Low temperature quenching and high efficiency Tm 3+, La 3+ or Tb 3+ co-doped CaSc 2O 4:Ce 3+ phosphors for light-emitting diodes

Abstract

Low temperature quenching and high efficiency CaSc 2O 4:Ce 3+ (CSO:Ce 3+) phosphors co-doped with Tm 3+, La 3+ and Tb 3+ ions were prepared by a solid state method and the phase-forming, morphology, luminescence and application properties of these phosphors were investigated. The results showed that co-doping of Tm 3+, La 3+ and Tb 3+ ions can improve the luminescence properties and decrease temperature quenching of CSO:Ce 3+ phosphor remarkably. High efficiency green-light-emitting diodes were fabricated with the prepared phosphors and InGaN blue-emitting (∼460 nm) chips. The good performances of the green-light-emitting LEDs made from co-doped CSO:Ce 3+ phosphors confirm the luminescence enhancement and indicate that Tm 3+, La 3+ and Tb 3+ co-doped CSO:Ce 3+ phosphors are suitable candidates for the fabrication of high efficiency white LEDs.