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, Ce 3+ 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, Ce 4+ →Ce 3+ self-reduction phenomenon in the layered phosphate MgIn 2 P 4 O 14 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 MgIn 2 P 4 O 14 : Ce x phosphors were investigated, with the relative mechanism discussed. Moreover, the sensitization of Dy 3+ by Ce 3+ was observed in Ce 3+ /Dy 3+ co-doped MgIn 2 P 4 O 14 phosphors. The excitation region of Dy 3+ in MgIn 2 P 4 O 14 : CeDy (220–460 nm) is markedly broadened compared to that of the Dy 3+ single-doped phosphor (270–460 nm) on account of the Ce 3+ →Dy 3+ energy transfer process . Present work shows that the MgIn 2 P 4 O 14 : CeDy phosphor can be promising phosphor using for fabrication of both light-emitting diodes (LEDs) and fluorescent lamps (FLs).