Synthesis and Luminescence Studies of Tb3+-Doped Li2CaSiO4 Phosphor for Optical Device Application

A series of Tb 3+ -doped Li 2 CaSiO 4 phosphors were prepared by high-temperature solid-state reaction method. The structural studies were done using the X-ray diffraction (XRD) technique. The XRD patterns revealed that the sample was monophased and crystallizes in a cubic structure. Scanning electron microscopy (SEM) was used to obtain information about the morphology of the prepared samples. SEM micrographs clearly indicated that the particles crystallized in inhomogeneous morphology, with the particle size ranging from 1 μm to 100 nm. Also, photoluminescence (PL) analysis of the phosphor samples for different concentrations of doping ions with variable excitations were presented. The PL excitation spectrum of Tb 3+ ion-doped Li 2 CaSiO 4 has many sharp peaks, mainly at 418 nm ( 5 D 3 → 7 F 5 ), 436 nm ( 5 D 3 → 7 F 4 ), 456 nm ( 5 D 3 → 7 F 3 ), 472 nm ( 5 D 3 → 7 F 2,1,0 ), 487 nm ( 5 D 4 → 7 F 6 ), 550 nm ( 5 D 4 → 7 F 5 ), and 590 nm ( 5 D 4 → 7 F 4 ), assigned to the transitions of Tb- ion respectively (excited at 237 nm). The 1931 CIE (x, y) chromaticity coordinates showed the distribution of the spectral region calculated from PL emission spectra, and found to be (0.19, 0.22) in a bluish-green region of Tb 3+ (0.01 wt (in grams)) Li 2 CaSiO 4 phosphor. Our study shows that as-prepared phosphor may be useful for optical devices, mainly for LEDs, as a bluish-green component.