Praseodym or praseodym-europim doped strontium lithium silicate yellow-red fluorescent powder and preparation method thereof

Abstract

The invention relates to praseodym or praseodym-europim doped strontium lithium silicate yellow-red fluorescent powder and a preparation method thereof. The fluorescent powder utilizes strontium lithium silicate as a medium, can be effectively triggered by blue light with the wavelength of 400-500nm by codope of the praseodym and europium, and has a doublet broadband transmission characteristic (the main peaks are respectively 580nm and 610nm); and the fluorescent powder can be triggered by blue light with the wavelength of 440-490nm to transmit strong red fluorescence (the main peak is a narrow band of 610nm) by single dope of praseodym. The chemical composition of the fluorescent powder has a general formula as Li2Sr1-x-ySiO4:xEu2+, yPr3+, wherein x is no less than 0 and no more than 0.02, so is y. The excitation spectrum of the fluorescent powder has good matching with a blue light LED chip, so the fluorescent powder can be used in assembly of a white light LED with a high color rendering index; and the preparation process is easy to control, and the basic equipment of the current fluorescent powder plants can be used for realizing industrialized production, thus the fluorescent powder is novel and has application potential.

Description

technical field

[0001] The invention relates to a yellow-red fluorescent powder based on praseodymium or praseodymium-europium doping that can be effectively excited by blue LED light and a preparation method thereof, belonging to the technical field of rare earth luminescent materials. Background technique

[0002] White LED lighting is called the fourth-generation lighting source, which can be widely used in various lighting facilities and has a tendency to replace traditional lighting. At present, the mainstream solution for commercializing white LEDs is: blue LED + yellow phosphor. The solution is a combination of a blue LED chip and a yellow-emitting YAG phosphor that can be effectively excited by blue light, wherein a part of the blue light emitted by the blue LED is absorbed by the YAG phosphor to emit yellow light. The resulting yellow light and the remaining blue light mix into white light. White light with various color temperatures can be obtained by adjusting t...

Examples

Embodiment 1

[0035] Weigh Li according to the molar ratio: Li:Sr:Si:Eu=2:0.995:1:0.005 2 CO 3 , SrCO 3 , SiO 2 , Eu 2 o 3 , the above raw materials are all analytically pure, after mixing the above raw materials evenly, put them into an alumina crucible and bake in air, keep the temperature at 600°C for 6 hours, and then bake at 850°C for 4 hours in a reducing atmosphere. The resulting product is crushed, washed with water, removed of impurities, and dried to obtain the chemical composition of Li 2 Sr 0.995 SiO 4 :0.005Eu 2+ sample. Its excitation spectrum see figure 1 , 3 center line 1, emission spectrum see Fig.

[0036] 2, 4 midline 1.

Embodiment 2

[0038] Weigh Li according to the molar ratio: Li:Sr:Si:Eu:Pr=2:0.993:1:0.005:0.002 2 CO 3 , SrCO 3 , SiO 2 , Eu 2 o 3 , Pr 6 o 11 , the above raw materials are all analytically pure, after mixing the above raw materials evenly, put them into an alumina crucible and bake in air, keep the temperature at 600°C for 6 hours, and then bake at 850°C for 4 hours in a reducing atmosphere. The resulting product is crushed, washed with water, removed of impurities, and dried to obtain the chemical composition of Li 2 Sr 0.993 SiO 4 :0.005Eu 2+ , 0.002Pr 3+ sample. Its excitation spectrum see image 3 Centerline 2, emission spectrum see Figure 4 Midline 2.

Embodiment 3

[0040] Weigh Li according to the molar ratio: Li:Sr:Si:Eu:Pr=2:0.991:1:0.005:0.004 2 CO 3 , SrCO 3 , SiO 2 , Eu 2 o 3 , Pr 6 o 11 , the above raw materials are all analytically pure, after mixing the above raw materials evenly, put them into an alumina crucible and bake in air, keep the temperature at 600°C for 6 hours, and then bake at 850°C for 4 hours in a reducing atmosphere. The resulting product is crushed, washed with water, removed of impurities, and dried to obtain the chemical composition of Li 2 Sr 0.991 SiO 4 :0.005Eu 2+ , 0.004Pr 3+ sample. Its excitation spectrum see figure 1 , 3 midline 3, emission spectrum see figure 2 , 4 midline 3.

technical field

[0001] The invention relates to a yellow-red fluorescent powder based on praseodymium or praseodymium-europium doping that can be effectively excited by blue LED light and a preparation method thereof, belonging to the technical field of rare earth luminescent materials. Background technique

[0002] White LED lighting is called the fourth-generation lighting source, which can be widely used in various lighting facilities and has a tendency to replace traditional lighting. At present, the mainstream solution for commercializing white LEDs is: blue LED + yellow phosphor. The solution is a combination of a blue LED chip and a yellow-emitting YAG phosphor that can be effectively excited by blue light, wherein a part of the blue light emitted by the blue LED is absorbed by the YAG phosphor to emit yellow light. The resulting yellow light and the remaining blue light mix into white light. White light with various color temperatures can be obtained by adjusting t...

Examples

Embodiment 1

[0035] Weigh Li according to the molar ratio: Li:Sr:Si:Eu=2:0.995:1:0.005 2 CO 3 , SrCO 3 , SiO 2 , Eu 2 o 3 , the above raw materials are all analytically pure, after mixing the above raw materials evenly, put them into an alumina crucible and bake in air, keep the temperature at 600°C for 6 hours, and then bake at 850°C for 4 hours in a reducing atmosphere. The resulting product is crushed, washed with water, removed of impurities, and dried to obtain the chemical composition of Li 2 Sr 0.995 SiO 4 :0.005Eu 2+ sample. Its excitation spectrum see figure 1 , 3 center line 1, emission spectrum see Fig.

[0036] 2, 4 midline 1.

Embodiment 2

[0038] Weigh Li according to the molar ratio: Li:Sr:Si:Eu:Pr=2:0.993:1:0.005:0.002 2 CO 3 , SrCO 3 , SiO 2 , Eu 2 o 3 , Pr 6 o 11 , the above raw materials are all analytically pure, after mixing the above raw materials evenly, put them into an alumina crucible and bake in air, keep the temperature at 600°C for 6 hours, and then bake at 850°C for 4 hours in a reducing atmosphere. The resulting product is crushed, washed with water, removed of impurities, and dried to obtain the chemical composition of Li 2 Sr 0.993 SiO 4 :0.005Eu 2+ , 0.002Pr 3+ sample. Its excitation spectrum see image 3 Centerline 2, emission spectrum see Figure 4 Midline 2.

Embodiment 3

[0040] Weigh Li according to the molar ratio: Li:Sr:Si:Eu:Pr=2:0.991:1:0.005:0.004 2 CO 3 , SrCO 3 , SiO 2 , Eu 2 o 3 , Pr 6 o 11 , the above raw materials are all analytically pure, after mixing the above raw materials evenly, put them into an alumina crucible and bake in air, keep the temperature at 600°C for 6 hours, and then bake at 850°C for 4 hours in a reducing atmosphere. The resulting product is crushed, washed with water, removed of impurities, and dried to obtain the chemical composition of Li 2 Sr 0.991 SiO 4 :0.005Eu 2+ , 0.004Pr 3+ sample. Its excitation spectrum see figure 1 , 3 midline 3, emission spectrum see figure 2 , 4 midline 3.

Images