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

Abstract

By Sm 3+ –Eu 3+ co-doping, the phosphor Na 5 Eu 0.90 Sm 0.10 (MoO 4 ) 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 Na 5 Eu 0.90 Sm 0.10 (MoO 4 ) 4 . ► The excitation bands around 400 nm of these phosphors are broadened by Sm 3+ –Eu 3+ co-doping. ► The phosphor Na 5 Eu 0.90 Sm 0.10 (MoO 4 ) 4 exhibits efficient red-emitting under near-UV excitation, compared with. Na 5 Eu(MoO 4 ) 4 . ► Bright red light can be observed from the red LED based Na 5 Eu 0.90 Sm 0.10 (MoO 4 ) 4 . ► The possible energy transfer process from Sm 3+ to Eu 3+ in these compounds was discussed. The red phosphors, Na 5 La 1− x Sm x (MoO 4 ) 4 and Na 5 Eu 1− x Sm x (MoO 4 ) 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 Sm 3+ –Eu 3+ co-doping. And the possible energy transfer process from Sm 3+ to Eu 3+ in these compounds is also discussed briefly. The phosphor Na 5 Eu 0.90 Sm 0.10 (MoO 4 ) 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 Na 5 Eu 0.90 Sm 0.10 (MoO 4 ) 4 .