Luminescence studies on the blue-green emitting Sr4Al14O25:Ce3+ phosphor synthesized through solution combustion route

New blue-green emitting Sr4Al14O25:Ce3+ phosphor is reported in this paper. The polycrystalline samples of phosphor were prepared by the conventional solution combustion method and checked for crystallization and phase by X-ray diffraction. Photoluminescence studies reveal the emission at 472 and 511 nm that correspond to the transition between lowest T-2g level of the 5d state to the F-2(5/2) and F-2(7/2) ground state levels of the Ce3+. The excitation at 275 nm corresponds to O2--->Ce4+ charge transfer processes to lowest 5d state of Ce ion (T-2g). Phosphorescence decay procedures reveal the existence of slow, medium, and fast component involved in the process. Varying the gamma-dose (1-6Gy), thermoluminescence (TL) measurements were made and glow curve maximum is obtained at 383 K. The phosphor seems to follow a first-order kinetics due to non-shifting T-m property. The T-m-T-stop method followed by the repeated initial rise method is applied to determine the distribution of activation energies and corresponding maximum positions. Chi-square minimization procedures provide the appropriate peak positions and other trapping parameters. From deconvolution results, the activation energies are found to be 0.84 and 1.06 eV, while the frequency factor is of the order of 10(10) and 10(11) s(-1), respectively. (C) 2008 Elsevier B.V. All rights reserved.