CN107129805B

CN107129805B - Europium ion doped silicate white light fluorescent powder and preparation method thereof

Info

Publication number: CN107129805B
Application number: CN201710247098.4A
Authority: CN
Inventors: 于立新; 钟检林; 李宋楚; 满孝琴
Original assignee: Lattice Power Jiangxi Corp
Current assignee: Lattice Power Jiangxi Corp
Priority date: 2017-04-17
Filing date: 2017-04-17
Publication date: 2020-04-03
Anticipated expiration: 2037-04-17
Also published as: CN107129805A

Abstract

A silicate white light fluorescent powder doped with europium ions and a preparation method thereof, the silicate white light fluorescent powder comprises the following chemical components: BaZr_xSi₂O_5+2x：Eu²⁺,Eu³⁺Wherein x = 0-0.5; (1) with BaCO₃、ZrO₂、SiO₂、Eu₂O₃Weighing the raw materials according to a stoichiometric ratio. Wherein the molar concentration of europium ions is 1 to 6 percent of that of 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) and (3) placing the mixture in a muffle furnace to perform high-temperature solid-phase reaction at 1000-1350 ℃ for 8-12h in an air atmosphere, and taking out and cooling to room temperature when the furnace is cooled to 900 ℃. The white light fluorescent powder has the advantages of cheap raw materials, safety, environmental protection and simple process, can emit strong white light under the excitation of wide ultraviolet light and near ultraviolet light, has high color purity, and can be widely used as WLED white light fluorescent powder.

Description

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

Technical Field

The invention belongs to the technical field of preparation of solid photoluminescence materials, and 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 doped BaZr_xSi₂O_5+2xHigh-efficiency white light fluorescent powder and a preparation method thereof. Partial Eu in air atmosphere³⁺High temperature self-reduction to Eu²⁺And by changing ZrO₂The doping amount of the Eu is effectively adjusted³⁺/Eu²⁺Thereby obtaining a white phosphor.

The invention is realized by the following technical scheme.

The europium ion doped silicate white light fluorescent powder disclosed by the invention comprises the main chemical components.

BaZr_xSi₂O_5+2x：Eu²⁺,Eu³⁺

Wherein x = 0-0.5, wherein europium ion (including Eu)²⁺And Eu³⁺) Is an activator ion, and the molar concentration of the activator ion is 1 to 6 percent of that of the alkaline earth metal cation.

The preparation method of the europium ion doped silicate white light fluorescent powder comprises the following steps.

(1) Selecting and weighing the raw materials of the fluorescent material.

With BaCO₃、ZrO₂、SiO₂、Eu₂O₃Weighing the raw materials according to a stoichiometric ratio. Wherein the 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 1000-1350 ℃ for 8-12h in an air atmosphere, taking out the mixture when the furnace is cooled to 900 ℃, and cooling the mixture to room temperature to obtain a sample.

The BaCO of the invention₃For analytical purification, ZrO₂、SiO₂、Eu₂O₃The purity was 99.99%.

The preparation process has the advantages of cheap raw materials, safety, environmental protection and simple 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 fluorescent material samples of examples 1 and 2 under 300nm ultraviolet excitation.

FIG. 3 is a color coordinate diagram of the emission spectrum of the fluorescent material samples of examples 1 and 2 under the ultraviolet excitation of 300 nm.

Detailed Description

The invention will be further illustrated by the following examples.

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

Example 1.

Weighing BaCO₃：1.97 g、ZrO₂：0.246 g、SiO₂：1.2 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 the room temperature when the corundum crucible is cooled to 900 ℃. 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 =0.2, the substance was almost BaSi₂O₅Phase of BaZrSi in small amount₃O₉And Ba₂Si₅O₁₃Phase (1); when x =0.3, doOnly the phase present when x =0.2 is present, Ba is also formed₂Zr₂Si₃O₁₂This new phase. After grinding the sample, the room temperature emission spectrum was measured using an F-4600 fluorescence spectrophotometer (see FIG. 2). As can be seen from FIG. 2, under the excitation of 300nm near ultraviolet light, the main emission peak of the excitation spectrum is 487nm, and the emission peak 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 result of the chromoscope color coordinate is shown in figure 3, wherein the emission spectrum color coordinate positions are as follows: x =0.3118 y =0.318 (point a in fig. 3), and is located in the white light region, and the fluorescent material can emit high-efficiency white light when seen with the naked eye.

Example 2.

Weighing BaCO₃：1.97 g、ZrO₂：0.369 g、SiO₂：1.2 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 the room temperature when the corundum crucible is naturally cooled to 900 ℃. 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 =0.2, the substance was almost BaSi₂O₅Phase of BaZrSi in small amount₃O₉And BaSi₅O₁₃Phase (1); when x =0.3, not only the phase present when x =0.2 occurs, but also Ba is formed₂Zr₂Si₃O₁₂This new phase. After grinding the sample, the room temperature emission spectrum was measured using an F-4600 fluorescence spectrophotometer (see FIG. 2). As can be seen from FIG. 2, under the excitation of 300nm near ultraviolet light, the main emission peak of the excitation spectrum is 500nm, and the emission peak 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: its emission spectrum color coordinate positionComprises the following steps: x =0.3251y =0.3649 (fig. 3B), and is located in the white light region, and the fluorescent material emits strong white light visible to the naked eye.

Claims

1. An europium ion doped silicate white light fluorescent powder is characterized by comprising the following main chemical components:

BaZr_xSi₂O_5+2x：Eu²⁺,Eu³⁺

wherein x is more than 0 and less than or equal to 0.5, and the molar concentration of europium ions is 1-6 percent of that of alkaline earth metal cations.

2. The method for preparing europium ion doped silicate white light phosphor of claim 1, which comprises the following steps:

(1) with BaCO₃、ZrO₂、SiO₂、Eu₂O₃Weighing the raw materials according to a stoichiometric ratio; wherein the molar concentration of europium ions is 1 to 6 percent of that of 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) and (3) placing the mixture in a muffle furnace to perform high-temperature solid-phase reaction at 1000-1350 ℃ for 8-12h in an air atmosphere, and taking out and cooling to room temperature when the furnace is cooled to 900 ℃.