WO2019096204A1

WO2019096204A1 - Fluorescent substance and light-emitting device made therefrom

Info

Publication number: WO2019096204A1
Application number: PCT/CN2018/115637
Authority: WO
Inventors: 刘荣辉; 刘元红; 邵冷冷; 马小乐; 蒋周青
Original assignee: 有研稀土新材料股份有限公司; 国科稀土新材料有限公司
Priority date: 2017-11-20
Filing date: 2018-11-15
Publication date: 2019-05-23
Also published as: CN110234736A; CN109810695A; CN109810695B

Abstract

Provided by the present invention are a fluorescent substance and a light-emitting device made therefrom. The composition of the fluorescent substance is xABmOn·y(aAl2O3·bAlN); A is a combination of two or more selected from among the elements of Ca, Sr, Ba, Mg, Zn, Mn, and Si, and necessarily contains the element of Mn; B is one or a combination of two or more selected from among the elements of Al, B, and Ga; 1.8 ≤ m ≤ 2.2, 3.5 ≤ n ≤ 4.5, 0.5 ≤ x ≤ 1, 0.22 ≤ b ≤ 0.35, x + y = 1, and a + b = 1. The fluorescent substance of the present invention may emit green light between 510-540 nm when excited at 400-470 nm, has high color purity, and is expected to meet the application requirements for white LED devices for high color gamut liquid crystal display.

Description

Fluorescent substance and light-emitting device made thereof

The present application is based on a Chinese patent application filed on Jan. 20, 2017, the filing date of which is hereby incorporated by reference.

Technical field

The invention relates to a fluorescent substance and a light-emitting device thereof, and belongs to the field of white light LED illumination.

Background technique

White LED has the advantages of green, environmental protection and long life, and has been widely used in lighting and display fields. At present, in terms of the generation mode of white LEDs, mainly the implementation of chips and phosphors is dominant. Therefore, the luminescent properties of the phosphor directly affect and determine the performance of the white LED device.

In recent years, a new type of MgAl ₂ O ₄ :Mn ²⁺ with high melting point, strong stability, optical band gap tunable MgAl ₂ O ₄ or ZnAl ₂ O ₄ as luminescent substrate and Mn ²⁺ as activator ZnAl ₂ O ₄ :Mn ²⁺ phosphors have attracted much attention. For example, MgAl ₂ O ₄ and ZnAl ₂ O ₄ activated by Mn ²⁺ can be excited by light of a wide range of wavelengths from ultraviolet to blue light at 510-540 nm. The wavelength region emits green light and the color purity is high. Therefore, as a phosphor that can be used for white LEDs, it has been intensively studied and studied. A transition metal Mn doped MgAl ₂ O ₄ fluorescent substance, a preparation method, and a laser apparatus containing the same are disclosed, for example, in US20060243197 A1. Among them, Mg _1-x Mn _x AlO ₄ (0.003 _{≤ x ≤} 0.01) achieved green light emission of 520 nm under blue light excitation of 450 nm. Jiao Xueyu et al. developed a series of MgAl ₂ O ₄ :xMn ²⁺ fluorescent materials. Under the blue light excitation of 450 nm, Mn ²⁺ undergoes ⁴ T ₁ → ⁶ A ₁ transition to achieve green luminescence, and the emitted light is 10% at x. The maximum luminescence brightness is reached at the time of content (Chinese of journal of luminescence, 2011, 32, 1139-1142). CN103849383A provides a Zn _1-x Al ₂ O ₄ :Mn ²⁺ _x (0<x≤0.1) luminescent material chemically doped with metal nanoparticles, which enhances the luminescent properties of the material by doping metal nanoparticles.

However, the current problem of limiting the application of MgAl ₂ O ₄ :Mn ²⁺ or ZnAl ₂ O ₄ :Mn ²⁺ fluorescent materials is still that their luminous efficiency is low.

Summary of the invention

To this end, one of the objects of the present invention is to provide a fluorescent substance which has superior light color properties.

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

A fluorescent substance having a chemical formula of the following formula I:

xAB _m O _n ·y(aAl ₂ O ₃ ·bAlN) I

Wherein A is selected from the group consisting of two or more of Ca, Sr, Ba, Mg, Zn, Mn, and Si elements, and must contain Mn element;

B is selected from one or a combination of two or more of Al, B, and Ga elements;

And 1.8 ≤ m ≤ 2.2, 3.5 ≤ n ≤ 4.5, 0.5 ≤ x ≤ 1, 0.22 ≤ b ≤ 0.35, x + y = 1, a + b = 1.

The fluorescent substance of the invention can emit green light between 510-540 nm under the excitation of 400-470 nm, and has high color purity, and is expected to meet the application requirements of the white LED device for high color gamut liquid crystal display.

Preferably, the fluorescent substance has the same crystal structure as MgAl ₂ O ₄ .

Preferably, A is an element of Mn and Zn, or an element of Mn and Mg. High-intensity fluorescence is formed by two-phase solid solution of MgAl ₂ O ₄ :Mn ²⁺ or ZnAl ₂ O ₄ :Mn ²⁺ fluorescent substance with (aAl ₂ O ₃ ·bAlN) fluorescent substance of similar structure and luminescence property Substance to meet the application needs of white LED devices for high color gamut liquid crystal display.

Preferably, the molar percentage z of the Mn element in the A element satisfies 0.1% ≤ z ≤ 20%.

Preferably, B is an Al element.

Preferably, 0.38 ≤ b / a ≤ 0.44.

Preferably, A contains a Si element. In the phosphor of the present invention, Ca, Sr, Ba, Mg, and Zn in A are both divalent elements and occupy a trivalent B site (such as B, Al, Ga), thus causing vacancies, so A The addition of tetravalent Si serves to balance the valence state, thereby making the performance of the phosphor produced more excellent.

Preferably, the molar percentage d of the Si element in the A element satisfies 10% ≤ d ≤ 50%.

Preferably, A is an element of Si, Mn and Zn, or an element of Si, Mn and Mg.

Preferably, B is an Al element.

Preferably, 0.38 ≤ b / a ≤ 0.44.

The preparation method of the fluorescent substance of the present invention can be carried out by using a prior art or a new technique discovered in the future.

For example, the fluorescent substance of the present invention can be prepared by mixing Al ₂ O ₃ , AlN, MnCO ₃ and other corresponding metal oxides or metal carbonates and then calcining in an inert atmosphere; the calcined product is crushed, The fluorescent substance of the present invention is obtained after classification and post-treatment.

Other corresponding metal oxides or metal carbonates may be determined according to the elements selected by A and B. For example, A also contains Mg, and when B is Al, the other corresponding metal oxides are MgO or MgCO ₃ , and A also contains In the case of Si, the other corresponding metal oxides described above are SiO ₂ .

The calcination temperature may be 1600 to 2000 ° C, preferably 1800 ° C, and the calcination time is 2 h or more, preferably 4 h. The calcination pressure may be from 0.3 to 0.8 MPa, preferably from 0.5 MPa.

In a preferred embodiment, the calcination is carried out under an inert atmosphere at a temperature of 1800 ° C under a pressure of 0.5 MPa for 4 h.

It is also an object of the present invention to provide a light-emitting device comprising an excitation source and a fluorescent substance according to the present invention, the excitation source being a semiconductor chip having an emission wavelength in the range of 400 to 430 nm or 430 to 470 nm.

The fluorescent substance xAB _m O _n ·y(aAl ₂ O ₃ ·bAlN) of the present invention can be excited to emit green light in a wavelength region of a wide range of 400-470 nm, and pass the solid solubility between the two-phase fluorescent substances ( The linkage between x and y values can significantly improve the luminescence intensity of fluorescent substances, which is very beneficial as a green phosphor for white LED devices. The fluorescent substance of the present invention has good thermal stability and can be used alone or in combination with other phosphors for various light-emitting elements, particularly white LEDs using ultraviolet LEDs or blue LEDs as light sources.

DRAWINGS

1 is an XRD pattern of a fluorescent substance obtained in Example 1 of the present invention;

2 is an excitation spectrum and an emission spectrum of a fluorescent substance obtained in Example 1 of the present invention.

Detailed ways

The following is a description of the preferred embodiments of the present invention. The scope of the present invention is not limited by the scope of the invention, and the scope of the invention is determined by the appended claims.

In order to overcome the outstanding problem of low luminous efficiency in the application of MgAl ₂ O ₄ :Mn ²⁺ or ZnAl ₂ O ₄ :Mn ²⁺ fluorescent materials, the present invention provides a novel fluorescent material having high luminous efficiency. The fluorescent substance in the present invention is a two-phase solid solution represented by the general formula xAB _m O _n ·y(aAl ₂ O ₃ ·bAlN), wherein A is selected from the group consisting of Ca, Sr, Ba, Mg, Zn, Mn, and Si elements. Two or more combinations, and must contain Mn element, B is selected from one or a combination of two or more of Al, B, Ga elements, preferably one or two, and 1.8 ≤ m ≤ 2.2 , 3.5 ≤ n ≤ 4.5, 0.5 ≤ x ≤ 1, 0.22 ≤ b ≤ 0.35, x + y = 1, a + b = 1. The fluorescent substance preferably has the same crystal structure as MgAl ₂ O ₄ .

Based on the above invention, the experiments and effects are as described in the specific embodiments, wherein the test conditions are as follows:

Test Conditions:

The fluorescent substance in Example 1 was excited with blue light having a wavelength of 460 nm, and the emission spectrum intensity and relative luminance of the fluorescent substance were measured.

The XRD test was carried out using a Co target (λ = 1.78892 nm) with an operating voltage of 40 kV and an operating current of 40 mA.

Comparative example 1

40 g of MgO, 101.96 g of Al ₂ O ₃ and 3.44 g of MnCO ₃ were weighed and mixed according to stoichiometric ratio; the above mixture was calcined under an inert atmosphere at a temperature of 1450 ° C for 4 h; the calcined product was crushed, classified, and then After the treatment, the fluorescent substance MgAl ₂ O ₄ of Comparative Example 1 was obtained: 0.03Mn ²⁺ .

Comparative example 2

30 g of ZnO, 37.58 g of Al ₂ O ₃ and 1.69 g of MnCO ₃ were weighed according to a stoichiometric ratio; the above mixture was calcined under an inert atmosphere at a temperature of 1750 ° C for 2 h; the calcined product was crushed, classified, and post-treated. Thereafter, the fluorescent substance ZnAl ₂ O ₄ : 0.04Mn ²⁺ of Comparative Example 2 was obtained.

Example 1

Accurately weigh 115.21g Al ₂ O ₃ , 18.45g AlN, 20.69g MnCO ₃ and 7.25g MgO for mixing; the above mixture is calcined under an inert atmosphere at a temperature of 1800 ° C and a pressure of 0.5 Mpa for 4 h; the above calcined product After the crushing, classification, and post-treatment, 0.6MgMn _0.15 Al ₂ O ₄ ·0.4 (0.72Al ₂ O ₃ ·0.28AlN) of the fluorescent substance of Example 1 was obtained.

The XRD of the above fluorescent substance under the test conditions of the Co target (λ = 0.178892 nm) is shown in Fig. 1, and the excitation and emission spectra are shown in Fig. 2 (wherein the excitation wavelength is 460 nm, and the detection wavelength of the excitation spectrum is 520 nm). As can be seen from Fig. 1, the material obtained in Example 1 of the present invention is 0.6MgMn _0.15 Al ₂ O ₄ ·0.4 (0.72Al ₂ O ₃ ·0.28AlN) fluorescent substance, as can be seen from Fig. 2, the embodiment 1 system The resulting material emits 520 nm of light at 460 nm excitation.

Example 2-15

According to the procedure shown in Example 1, the raw materials of the respective stoichiometric ratios were weighed and calcined and post-treated to obtain the corresponding phosphor materials shown in Examples 2-15.

The composition of the phosphor is shown in Table 1. The test results of the luminescence brightness and the peak wavelength of the emission spectrum are shown in Table 2.

Table 1. Preparation of fluorescent components

Table 2 Luminescent properties of fluorescent substances

It is apparent that the above-described embodiments are merely illustrative of the examples, and are not intended to limit the embodiments. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. Obvious changes or variations resulting therefrom are still within the scope of the invention.

Claims

A fluorescent substance characterized in that the chemical formula of the substance is the following formula I:

xAB m O n ·y(aAl 2 O 3 ·bAlN) I

Wherein A is selected from the group consisting of two or more of Ca, Sr, Ba, Mg, Zn, Mn, and Si elements, and must contain Mn element;

B is selected from one or a combination of two or more of Al, B, and Ga elements;

And 1.8 ≤ m ≤ 2.2, 3.5 ≤ n ≤ 4.5, 0.5 ≤ x ≤ 1, 0.22 ≤ b ≤ 0.35, x + y = 1, a + b = 1.
The fluorescent substance according to claim 1, wherein the fluorescent substance has the same crystal structure of MgAl 2 O 4 .
The fluorescent substance according to claim 1 or 2, wherein A is an element of Mn and Zn, or an element of Mn and Mg.
The fluorescent substance according to claim 1 or 2, wherein A contains a Si element.
The fluorescent substance according to claim 4, wherein the molar percentage d of the Si element in the element A satisfies 10% ≤ d ≤ 50%.
The fluorescent substance according to any one of claims 1 to 5, wherein A is an element of Si, Mn and Zn, or an element of Si, Mn and Mg.
The fluorescent substance according to any one of claims 1 to 6, wherein B is an Al element.
The fluorescent substance according to any one of claims 1 to 7, characterized in that the molar percentage z of the Mn element in the element A satisfies 0.1% ≤ z ≤ 20%.
The fluorescent substance according to any one of claims 1 to 8, wherein 0.38 ≤ b / a ≤ 0.44.
A light-emitting device, comprising: an excitation source; and the fluorescent substance according to any one of claims 1-9;

Preferably, the excitation source is a semiconductor chip having an emission wavelength in the range of 400 to 430 nm or 430 to 470 nm.