Time evolution of luminescence of Sr₂SiO₄:Eu²⁺

In this contribution, the photoluminescence, time-resolved luminescence and luminescence kinetics of α'-Sr2SiO4:Eu(2+) are studied. The luminescence of Sr2SiO4:Eu(2+) consists of two broad bands, peaked at 490 nm (blue-green) and 570 nm (yellow-orange), which originate from two luminescence centers, related to Eu(2+) in ten-coordinated SI and nine-coordinated SII sites, respectively. Based on spectroscopic data the energetic structure of Sr2SiO4:Eu(2+) has been developed, which includes the bands edges, energies of Eu(2+) in the SI and SII sites and energies of strontium and oxygen vacancies. To investigate the long-lasting luminescence phenomenon in Sr2SiO4:Eu(2+) the temperature influence on the time evolution of luminescence was analyzed. It has been found that the long-lasting luminescence is related to the Eu(2+) in SII site. The shallowest traps responsible for emission decaying within a few seconds are tentatively attributed to the [Eu(3+)(SII)-[Formula: see text]] centers. The depth of traps responsible for the long-lasting luminescence observed at room temperature has been estimated as equal 0.73 eV.