Synthesis and luminescent behavior of UV induced Dy³⁺ activated LaAlO₃

Dy³⁺ doped Lanthanum Aluminate phosphors are prepared for different concentrations of dopant and the luminescent properties of the phosphor are studied. High temperature modified solid-state reaction method is used for the synthesis. XRD analysis confirms the formation of LaAlO₃:Dy³⁺ phosphor. Average crystallite size calculated is 40.085 nm.Thermoluminescence study of UV induced LaAlO₃:Dy³⁺ phosphor is discussed in this paper. Thermoluminescence glow peak is recorded for different UV exposure time and for different concentrations of dopant. Kinetic parameters such as shape factor, activation energy, order of kinetics are calculated by using computerized glow curve deconvolution technique. Activation energy varies from 0.63 to 0.72 eV. The TL glow curve intensity varies nearly linear with increasing UV dose. Photoluminescence (PL) emission spectra are recorded for different concentrations of dopant. Highest intensity of PL emission was obtained for 1.5 mol% of Dy³⁺ doped LaAlO₃ phosphor. The excitation spectra of Dy³⁺ doped LaAlO₃ phosphor monitored at 550 nm shows broad band around 260 nm and a sharp peak at 394 nm. Peaks with lower intensity are obtained at 320 nm, 363 nm and 384 nm. In the Pl emission spectra, peak at 554 nm (yellow greenish) has highest intensity. Peaks with less intensity are obtained at 466 nm (blue), 645 nm (orange red) and 740 nm (brownish red). Pl intensity varies linearly with increasing concentration of dopant. CIE chromaticity coordinates are calculated for LaAlO₃:Dy³⁺ (1.5 mol%), x = 0.3586 and y = 0.5421 which corresponds to yellow–greenish region. The prepared phosphor may find application in dosimetry and optical devices.