10-14 h in an air atmosphere, and taking out and cooling to room temperature when the furnace is cooled to 950 ℃.