Photoluminescence （PL） and colorimetric properties of white-light emission SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were tuned effectively through incorporating Si–N bond to the host in the form of Si3N4. A maximum solubil...Photoluminescence （PL） and colorimetric properties of white-light emission SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were tuned effectively through incorporating Si–N bond to the host in the form of Si3N4. A maximum solubility of Si–N bond in SrAl2–xSi2＋xO8–xNx was estimated theoretically to be in a value of x=1.0. Under 365 nm irradiation, a distinct red-shift of blue band emission from 406 to 473 nm for Eu2＋ and an enhancement of yellow band emission peaked at ~565 nm for Mn2＋ were observed with the increase of Si–N content. These effects resulted from partial substitution of Si–N for Al1–O1 and Al4–O2 sites in SrAl2Si2O8 lattice. Eventually, a white emission with CIE chromaticity coordinates （0.287, 0.337） and color rendering index （CRI） 78.3 for SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were achieved upon optimization to a suitable amount of Si–N.展开更多
The influence of the polarized state of blue light on light scattering in InGaN blue chip nano-crystal luminescent glass for solid state lighting is investigated.Based on Rayleigh-Debye approximation theory,theoretica...The influence of the polarized state of blue light on light scattering in InGaN blue chip nano-crystal luminescent glass for solid state lighting is investigated.Based on Rayleigh-Debye approximation theory,theoretical relationships between the light scattering turbidity and wavelength of the incident light,radius and refractive index of the nano-crystals are established to simulate the situations in yttrium aluminate garnet(YAG),silicate and oxynitride based luminescence glass.It is revealed that the scattering turbidity in luminescent glass turns to be the smallest as the effective refractive index of nanocrystals is equal to that of parent glass,and the scattering turbidity for the vertically polarized incident light is greater than that for the un-polarized incident light,while that for the horizontally polarized incident light is smaller than that for the unpolarized incident light under the same conditions.展开更多
Precisely adjusting the color purity of LaAlO3:Eu3+ red phosphor with 593 and 618 nm emissions is achieved in a strategy of suppressing transitions of high energy levels of Eu3+ ions through varying the doping concent...Precisely adjusting the color purity of LaAlO3:Eu3+ red phosphor with 593 and 618 nm emissions is achieved in a strategy of suppressing transitions of high energy levels of Eu3+ ions through varying the doping concentration.As the doping concentration increases,the transitions from high levels 5D3,2,1 will be weakened,while those from 5D0 are enhanced up to a critical value with the aid of the cross relaxation.As a result,an increase of the color purity from 95.2% to 97.4% is obtained.It indicates that the red phosphor could be one of the excellent red-light-emitting phosphors in illuminating and display devices.展开更多
基金Project supported by the National Natural Science Foundation of China (50802062, 21076161, 50872091)Key Discipline of Materials Physics and Chemistry (Tianjin, China) (2006ZD30)
文摘Photoluminescence （PL） and colorimetric properties of white-light emission SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were tuned effectively through incorporating Si–N bond to the host in the form of Si3N4. A maximum solubility of Si–N bond in SrAl2–xSi2＋xO8–xNx was estimated theoretically to be in a value of x=1.0. Under 365 nm irradiation, a distinct red-shift of blue band emission from 406 to 473 nm for Eu2＋ and an enhancement of yellow band emission peaked at ~565 nm for Mn2＋ were observed with the increase of Si–N content. These effects resulted from partial substitution of Si–N for Al1–O1 and Al4–O2 sites in SrAl2Si2O8 lattice. Eventually, a white emission with CIE chromaticity coordinates （0.287, 0.337） and color rendering index （CRI） 78.3 for SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were achieved upon optimization to a suitable amount of Si–N.
基金supported by the National Natural Science Foundation of China (No. 50872091)Tianjin Key Subject for Materials Physics and Chemistry (No. 2006ZD30,06YFJMJC02300)
文摘The influence of the polarized state of blue light on light scattering in InGaN blue chip nano-crystal luminescent glass for solid state lighting is investigated.Based on Rayleigh-Debye approximation theory,theoretical relationships between the light scattering turbidity and wavelength of the incident light,radius and refractive index of the nano-crystals are established to simulate the situations in yttrium aluminate garnet(YAG),silicate and oxynitride based luminescence glass.It is revealed that the scattering turbidity in luminescent glass turns to be the smallest as the effective refractive index of nanocrystals is equal to that of parent glass,and the scattering turbidity for the vertically polarized incident light is greater than that for the un-polarized incident light,while that for the horizontally polarized incident light is smaller than that for the unpolarized incident light under the same conditions.
基金supported by the National Natural Science Foundation of China (No.50872091)the Science and Technology Programs of Tianjin in China (No.2006ZD30)
文摘Precisely adjusting the color purity of LaAlO3:Eu3+ red phosphor with 593 and 618 nm emissions is achieved in a strategy of suppressing transitions of high energy levels of Eu3+ ions through varying the doping concentration.As the doping concentration increases,the transitions from high levels 5D3,2,1 will be weakened,while those from 5D0 are enhanced up to a critical value with the aid of the cross relaxation.As a result,an increase of the color purity from 95.2% to 97.4% is obtained.It indicates that the red phosphor could be one of the excellent red-light-emitting phosphors in illuminating and display devices.
