Luminescence and energy transfer of single-phase and color-tunable Ca2Y3Sb3O14:Bi3+, Eu3+ phosphor for white light-emitting diodes

Novel single-phase and color-tunable Ca2Y3Sb3O14: Bi3+, Eu3+ phosphors were synthesized by conventional solid-state reaction. The obtained Ca2Y3Sb3O14: Bi3+ phosphor exhibits a blue light emission band peaking at 460 nm due to the P-3(1)-S-1(0) transition of Bi3+, whereas Ca2Y3Sb3O14: Eu3+ phosphor exhibits the typical red emission aroused from the D-5(0) -> F-7(J) (J = 0, 1, 2) transitions of Eu3+. Due to the energy transfer from Bi3+ to Eu3+ ions, Ca2Y3Sb3O14: Bi3+, Eu3+ exhibits both the blue emission of Bi3+ and the red emission of Eu3+ under 350 nm excitation. By tuning the Bi3+/Eu3+ ratio, the emission color of Ca2Y3Sb3O14:Bi3+, Eu3+ could vary from blue (0.16, 0.18) to red (0.62, 0.38), and white-light emission with superior CIE chromaticity coordinates (0.35, 0.30) and low correlated color temperature (CCT approximate to 3500 K) was obtained as a result of color tuning. The mechanism of energy transfer from the sensitizer Bi3+ to the activator Eu3+ in Ca2Y3Sb3O14: Bi3+, Eu3+ phosphors was demonstrated to be an exchange interaction. (C) 2015 Elsevier B.V. All rights reserved.