Highly enhanced photoluminescence of SrTiO3 : Pr by substitution of (Li-0.5, La-0.5) pair for Sr

Photoluminescence (PL) of SrTiO3-(Li0.5La0.5)TiO3:Pr system was investigate d. This system was characterized by a very intense red emission at 611 nm c orresponding to the D-1(2) --> H-3(4) inner transition of Pr3+ ions. A weak PL intensity of SrTiO3:Pr was remarkably increased when the Sr atom was re placed by the (Li, La) pair. Through the elemental analysis for the Li atom , the dependence of PL intensity on the composition and heating temperature is correlated with the amount of defect sites for the Li atoms. Based on t he experimental data, it is proposed that the substitution of the (Li, La) pair for Sr of SrTiO3 likely produces the holes trapped near Li+. The incre ased recombination probability of electrons and trapped holes would then ca use the highly enhanced emission intensity of Pr3+ by the resultant energy transfer. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.