Ce ³⁺ / Pr ³⁺ : YAGG : A Long Persistent Phosphor Activated by Blue‐Light

Abstract

The requirement of using ultraviolet light to stimulate afterglow luminescence has seriously restricted indoors/outdoors applications of most persistent materials developed hitherto. Herein, efficient blue‐light‐activated Ce 3+ , Pr 3+ : YAGG phosphors, showing optimized long‐persistent luminescence lasting for 1 h, were prepared and investigated in detail with the aid of X‐ray diffraction refinement, steady‐state/persistent photoluminescence spectra, room/low‐temperature persistent decay curves, and three‐dimensional thermo‐luminescence spectra. Notably, the afterglow properties were found highly dependent on the Ga content which greatly alters both the host band gap energy and the Ce 3+ : 5 d level structure and thus is beneficial to the electrons' photoionization and trapping processes. Moreover, Pr 3+ additive was found not only prolonged the afterglow lifetime of Ce 3+ through improving concentration of carriers captured at the trap, but also served as the red‐emissive centers for color tuning. The persistent energy transfer from Ce 3+ to Pr 3+ was experimentally demonstrated for the first time.