Luminescent Enhancement of Na+ and Sm3+ Co-doping Reddish Orange SrCa3Si2O8 Phosphors

Reddish orange SrCa3Si2O8 phosphors, prepared by the facile solid state reaction method, are a luminescent enhancement of Na+ and Sm3+ co-doping luminescent material. Na+ was designed to compensate the charge imbalance of Sm3+ ion substituting for the Sr2+ ion of orthorhombic SrCa3Si2O8 crystals. The results suggest that Na+ can effectively enhance the luminescent intensity of the reddish orange light peaked at about 562 nm ((4) G (5/2) -> (6) H (5/2)), 600 nm ((4) G (5/2) -> (6) H (7/2)) and 645 nm ((4) G (5/2) -> (6) H (9/2)) excited by the near ultraviolet excited light 404 nm ((4) L (13/2) -> (6) H (5/2)). The energy transfer has been further verified by the florescence lifetime. Additionally, the luminescent lifetime tau of as-grown phosphors was separated into two parts, a rapid lifetime and a slow lifetime. The average lifetime results ranged from 2.098 to 1.329 ms which were influenced by the concentration of Sm3+ doping. The systematic researches of as-grown phosphors have clearly suggested a potential application for white-light-emitting diodes (w-LEDs).