CN104531144A

CN104531144A - CaMg<2>Al<16>O<27>:Mn <4+> red fluorescent powder and preparation technology thereof

Info

Publication number: CN104531144A
Application number: CN201410768444.XA
Authority: CN
Inventors: 王波; 林航; 王元生
Original assignee: Fujian Institute of Research on the Structure of Matter of CAS
Current assignee: Fujian Institute of Research on the Structure of Matter of CAS
Priority date: 2014-12-14
Filing date: 2014-12-14
Publication date: 2015-04-22

Abstract

The invention relates to red light emission fluorescent powder which can be produced under excitation of ultraviolet/blue light. A chemical expression formula of the material is xMn<4+>: CaMg<2>Al<16>O<27> (x is more than or equal to 0.016 and less than or equal to 0.48). The invention also provides a preparation method of the red fluorescent powder. The red fluorescent powder is high in stability, and can be effectively excited by 250-500 nanometers of ultraviolet/blue light so as to produce 620-700 nanometers of red light emission so that the fluorescence quantum efficiency reaches 47.2 percent. The fluorescent powder can be used for building warm white LED excited by an ultraviolet/blue light chip.

Description

CaMg 2al 16o 27: Mn 4+-red fluorescence powder and technology of preparing thereof

Technical field

The present invention relates to solid luminescent material field, especially relate to red fluorescence powder that a kind of manganese (IV) that can be used for warm white LED adulterates and preparation method thereof.

Technical background

White light LEDs has the remarkable advantages such as specular removal, long lifetime, energy-conserving and environment-protective, has broad application prospects at green illumination and information displaying lamp field.At present, on market, the main way of white light LEDs is that the garnet structure yttrium aluminate yellow fluorescent powder (Ce:YAG) activated with cerium is arranged in pairs or groups blue-light LED chip, and its luminescent lumen efficiency breaks through 200lm/W.But, in the emmission spectrum of Ce:YAG fluorescent material, red color light component is not enough, when throwing light on human eye perceives too sombre, develop the color poor, therefore, in order to adapt to the demand of interior lighting, often need the rouge and powder adding proper ratio to improve colour rendering index and the colour temperature of LED light source.

In recent years, Mn ⁴⁺the LED rouge and powder activated becomes the study hotspot of fluorescent material circle gradually because its synthesis is easy, cheap.Mn ⁴⁺be emitted as arrowband line spectrum, can effectively improve optical radiation efficiency and colour rendering index, and it is less to the Reabsorption of bloom and green powder.2010, U.S. GE Global Research Center adopted K ₂tiF ₆: Mn ⁴⁺with (Sr, Ca) ₃(Al, Si) O ₄(F, O): Ce ³⁺coordinate blue chip Successful encapsulation go out colour rendering index up to 90, the white light LEDs of colour temperature 3088K, light efficiency 82lm/W.At present, common Mn ⁴⁺the substrate material of doping is fluoride system, such as, and Na ₂siF ₆: Mn ⁴⁺, Na ₂geF ₆: Mn ⁴⁺, Na ₂snF ₆: Mn ⁴⁺and Cs ₂siF ₆: Mn ⁴⁺, etc.But, the HF acid of high density during the synthesis of these fluorochemicals, must be used; HF acid not only can corrode human respiratory tract, and huge to environmental hazard.Compared to fluoride-based material, matrix of oxide covalency is stronger, can effectively reduce excited state barycenter by electronic cloud bulking effect, advantageously in acquisition red emission.In addition, alkaline earth aluminate base status is not only cheap, and chemical stability good, be easy to synthesis.

The present invention proposes a kind of Mn ⁴⁺ion doping CaMg ₂al ₁₆o ₂₇(Mn ⁴⁺: CMA) component of fluorescent material and preparation technology thereof, object is to prepare stable performance, can excite the lower little new phosphors realizing red emission in UV/blue.

Summary of the invention

The present invention proposes a kind of Mn ⁴⁺cMA red fluorescence powder of doping and preparation method thereof.This phosphor raw material is cheap, and stable performance, can exciting the ruddiness of lower generation high brightness, being expected to for building warm white LED product in UV/blue.The invention solves the red fluorescence powder physicochemical property that exist in prior art unstable and because preparation condition is harsh, expensive starting materials and the difficult problem of high cost that causes.

The present invention is achieved through the following technical solutions:

A kind of warm white LED perhafnate fluorescent material, its chemical expression is xMn ⁴⁺: CaMg ₂al _16-xo ₂₇(0.0016≤x≤0.48).

According to the present invention, described preparation method comprises:

1) Ca in molar ratio ²⁺: Mg ²⁺: Al ³⁺: Mn ⁴⁺=1:2:16-x:x (0.0016≤x≤0.48) takes raw material powder CaCO ₃, MgO, Al ₂o ₃, MnCO ₃, after grinding evenly, obtain compound;

2) gained compound in step 1 is inserted in chamber type electric resistance furnace, be warming up to 1400-1600 DEG C with stove and sinter, take out after cooling, grind and sieve, obtain described fluorescent material.Preferably, described method also comprises fully grinds raw material, and enters in high temperature section when sintering

Row long-time heat preservation.

2. particularly, described preparation method comprises the steps:

1) Ca in molar ratio ²⁺: Mg ²⁺: Al ³⁺: Mn ⁴⁺=1:2:16-x:x (0.0016≤x≤0.48) takes raw material powder CaCO ₃, MgO, Al ₂o ₃, MnCO ₃, fully grinding is after 10 minutes to 3 hours, obtains compound;

2) gained compound in step 1 is inserted in chamber type electric resistance furnace, be warming up to 1400-1600 DEG C with stove and carry out sintering 2-6 hour, take out after cooling, grind and sieve, obtain described fluorescent material.

The fluorescent material sample adopting above component and preparation technology to obtain, has following luminescence feature: described red fluorescence powder effectively can be excited by 250 nanometer-500 nanometer UV/blue, produces the red emission of 620 nanometer-700 nanometers.

The invention still further relates to a kind of application of devitrified glass, it is characterized in that, the warm white LED device that described red fluorescence powder excites for building UV/blue chip.

Fluorescent material preparation technology of the present invention is simple, with low cost, and nontoxic pollution-free has good physics, chemical stability, is expected to be applied to warm white LED device.

Accompanying drawing explanation

Fig. 1 is the SEM figure of Mn:CMA sample in example 1;

Fig. 2 is the X-ray diffractogram of 0.08Mn:CMA rouge and powder in example 1;

Fig. 3 is 0.08Mn in example 1 ⁴⁺: CMA excites and launches spectrogram; Wherein excitation wavelength is 468nm, and the emission wavelength of monitoring is 655nm.

Fig. 4 is 0.08Mn in example 1 ⁴⁺: the utilizing emitted light spectrogram of CMA fluorescent material sample and reference sample, the luminous quantum efficiency calculated (QY) is marked in figure.

Embodiment

Example 1: by analytically pure CaCO ₃, Al ₂o ₃, MgO and MnCO ₃powder, by CaCO ₃: 2MgO:7.96Al ₂o ₃: 0.08MnCO ₃the proportioning accurate weighing of (mol ratio) is placed in agate mortar, adds after ethanol in proper amount grinds 30 minutes, makes it Homogeneous phase mixing; And be placed in 60 DEG C of baking ovens and dry about 3-5 minute, after taking-up, continue grinding 15 minutes in mortar, be then placed in square crucible, be heated to 1550 DEG C in the high temperature box type resistance furnace of temperature programmed control, as a child, furnace cooling obtains sample in insulation 4.Grind, cross mesh sieve, obtain fluorescent material, the color and luster observing fluorescent material is pale pink.According to scanning electron microscopic observation, the powdered sample prepared be size at 20 microns, as shown in Figure 1; X-ray diffraction analysis result, the fluorescent material obtained is CMA pure phase, as shown in Figure 2; Measure its room temperature by FLS920 fluorescence spectrophotometer to excite and emission spectrum, find that it can be excited by 250 nanometer-500 nanometer UV/blue, and produce the red emission that centre wavelength is positioned at 650 nanometers, as shown in Figure 3.According to calculating, the luminous quantum efficiency of this fluorescent material sample can arrive 47.2%, as shown in Figure 4.

Example 2: by analytically pure CaCO ₃, Al ₂o ₃, MgO and MnCO ₃powder, by CaCO ₃: 2MgO:7.992Al ₂o ₃: 0.016MnCO ₃the proportioning accurate weighing of (mol ratio) is placed in agate mortar, adds after appropriate ethanol grinds 20 minutes, makes it Homogeneous phase mixing; And be placed in 60 DEG C of baking ovens and dry about 2 minutes, after taking-up, grind 1 hour in mortar, dry 10 minutes in 60 DEG C of baking ovens, after taking out, grinding 10 minutes, is then placed in square crucible again, in the high temperature box furnace of temperature programmed control, be heated to 1450 DEG C, be incubated after 6 hours, furnace cooling obtains sample.Grind, cross mesh sieve, obtain fluorescent material, the color and luster observing fluorescent material is pale pink.Be CMA pure phase according to the fluorescent material that X-ray diffraction analysis result obtains; Measure its room temperature by FLS920 fluorescence spectrophotometer to excite and emission spectrum, find that it can be excited by 250 nanometer-500 nanometer UV/blue, and produce the red emission that centre wavelength is positioned at 650 nanometers.

Example 3: by analytically pure CaCO ₃, Al ₂o ₃, MgO and MnCO ₃powder, by CaCO ₃: 2MgO:7.76Al ₂o ₃: 0.48MnCO ₃the proportioning accurate weighing of (mol ratio) is placed in agate mortar, adds after ethanol in proper amount grinds 20 minutes, makes it Homogeneous phase mixing; And be placed in 60 DEG C of baking ovens and dry about 3-5 minute, after taking-up, continue grinding 45 minutes in mortar, be then placed in square crucible, be heated to 1500 DEG C in the high temperature box type resistance furnace of temperature programmed control, be incubated after 2 hours, furnace cooling obtains sample.Grind, cross mesh sieve, obtain fluorescent material, the color and luster observing fluorescent material is scarlet.Be CMA pure phase according to the fluorescent material that X-ray diffraction analysis result obtains; Measure its room temperature by FLS920 fluorescence spectrophotometer to excite and emission spectrum, find that it can be excited by 250 nanometer-500 nanometer UV/blue, and produce the red emission that centre wavelength is positioned at 650 nanometers.

Claims

1. the perhafnate red fluorescence powder that adulterates of manganese (IV), its chemical composition is CaMg ₂al _16-xo ₂₇: xMn ⁴⁺, be abbreviated as: CMA:Mn ⁴⁺, wherein 0.0016≤x≤0.48.

2. additive Mn red fluorescence powder according to claim 1, is characterized by: CMA:Mn ⁴⁺for magneto plumbite structure; Further, described red fluorescence powder effectively can be excited by 250 nanometer-500 nanometer UV/blue, produces the red emission of 620 nanometer-700 nanometers.

3. any one CMA:Mn in a claim 1-2 ⁴⁺the preparation method of red fluorescence powder, is characterized in that, described method is high temperature solid state reaction.

4. according to the preparation method mixing manganese red fluorescence powder described in claim 3, described in comprise:

(1) Ca in molar ratio ²⁺: Mg ²⁺: Al ³⁺: Mn ⁴⁺=1:2:16-x:x takes raw material powder CaCO ₃, MgO, Al ₂o ₃, MnCO ₃, wherein, 0.0016≤x≤0.48, after grinding evenly, obtains compound;

(2) gained compound in step 1 is inserted in chamber type electric resistance furnace, be warming up to 1400-1600 DEG C with stove and sinter, take out after cooling, grind and sieve, obtain described fluorescent material;

Preferably, described method also comprises fully grinds raw material, and carries out long-time heat preservation when sintering in high temperature section.

5. the preparation method any one of claim 3-4, described high temperature solid state reaction comprises the steps:

(1) Ca in molar ratio ²⁺: Mg ²⁺: Al ³⁺: Mn ⁴⁺=1:2:16-x:x takes raw material powder CaCO ₃, MgO, Al ₂o ₃, MnCO ₃, wherein, 0.0016≤x≤0.48, fully grinding is after 10 minutes to 3 hours, obtains compound;

(2) gained compound in step 1 is inserted in chamber type electric resistance furnace, be warming up to 1400-1600 DEG C with stove and carry out sintering 2-6 hour, take out after cooling, grind and sieve, obtain described fluorescent material.

6. the CMA:Mn of an any one of 1-2 ⁴⁺the application of rouge and powder, is characterized in that, the warm white LED that described fluorescent material excites for building UV/blue chip.