Photoluminescence behavior of Eu 3+  doped XAl 2 O 4 (X = Mg, Ca, Sr and Ba) phosphors: a comparative study.

In this work, the Eu 3+ doped stuffed tridymite type structure of alkaline earths aluminate i.e. XAl 2 O 4 (X = Mg, Ca, Sr and Ba) phosphor materials have been synthesized by conventional high temperature solid state reaction method at 1623 K. The Samples were structurally and morphologically characterized by x-ray diffraction (XRD) and Scanning electron microscope (SEM) measurements. The vibrational behavior of the phosphor samples were investigated by Fourier transform infrared (FTIR) measurements. The phosphor samples emit intense red emission in 610-615 nm range due to 5 D 0  →  7 F 2 transition of Eu 3+ ion on excitation with charge transfer band (CTB) wavelength arising due to Eu 3+ -O 2- and also by the discrete bands of Eu 3+ ions .The decay time of 5 D 0 level of Eu 3+ ion were recorded on excitation with 393 nm and by the CTB wavelength for all the four samples. The optimized 1 mol% Eu 3+ doped CaAl 2 O 4 phosphor exhibits optimum emission intensity and color purity under the excitation with 393 nm than others. The decay time is also found to be larger in the case of Eu 3+ doped CaAl 2 O 4 phosphor sample. Therefore, Eu 3+ doped CaAl 2 O 4 phosphor may be promising material for red color light emitting applications and white light generation.