CN102477292A - Green fluorescent powder used in white light LED, and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of luminescent materials, and discloses green fluorescent powder used in a white light LED. The molecular formula of the green fluorescent powder is that: Ca2SrMgSi2O7: Eu<2+>. According to the invention, 145g-155g of CaCO3, 8g-15g of Eu2O3, 3g-6g of SrCO3, 115g-125g of SiO2, 260g-270g of CaCl2.2H2O, and 50g-65g of Mg(HO)2 are weighed. That is to say, 20-30% of CaCO3, 1-5% of Eu2O3, 0.6-1% of SrCO3, 15-20% of SiO2, 40-50% of CaCl2.2H2O, and 8-16% of Mg(HO)2 are weighed. The preparation method is a high-temperature solid-phase method. Preferably, the weight ratio of CaCO3:Eu2O3:SrCO3:SiO2:CaCl2.2H2O:Mg(HO)2 is 0.242:0.02:0.009:0.2:0433:0.096. The fluorescent powder can be excited by 360-480nm lights with high efficiency, and high-efficiency green lights are emitted. The emission main peak is 529nm. The green fluorescent powder is advantaged in good stability and high luminous intensity. The preparation method is advantaged in simple preparation technology and easy industrialization. Therefore, the green fluorescent powder can be used as a high-quality green component in a three-primary-color white light LED excited by near ultraviolet lights.

Description

A kind of green emitting phosphor that is used for white light LEDs and preparation method thereof

Technical field

The invention belongs to field of light emitting materials, particularly a kind of green emitting phosphor that is used for white light LEDs and preparation method thereof.

Background technology

The technology of producing white light LEDs mainly contains two kinds at present, and the one, utilize super brightness In-GaN blue led, add on its tube core that the yttrium aluminum garnet (YAG) of a little is the fluorescent material of main body.In-GaN chip blue light-emitting, YAG fluorescent material sends sodium yellow after receiving this blue-light excited.The blue light that chip appears is in the same place with the yellow light mix of fluorescent material, forms white light; The 2nd, the principle of three primary colours and three kinds of ultra-high brightness LEDs of fertile at present red, green, blue form white by 1: 2: 0.38 mixed of light intensity.

First kind of its white light is to be formed by the yellow fluorescence of luminescent powder and the blue light of led chip, stability better, but too low about 82 of its luminous more perverse eye, colour rendering index are to showing that the high occasion of object color can't use.

Second kind is adopted near-ultraviolet light InGaN tube core to excite the red, green, blue three primary colors fluorescent powder to realize that white light LEDs is better than first kind.Because near-ultraviolet light is invisible to naked eyes, the color of this type white light LEDs is determined that by fluorescent material colour rendering index is high.

Summary of the invention

The purpose of this invention is to provide a kind of green emitting phosphor that is used for white light LEDs;

Another object of the present invention provides a kind of preparation method of green emitting phosphor that is used for white light LEDs.

The molecular formula that the present invention is used for the green emitting phosphor of white light LEDs is: Ca ₂SrMgSi ₂O ₇: Eu ²⁺, the preparation method of green emitting phosphor that the present invention is used for white light LEDs may further comprise the steps:

(1) takes by weighing CaCO ₃145g-155g, Eu ₂O ₃8g-15g, SrCO ₃3g-6g, SiO ₂115g-125, CaCl ₂2H ₂O260g-270g, Mg (HO) ₂50g-65g, promptly each raw material weight ratio is: CaCO ₃20-30%, Eu ₂O ₃1-5%, SrCO ₃0.6-1%, SiO ₂15-20%, CaCl ₂2H ₂O40-50%, Mg (HO) ₂8-16%, each raw materials mix is even;

(2) mixed raw material is put into aire tunnel kiln 1000-1200 degree calcination 2～4 hours, take out and be cooled to room temperature;

(3) powder with calcination pulverized 50 mesh sieves;

(4) will sieve good powder and put into hydrogen reducing furnace 1100～1200 degree calcinations 2～4 hours, and take out and be cooled to room temperature, obtain work in-process, indexs such as test relative brightness, emission main peak, granularity;

(5) with work in-process pulverize, scalping washing, wet screening, centrifugal, dried 100 mesh sieves, the test synthesis data obtain finished product.

The present invention is used for the preparation of the green emitting phosphor of white light LEDs, and each raw material preferred weight ratio is CaCO ₃: Eu ₂O ₃: SrCO ₃: SiO ₂: CaCl ₂2H ₂O: Mg (HO) ₂=0.242: 0.02: 0.009: 0.2: 0.433: 0.096.

The invention has the advantages that: the green emitting phosphor that is used for white light LEDs can be efficiently by 360nm～480nm optical excitation,, send highly effective green light, the emission main peak is 529nm, good stability, luminous intensity are high.Preparation technology is simple, be easy to industrialization, so the present invention can be used for the good green component in the near ultraviolet excitation three primary colours white light LEDs.

Embodiment

Do a detailed description in the face of the present invention down

The molecular formula that is used for the green emitting phosphor of white light LEDs is: Ca ₂SrMgSi ₂O ₇: Eu ²⁺, take by weighing CaCO ₃145g-155g, Eu ₂O ₃8g-15g, SrCO ₃3g-6g, SiO ₂115g-125, CaCl ₂2H ₂O260g-270g, Mg (HO) ₂50g-65g, promptly each raw material weight ratio is: CaCO ₃20-30%, Eu ₂O ₃1-5%, SrCO ₃0.6-1%, SiO ₂15-20%, CaCl ₂2H ₂O40-50%, Mg (HO) ₂8-16%; Each raw materials mix is even, in the aire tunnel kiln air tunnel 1000-1200 hour, take out and be cooled to room temperature; The powder of calcination was pulverized 50 mesh sieves will be sieved good powder and put into hydrogen reducing furnace 1100～1200 degree calcinations 2～4 hours; Taking-up is cooled to room temperature, obtains work in-process, indexs such as test relative brightness, emission main peak, granularity; With work in-process pulverize, scalping washing, wet screening, centrifugal, dried 100 mesh sieves, the test synthesis data obtain finished product.Use fluorescence spectrum tester test emission main peak to be 529nm.

The present invention is used for the preparation of the green emitting phosphor of white light LEDs, and each raw material preferred weight ratio is CaCO ₃: Eu ₂O ₃: SrCO ₃: SiO ₂: CaCl ₂2H ₂O: Mg (HO) ₂=0.242: 0.02: 0.009: 0.2: 0.433: 0.096.

Claims (3)

1. green emitting phosphor that is used for white light LEDs, it is characterized in that: the molecular formula that is used for the green emitting phosphor of white light LEDs is: Ca ₂SrMgSi ₂O ₇: Eu ²⁺

2. a kind of preparation method of green emitting phosphor that is used for white light LEDs according to claim 1, it is characterized in that: described method steps comprises:

(1) takes by weighing CaCO ₃145g-155g, Eu ₂O ₃8g-15g, SrCO ₃3g-6g, SiO ₂115g-125, CaCl ₂2H ₂O260g-270g, Mg (HO) ₂50g-65g, promptly each raw material weight ratio is: CaCO ₃20-30%, Eu ₂O ₃1-5%, SrCO ₃0.6-1%, SiO ₂15-20%, CaCl ₂2H ₂O40-50%, Mg (HO) ₂8-16%, each raw materials mix is even;

(2) mixed raw material is put into aire tunnel kiln 1000-1200 degree calcination 2～4 hours, take out and be cooled to room temperature;

(3) powder with calcination pulverized 50 mesh sieves;

(4) will sieve good powder and put into hydrogen reducing furnace 1100～1200 degree calcinations 2～4 hours, and take out and be cooled to room temperature, obtain work in-process, indexs such as test relative brightness, emission main peak, granularity;

(5) with work in-process pulverize, scalping washing, wet screening, centrifugal, dried 100 mesh sieves, the test synthesis data obtain finished product.

3. a kind of preparation method of green emitting phosphor that is used for white light LEDs according to claim 2: it is characterized in that: each raw material preferred weight ratio is CaCO ₃: Eu ₂O ₃: SrCO ₃: SiO ₂: CaCl ₂2H ₂O: Mg (HO) ₂=0.242: 0.02: 0.009: 0.2: 0.433: 0.096.