Intense Red-Emitting Phosphors for White Light Emitting Diodes

Intense red phosphors, have been synthesized and characterized by powder X-ray diffraction (XRD) and photoluminescence. Powder XRD results reveal a phase transition from monoclinic to tetragonal structure at . All compositions with show red emission on excitation either in the charge-transfer band or levels. Intense red emission is obtained in the molybdates, under 465-nm excitation. Studies on and ( in steps of 0.1) show that the emission intensity is maximum for compositions with and 0.3, respectively, and a decrease in emission intensity is observed for higher values. The intense red emission of the tungstate and molybdate phosphors under 394 and 465 nm excitation, respectively, suggests that these materials are promising candidates as red-emitting phosphors for near-UV/blue GaN-based light-emitting diodes for white light generation.