Photoluminescence, site occupation and optical thermometry of Ba2La6Y2(SiO4)6O2: Eu3+ phosphors with high thermal stability

Eu3+ singly-doped Ba2La6Y2(SiO4)6O2 phosphors with hexagonal structure have been synthesized by the high-temperature solid-state reaction method. The crystal structure of the samples was analyzed. To investigate the site occupation of Eu3+ in Ba2La6Y2(SiO4)6O2, the photoluminescence behavior of the phosphor was studied systematically. The emission spectra under specific wavelength excitations and the excitation spectra by monitoring emissions at 5D0→7F0 transition wavelengths indicated that Eu3+ ions have entered two distinct sites in the compound. According to the concentration-dependent photoluminescence properties, the preferential site occupation was illustrated. In addition, the temperature-dependent PL measurement results revealed the high thermal stability of the sample and its application potential as a noninvasive optical thermometer. This work may help to provide an alternative approach to study the site occupation of Eu3+ ions in other functional materials.