Preparation, Design, and Characterization of the Novel Long Persistent Phosphors: Na 2 ZnGeO 4 and Na 2 ZnGeO 4 :Mn 2+

A novel blue‐emitting phosphor Na 2 ZnGeO 4 and a novel green‐emitting phosphor Na 2 ZnGeO 4 :Mn 2+ have been newly developed via high‐temperature solid‐state reaction. The crystal structure of Na 2 ZnGeO 4 has been identified. Energy transfer from Na 2 ZnGeO 4 host to Mn 2+ ions was affirmed. Undoped and Mn 2+ ‐doped Na 2 ZnGeO 4 phosphors exhibit blue and green long persistent luminescence ( LPL ) with persistent duration more than 40 min and 4 h, respectively. The traps created in host lattice were clarified. The LPL mechanism in Na 2 ZnGeO 4 and Na 2 ZnGeO 4: Mn 2+ was discussed briefly. This investigation provides two new and efficient long persistent phosphors ( LPP s).