Luminescence in Sr4 Al14 O25 :Ce(3+) aluminate phosphor.

Abstract

Cerium-doped Sr4 Al14 O25 phosphor is prepared using a single-step combustion synthesis and its X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and thermoluminescence (TL) properties are characterized. XRD reveals the formation of the desired phase in the prepared sample. SEM micrographs of the prepared Sr4 Al14 O25 phosphor show that the particle size is 10 µm. The prepared Sr4 Al14 O25 , along with Sr4 Al14 O25 :Cex (x = 0.5-5 mol%) shows a PL emission peak at 314 nm under UV excitation of 262 nm wavelength due to 5d → 4f transition. The phosphor is suitable for higher concentrations of Ce ions. The TL glow peak reveals three clearly visible distinct peaks at temperatures around 130, 231 and 336ºC. The three peaks are separated by deconvolution and kinetic parameters calculated using Chen's peak shape method. The calculation shows that the reaction follows second-order kinetics with activation energy (E) values of 0.52, 0.81 and 1.12 eV, and frequency factor (s) values of 5.58 × 10(5) , 4.53 × 10(7) and 4.57 × 10(8) s(-1) for the three individual peaks.