SrAl₄O₇ : Eu²⁺nanocrystals: synthesis and fluorescence properties

Divalent europium doped strontium di-aluminate (SrAl 4 O 7 : Eu 2+ ) nanocrystals have been synthesized using a facile sol–gel polymer thermolysis method. The photoluminescence characteristics of smaller particles (ϕ ∼ 15 nm) show a significant difference with respect to their bulk counterpart. In this nanocrystalline system, the electronic structure of the Eu 2+ excited state seems to undergo considerable modification induced by the surface states involved in slow relaxation kinetics that mimic phosphorescence like features.