In this contribution luminescence and luminescence kinetics of Sr₂SiO₄:Eu²⁺ and Sr₂Si_0.95Ti_0.05O₄:Eu²⁺ are studied. The samples were synthesized using solid state method. Sr₂SiO₄:Eu²⁺ and Sr₂Si_0.95Ti_0.05O₄:Eu²⁺ have strong luminescence which consists of two partially overlapping broad bands with maxima at 480 nm and 570 nm. The bands are attributed to the 4f⁶5d¹ → 4f⁷ transitions in Eu²⁺ occupying in Sr₂SiO₄ crystal lattice two different Sr²⁺ sites, respectively ten-coordinated SI and nine-coordinated SII. Contribution of these two bands to the total luminescence can be controlled by choosing excitation wavelength.

Besides described above two strong emission bands, which decay in microseconds range, Sr₂SiO₄:Eu²⁺ exhibits also luminescence that lasts at room temperature for few seconds after stopping the excitation. The persistent luminescence is relatively weak at ambient conditions but can be easily seen in dark with eye. In the case of the samples co-doped with Ti⁴⁺ the persistent luminescence is significantly enhanced. We have proved that besides the concentration of Eu²⁺ and Ti⁴⁺ also the form of the titanium precursor used in synthesis influences on the persistent luminescence phenomenon observed in Sr₂Si_0.95Ti_0.05O₄:Eu²⁺ phosphor. For all investigated samples the persistent luminescence is dominated only by the one band with maximum at 570 nm, independently of the excitation wavelength. It leads to the conclusion, that traps responsible for long lasting luminescence of Sr₂SiO₄:Eu²⁺ observed at room temperature, deactivate directly and only through Eu²⁺ ions occupying nine coordinated SII sites.

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