Intense red phosphors, AgGd0.95Eu0.05(WO4)2−x(MoO4)x0.3em(x=0−2) 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 x⩾0.5 . All compositions with Eu3+ show red emission on excitation either in the charge-transfer band or Eu3+ levels. Intense red emission is obtained in the molybdates, AgGd0.95Eu0.05(MoO4)2 under 465-nm excitation. Studies on AgGd1−yEuy(WO4)2 and AgGd1−yEuy(MoO4)2 ( y=0.1−1 in steps of 0.1) show that the emission intensity is maximum for compositions with y=0.2 and 0.3, respectively, and a decrease in emission intensity is observed for higher y 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.

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A series of orange-red emitting phosphor compositions Sr 1.9−x Ba x Eu 0.05 Li 0.05 MoO 6 ͑x = 0-1.9͒ have been synthesized and characterized by powder X-ray diffraction ͑XRD͒ and photoluminescence. XRD results reveal a phase transition from orthorhombic to pseudocubic structure for x Ն 0.2. All the compositions show broad charge-transfer band absorption in the near-ultraviolet ͑UV͒ region. Orange-red emission is observed for compositions with lower x values ͑x Յ 0.6͒, whereas orange emission is observed for compositions with higher x values. Select compositions in this system of compounds could find potential applications as orangered phosphors for white light generation using near-UV/blue GaN-based light emitting diodes.

A series of novel red-emitting phosphors AgLa 0.95 Eu 0.05 ͑WO 4 ͒ 2−x ͑MoO 4 ͒ x ͓x = 0-2͔ have been synthesized and their luminescence properties investigated. All Eu 3+ activated compositions show red emission on excitation either in the charge-transfer band or Eu 3+ levels. All compositions show remarkably intense red emission with excitation at 465 nm. The photoluminescence studies on AgLa 1−y Eu y ͑WO 4 ͒ 2 and AgLa 1−y Eu y ͑MoO 4 ͒ 2 ͑y = 0.1-1 in steps of 0.1͒ show that the emission intensity is maximum for compositions with y = 0.4 and 0.3, respectively, and a decrease in emission intensity is observed for compositions with higher y values. Select compositions in this system of compounds could find potential application as red phosphors for white-light generation using blue GaN-based light-emitting diodes ͑LEDs͒.