Exploration of Photoluminescence, Colorimetric, and Decay Performance of Sm-activated CaWO₄ Ceramic

This paper represents structure, photoluminescence, and colorimetric investigations of Sm-activated CaWO₄ ceramic made with the help of a solid-state reaction process. Structures of the ceramics are examined through X-ray diffraction spectroscopy. It indicates that these materials have a tetragonal structure and I4₁/a space group without having any other secondary phase. Energy band gaps are increased with the higher concentrations of Sm dopants. Photoluminescence analyses show that concentration quenching is found at x = 0.02 Sm incorporated CaWO₄. The critical distance of energy transfer is obtained as about 20 Å. Q-value is observed approximately equal to 6 which denotes that dipole-dipole interactions occur in the materials that create the critical energy transfer distance in them. Chromaticity values are described in that the ceramics emit orange-red color as well as excellent colorimetric parameters. Quantum efficiency of x = 0.02 Sm composition in CaWO₄ is measured under 405 nm EX wavelength. Photoluminescence decay behaviors are observed and average lifetime values are evaluated.