posted on 2024-08-29, 12:46authored byManuel Romero, Victor Castaing, Gabriel Lozano, Hernán Míguez
Persistent luminescence materials have applications in
diverse
fields such as smart signaling, anticounterfeiting, and in vivo imaging.
However, the lack of a thorough understanding of the precise mechanisms
that govern persistent luminescence makes it difficult to develop
ways to optimize it. Here we present an accurate model to describe
the various processes that determine persistent luminescence in ZnGa2O4:Cr3+, a workhorse material in the
field. A set of rate equations has been solved, and a global fit to
both charge/discharge and thermoluminescence measurements has been
performed. Our results establish a direct link between trap depth
distribution and afterglow kinetics and shed light on the main challenges
associated with persistent luminescence in ZnGa2O4:Cr3+ nanoparticles, identifying low trapping probability
and optical detrapping as the main factors limiting the performance
of ZnGa2O4:Cr3+, with a large margin
for improvement. Our results highlight the importance of accurate
modeling for the design of future afterglow materials and devices.