Green persistent luminescence excitable by multiple wavelengths in the CaSc2O4:Ce3+ phosphor co-doped with Mg2+
Journal article, 2018

Calcium scandate (CaSc 2 O 4 ), when substituted with a small amount of the activator ion Ce 3+ to replace Ca 2+ , is a recently discovered green-emitting phosphor promising for solid-state lighting applications. The co-doping with aliovalent ions to compensate for the net positive charge, as induced by the Ce 3+ dopants, is a common approach to change the defect structure and tune the performance of the phosphor, but the underlying mechanisms are unclear. Here we investigate the effect of co-doping with charge-compensating Mg 2+ to substitute for Sc 3+ , using photoluminescence and thermoluminescence techniques. In comparison to the defect structure in Ce 3+ doped CaSc 2 O 4 , the co-doping with charge-compensating Mg 2+ leads to the formation of new traps. These traps are featured by activation energies in the range 0.58–0.64 eV, can be emptied at room temperature and show green long-lasting phosphorescence after excitation at 454, 340, and 254 nm, respectively. Analysis of the spectroscopic results in terms of a vacuum referred binding energy diagram allows us to reach at a plausible luminescence mechanism in {Ce 3+ /Ce 3+ Mg 2+ }-doped CaSc 2 O 4 .

LED

Green light

Phosphor

Long-lasting phosphorescence

Author

Suchinder Sharma

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

M. Bettinelli

Verona University

Maths Karlsson

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Journal of Luminescence

0022-2313 (ISSN)

Vol. 196 437-441

Subject Categories

Inorganic Chemistry

Theoretical Chemistry

Condensed Matter Physics

DOI

10.1016/j.jlumin.2017.12.047

More information

Latest update

4/5/2018 7