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
The dependence of color points of white light on the composition of bomphosphate glasses co-doped with europium （En） and terbium （Tb） has been investigated in terms of valence change of rare earth ions. Under ultr...The dependence of color points of white light on the composition of bomphosphate glasses co-doped with europium （En） and terbium （Tb） has been investigated in terms of valence change of rare earth ions. Under ultraviolet （UV） excitation, the white light is observed to be from a combination of 4f65d → 4f7 band transition emission at 425 nm for Eu^2＋, 5D0 → ^7Fj （J= 1, 2） lineemissions at 593 nm and 611 nm for Eu^3＋, and 5D4 → 7F5 band transition emission at 545 nm for Tb^3＋. By varying the glass composition, the resultant emission color can be tuned efficiently. Eventually, the optimized white light with commission international de I＇Eclairage （CIE） coordinate of （0.3382. 0.2763） and the correlate color temperature （CCT） at 5010 K are achieved.展开更多
A simultaneous blue-light and red-light emitting glass of SrO-B2O3-P2O5 doped with Eu2O3 is prepared in air, and then heat-treated without any reductive reagent. A transition combination is found to consist of a band ...A simultaneous blue-light and red-light emitting glass of SrO-B2O3-P2O5 doped with Eu2O3 is prepared in air, and then heat-treated without any reductive reagent. A transition combination is found to consist of a band emission peaked around 430 nm and a series of line emission from 593 nm to 611 nm, corresponding to the typical 4f65d→ 4f7 transition of Eu2+ and 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+, respectively. Some unidentified crystals such as Sr (PO3)2 and SrB2O4 as hosts for Eu2+ with more stronger crystal field lead to this enhancement of photoluminescence (PL) intensity superior to the asprepared parent glass.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 (Nos.50872091 and 21076161)the Key Discipline of Materials Physics and Chemistry in Tianjin of China (No.2006ZD30)
文摘The dependence of color points of white light on the composition of bomphosphate glasses co-doped with europium （En） and terbium （Tb） has been investigated in terms of valence change of rare earth ions. Under ultraviolet （UV） excitation, the white light is observed to be from a combination of 4f65d → 4f7 band transition emission at 425 nm for Eu^2＋, 5D0 → ^7Fj （J= 1, 2） lineemissions at 593 nm and 611 nm for Eu^3＋, and 5D4 → 7F5 band transition emission at 545 nm for Tb^3＋. By varying the glass composition, the resultant emission color can be tuned efficiently. Eventually, the optimized white light with commission international de I＇Eclairage （CIE） coordinate of （0.3382. 0.2763） and the correlate color temperature （CCT） at 5010 K are achieved.
基金the National Natural Science Foundation of China(No.50872091)the Key Discipline of Materials Physics and Chemistry of Tianjin,(No.10SYSYJC28100)
文摘A simultaneous blue-light and red-light emitting glass of SrO-B2O3-P2O5 doped with Eu2O3 is prepared in air, and then heat-treated without any reductive reagent. A transition combination is found to consist of a band emission peaked around 430 nm and a series of line emission from 593 nm to 611 nm, corresponding to the typical 4f65d→ 4f7 transition of Eu2+ and 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+, respectively. Some unidentified crystals such as Sr (PO3)2 and SrB2O4 as hosts for Eu2+ with more stronger crystal field lead to this enhancement of photoluminescence (PL) intensity superior to the asprepared parent glass.
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.
