CN103265955A - Method for enhancing YAG fluorescent powder thermal stability - Google Patents

Abstract

The present invention relates to a method for enhancing YAG fluorescent powder thermal stability, comprising: (1) culturing cerium-doped yttrium aluminum garnet microcrystalline, so that each particle in the fluorescent powder is a single perfect crystal; and (2) processing the cerium-doped yttrium aluminum garnet perfect freedom microcrystalline in three steps, including firstly melting condensed and agglomerate organizations by a microwave water bath kettle; further stripping an adhesion layer on crystal surfaces through ultrasonic treatment; and finally performing coating treatment on the crystal surface to modify surface chemical compositions, reduce a surface no response effect and to improve thermal stability.

Description

A kind of method of strengthening YAG fluorescent material thermostability

One, technical field

The present invention relates to YAG fluorescent material modification field, particularly a kind of YAG fluorescent material is strengthened the method for thermostability.

Two, background technology

Along with the importance of white light LEDs in the future feature lighting field highlights day by day, it is more and more general that high-power light emitting becomes, more and more higher to the thermostability requirement of fluorescent material.The cerium-doped yttrium aluminum garnet fluorescent powder is the main fluorescent material of present LED an illuminating material, and often there is the unsettled phenomenon of powder agglomeration, surface electrical properties and chemical property in conventional fluorescent body particle, can not satisfy the thermostability requirement.Especially at present also there are a large amount of defectives in plane of crystal, the not response layer of one micron thickness of ubiquity, and the energy band structure of plane of crystal is different with the energy band structure of crystals, especially the energy state density in the forbidden band.How to improve fluorescent material and particle surface thereof, make this not the influence of response layer drop to minimumly, be a challenge to the fluorescent material synthesis technique.

Three, summary of the invention

The purpose of this invention is to provide a kind of YAG fluorescent material and strengthen the method for thermostability, this method is freely improved crystallite by synthetic cerium-doped yttrium aluminum garnet, and the improvement of plane of crystal characteristic makes the fluorescent material thermostability strengthen.

Technical scheme of the present invention may further comprise the steps:

1) taking by weighing purity by stoichiometric ratio (3-x) Y: 5Al: xCe is Y more than 99% ₂O ₃, CeO ₂, Al (OH) ₃Mix, added mass ratio and be 1: 1 and total amount is the BaF of 1.1%-1.2% ₂And H ₃BO ₃As fusing assistant.

2) in said mixture, add the 0.2%-0.5% dehydrated alcohol, with 300-500r/min high speed ball milling 6～8h, make it abundant mixing, in the closelypacked mode of particulate state mixture is loaded in the corundum crucible then, the overcoat quartz crucible is put into gac as reducing atmosphere between two crucibles, put into high temperature reduction stove calcination 3～5h under 1300 ℃～1600 ℃ environment after the sealing, after reaction finishes, naturally cool to room temperature and namely obtain the cerium-doped yttrium aluminum garnet and freely improve crystallite.

3) above-mentioned cerium-doped yttrium aluminum garnet freely being improved crystallite fully is dissolved in the ionized water, obtain mixing solutions, sealing is placed in the microwave oven, in 140 ℃～250 ℃, crystallization 5～8h in 50kpa～80kpa environment, through washing, dry, obtain crystal after grinding, sieving.

4) above-mentioned crystal is added distilled water and transfer to the 70%-90% concentration ratio, mix the back and soak 2～3h, put into ultrasonic cleaner and under 50 ℃～80 ℃ and ultrasonic wave effect, carry out dispersion treatment 50～60min, behind the standing demix surperficial clear water is outwelled, after the distilled water cleaning, carry out ultrasonic dispersing again and handle 1～3h, under 100 ℃～150 ℃ conditions, dry, the processing of sieving after the grinding obtains the suitable crystal of big small particle size and handles.

5) with above-mentioned crystal and the particle diameter SiO less than 1um ₂Powder shakes 15～20min and mixes in mechanical vibrator, behind the granulated glass sphere dry bulb mill 15～45min with particle diameter 5～7mm, namely obtain being coated with SiO ₂Fluorescent powder crystal.

Four, embodiment

The present invention is not limited by following examples.

Embodiment 1

Accurately taking by weighing purity by stoichiometric ratio 2.82Y: 5Al: 0.18Ce is 166gY more than 99% ₂O ₃, 10gCeO ₂, 128gAl (OH) ₃Mix, add 8gBaF ₂And 8gH ₃BO ₃As solubility promoter.

1) in said mixture, adds 0.3% dehydrated alcohol, with 300r/min high speed ball milling 7h, make it abundant mixing, in the closelypacked mode of particulate state mixture is loaded in the corundum crucible then, the overcoat quartz crucible is put into gac as reducing atmosphere between two crucibles, put into high temperature reduction stove calcination 5h under 1350 ℃ of environment after the sealing, after reaction finishes, naturally cool to room temperature and namely obtain the cerium-doped yttrium aluminum garnet and freely improve crystallite.

2) above-mentioned cerium-doped yttrium aluminum garnet is freely improved crystallite and fully be dissolved in the ionized water, obtain mixing solutions, sealing is placed in the microwave oven, in 140 ℃, crystallization 8h in the 60kpa environment, through washing, dry, grind, obtain crystal powder after crossing 200 mesh sieves..

3) above-mentioned crystal is added distilled water and transfer to 80% concentration ratio, mix the back and soak 2h, put into ultrasonic cleaner and under 60 ℃ and ultrasonic wave effect, carry out dispersion treatment 50min, behind the standing demix surperficial clear water is outwelled, after the distilled water cleaning, carry out ultrasonic dispersing again and handle 2h, under 100 ℃ of conditions, dry, grind the back and cross 500 mesh sieves, obtain the suitable crystal powder of big small particle size.

4) with above-mentioned crystal and the particle diameter SiO less than 1um ₂Powder shakes 20min and mixes in mechanical vibrator, behind the granulated glass sphere dry bulb mill 30min with particle diameter 5～7mm, namely obtain being coated with SiO ₂Fluorescent powder crystal.

Embodiment 2

Accurately taking by weighing purity by stoichiometric ratio 2.82Y: 5Al: 0.18Ce is 1166gY more than 99% ₂O ₃, 10gCeO ₂, 128gAl (OH) ₃Mix, add 8gBaF ₂And 8gH ₃BO ₃As solubility promoter.

1) in said mixture, adds 0.3% dehydrated alcohol, with 400r/min high speed ball milling 6h, make it abundant mixing, in the closelypacked mode of particulate state mixture is loaded in the corundum crucible then, the overcoat quartz crucible is put into gac as reducing atmosphere between two crucibles, put into high temperature reduction stove calcination 5h under 1350 ℃ of environment after the sealing, after reaction finishes, naturally cool to room temperature and namely obtain the cerium-doped yttrium aluminum garnet and freely improve crystallite.

2) above-mentioned cerium-doped yttrium aluminum garnet is freely improved crystallite and fully be dissolved in the ionized water, obtain mixing solutions, sealing is placed in the microwave oven, in 140 ℃, crystallization 8h in the 60kpa environment, through washing, dry, grind, obtain crystal powder after crossing 200 mesh sieves.

3) above-mentioned crystal is added distilled water and transfer to 85% concentration ratio, mix the back and soak 2h, put into ultrasonic cleaner and under 60 ℃ and ultrasonic wave effect, carry out dispersion treatment 60min, behind the standing demix surperficial clear water is outwelled, after the distilled water cleaning, carry out ultrasonic dispersing again and handle 2h, under 120 ℃ of conditions, dry, grind the back and cross 500 mesh sieves, obtain the suitable crystal powder of big small particle size.

4) with above-mentioned crystal and the particle diameter SiO less than 1um ₂Powder shakes 20min and mixes in mechanical vibrator, behind the granulated glass sphere dry bulb mill 30min with particle diameter 5～7mm, namely obtain being coated with SiO ₂Fluorescent powder crystal.

Claims (2)

1. a method of strengthening YAG fluorescent material thermostability is characterized in that at first adopting the synthetic cerium-doped yttrium aluminum garnet of high temperature solid-state method freely to improve crystallite, then the crystal that obtains is divided for three steps carried out surface treatment, thereby improves the thermostability of fluorescent material.

2. a kind of method of strengthening YAG fluorescent material thermostability according to claim 1, its feature may further comprise the steps:

1) taking by weighing purity by stoichiometric ratio (3-x) Y: 5Al: xCe is Y more than 99% ₂O ₃, CeO ₂, Al (OH) ₃Mix, added mass ratio and be 1: 1 and total amount is the BaF of 1.1%-1.2% ₂And H ₃BO ₃As fusing assistant.

2) in said mixture, add the 0.2%-0.5% dehydrated alcohol, with 300-500r/min high speed ball milling 6～8h, make it abundant mixing, in the closelypacked mode of particulate state mixture is loaded in the corundum crucible then, the overcoat quartz crucible is put into gac as reducing atmosphere between two crucibles, put into high temperature reduction stove calcination 3～5h under 1300 ℃～1600 ℃ environment after the sealing, after reaction finishes, naturally cool to room temperature and namely obtain the cerium-doped yttrium aluminum garnet and freely improve crystallite.

3) above-mentioned cerium-doped yttrium aluminum garnet freely being improved crystallite fully is dissolved in the ionized water, obtain mixing solutions, sealing is placed in the microwave oven, in 140 ℃～250 ℃, crystallization 5～8h in 50kpa～80kpa environment, through washing, dry, obtain crystal after grinding, sieving.

4) above-mentioned crystal is added distilled water and transfer to the 70%-90% concentration ratio, mix the back and soak 2～3h, put into ultrasonic cleaner and under 50 ℃～80 ℃ and ultrasonic wave effect, carry out dispersion treatment 50～60min, behind the standing demix surperficial clear water is outwelled, after the distilled water cleaning, carry out ultrasonic dispersing again and handle 1～3h, under 100 ℃～150 ℃ conditions, dry, the processing of sieving after the grinding obtains the suitable crystal of big small particle size and handles.

5) with above-mentioned crystal and the particle diameter SiO less than 1um ₂Powder shakes 15～20min and mixes in mechanical vibrator, behind the granulated glass sphere dry bulb mill 15～45min with particle diameter 5～7mm, namely obtain being coated with SiO ₂Fluorescent powder crystal.