The long persistent luminescence properties of phosphors: Li2ZnGeO4 and Li2ZnGeO4:Mn2+

Abstract

The blue emitting long persistent phosphor (LPP) Li₂ZnGeO₄ and green emitting LPP Li₂ZnGeO₄:Mn²⁺ were newly prepared by a high temperature solid-state reaction method. The blue and green afterglow with duration of 5 and 8 h were confirmed to originate from host emission and d–d transitions of Mn²⁺ ions, respectively. The density of traps with suitable depth was significantly increased with the incorporation of Mn²⁺ ions. The energy transfer from host emission to Mn²⁺ ions was observed. The motion of charge carriers and a possible LAG mechanism based on a tentative model were illuminated and discussed in detail.