Correlation of Structure, Tunable Colors, and Lifetimes of (Sr, Ca, Ba)Al2O4:Eu2+, Dy3+ Phosphors
نویسندگان
چکیده
(Sr, Ca, Ba)Al₂O₄:Eu2+, Dy3+ phosphors were prepared via a high temperature solid-state reaction method. The correlation of phase structure, optical properties and lifetimes of the phosphors are investigated in this work. For the (Sr, Ca)Al₂O₄:Eu2+,Dy3+ phosphors, the different phase formation from monoclinic SrAl₂O₄ phase to hexagonal SrAl₂O₄ phase to monoclinic CaAl₂O₄ phase was observed when the Ca content increased. The emission color of SrAl₂O₄:Eu2+, Dy3+ phosphors varied from green to blue. For the (Sr, Ba)Al₂O₄:Eu2+, Dy3+ phosphors, different phase formation from the monoclinic SrAl₂O₄ phase to the hexagonal BaAl₂O₄ phase was observed, along with a shift of emission wavelength from 520 nm to 500 nm. More interestingly, the decay time of SrAl₂O₄:Eu2+, Dy3+changed due to the different phase formations. Lifetime can be dramatically shortened by the substitution of Sr2+ with Ba2+ cations, resulting in improving the performance of the alternating current light emitting diode (AC-LED). Finally, intense LEDs are successfully obtained by combining these phosphors with Ga(In)N near UV chips.
منابع مشابه
Effect of Composition and Impurities on the Phosphorescence of Green-Emitting Alkaline Earth Aluminate Phosphor
Recent improvements to SrAl2O4:Eu2+, Dy3+ phosphors have enabled the use of luminescent hosts with a stable crystal structure and high physical and chemical stability, thus overcoming the bottleneck in the applicability of ZnS:Cu phosphors. However, enhancement of afterglow lifetime and brightness in SrAl2O4:Eu2+, Dy3+ phosphors remains a challenging task. Here, we have improved the afterglow c...
متن کاملNanosized strontium aluminate phosphors prepared via a reverse microemulsion route
Nanosized strontium aluminate phosphors co-activated by Eu2+ and Dy3+ were prepared via a novel reverse microemulsion process. This new ynthesis technique lowered the synthesis temperature of SrAl2O4: Eu2+, Dy3+ phosphors to as low as 900 ◦C, and also reduced the particle size o the nanometer scale (around 40 nm). In the microemulsion process, the constituent cations were trapped by numerous na...
متن کاملLarge Redshifts in Emission and Excitation from Eu2+-Activated Sr2SiO4 and Ba2SiO4 Phosphors Induced by Controlling Eu2+ Occupancy on the Basis on Crystal-Site Engineering
The photoluminescence properties of Eu2+-activated α’-Sr2SiO4 and α’-Ba2SiO4 with a high Eu2+ concentration were investigated. In the case of Sr2−xEuxSiO4, emission was shifted from 585 to 611 nm with increasing the total Eu2+ concentration (x) from 0.1 to 0.8. This trend was similar to that in Ba2−xEuxSiO4, where the emission was shifted from 513 to 545 nm. The large redshifts in both the exci...
متن کاملel combustion synthesis and luminescence properties of nanoparticles of onoclinic SrAl 2 O 4 : Eu 2 + , Dy 3 +
Nanoparticles of strontium aluminate phosphors co-a tivated by Eu2+ and Dy3+ have been prepared by heating theprecursorsobtained fromnitrate salt–ammoniumacetic–urea–gel combustionprocess at temperature of 1150 ◦C in a weak reductive atmosphere of thermal carbon. Transmission electronmicroscope
متن کاملSrAl2O4: Eu2+, Dy3+ phosphors derived from a new sol-gel route
The SrAl2O4: Eu 2þ, Dy3þ phosphor powders were prepared by a new sol–gel method using aluminum isopropoxide and strontium acetate as precursors. The sol–gel process and the structure of the phosphor powders were investigated by means of DSC-TG and XRD. It was found that the single-phase SrAl2O4 was formed at 900 8C, which is 300 8C lower than that required for the conventional solid-state react...
متن کامل