Enhancement of red fluorescence and afterglow in CaWO4:Eu3+ by addition of MoO3

In this study, Eu3+ doped Ca(WO4)1−x(MoO4)x phosphors were synthesized via high temperature solid-state reaction. Compared with the Eu3+ activated CaWO4 sample, an increment of MoO3 doping concentration could improve the emission intensity. Improved red afterglow originating from the 5D0 to 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+ was observed after appropriate amount of MoO3 was added, and the optimal MoO3 doping concentration was experimentally determined to be 0.02. The proposed explanation for the afterglow property was also discussed.

► The afterglow and luminescent properties of CaWO4:Eu3+ can be enhanced by MoO3 incorporation.
► An optimal MoO3 concentration for the Eu3+ afterglow property is experimentally found.
► It is validated that the afterglow phenomenon is induced by the defects created by the substitution of Ca2+ with Eu3+.