Sol-Jel Tekniği ile Sentezlenmiş Sr0,5Ca0,5WO4 Fosforunda Eu3+ İyonunun Lüminesans, TL Kinetik Parametreler ve Elektrokimyasal Davranışındaki Rolü

Abstract

The Eu3+doped Sr0,5Ca0,5WO4 has been synthesized by the sol-gel method for the first time. The phosphors were analyzed by XRD, SEM, DTA/TG optical absorption spectra, radioluminescence (RL), photoluminescence (PL), and thermoluminescence (TL) spectra. The energy transfer mechanism was determined on Eu3+ doped Sr0,5Ca0,5WO4 phosphor. The XRD results reveal that the samples exhibit a tetragonal scheelite structure. FT-IR spectra provide the proof of scheelite structure with W-O anti-symmetric stretching vibration in [WO4]2- tetrahedrons at 750-910 cm-1. The Sr0,5Ca0,5WO4 phosphor showed a broad emission between 350-750 nm with a maximum of 506 nm. Sr0,5Ca0,5WO4:0.5Eu3+ phosphor exhibit characteristic emissions of Eu+3 (545, 592, 614, 650, and 700 nm) in the RL spectrum. The host material has excellent energy transfer efficiency for lanthanide ions. The kinetic parameters were calculated by the computerized glow curve deconvolution (CGCD) analysis method. As a result of CGCD, three peaks (Etrap:0.74-1.46 eV) for un-doped Sr0,5Ca0,5WO4 and five peaks (Etrap:0.75-1.28 eV) for Sr0,5Ca0,5WO4: Eu3+ were determined under main TL glow curve. In the cyclic voltammogram of the doped sample, an oxidation peak of about -0.4 eV, which is thought to be derived from Eu3+, was observed. Based on the results, the Sr0,5Ca0,5WO4:Eu+3 phosphors may be potential applicants for LEDs.