Luminescence investigation of Eu3+ activated molybdates red phosphors and their applications in near-UV light-emitting diodes

The red phosphors, Na5La1−xSmx(MoO4)4 and Na5Eu1−xSmx(MoO4)4, were prepared by solid-state reaction technique at high temperature. Their structure and photo-luminescent properties were investigated. The excitation bands around 400 nm of these phosphors are broadened by Sm3+–Eu3+ co-doping. And the possible energy transfer process from Sm3+ to Eu3+ in these compounds is also discussed briefly. The phosphor Na5Eu0.90Sm0.10(MoO4)4 exhibits efficient red-emitting with broadened absorption around 400 nm and appropriate CIE chromaticity coordinates (x = 0.66, y = 0.34), bright red light can be observed from the red LED based Na5Eu0.90Sm0.10(MoO4)4.