Reduction of Ce(IV) to Ce(III) induced by structural characteristics and performance characterization of pyrophosphate MgIn2P4O14-based phosphors

Due to the high sensitivity of the unshielded 5d orbit to the host environment, Ce3+ has a wide-spread emission ranging from near ultraviolet to the red light region, making it a favorable choice for being UV-emitting phosphor activator and sensitizer of other co-doped lanthanide ions in luminescent materials. In present work, Ce4+→Ce3+ self-reduction phenomenon in the layered phosphate MgIn2P4O14 was observed. Noting that self-reduction ability is a valuable characteristic of new host materials, a new viewpoint underlying mechanism was put forward. Structure-, composition-, and temperature-dependence of photoluminescence of the new UV-emitting MgIn2P4O14: Cex phosphors were investigated, with the relative mechanism discussed. Moreover, the sensitization of Dy3+ by Ce3+ was observed in Ce3+/Dy3+ co-doped MgIn2P4O14 phosphors. The excitation region of Dy3+ in MgIn2P4O14: CeDy (220–460 nm) is markedly broadened compared to that of the Dy3+ single-doped phosphor (270–460 nm) on account of the Ce3+→Dy3+ energy transfer process. Present work shows that the MgIn2P4O14: CeDy phosphor can be promising phosphor using for fabrication of both light-emitting diodes (LEDs) and fluorescent lamps (FLs).