Investigation of light induced interactions between ZnO nano-particles and red emitting phosphor blends of Eu2+/Dy3+ doped strontium aluminate and Eu2+ doped Ca-α-Sialon

Up to now, luminescence properties of the Eu2+ doped strontium aluminates and Ca-alpha-Sialons have been widely studied, individually. Herein we investigated excitation and emission based spectral properties of the phosphorblends comprising SrAl2O4:Eu2+,Dy3+, Ca-alpha-SiAlON:Eu2+ and ZnO nanoparticles in a polymethylmethacrylate (PMMA) matrix into detail. The emission bandwidth of the Ca-alpha-SiAlON expanded from 250 nm to 300 nm when used in the form of phosphor blend along with the strontium aluminate. Addition of nano-scale zinc oxide into the phosphorus blend resulted in 56% enhancement in the emission intensity and 24 nm of additional red-shift with respect to its ZnO-free form. Luminescence and decay characteristics of the phosphors were also investigated in nanosecond and microsecond time scales. The proposed material may bring a new inside for the existing problems of the red phosphors regarding the brightness, color correlation temperature, and color rendering index.