CN103805175A - Fluorescent powder and synthesis method thereof - Google Patents

Abstract

The invention discloses fluorescent powder, of which the structural formula is (Cax+y, Sry) MxS: zEu<2+>, wherein M is Ga, x is smaller than 0.2 and greater than 0, y is smaller than 0.2 and greater than 0, and z is smaller than 0.2 and greater than 0. The fluorescent powder disclosed by the invention is broad in excitation spectrum range, and especially good in excitation efficiency near a blue light of 430-490nm, and can play the roles of improving the color rendering index of a white light-emitting diode (LED) and the like, and the material powder is not easily oxidized again, and is high in luminance.

Description

A kind of fluorescent material and synthetic method thereof

Technical field

The present invention relates to the synthetic method of a kind of white light LEDs luminophore, particularly excite the synthetic method of the red fluorescence powder of lower use at blue light (430 ~ 490nm).

Background technology

At present, white light LEDs is applied to main in demonstration or illumination or produces white light in the mode of blue and yellow complementary color, and namely most blue light-emitting chips that adopt add the fluorescent material of Yellow light-emitting low temperature, through producing white light after lighting.Compare differs greatly the emmission spectrum of this white light with natural spectrum (also claiming standard spectrum), so color developing is poor, thereby causes colour rendering index (colour rendering index Ra represents) not high.If adopt the chip of sending out UV-light to add respectively the white light that red, green, blue (or using blue chip) forms, colour rendering index will improve a lot, but the efficiency of giving out light but significantly reduces.

No matter be which kind of lighting source, comprise LED light source, colour rendering index is all relevant with the distribution of its emmission spectrum.More approach nature spectrum (also claiming standard spectrum), its colour rendering index is just higher.In order to improve color developing, promote colour rendering index, can take theoretically to supplement the part spectrum lacking on spectrum band, but when doing like this, also can cause optical throughput to reduce.The phosphor material powder choosing in the time improving the Ra of white light LEDs is quite important, use red and green fluorescent material in blue led collocation at present, and utilize in ultraviolet leds, add the technology of red bluish-green fluorescent material to improve Ra value, reach the target of high-color rendering.The Ra that improves white light LEDs is to have good light conversion efficiency to the requirement of luminescent material, possesses again good ageing resistance.Analyze from emmission spectrum, at least need to have the luminescent material of a kind of transmitting main peak at red area (600 ~ 680nm), and this luminophore can be excited by near ultraviolet to the light of blue region and launch ruddiness, and this project luminophore feature possesses above characteristic exactly.A kind of red fluorescence powder is through adding in the fluorescent material of traditional Yellow light-emitting low temperature, after encapsulation after blue chip excites, the white light colour rendering index producing has obtained significantly improving, also can mix from 2000k ~ 5500k different-colour white light LEDs, this series products has good business use value simultaneously.

Summary of the invention

The invention provides a kind of synthetic method of luminescent material of red fluorescence, particularly a kind of synthetic method that excites the fluorescent material of lower use at blue light (430 ~ 490nm).

In order to solve above-mentioned technical problem, technical scheme of the present invention is:

A kind of fluorescent material, is characterized in that: its structural formula is (Ca _x+y, Sr _y) M _xs:zEu ²⁺, wherein, M is Ga, and 0 < x < 0.2, and 0 < y < 0.2,0 < z < 0.2.

The synthetic method of above-mentioned fluorescent material, comprises the following steps:

(1) according to (Ca _x+y, Sr _y) M _xs:zEu ²⁺stoichiometric ratio take raw material, wherein, M is Ga, and 0 < x < 0.2, and 0 < y < 0.2,0 < z < 0.2;

(2) take barium fluoride or the strontium fluoride that quality consumption is raw material weight 0.5～3%, with raw material blending, pack in corundum crucible and also cover tightly with corundum lid, put in hydrogen nitrogen reducing atmosphere stove and carry out calcination, calcination soaking time is controlled at 3 ~ 10 hours, and temperature is controlled at 1300 ~ 1400 ℃;

(3) powder is crossed after 200 order dry screens after break process, carry out lanthanum orthophosphate solution coated, material is slowly added in lanthanum orthophosphate solution, stir simultaneously, after material adds, continue churning time and be controlled at 1～1.2 hour, regulator solution PH, to neutral, take out throw out to filter, put oven for drying into, bake out temperature is controlled at 130 ~ 150 ℃;

(4) powder after drying is sieved through 200 orders, obtain fluorescent material.

In the synthetic method of emitting red light material of the present invention, adopt following main raw material: fluorescence europium oxide (Eu ₂o ₃), analytical pure sulfuric acid calcium (CaSO ₄), high-purity strontium carbonate (SrCO ₃), high-purity calcium carbonate (CaCO ₃), high-purity magnesium oxide (MgO), high-purity zinc oxide (ZnO), high purity aluminium oxide (Al ₂o ₃), high-purity gallium oxide (Ga ₂o ₃).Other trace additive of fluxing is selected barium fluoride (BaF ₂), strontium fluoride (SrF ₂), lithium chloride (LiCl), lithium fluoride (LiF), get wherein one or more.

The present invention is by the adulterate synthetic method of Ga, Al, Mg or mono-kind of Zn and micro-fusing assistant of component, final passing through in the coated processing to particle surface, having solved the sulfidic material that general technology skill produces easily causes the sulphur to separate out problem, and powder granularity is evenly distributed, good fluidity, product has also obtained on aging significantly improving in luminous intensity and heatproof degree, and the lifting of white light LEDs color developing has also been played to remarkable effect.

Embodiment

Embodiment 1

By raw material: europium sesquioxide 0.02g, calcium sulfate 81.44g, calcium carbonate 4.22g, Strontium carbonate powder 13.48g, magnesium oxide 1.10g, barium fluoride 0.5g mix grinding 1.5 hours in the ball grinder of the corundum material of 1 liter capacity, abrasive substance uses diameter to be about 10mm agate ball, the material that mix grinding is good packs in corundum crucible to be put under hydrogen and nitrogen gas reducing atmosphere and carries out pyroreaction 3 hours, reduction temperature is controlled at 1400 ℃, after pyroreaction lumpy material after break process through 200 mesh sieves, then carry out after the processing of lanthanum orthophosphate coating, carry out lanthanum orthophosphate solution coated, material is slowly added in lanthanum orthophosphate solution, stir simultaneously, after material adds, continue churning time and be controlled at 1.0 hours, finally carry out regulator solution PH to neutral according to the acid-basicity of solution with ammoniacal liquor, after stopping stirring, after precipitating completely, remove supernatant liquor, throw out is taken out and filtered, put oven for drying into, bake out temperature is controlled at 100 ℃, after drying, finished product sieves.

Embodiment 2

By raw material: europium sesquioxide 0.01g, calcium sulfate 81.72g, Strontium carbonate powder 12.17g, magnesium oxide 1.70g, barium fluoride 2.2g, strontium fluoride 0.5g mix grinding 1.5 hours in the ball grinder of the corundum material of 1 liter capacity, abrasive substance uses diameter to be about 10mm agate ball, the material that mix grinding is good packs in corundum crucible to be put under hydrogen and nitrogen gas reducing atmosphere and carries out pyroreaction 5 hours, reduction temperature is controlled at 1300 ℃, after pyroreaction lumpy material after break process through 200 mesh sieves, then carry out the processing of lanthanum orthophosphate coating, it is coated that product carries out lanthanum orthophosphate solution after test, material is slowly added in lanthanum orthophosphate solution, stir simultaneously, after material adds, continue churning time and be controlled at 1.5 hours, finally carry out regulator solution PH to neutral according to the acid-basicity of solution with ammoniacal liquor, after stopping stirring, after precipitating completely, remove supernatant liquor, throw out is taken out and filtered, put oven for drying into, bake out temperature is controlled at 120 ℃, after drying, finished product sieves, tests.

Above-described embodiment and reference sample related data synopsis:

Note: reference sample is that domestic conventional fabrication processes is produced sulfurated lime: europium (CaS:Eu) rouge and powder, being decided to be normal brightness is 100%.

Above-described embodiment does not limit the present invention in any way, and every employing is equal to replaces or technical scheme that the mode of equivalent transformation obtains all drops in protection scope of the present invention.

Claims (2)

1. a fluorescent material, it is characterized in that: its structural formula is (Cax+y, Sry) MxS:zEu2+, wherein, M is Ga, and 0 < x < 0.2, and 0 < y < 0.2,0 < z < 0.2.

2. a synthetic method for fluorescent material, is characterized in that: comprise the following steps:

(1) according to (Cax+y, Sry) stoichiometric ratio of MxS:zEu2+ takes raw material, wherein, M is Ga, and 0 < x < 0.2, and 0 < y < 0.2,0 < z < 0.2;

(2) take barium fluoride or the strontium fluoride that quality consumption is raw material weight 0.5～3%, with raw material blending, pack in corundum crucible and also cover tightly with corundum lid, put in hydrogen nitrogen reducing atmosphere stove and carry out calcination, calcination soaking time is controlled at 3 ~ 10 hours, and temperature is controlled at 1300 ~ 1400 ℃;

(3) powder is crossed after 200 order dry screens after break process, carry out lanthanum orthophosphate solution coated, material is slowly added in lanthanum orthophosphate solution, stir simultaneously, after material adds, continue churning time and be controlled at 1～1.2 hour, regulator solution PH, to neutral, take out throw out to filter, put oven for drying into, bake out temperature is controlled at 130 ~ 150 ℃;

(4) powder after drying is sieved through 200 orders, obtain fluorescent material.