Broadly tunable emission from Mn-doped zinc gallogermanate phosphors through composition modification

Abstract

Nowadays, one-phase and full-color phosphors have gained increasing interest. Here, we show that Mn-activated zinc gallogermanate, Zn1+xGa2-2xGexO4: Mn, x = 0 ~1, phosphors exhibit a broadly tunable luminescence from green to deep red with the substitution of Ga3+ by Ge4+. The green and deep red emissions are attributed to Mn2+ and Mn4+ occupying the tetrahedrally coordinated Zn2+ and octahedrally coordinated Ga3+ sites, respectively. The origin of the tunable luminescence is discussed. The present phosphors have potential uses in field emission displays and in vivo bio-imaging.